diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Active-Active.xml b/doc/Clusters_from_Scratch/en-US/Ch-Active-Active.xml index 636a51ea2e..d8a6b86a0c 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Active-Active.xml +++ b/doc/Clusters_from_Scratch/en-US/Ch-Active-Active.xml @@ -1,233 +1,711 @@ %BOOK_ENTITIES; ]> Conversion to Active/Active - - The primary requirement for an Active/Active cluster is that the data required for your services are available, simultaneously, on both machines. - Pacemaker makes no requirement on how this is achieved, you could use a SAN if you had one available, however since DRBD supports multiple Primaries, we can also use that. - - - The only hitch is that we need to use a cluster-aware filesystem (and the one we used earlier with DRBD, ext4, is not one of those). - Both OCFS2 and GFS2 are supported, however here we will use GFS2 which comes with &DISTRO; &DISTRO_VERSION; . - +
+ Requirements + + The primary requirement for an Active/Active cluster is that the data required for your services are available, simultaneously, on both machines. + Pacemaker makes no requirement on how this is achieved, you could use a SAN if you had one available, however since DRBD supports multiple Primaries, we can also use that. + + + The only hitch is that we need to use a cluster-aware filesystem (and the one we used earlier with DRBD, ext4, is not one of those). + Both OCFS2 and GFS2 are supported, however here we will use GFS2 which comes with &DISTRO; &DISTRO_VERSION; . + +
+
+ Install a Cluster Filesystem - GFS2 + + The first thing to do is install gfs2-utils on each machine. + + +[root@pcmk-1 ~]# yum install -y gfs2-utils gfs-pcmk +Setting up Install Process +Resolving Dependencies +--> Running transaction check +---> Package gfs-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated +--> Processing Dependency: libSaCkpt.so.3(OPENAIS_CKPT_B.01.01)(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +--> Processing Dependency: dlm-pcmk for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +--> Processing Dependency: libccs.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +--> Processing Dependency: libdlmcontrol.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +--> Processing Dependency: liblogthread.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +--> Processing Dependency: libSaCkpt.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 +---> Package gfs2-utils.x86_64 0:3.0.5-2.fc12 set to be updated +--> Running transaction check +---> Package clusterlib.x86_64 0:3.0.5-2.fc12 set to be updated +---> Package dlm-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated +---> Package openaislib.x86_64 0:1.1.0-1.fc12 set to be updated +--> Finished Dependency Resolution + +Dependencies Resolved + +=========================================================================================== + Package                Arch               Version                   Repository        Size +=========================================================================================== +Installing: + gfs-pcmk               x86_64             3.0.5-2.fc12              custom           101 k + gfs2-utils             x86_64             3.0.5-2.fc12              custom           208 k +Installing for dependencies: + clusterlib             x86_64             3.0.5-2.fc12              custom            65 k + dlm-pcmk               x86_64             3.0.5-2.fc12              custom            93 k + openaislib             x86_64             1.1.0-1.fc12              fedora            76 k + +Transaction Summary +=========================================================================================== +Install       5 Package(s) +Upgrade       0 Package(s) + +Total download size: 541 k +Downloading Packages: +(1/5): clusterlib-3.0.5-2.fc12.x86_64.rpm                                |  65 kB     00:00 +(2/5): dlm-pcmk-3.0.5-2.fc12.x86_64.rpm                                  |  93 kB     00:00 +(3/5): gfs-pcmk-3.0.5-2.fc12.x86_64.rpm                                  | 101 kB     00:00 +(4/5): gfs2-utils-3.0.5-2.fc12.x86_64.rpm                                | 208 kB     00:00 +(5/5): openaislib-1.1.0-1.fc12.x86_64.rpm                                |  76 kB     00:00 +------------------------------------------------------------------------------------------- +Total                                                           992 kB/s | 541 kB     00:00 +Running rpm_check_debug +Running Transaction Test +Finished Transaction Test +Transaction Test Succeeded +Running Transaction +  Installing     : clusterlib-3.0.5-2.fc12.x86_64                                       1/5 +  Installing     : openaislib-1.1.0-1.fc12.x86_64                                       2/5 +  Installing     : dlm-pcmk-3.0.5-2.fc12.x86_64                                         3/5 +  Installing     : gfs-pcmk-3.0.5-2.fc12.x86_64                                         4/5 +  Installing     : gfs2-utils-3.0.5-2.fc12.x86_64                                       5/5 + +Installed: +  gfs-pcmk.x86_64 0:3.0.5-2.fc12                    gfs2-utils.x86_64 0:3.0.5-2.fc12 + +Dependency Installed: +  clusterlib.x86_64 0:3.0.5-2.fc12   dlm-pcmk.x86_64 0:3.0.5-2.fc12 +  openaislib.x86_64 0:1.1.0-1.fc12   + +Complete! +[root@pcmk-1 x86_64]# + +
+ +
+ Setup Pacemaker-GFS2 Integration + + GFS2 needs two services to be running, the first is the user-space interface to the kernel’s distributed lock manager (DLM). The DLM is used to co-ordinate which node(s) can access a given file (and when) and integrates with Pacemaker to obtain node membership + + The list of nodes the cluster considers to be available + + information and fencing capabilities. + + + The second service is GFS2’s own control daemon which also integrates with Pacemaker to obtain node membership data. + +
+ Add the DLM service + + The DLM control daemon needs to run on all active cluster nodes, so we will use the shells interactive mode to create a cloned resource. + + + +[root@pcmk-1 ~]# crm +crm(live)# cib new stack-glue +INFO: stack-glue shadow CIB created +crm(stack-glue)# configure primitive dlm ocf:pacemaker:controld op monitor interval=120s +crm(stack-glue)# configure clone dlm-clone dlm meta interleave=true +crm(stack-glue)# configure show xml +crm(stack-glue)# configure show +node pcmk-1 +node pcmk-2 +primitive WebData ocf:linbit:drbd \ +        params drbd_resource="wwwdata" \ +        op monitor interval="60s" +primitive WebFS ocf:heartbeat:Filesystem \ +        params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4" +primitive WebSite ocf:heartbeat:apache \ +        params configfile="/etc/httpd/conf/httpd.conf" \ +        op monitor interval="1min" +primitive ClusterIP ocf:heartbeat:IPaddr2 \ +        params ip="192.168.122.101" cidr_netmask="32" \ +        op monitor interval="30s" +primitive dlm ocf:pacemaker:controld \ + op monitor interval="120s" +ms WebDataClone WebData \ +        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" +clone dlm-clone dlm \ + meta interleave="true" +location prefer-pcmk-1 WebSite 50: pcmk-1 +colocation WebSite-with-WebFS inf: WebSite WebFS +colocation fs_on_drbd inf: WebFS WebDataClone:Master +colocation website-with-ip inf: WebSite ClusterIP +order WebFS-after-WebData inf: WebDataClone:promote WebFS:start +order WebSite-after-WebFS inf: WebFS WebSite +order apache-after-ip inf: ClusterIP WebSite +property $id="cib-bootstrap-options" \ +        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ +        cluster-infrastructure="openais" \ +        expected-quorum-votes=”2” \ +        stonith-enabled="false" \ +        no-quorum-policy="ignore" +rsc_defaults $id="rsc-options" \ +        resource-stickiness=”100” + + + + TODO: Explain the meaning of the interleave option + + + + Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response + + + +crm(stack-glue)# cib commit stack-glue +INFO: commited 'stack-glue' shadow CIB to the cluster +crm(stack-glue)# quit +bye +[root@pcmk-1 ~]# crm_mon +============ +Last updated: Thu Sep  3 20:49:54 2009 +Stack: openais +Current DC: pcmk-2 - partition with quorum +Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 +2 Nodes configured, 2 expected votes +5 Resources configured. +============ + +Online: [ pcmk-1 pcmk-2 ] + +WebSite (ocf::heartbeat:apache):        Started pcmk-2 +Master/Slave Set: WebDataClone +        Masters: [ pcmk-1 ] +        Slaves: [ pcmk-2 ] +ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 +Clone Set: dlm-clone + Started: [ pcmk-2 pcmk-1 ] +WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2 + +
+ +
+ Add the GFS2 service + + Once the DLM is active, we can add the GFS2 control daemon. + + + Use the crm shell to create the gfs-control cluster resource: + + + +[root@pcmk-1 ~]# crm +crm(live)# cib new gfs-glue --force +INFO: gfs-glue shadow CIB created +crm(gfs-glue)# configure primitive gfs-control ocf:pacemaker:controld params daemon=gfs_controld.pcmk args="-g 0" op monitor interval=120s +crm(gfs-glue)# configure clone gfs-clone gfs-control meta interleave=true + + + Now ensure Pacemaker only starts the gfs-control service on nodes that also have a copy of the dlm service (created above) already running + + + +crm(gfs-glue)# configure colocation gfs-with-dlm INFINITY: gfs-clone dlm-clone +crm(gfs-glue)# configure order start-gfs-after-dlm mandatory: dlm-clone gfs-clone + + + Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response + + + +crm(gfs-glue)# configure show +node pcmk-1 +node pcmk-2 +primitive WebData ocf:linbit:drbd \ +        params drbd_resource="wwwdata" \ +        op monitor interval="60s" +primitive WebFS ocf:heartbeat:Filesystem \ +        params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4" +primitive WebSite ocf:heartbeat:apache \ +        params configfile="/etc/httpd/conf/httpd.conf" \ +        op monitor interval="1min" +primitive ClusterIP ocf:heartbeat:IPaddr2 \ +        params ip="192.168.122.101" cidr_netmask="32" \ +        op monitor interval="30s" +primitive dlm ocf:pacemaker:controld \ +        op monitor interval="120s" +primitive gfs-control ocf:pacemaker:controld \ + params daemon=”gfs_controld.pcmk” args=”-g 0” \ + op monitor interval="120s" +ms WebDataClone WebData \ +        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" +clone dlm-clone dlm \ +        meta interleave="true" +clone gfs-clone gfs-control \ + meta interleave="true" +location prefer-pcmk-1 WebSite 50: pcmk-1 +colocation WebSite-with-WebFS inf: WebSite WebFS +colocation fs_on_drbd inf: WebFS WebDataClone:Master +colocation gfs-with-dlm inf: gfs-clone dlm-clone +colocation website-with-ip inf: WebSite ClusterIP +order WebFS-after-WebData inf: WebDataClone:promote WebFS:start +order WebSite-after-WebFS inf: WebFS WebSite +order apache-after-ip inf: ClusterIP WebSite +order start-gfs-after-dlm inf: dlm-clone gfs-clone +property $id="cib-bootstrap-options" \ +        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ +        cluster-infrastructure="openais" \ +        expected-quorum-votes=”2” \ +        stonith-enabled="false" \ +        no-quorum-policy="ignore" +rsc_defaults $id="rsc-options" \ +        resource-stickiness=”100” +crm(gfs-glue)# cib commit gfs-glue +INFO: commited 'gfs-glue' shadow CIB to the cluster +crm(gfs-glue)# quit +bye +[root@pcmk-1 ~]# crm_mon +============ +Last updated: Thu Sep  3 20:49:54 2009 +Stack: openais +Current DC: pcmk-2 - partition with quorum +Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 +2 Nodes configured, 2 expected votes +6 Resources configured. +============ + +Online: [ pcmk-1 pcmk-2 ] + +WebSite (ocf::heartbeat:apache):        Started pcmk-2 +Master/Slave Set: WebDataClone +        Masters: [ pcmk-1 ] +        Slaves: [ pcmk-2 ] +ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 +Clone Set: dlm-clone +        Started: [ pcmk-2 pcmk-1 ] +Clone Set: gfs-clone + Started: [ pcmk-2 pcmk-1 ] +WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-1 + +
+ +
+ +
+ Create a GFS2 Filesystem +
+ Preparation + + Before we do anything to the existing partition, we need to make sure it is unmounted. We do this by tell the cluster to stop the WebFS resource. This will ensure that other resources (in our case, Apache) using WebFS are not only stopped, but stopped in the correct order. + + + +[root@pcmk-1 ~]# crm_resource --resource WebFS --set-parameter target-role --meta --parameter-value Stopped +[root@pcmk-1 ~]# crm_mon +============ +Last updated: Thu Sep  3 15:18:06 2009 +Stack: openais +Current DC: pcmk-1 - partition with quorum +Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 +2 Nodes configured, 2 expected votes +6 Resources configured. +============ + +Online: [ pcmk-1 pcmk-2 ] + +Master/Slave Set: WebDataClone +        Masters: [ pcmk-1 ] +        Slaves: [ pcmk-2 ] +ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 +Clone Set: dlm-clone +        Started: [ pcmk-2 pcmk-1 ] +Clone Set: gfs-clone +        Started: [ pcmk-2 pcmk-1 ] + + + + Note that both Apache and WebFS have been stopped. + + +
+ +
+ Create and Populate an GFS2 Partition + + Now that the cluster stack and integration pieces are running smoothly, we can create an GFS2 partition. + + + + This will erase all previous content stored on the DRBD device. Ensure you have a copy of any important data. + + + + We need to specify a number of additional parameters when creating a GFS2 partition. + + + First we must use the -p option to specify that we want to use the the Kernel’s DLM. Next we use -j to indicate that it should reserve enough space for two journals (one per node accessing the filesystem). + + + Lastly, we use -t to specify the lock table name. The format for this field is clustername:fsname. For the fsname, we just need to pick something unique and descriptive and since we haven’t specified a clustername yet, we will use the default (pcmk). + + + To specify an alternate name for the cluster, locate the service section containing “name: pacemaker” in corosync.conf and insert the following line anywhere inside the block: + + + clustername: myname + + + Do this on each node in the cluster and be sure to restart them before continuing. + + + +mkfs.gfs2 -p lock_dlm -j 2 -t pcmk:web /dev/drbd1 +[root@pcmk-1 ~]# mkfs.gfs2 -t pcmk:web -p lock_dlm -j 2 /dev/vdb +This will destroy any data on /dev/vdb. +It appears to contain: data + +Are you sure you want to proceed? [y/n] y + +Device:                    /dev/vdb +Blocksize:                 4096 +Device Size                1.00 GB (131072 blocks) +Filesystem Size:           1.00 GB (131070 blocks) +Journals:                  2 +Resource Groups:           2 +Locking Protocol:          "lock_dlm" +Lock Table:                "pcmk:web" +UUID:                      6B776F46-177B-BAF8-2C2B-292C0E078613 + +[root@pcmk-1 ~]# + + + Then (re)populate the new filesystem with data (web pages). For now we’ll create another variation on our home page. + + + +[root@pcmk-1 ~]# mount /dev/drbd1 /mnt/ +[root@pcmk-1 ~]# cat <<-END >/mnt/index.html +<html> +<body>My Test Site - GFS2</body> +</html> +END +[root@pcmk-1 ~]# umount /dev/drbd1 +[root@pcmk-1 ~]# drbdadm verify wwwdata +[root@pcmk-1 ~]# + +
+ +
+ +
+ Reconfigure the Cluster for GFS2 + + +[root@pcmk-1 ~]# crm +crm(live)# cib new GFS2 +INFO: GFS2 shadow CIB created +crm(GFS2)# configure delete WebFS +crm(GFS2)# configure primitive WebFS ocf:heartbeat:Filesystem params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” + + + Now that we’ve recreated the resource, we also need to recreate all the constraints that used it. This is because the shell will automatically remove any constraints that referenced WebFS. + + + +crm(GFS2)# configure colocation WebSite-with-WebFS inf: WebSite WebFS +crm(GFS2)# configure colocation fs_on_drbd inf: WebFS WebDataClone:Master +crm(GFS2)# configure order WebFS-after-WebData inf: WebDataClone:promote WebFS:start +crm(GFS2)# configure order WebSite-after-WebFS inf: WebFS WebSite +crm(GFS2)# configure colocation WebFS-with-gfs-control INFINITY: WebFS gfs-clone +crm(GFS2)# configure order start-WebFS-after-gfs-control mandatory: gfs-clone WebFS +crm(GFS2)# configure show +node pcmk-1 +node pcmk-2 +primitive WebData ocf:linbit:drbd \ +        params drbd_resource="wwwdata" \ +        op monitor interval="60s" +primitive WebFS ocf:heartbeat:Filesystem \ + params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” +primitive WebSite ocf:heartbeat:apache \ +        params configfile="/etc/httpd/conf/httpd.conf" \ +        op monitor interval="1min" +primitive ClusterIP ocf:heartbeat:IPaddr2 \ +        params ip="192.168.122.101" cidr_netmask="32" \ +        op monitor interval="30s" +primitive dlm ocf:pacemaker:controld \ +        op monitor interval="120s" +primitive gfs-control ocf:pacemaker:controld \ +   params daemon=”gfs_controld.pcmk” args=”-g 0” \ +        op monitor interval="120s" +ms WebDataClone WebData \ +        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" +clone dlm-clone dlm \ +        meta interleave="true" +clone gfs-clone gfs-control \ +        meta interleave="true" +colocation WebFS-with-gfs-control inf: WebFS gfs-clone +colocation WebSite-with-WebFS inf: WebSite WebFS +colocation fs_on_drbd inf: WebFS WebDataClone:Master +colocation gfs-with-dlm inf: gfs-clone dlm-clone +colocation website-with-ip inf: WebSite ClusterIP +order WebFS-after-WebData inf: WebDataClone:promote WebFS:start +order WebSite-after-WebFS inf: WebFS WebSite +order apache-after-ip inf: ClusterIP WebSite +order start-WebFS-after-gfs-control inf: gfs-clone WebFS +order start-gfs-after-dlm inf: dlm-clone gfs-clone +property $id="cib-bootstrap-options" \ +        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ +        cluster-infrastructure="openais" \ +        expected-quorum-votes=”2” \ +        stonith-enabled="false" \ +        no-quorum-policy="ignore" +rsc_defaults $id="rsc-options" \ +        resource-stickiness=”100” + + + Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response + + + +crm(GFS2)# cib commit GFS2 +INFO: commited 'GFS2' shadow CIB to the cluster +crm(GFS2)# quit +bye +[root@pcmk-1 ~]# crm_mon +============ +Last updated: Thu Sep  3 20:49:54 2009 +Stack: openais +Current DC: pcmk-2 - partition with quorum +Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 +2 Nodes configured, 2 expected votes +6 Resources configured. +============ + +Online: [ pcmk-1 pcmk-2 ] + +WebSite (ocf::heartbeat:apache):        Started pcmk-2 +Master/Slave Set: WebDataClone +        Masters: [ pcmk-1 ] +        Slaves: [ pcmk-2 ] +ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 +Clone Set: dlm-clone +        Started: [ pcmk-2 pcmk-1 ] +Clone Set: gfs-clone +        Started: [ pcmk-2 pcmk-1 ] +WebFS (ocf::heartbeat:Filesystem): Started pcmk-1 + +
Reconfigure Pacemaker for Active/Active Almost everything is in place. Recent versions of DRBD are capable of operating in Primary/Primary mode and the filesystem we’re using is cluster aware. All we need to do now is reconfigure the cluster to take advantage of this. This will involve a number of changes, so we’ll again use interactive mode. -crm -cib new active +[root@pcmk-1 ~]# crm +[root@pcmk-1 ~]# cib new active There’s no point making the services active on both locations if we can’t reach them, so lets first clone the IP address. Cloned IPaddr2 resources use an iptables rule to ensure that each request only processed by one of the two clone instances. The additional meta options tell the cluster how many instances of the clone we want (one “request bucket” for each node) and that if all other nodes fail, then the remaining node should hold all of them. Otherwise the requests would be simply discarded. -configure clone WebIP ClusterIP  \ -        meta globally-unique=”true” clone-max=”2” clone-node-max=”2” +[root@pcmk-1 ~]# configure clone WebIP ClusterIP  \ +        meta globally-unique=”true” clone-max=”2” clone-node-max=”2” Now we must tell the ClusterIP how to decide which requests are processed by which hosts. To do this we must specify the clusterip_hash parameter. Open the ClusterIP resource - configure edit  ClusterIP + [root@pcmk-1 ~]# configure edit  ClusterIP And add the following to the params line clusterip_hash="sourceip" So that the complete definition looks like: primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" clusterip_hash="sourceip" \         op monitor interval="30s" Here is the full transcript -[root@pcmk-1 ~]# crm -crm(live)# cib new active +[root@pcmk-1 ~]# crm +crm(live)# cib new active INFO: active shadow CIB created -crm(active)# configure clone WebIP ClusterIP  \ +crm(active)# configure clone WebIP ClusterIP  \         meta globally-unique=”true” clone-max=”2” clone-node-max=”2” -crm(active)# configure show +crm(active)# configure show node pcmk-1 node pcmk-2 primitive WebData ocf:linbit:drbd \         params drbd_resource="wwwdata" \         op monitor interval="60s" primitive WebFS ocf:heartbeat:Filesystem \         params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip=”192.168.122.101” cidr_netmask=”32” clusterip_hash=”sourceip” \         op monitor interval="30s" primitive dlm ocf:pacemaker:controld \         op monitor interval="120s" primitive gfs-control ocf:pacemaker:controld \    params daemon=”gfs_controld.pcmk” args=”-g 0” \         op monitor interval="120s" ms WebDataClone WebData \         meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" clone WebIP ClusterIP \ meta globally-unique=”true” clone-max=”2” clone-node-max=”2” clone dlm-clone dlm \         meta interleave="true" clone gfs-clone gfs-control \         meta interleave="true" colocation WebFS-with-gfs-control inf: WebFS gfs-clone colocation WebSite-with-WebFS inf: WebSite WebFS colocation fs_on_drbd inf: WebFS WebDataClone:Master colocation gfs-with-dlm inf: gfs-clone dlm-clone colocation website-with-ip inf: WebSite WebIP order WebFS-after-WebData inf: WebDataClone:promote WebFS:start order WebSite-after-WebFS inf: WebFS WebSite order apache-after-ip inf: WebIP WebSite order start-WebFS-after-gfs-control inf: gfs-clone WebFS order start-gfs-after-dlm inf: dlm-clone gfs-clone property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes=”2” \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness=”100” Notice how any constraints that referenced ClusterIP have been updated to use WebIP instead. This is an additional benefit of using the crm shell. Next we need to convert the filesystem and Apache resources into clones. Again, the shell will automatically update any relevant constraints. -configure clone WebFSClone WebFS -configure clone WebSiteClone WebSite +crm(active)# configure clone WebFSClone WebFS +crm(active)# configure clone WebSiteClone WebSite The last step is to tell the cluster that it is now allowed to promote both instances to be Primary (aka. Master). -configure edit WebDataClone +crm(active)# configure edit WebDataClone Change master-max to 2 - +crm(active)# configure show node pcmk-1 node pcmk-2 primitive WebData ocf:linbit:drbd \         params drbd_resource="wwwdata" \         op monitor interval="60s" primitive WebFS ocf:heartbeat:Filesystem \         params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip=”192.168.122.101” cidr_netmask=”32” clusterip_hash=”sourceip” \         op monitor interval="30s" primitive dlm ocf:pacemaker:controld \         op monitor interval="120s" primitive gfs-control ocf:pacemaker:controld \    params daemon=”gfs_controld.pcmk” args=”-g 0” \         op monitor interval="120s" ms WebDataClone WebData \         meta master-max="2" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" clone WebFSClone WebFS clone WebIP ClusterIP  \         meta globally-unique=”true” clone-max=”2” clone-node-max=”2” clone WebSiteClone WebSite clone dlm-clone dlm \         meta interleave="true" clone gfs-clone gfs-control \         meta interleave="true" colocation WebFS-with-gfs-control inf: WebFSClone gfs-clone colocation WebSite-with-WebFS inf: WebSiteClone WebFSClone colocation fs_on_drbd inf: WebFSClone WebDataClone:Master colocation gfs-with-dlm inf: gfs-clone dlm-clone colocation website-with-ip inf: WebSiteClone WebIP order WebFS-after-WebData inf: WebDataClone:promote WebFSClone:start order WebSite-after-WebFS inf: WebFSClone WebSiteClone order apache-after-ip inf: WebIP WebSiteClone order start-WebFS-after-gfs-control inf: gfs-clone WebFSClone order start-gfs-after-dlm inf: dlm-clone gfs-clone property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes=”2” \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness=”100” Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response -crm(active)# cib commit active +crm(active)# cib commit active INFO: commited 'active' shadow CIB to the cluster -crm(active)# quit +crm(active)# quit bye -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Thu Sep  3 21:37:27 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 6 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] Master/Slave Set: WebDataClone         Masters: [ pcmk-1 pcmk-2 ] Clone Set: dlm-clone         Started: [ pcmk-2 pcmk-1 ] Clone Set: gfs-clone         Started: [ pcmk-2 pcmk-1 ] Clone Set: WebIP Started: [ pcmk-1 pcmk-2 ] Clone Set: WebFSClone Started: [ pcmk-1 pcmk-2 ] Clone Set: WebSiteClone Started: [ pcmk-1 pcmk-2 ] +
+ Testing Recovery + + + TODO: Put one node into standby to demonstrate failover + + +
-
- Testing Recovery - - - TODO: Put one node into standby to demonstrate failover - - -
+
diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.xml b/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.xml index 61a0eb353a..bb9a07ef13 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.xml +++ b/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.xml @@ -1,391 +1,391 @@ %BOOK_ENTITIES; ]> Creating an Active/Passive Cluster
Exploring the Existing Configuration When Pacemaker starts up, it automatically records the number and details of the nodes in the cluster as well as which stack is being used and the version of Pacemaker being used. This is what the base configuration should look like. [root@pcmk-2 ~]# crm configure show node pcmk-1 node pcmk-2 property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" For those that are not of afraid of XML, you can see the raw configuration by appending “xml” to the previous command. [root@pcmk-2 ~]# crm configure show xml <?xml version="1.0" ?> <cib admin_epoch="0" crm_feature_set="3.0.1" dc-uuid="pcmk-1" epoch="13" have-quorum="1" num_updates="7" validate-with="pacemaker-1.0">   <configuration>     <crm_config>       <cluster_property_set id="cib-bootstrap-options">         <nvpair id="cib-bootstrap-options-dc-version" name="dc-version" value="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7"/>         <nvpair id="cib-bootstrap-options-cluster-infrastructure" name="cluster-infrastructure" value="openais"/>         <nvpair id="cib-bootstrap-options-expected-quorum-votes" name="expected-quorum-votes" value="2"/>       </cluster_property_set>     </crm_config>     <rsc_defaults/>     <op_defaults/>     <nodes>       <node id="pcmk-1" type="normal" uname="pcmk-1"/>       <node id="pcmk-2" type="normal" uname="pcmk-2"/>     </nodes>     <resources/>     <constraints/>   </configuration> </cib> The last XML you’ll see in this document Before we make any changes, its a good idea to check the validity of the configuration. [root@pcmk-1 ~]# crm_verify -L crm_verify[2195]: 2009/08/27_16:57:12 ERROR: unpack_resources: Resource start-up disabled since no STONITH resources have been defined crm_verify[2195]: 2009/08/27_16:57:12 ERROR: unpack_resources: Either configure some or disable STONITH with the stonith-enabled option crm_verify[2195]: 2009/08/27_16:57:12 ERROR: unpack_resources: NOTE: Clusters with shared data need STONITH to ensure data integrity Errors found during check: config not valid   -V may provide more details [root@pcmk-1 ~]# As you can see, the tool has found some errors. In order to guarantee the safety of your data If the data is corrupt, there is little point in continuing to make it available , Pacemaker ships with STONITH A common node fencing mechanism. Used to ensure data integrity by powering off “bad” nodes. enabled. However it also knows when no STONITH configuration has been supplied and reports this as a problem (since the cluster would not be able to make progress if a situation requiring node fencing arose). For now, we will disable this feature and configure it later in the Configuring STONITH section. It is important to note that the use of STONITH is highly encouraged, turning it off tells the cluster to simply pretend that failed nodes are safely powered off. Some vendors will even refuse to support clusters that have it disabled. To disable STONITH, we set the stonith-enabled cluster option to false.
crm configure property stonith-enabled=false crm_verify -L
With the new cluster option set, the configuration is now valid.
Adding a Resource The first thing we should do is configure an IP address. Regardless of where the cluster service(s) are running, we need a consistent address to contact them on. Here I will choose and add 192.168.122.101 as the floating address, give it the imaginative name ClusterIP and tell the cluster to check that its running every 30 seconds. The chosen address must not be one already associated with a physical node crm configure primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip=192.168.122.101 cidr_netmask=32 \         op monitor interval=30s The other important piece of information here is ocf:heartbeat:IPaddr2. This tells Pacemaker three things about the resource you want to add. The first field, ocf, is the standard to which the resource script conforms to and where to find it. The second field is specific to OCF resources and tells the cluster which namespace to find the resource script in, in this case heartbeat. The last field indicates the name of the resource script. To obtain a list of the available resource classes, run [root@pcmk-1 ~]# crm ra classes heartbeat lsb ocf / heartbeat pacemaker stonith To then find all the OCF resource agents provided by Pacemaker and Heartbeat, run [root@pcmk-1 ~]# crm ra list ocf pacemaker ClusterMon     Dummy          Stateful       SysInfo        SystemHealth   controld ping           pingd           [root@pcmk-1 ~]# crm ra list ocf heartbeat AoEtarget              AudibleAlarm           ClusterMon             Delay Dummy                  EvmsSCC                Evmsd                  Filesystem ICP                    IPaddr                 IPaddr2                IPsrcaddr LVM                    LinuxSCSI              MailTo                 ManageRAID ManageVE               Pure-FTPd              Raid1                  Route SAPDatabase            SAPInstance            SendArp                ServeRAID SphinxSearchDaemon     Squid                  Stateful               SysInfo VIPArip                VirtualDomain          WAS                    WAS6 WinPopup               Xen                    Xinetd                 anything apache                 db2                    drbd                   eDir88 iSCSILogicalUnit       iSCSITarget            ids                    iscsi ldirectord             mysql                  mysql-proxy            nfsserver oracle                 oralsnr                pgsql                  pingd portblock              rsyncd                 scsi2reservation       sfex tomcat                 vmware                 [root@pcmk-1 ~]# Now verify that the IP resource has been added and display the cluster’s status to see that it is now active. [root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive ClusterIP ocf:heartbeat:IPaddr2 \ params ip="192.168.122.101" cidr_netmask="32" \ op monitor interval="30s" property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \ [root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 15:23:48 2009 Stack: openais Current DC: pcmk-1 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP (ocf::heartbeat:IPaddr): Started pcmk-1
Perform a Failover Being a high-availability cluster, we should test failover of our new resource before moving on. First, find the node on which the IP address is running. -[root@pcmk-1 ~]# crm resource status ClusterIP +[root@pcmk-1 ~]# crm resource status ClusterIP resource ClusterIP is running on: pcmk-1 [root@pcmk-1 ~]# Shut down Corosync on that machine. -[root@pcmk-1 ~]# ssh pcmk-1 -- /etc/init.d/corosync stop +[root@pcmk-1 ~]# ssh pcmk-1 -- /etc/init.d/corosync stop Stopping Corosync Cluster Engine (corosync): [ OK ] Waiting for services to unload: [ OK ] [root@pcmk-1 ~]# Once Corosync is no longer running, go to the other node and check the cluster status with crm_mon. -[root@pcmk-2 ~]# crm_mon +[root@pcmk-2 ~]# crm_mon ============ Last updated: Fri Aug 28 15:27:35 2009 Stack: openais Current DC: pcmk-2 - partition WITHOUT quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-2 ] OFFLINE: [ pcmk-1 ] There are three things to notice about the cluster’s current state. The first is that, as expected, pcmk-1 is now offline. However we can also see that ClusterIP isn’t running anywhere!
Quorum and Two-Node Clusters This is because the cluster no longer has quorum, as can be seen by the text “partition WITHOUT quorum” (emphasised green) in the output above. In order to reduce the possibility of data corruption, Pacemaker’s default behavior is to stop all resources if the cluster does not have quorum. A cluster is said to have quorum when more than half the known or expected nodes are online, or for the mathematically inclined, whenever the following equation is true: total_nodes - 1 < 2 * active_nodes Therefore a two-node cluster only has quorum when both nodes are running, which is no longer the case for our cluster. This would normally make the creation of a two-node cluster pointless Actually some would argue that two-node clusters are always pointless, but that is an argument for another time. , however it is possible to control how Pacemaker behaves when quorum is lost. In particular, we can tell the cluster to simply ignore quorum altogether. -[root@pcmk-1 ~]# crm configure property no-quorum-policy=ignore -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure property no-quorum-policy=ignore +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" After a few moments, the cluster will start the IP address on the remaining node. Note that the cluster still does not have quorum. -[root@pcmk-2 ~]# crm_mon +[root@pcmk-2 ~]# crm_mon ============ Last updated: Fri Aug 28 15:30:18 2009 Stack: openais Current DC: pcmk-2 - partition WITHOUT quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-2 ] OFFLINE: [ pcmk-1 ] ClusterIP (ocf::heartbeat:IPaddr): Started pcmk-2 Now simulate node recovery by restarting the cluster stack on pcmk-1 and check the cluster’s status. -[root@pcmk-1 ~]# /etc/init.d/corosync start +[root@pcmk-1 ~]# /etc/init.d/corosync start Starting Corosync Cluster Engine (corosync): [ OK ] -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 15:32:13 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 Here we see something that some may consider surprising, the IP is back running at its original location!
Prevent Resources from Moving after Recovery In some circumstances it is highly desirable to prevent healthy resources from being moved around the cluster. Move resources almost always requires a period of downtime and for complex services like Oracle databases, this period can be quite long. To address this, Pacemaker has the concept of resource stickiness which controls how much a service prefers to stay running where it is. You may like to think of it as the “cost” of any downtime. By default, Pacemaker assumes there is zero cost associated with moving resources and will do so to achieve “optimal It should be noted that Pacemaker’s definition of optimal may not always agree with that of a human’s. The order in which Pacemaker processes lists of resources and nodes create implicit preferences (required in order to create a stabile solution) in situations where the administrator had not explicitly specified some. ” resource placement. We can specify a different stickiness for every resource, but it is often sufficient to change the default. crm configure rsc_defaults resource-stickiness=100 -[root@pcmk-2 ~]# crm configure show +[root@pcmk-2 ~]# crm configure show node pcmk-1 node pcmk-2 primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \ resource-stickiness="100" If we now retry the failover test, we see that as expected ClusterIP still moves to pcmk-2 when pcmk-1 is taken offline. -[root@pcmk-1 ~]# ssh pcmk-1 -- /etc/init.d/corosync stop +[root@pcmk-1 ~]# ssh pcmk-1 -- /etc/init.d/corosync stop Stopping Corosync Cluster Engine (corosync):               [  OK  ] Waiting for services to unload:                            [  OK  ] -[root@pcmk-1 ~]# ssh pcmk-2 -- crm_mon -1 +[root@pcmk-1 ~]# ssh pcmk-2 -- crm_mon -1 ============ Last updated: Fri Aug 28 15:39:38 2009 Stack: openais Current DC: pcmk-2 - partition WITHOUT quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-2 ] OFFLINE: [ pcmk-1 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 However when we bring pcmk-1 back online, ClusterIP now remains running on pcmk-2. -[root@pcmk-1 ~]# /etc/init.d/corosync start +[root@pcmk-1 ~]# /etc/init.d/corosync start Starting Corosync Cluster Engine (corosync): [ OK ] -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 15:41:23 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 1 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2
diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Apache.xml b/doc/Clusters_from_Scratch/en-US/Ch-Apache.xml index 829e8388de..98349d6668 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Apache.xml +++ b/doc/Clusters_from_Scratch/en-US/Ch-Apache.xml @@ -1,456 +1,456 @@ %BOOK_ENTITIES; ]> Apache - Adding More Services Now that we have a basic but functional active/passive two-node cluster, we’re ready to add some real services. We’re going to start with Apache because its a feature of many clusters and relatively simple to configure.
Installation Before continuing, we need to make sure Apache is installed on both hosts. -[root@ppcmk-1 ~]# yum install -y httpd +[root@ppcmk-1 ~]# yum install -y httpd Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package httpd.x86_64 0:2.2.13-2.fc12 set to be updated --> Processing Dependency: httpd-tools = 2.2.13-2.fc12 for package: httpd-2.2.13-2.fc12.x86_64 --> Processing Dependency: apr-util-ldap for package: httpd-2.2.13-2.fc12.x86_64 --> Processing Dependency: /etc/mime.types for package: httpd-2.2.13-2.fc12.x86_64 --> Processing Dependency: libaprutil-1.so.0()(64bit) for package: httpd-2.2.13-2.fc12.x86_64 --> Processing Dependency: libapr-1.so.0()(64bit) for package: httpd-2.2.13-2.fc12.x86_64 --> Running transaction check ---> Package apr.x86_64 0:1.3.9-2.fc12 set to be updated ---> Package apr-util.x86_64 0:1.3.9-2.fc12 set to be updated ---> Package apr-util-ldap.x86_64 0:1.3.9-2.fc12 set to be updated ---> Package httpd-tools.x86_64 0:2.2.13-2.fc12 set to be updated ---> Package mailcap.noarch 0:2.1.30-1.fc12 set to be updated --> Finished Dependency Resolution Dependencies Resolved =======================================================================================  Package               Arch             Version                Repository         Size ======================================================================================= Installing:  httpd               x86_64           2.2.13-2.fc12            rawhide           735 k Installing for dependencies:  apr                 x86_64           1.3.9-2.fc12             rawhide           117 k  apr-util            x86_64           1.3.9-2.fc12             rawhide            84 k  apr-util-ldap       x86_64           1.3.9-2.fc12             rawhide            15 k  httpd-tools         x86_64           2.2.13-2.fc12            rawhide            63 k  mailcap             noarch           2.1.30-1.fc12            rawhide            25 k Transaction Summary ======================================================================================= Install       6 Package(s) Upgrade       0 Package(s) Total download size: 1.0 M Downloading Packages: (1/6): apr-1.3.9-2.fc12.x86_64.rpm                                   | 117 kB     00:00     (2/6): apr-util-1.3.9-2.fc12.x86_64.rpm                             |  84 kB     00:00     (3/6): apr-util-ldap-1.3.9-2.fc12.x86_64.rpm                         |  15 kB     00:00     (4/6): httpd-2.2.13-2.fc12.x86_64.rpm                               | 735 kB     00:00     (5/6): httpd-tools-2.2.13-2.fc12.x86_64.rpm                         |  63 kB     00:00     (6/6): mailcap-2.1.30-1.fc12.noarch.rpm                             |  25 kB     00:00     ---------------------------------------------------------------------------------------- Total                                                       875 kB/s | 1.0 MB     00:01     Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction   Installing     : apr-1.3.9-2.fc12.x86_64                                         1/6   Installing     : apr-util-1.3.9-2.fc12.x86_64                                     2/6   Installing     : apr-util-ldap-1.3.9-2.fc12.x86_64                               3/6   Installing     : httpd-tools-2.2.13-2.fc12.x86_64                                 4/6   Installing     : mailcap-2.1.30-1.fc12.noarch                                     5/6   Installing     : httpd-2.2.13-2.fc12.x86_64                                       6/6 Installed:   httpd.x86_64 0:2.2.13-2.fc12                                                         Dependency Installed:   apr.x86_64 0:1.3.9-2.fc12            apr-util.x86_64 0:1.3.9-2.fc12   apr-util-ldap.x86_64 0:1.3.9-2.fc12  httpd-tools.x86_64 0:2.2.13-2.fc12   mailcap.noarch 0:2.1.30-1.fc12   Complete! [root@pcmk-1 ~]# Also, we need the wget tool in order for the cluster to be able to check the status of the Apache server. -[root@pcmk-1 ~]# yum install -y wget +[root@pcmk-1 ~]# yum install -y wget Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package wget.x86_64 0:1.11.4-5.fc12 set to be updated --> Finished Dependency Resolution Dependencies Resolved ===========================================================================================  Package        Arch             Version                      Repository               Size =========================================================================================== Installing:  wget         x86_64          1.11.4-5.fc12                   rawhide                393 k Transaction Summary =========================================================================================== Install       1 Package(s) Upgrade       0 Package(s) Total download size: 393 k Downloading Packages: wget-1.11.4-5.fc12.x86_64.rpm                                            | 393 kB     00:00     Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction   Installing     : wget-1.11.4-5.fc12.x86_64                                            1/1 Installed:   wget.x86_64 0:1.11.4-5.fc12 Complete! [root@pcmk-1 ~]#
Preparation First we need to create a page for Apache to serve up. On Fedora the default Apache docroot is /var/www/html, so we’ll create an index file there. -[root@pcmk-1 ~]# cat <<-END >/var/www/html/index.html +[root@pcmk-1 ~]# cat <<-END >/var/www/html/index.html <html> <body>My Test Site - pcmk-1</body> </html> END [root@pcmk-1 ~]# For the moment, we will simplify things by serving up only a static site and manually sync the data between the two nodes. So run the command again on pcmk-2. -[root@pcmk-2 ~]# cat <<-END >/var/www/html/index.html +[root@pcmk-2 ~]# cat <<-END >/var/www/html/index.html <html> <body>My Test Site - pcmk-2</body> </html> END [root@pcmk-2 ~]#
Update the Configuration At this point, Apache is ready to go, all that needs to be done is to add it to the cluster. Lets call the resource WebSite. We need to use an OCF script called apache in the heartbeat namespace Compare the key used here ocf:heartbeat:apache with the one we used earlier for the IP address: ocf:heartbeat:IPaddr2 , the only required parameter is the path to the main Apache configuration file and we’ll tell the cluster to check once a minute that apache is still running. -[root@pcmk-1 ~]# crm configure primitive WebSite ocf:heartbeat:apache params configfile=/etc/httpd/conf/httpd.conf op monitor interval=1min -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure primitive WebSite ocf:heartbeat:apache params configfile=/etc/httpd/conf/httpd.conf op monitor interval=1min +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \ params configfile="/etc/httpd/conf/httpd.conf" \ op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100" After a short delay, we should see the cluster start apache -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 16:12:49 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 WebSite        (ocf::heartbeat:apache):        Started pcmk-1 Wait a moment, the WebSite resource isn’t running on the same host as our IP address!
Ensuring Resources Run on the Same Host To reduce the load on any one machine, Pacemaker will generally try to spread the configured resources across the cluster nodes. However we can tell the cluster that two resources are related and need to run on the same host (or not at all). Here we instruct the cluster that WebSite can only run on the host that ClusterIP is active on. If ClusterIP is not active anywhere, WebSite will not be permitted to run anywhere. -[root@pcmk-1 ~]# crm configure colocation website-with-ip INFINITY: WebSite ClusterIP -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure colocation website-with-ip INFINITY: WebSite ClusterIP +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" colocation website-with-ip inf: WebSite ClusterIP property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100" -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 16:14:34 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 WebSite        (ocf::heartbeat:apache):        Started pcmk-2
Controlling Resource Start/Stop Ordering When Apache starts, it binds to the available IP addresses. It doesn’t know about any addresses we add afterwards, so not only do they need to run on the same node, but we need to make sure ClusterIP is already active before we start WebSite. We do this by adding an ordering constraint. We need to give it a name (chose something descriptive like apache-after-ip), indicate that its mandatory (so that any recovery for ClusterIP will also trigger recovery of WebSite) and list the two resources in the order we need them to start. -[root@pcmk-1 ~]# crm configure order apache-after-ip mandatory: ClusterIP WebSite -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure order apache-after-ip mandatory: ClusterIP WebSite +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" colocation website-with-ip inf: WebSite ClusterIP order apache-after-ip inf: ClusterIP WebSite property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100"
Specifying a Preferred Location Pacemaker does not rely on any sort of hardware symmetry between nodes, so it may well be that one machine is more powerful than the other. In such cases it makes sense to host the resources there if it is available. To do this we create a location constraint. Again we give it a descriptive name (prefer-pcmk-1), specify the resource we want to run there (WebSite), how badly we’d like it to run there (we’ll use 50 for now, but in a two-node situation almost any value above 0 will do) and the host’s name. -[root@pcmk-1 ~]# crm configure location prefer-pcmk-1 WebSite 50: pcmk-1 -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure location prefer-pcmk-1 WebSite 50: pcmk-1 +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" location prefer-pcmk-1 WebSite 50: pcmk-1 colocation website-with-ip inf: WebSite ClusterIP property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100" -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 16:17:35 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 WebSite        (ocf::heartbeat:apache):        Started pcmk-2 Wait a minute, the resources are still on pcmk-2! Even though we now prefer pcmk-1 over pcmk-2, that preference is (intentionally) less than the resource stickiness (how much we preferred not to have unnecessary downtime). To see the current placement scores, you can use a tool called ptest ptest -sL Include output There is a way to force them to move though...
Manually Moving Resources Around the Cluster There are always times when an administrator needs to override the cluster and force resources to move to a specific location. Underneath we use location constraints like the one we created above, happily you don’t need to care. Just provide the name of the resource and the intended location, we’ll do the rest. -[root@pcmk-1 ~]# crm resource move WebSite pcmk-1 -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm resource move WebSite pcmk-1 +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 16:19:24 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 WebSite        (ocf::heartbeat:apache):        Started pcmk-1 Notice how the colocation rule we created has ensured that ClusterIP was also moved to pcmk-1. For the curious, we can see the effect of this command by examining the configuration crm configure show -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" location cli-prefer-WebSite WebSite \ rule $id="cli-prefer-rule-WebSite" inf: #uname eq pcmk-1 location prefer-pcmk-1 WebSite 50: pcmk-1 colocation website-with-ip inf: WebSite ClusterIP property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100" Highlighted is the automated constraint used to move the resources to pcmk-1
Giving Control Back to the Cluster Once we’ve finished whatever activity that required us to move the resources to pcmk-1, in our case nothing, we can then allow the cluster to resume normal operation with the unmove command. Since we previously configured a default stickiness, the resources will remain on pcmk-1. -[root@pcmk-1 ~]# crm resource unmove WebSite -[root@pcmk-1 ~]# crm configure show +[root@pcmk-1 ~]# crm resource unmove WebSite +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" location prefer-pcmk-1 WebSite 50: pcmk-1 colocation website-with-ip inf: WebSite ClusterIP property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes="2" \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness="100" Note that the automated constraint is now gone. If we check the cluster status, we can also see that as expected the resources are still active on pcmk-1. -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Fri Aug 28 16:20:53 2009 Stack: openais Current DC: pcmk-2 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 WebSite        (ocf::heartbeat:apache):        Started pcmk-1
diff --git a/doc/Clusters_from_Scratch/en-US/Ch-ClusterFS.xml b/doc/Clusters_from_Scratch/en-US/Ch-ClusterFS.xml deleted file mode 100644 index 765359d23e..0000000000 --- a/doc/Clusters_from_Scratch/en-US/Ch-ClusterFS.xml +++ /dev/null @@ -1,489 +0,0 @@ - - -%BOOK_ENTITIES; -]> - - Cluster Filesystems - GFS2 -
- Install a Cluster Filesystem - GFS2 - - The first thing to do is install gfs2-utils on each machine. - - - -[root@pcmk-1 ~]# yum install -y gfs2-utils gfs-pcmk -Setting up Install Process -Resolving Dependencies ---> Running transaction check ----> Package gfs-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated ---> Processing Dependency: libSaCkpt.so.3(OPENAIS_CKPT_B.01.01)(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ---> Processing Dependency: dlm-pcmk for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ---> Processing Dependency: libccs.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ---> Processing Dependency: libdlmcontrol.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ---> Processing Dependency: liblogthread.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ---> Processing Dependency: libSaCkpt.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64 ----> Package gfs2-utils.x86_64 0:3.0.5-2.fc12 set to be updated ---> Running transaction check ----> Package clusterlib.x86_64 0:3.0.5-2.fc12 set to be updated ----> Package dlm-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated ----> Package openaislib.x86_64 0:1.1.0-1.fc12 set to be updated ---> Finished Dependency Resolution - -Dependencies Resolved - -=========================================================================================== - Package                Arch               Version                   Repository        Size -=========================================================================================== -Installing: - gfs-pcmk               x86_64             3.0.5-2.fc12              custom           101 k - gfs2-utils             x86_64             3.0.5-2.fc12              custom           208 k -Installing for dependencies: - clusterlib             x86_64             3.0.5-2.fc12              custom            65 k - dlm-pcmk               x86_64             3.0.5-2.fc12              custom            93 k - openaislib             x86_64             1.1.0-1.fc12              fedora            76 k - -Transaction Summary -=========================================================================================== -Install       5 Package(s) -Upgrade       0 Package(s) - -Total download size: 541 k -Downloading Packages: -(1/5): clusterlib-3.0.5-2.fc12.x86_64.rpm                                |  65 kB     00:00 -(2/5): dlm-pcmk-3.0.5-2.fc12.x86_64.rpm                                  |  93 kB     00:00 -(3/5): gfs-pcmk-3.0.5-2.fc12.x86_64.rpm                                  | 101 kB     00:00 -(4/5): gfs2-utils-3.0.5-2.fc12.x86_64.rpm                                | 208 kB     00:00 -(5/5): openaislib-1.1.0-1.fc12.x86_64.rpm                                |  76 kB     00:00 -------------------------------------------------------------------------------------------- -Total                                                           992 kB/s | 541 kB     00:00 -Running rpm_check_debug -Running Transaction Test -Finished Transaction Test -Transaction Test Succeeded -Running Transaction -  Installing     : clusterlib-3.0.5-2.fc12.x86_64                                       1/5 -  Installing     : openaislib-1.1.0-1.fc12.x86_64                                       2/5 -  Installing     : dlm-pcmk-3.0.5-2.fc12.x86_64                                         3/5 -  Installing     : gfs-pcmk-3.0.5-2.fc12.x86_64                                         4/5 -  Installing     : gfs2-utils-3.0.5-2.fc12.x86_64                                       5/5 - -Installed: -  gfs-pcmk.x86_64 0:3.0.5-2.fc12                    gfs2-utils.x86_64 0:3.0.5-2.fc12 - -Dependency Installed: -  clusterlib.x86_64 0:3.0.5-2.fc12   dlm-pcmk.x86_64 0:3.0.5-2.fc12 -  openaislib.x86_64 0:1.1.0-1.fc12   - -Complete! -[root@pcmk-1 x86_64]# - -
- -
- Setup Pacemaker-GFS2 Integration - - GFS2 needs two services to be running, the first is the user-space interface to the kernel’s distributed lock manager (DLM). The DLM is used to co-ordinate which node(s) can access a given file (and when) and integrates with Pacemaker to obtain node membership - - The list of nodes the cluster considers to be available - - information and fencing capabilities. - - - The second service is GFS2’s own control daemon which also integrates with Pacemaker to obtain node membership data. - -
- Add the DLM service - - The DLM control daemon needs to run on all active cluster nodes, so we will use the shells interactive mode to create a cloned resource. - - - -[root@pcmk-1 ~]# crm -crm(live)# cib new stack-glue -INFO: stack-glue shadow CIB created -crm(stack-glue)# configure primitive dlm ocf:pacemaker:controld op monitor interval=120s -crm(stack-glue)# configure clone dlm-clone dlm meta interleave=true -crm(stack-glue)# configure show xml -crm(stack-glue)# configure show -node pcmk-1 -node pcmk-2 -primitive WebData ocf:linbit:drbd \ -        params drbd_resource="wwwdata" \ -        op monitor interval="60s" -primitive WebFS ocf:heartbeat:Filesystem \ -        params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4" -primitive WebSite ocf:heartbeat:apache \ -        params configfile="/etc/httpd/conf/httpd.conf" \ -        op monitor interval="1min" -primitive ClusterIP ocf:heartbeat:IPaddr2 \ -        params ip="192.168.122.101" cidr_netmask="32" \ -        op monitor interval="30s" -primitive dlm ocf:pacemaker:controld \ - op monitor interval="120s" -ms WebDataClone WebData \ -        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" -clone dlm-clone dlm \ - meta interleave="true" -location prefer-pcmk-1 WebSite 50: pcmk-1 -colocation WebSite-with-WebFS inf: WebSite WebFS -colocation fs_on_drbd inf: WebFS WebDataClone:Master -colocation website-with-ip inf: WebSite ClusterIP -order WebFS-after-WebData inf: WebDataClone:promote WebFS:start -order WebSite-after-WebFS inf: WebFS WebSite -order apache-after-ip inf: ClusterIP WebSite -property $id="cib-bootstrap-options" \ -        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ -        cluster-infrastructure="openais" \ -        expected-quorum-votes=”2” \ -        stonith-enabled="false" \ -        no-quorum-policy="ignore" -rsc_defaults $id="rsc-options" \ -        resource-stickiness=”100” - - - - TODO: Explain the meaning of the interleave option - - - - Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response - - - -crm(stack-glue)# cib commit stack-glue -INFO: commited 'stack-glue' shadow CIB to the cluster -crm(stack-glue)# quit -bye -[root@pcmk-1 ~]# crm_mon -============ -Last updated: Thu Sep  3 20:49:54 2009 -Stack: openais -Current DC: pcmk-2 - partition with quorum -Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 -2 Nodes configured, 2 expected votes -5 Resources configured. -============ - -Online: [ pcmk-1 pcmk-2 ] - -WebSite (ocf::heartbeat:apache):        Started pcmk-2 -Master/Slave Set: WebDataClone -        Masters: [ pcmk-1 ] -        Slaves: [ pcmk-2 ] -ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 -Clone Set: dlm-clone - Started: [ pcmk-2 pcmk-1 ] -WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2 - -
- -
- Add the GFS2 service - - Once the DLM is active, we can add the GFS2 control daemon. - - - Use the crm shell to create the gfs-control cluster resource: - - - -[root@pcmk-1 ~]# crm -crm(live)# cib new gfs-glue --force -INFO: gfs-glue shadow CIB created -crm(gfs-glue)# configure primitive gfs-control ocf:pacemaker:controld params daemon=gfs_controld.pcmk args="-g 0" op monitor interval=120s -crm(gfs-glue)# configure clone gfs-clone gfs-control meta interleave=true - - - Now ensure Pacemaker only starts the gfs-control service on nodes that also have a copy of the dlm service (created above) already running - - - -crm(gfs-glue)# configure colocation gfs-with-dlm INFINITY: gfs-clone dlm-clone -crm(gfs-glue)# configure order start-gfs-after-dlm mandatory: dlm-clone gfs-clone - - - Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response - - - -crm(gfs-glue)# configure show -node pcmk-1 -node pcmk-2 -primitive WebData ocf:linbit:drbd \ -        params drbd_resource="wwwdata" \ -        op monitor interval="60s" -primitive WebFS ocf:heartbeat:Filesystem \ -        params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4" -primitive WebSite ocf:heartbeat:apache \ -        params configfile="/etc/httpd/conf/httpd.conf" \ -        op monitor interval="1min" -primitive ClusterIP ocf:heartbeat:IPaddr2 \ -        params ip="192.168.122.101" cidr_netmask="32" \ -        op monitor interval="30s" -primitive dlm ocf:pacemaker:controld \ -        op monitor interval="120s" -primitive gfs-control ocf:pacemaker:controld \ - params daemon=”gfs_controld.pcmk” args=”-g 0” \ - op monitor interval="120s" -ms WebDataClone WebData \ -        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" -clone dlm-clone dlm \ -        meta interleave="true" -clone gfs-clone gfs-control \ - meta interleave="true" -location prefer-pcmk-1 WebSite 50: pcmk-1 -colocation WebSite-with-WebFS inf: WebSite WebFS -colocation fs_on_drbd inf: WebFS WebDataClone:Master -colocation gfs-with-dlm inf: gfs-clone dlm-clone -colocation website-with-ip inf: WebSite ClusterIP -order WebFS-after-WebData inf: WebDataClone:promote WebFS:start -order WebSite-after-WebFS inf: WebFS WebSite -order apache-after-ip inf: ClusterIP WebSite -order start-gfs-after-dlm inf: dlm-clone gfs-clone -property $id="cib-bootstrap-options" \ -        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ -        cluster-infrastructure="openais" \ -        expected-quorum-votes=”2” \ -        stonith-enabled="false" \ -        no-quorum-policy="ignore" -rsc_defaults $id="rsc-options" \ -        resource-stickiness=”100” -crm(gfs-glue)# cib commit gfs-glue -INFO: commited 'gfs-glue' shadow CIB to the cluster -crm(gfs-glue)# quit -bye -[root@pcmk-1 ~]# crm_mon -============ -Last updated: Thu Sep  3 20:49:54 2009 -Stack: openais -Current DC: pcmk-2 - partition with quorum -Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 -2 Nodes configured, 2 expected votes -6 Resources configured. -============ - -Online: [ pcmk-1 pcmk-2 ] - -WebSite (ocf::heartbeat:apache):        Started pcmk-2 -Master/Slave Set: WebDataClone -        Masters: [ pcmk-1 ] -        Slaves: [ pcmk-2 ] -ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 -Clone Set: dlm-clone -        Started: [ pcmk-2 pcmk-1 ] -Clone Set: gfs-clone - Started: [ pcmk-2 pcmk-1 ] -WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-1 - -
- -
- -
- Create a GFS2 Filesystem -
- Preparation - - Before we do anything to the existing partition, we need to make sure it is unmounted. We do this by tell the cluster to stop the WebFS resource. This will ensure that other resources (in our case, Apache) using WebFS are not only stopped, but stopped in the correct order. - - - -[root@pcmk-1 ~]# crm_resource --resource WebFS --set-parameter target-role --meta --parameter-value Stopped -[root@pcmk-1 ~]# crm_mon -============ -Last updated: Thu Sep  3 15:18:06 2009 -Stack: openais -Current DC: pcmk-1 - partition with quorum -Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 -2 Nodes configured, 2 expected votes -6 Resources configured. -============ - -Online: [ pcmk-1 pcmk-2 ] - -Master/Slave Set: WebDataClone -        Masters: [ pcmk-1 ] -        Slaves: [ pcmk-2 ] -ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 -Clone Set: dlm-clone -        Started: [ pcmk-2 pcmk-1 ] -Clone Set: gfs-clone -        Started: [ pcmk-2 pcmk-1 ] - - - - Note that both Apache and WebFS have been stopped. - - -
- -
- Create and Populate an GFS2 Partition - - Now that the cluster stack and integration pieces are running smoothly, we can create an GFS2 partition. - - - - This will erase all previous content stored on the DRBD device. Ensure you have a copy of any important data. - - - - We need to specify a number of additional parameters when creating a GFS2 partition. - - - First we must use the -p option to specify that we want to use the the Kernel’s DLM. Next we use -j to indicate that it should reserve enough space for two journals (one per node accessing the filesystem). - - - Lastly, we use -t to specify the lock table name. The format for this field is clustername:fsname. For the fsname, we just need to pick something unique and descriptive and since we haven’t specified a clustername yet, we will use the default (pcmk). - - - To specify an alternate name for the cluster, locate the service section containing “name: pacemaker” in corosync.conf and insert the following line anywhere inside the block: - - - clustername: myname - - - Do this on each node in the cluster and be sure to restart them before continuing. - - - -mkfs.gfs2 -p lock_dlm -j 2 -t pcmk:web /dev/drbd1 -[root@pcmk-1 ~]# mkfs.gfs2 -t pcmk:web -p lock_dlm -j 2 /dev/vdb -This will destroy any data on /dev/vdb. -It appears to contain: data - -Are you sure you want to proceed? [y/n] y - -Device:                    /dev/vdb -Blocksize:                 4096 -Device Size                1.00 GB (131072 blocks) -Filesystem Size:           1.00 GB (131070 blocks) -Journals:                  2 -Resource Groups:           2 -Locking Protocol:          "lock_dlm" -Lock Table:                "pcmk:web" -UUID:                      6B776F46-177B-BAF8-2C2B-292C0E078613 - -[root@pcmk-1 ~]# - - - Then (re)populate the new filesystem with data (web pages). For now we’ll create another variation on our home page. - - - -[root@pcmk-1 ~]# mount /dev/drbd1 /mnt/ -[root@pcmk-1 ~]# cat <<-END >/mnt/index.html -<html> -<body>My Test Site - GFS2</body> -</html> -END -[root@pcmk-1 ~]# umount /dev/drbd1 -[root@pcmk-1 ~]# drbdadm verify wwwdata -[root@pcmk-1 ~]# - -
- -
- -
- Reconfigure the Cluster for GFS2 - - -[root@pcmk-1 ~]# crm -crm(live)# cib new GFS2 -INFO: GFS2 shadow CIB created -crm(GFS2)# configure delete WebFS -crm(GFS2)# configure primitive WebFS ocf:heartbeat:Filesystem params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” - - - Now that we’ve recreated the resource, we also need to recreate all the constraints that used it. This is because the shell will automatically remove any constraints that referenced WebFS. - - - -crm(GFS2)# configure colocation WebSite-with-WebFS inf: WebSite WebFS -crm(GFS2)# configure colocation fs_on_drbd inf: WebFS WebDataClone:Master -crm(GFS2)# configure order WebFS-after-WebData inf: WebDataClone:promote WebFS:start -crm(GFS2)# configure order WebSite-after-WebFS inf: WebFS WebSite -crm(GFS2)# configure colocation WebFS-with-gfs-control INFINITY: WebFS gfs-clone -crm(GFS2)# configure order start-WebFS-after-gfs-control mandatory: gfs-clone WebFS -crm(GFS2)# configure show -node pcmk-1 -node pcmk-2 -primitive WebData ocf:linbit:drbd \ -        params drbd_resource="wwwdata" \ -        op monitor interval="60s" -primitive WebFS ocf:heartbeat:Filesystem \ - params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” -primitive WebSite ocf:heartbeat:apache \ -        params configfile="/etc/httpd/conf/httpd.conf" \ -        op monitor interval="1min" -primitive ClusterIP ocf:heartbeat:IPaddr2 \ -        params ip="192.168.122.101" cidr_netmask="32" \ -        op monitor interval="30s" -primitive dlm ocf:pacemaker:controld \ -        op monitor interval="120s" -primitive gfs-control ocf:pacemaker:controld \ -   params daemon=”gfs_controld.pcmk” args=”-g 0” \ -        op monitor interval="120s" -ms WebDataClone WebData \ -        meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" -clone dlm-clone dlm \ -        meta interleave="true" -clone gfs-clone gfs-control \ -        meta interleave="true" -colocation WebFS-with-gfs-control inf: WebFS gfs-clone -colocation WebSite-with-WebFS inf: WebSite WebFS -colocation fs_on_drbd inf: WebFS WebDataClone:Master -colocation gfs-with-dlm inf: gfs-clone dlm-clone -colocation website-with-ip inf: WebSite ClusterIP -order WebFS-after-WebData inf: WebDataClone:promote WebFS:start -order WebSite-after-WebFS inf: WebFS WebSite -order apache-after-ip inf: ClusterIP WebSite -order start-WebFS-after-gfs-control inf: gfs-clone WebFS -order start-gfs-after-dlm inf: dlm-clone gfs-clone -property $id="cib-bootstrap-options" \ -        dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \ -        cluster-infrastructure="openais" \ -        expected-quorum-votes=”2” \ -        stonith-enabled="false" \ -        no-quorum-policy="ignore" -rsc_defaults $id="rsc-options" \ -        resource-stickiness=”100” - - - Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response - - - -crm(GFS2)# cib commit GFS2 -INFO: commited 'GFS2' shadow CIB to the cluster -crm(GFS2)# quit -bye -[root@pcmk-1 ~]# crm_mon -============ -Last updated: Thu Sep  3 20:49:54 2009 -Stack: openais -Current DC: pcmk-2 - partition with quorum -Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 -2 Nodes configured, 2 expected votes -6 Resources configured. -============ - -Online: [ pcmk-1 pcmk-2 ] - -WebSite (ocf::heartbeat:apache):        Started pcmk-2 -Master/Slave Set: WebDataClone -        Masters: [ pcmk-1 ] -        Slaves: [ pcmk-2 ] -ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 -Clone Set: dlm-clone -        Started: [ pcmk-2 pcmk-1 ] -Clone Set: gfs-clone -        Started: [ pcmk-2 pcmk-1 ] -WebFS (ocf::heartbeat:Filesystem): Started pcmk-1 - -
- -
- diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Shared-Storage.xml b/doc/Clusters_from_Scratch/en-US/Ch-Shared-Storage.xml index 18872dc7a8..60a4652f57 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Shared-Storage.xml +++ b/doc/Clusters_from_Scratch/en-US/Ch-Shared-Storage.xml @@ -1,534 +1,528 @@ %BOOK_ENTITIES; ]> - Shared Storage with DRBD + Replicated Storage with DRBD Even if you’re serving up static websites, having to manually synchronize the contents of that website to all the machines in the cluster is not ideal. For dynamic websites, such as a wiki, its not even an option. Not everyone care afford network-attached storage but somehow the data needs to be kept in sync. Enter DRBD which can be thought of as network based RAID-1. See http://www.drbd.org/ for more details.
Install the DRBD Packages Since its inclusion in the upstream 2.6.33 kernel, everything needed to use DRBD ships with &DISTRO; &DISTRO_VERSION;. All you need to do is install it: -[root@pcmk-1 ~]# yum install -y drbd-pacemaker +[root@pcmk-1 ~]# yum install -y drbd-pacemaker Loaded plugins: presto, refresh-packagekit Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package drbd-pacemaker.x86_64 0:8.3.7-2.fc13 set to be updated --> Processing Dependency: drbd-utils = 8.3.7-2.fc13 for package: drbd-pacemaker-8.3.7-2.fc13.x86_64 --> Running transaction check ---> Package drbd-utils.x86_64 0:8.3.7-2.fc13 set to be updated --> Finished Dependency Resolution Dependencies Resolved ================================================================================= Package Arch Version Repository Size ================================================================================= Installing: drbd-pacemaker x86_64 8.3.7-2.fc13 fedora 19 k Installing for dependencies: drbd-utils x86_64 8.3.7-2.fc13 fedora 165 k Transaction Summary ================================================================================= Install 2 Package(s) Upgrade 0 Package(s) Total download size: 184 k Installed size: 427 k Downloading Packages: Setting up and reading Presto delta metadata fedora/prestodelta | 1.7 kB 00:00 Processing delta metadata Package(s) data still to download: 184 k (1/2): drbd-pacemaker-8.3.7-2.fc13.x86_64.rpm | 19 kB 00:01 (2/2): drbd-utils-8.3.7-2.fc13.x86_64.rpm | 165 kB 00:02 --------------------------------------------------------------------------------- Total 45 kB/s | 184 kB 00:04 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : drbd-utils-8.3.7-2.fc13.x86_64 1/2 Installing : drbd-pacemaker-8.3.7-2.fc13.x86_64 2/2 Installed: drbd-pacemaker.x86_64 0:8.3.7-2.fc13 Dependency Installed: drbd-utils.x86_64 0:8.3.7-2.fc13 Complete! [root@pcmk-1 ~]#
Configure DRBD Before we configure DRBD, we need to set aside some disk for it to use.
Create A Partition for DRBD If you have more than 1Gb free, feel free to use it. For this guide however, 1Gb is plenty of space for a single html file and sufficient for later holding the GFS2 metadata. -[root@pcmk-1 drbd-8.3.6]# lvcreate -n drbd-demo -L 1G VolGroup +[root@pcmk-1 ~]# lvcreate -n drbd-demo -L 1G VolGroup   Logical volume "drbd-demo" created -[root@pcmk-1 drbd-8.3.6]# lvs +[root@pcmk-1 ~]# lvs   LV        VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert   drbd-demo VolGroup -wi-a- 1.00G                                         lv_root   VolGroup -wi-ao   7.30G                                         lv_swap   VolGroup -wi-ao 500.00M Repeat this on the second node, be sure to use the same size partition. -[root@pcmk-2 ~]# lvs +[root@pcmk-2 ~]# lvs   LV      VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert   lv_root VolGroup -wi-ao   7.30G                                         lv_swap VolGroup -wi-ao 500.00M                                       -[root@pcmk-2 ~]# lvcreate -n drbd-demo -L 1G VolGroup +[root@pcmk-2 ~]# lvcreate -n drbd-demo -L 1G VolGroup   Logical volume "drbd-demo" created -[root@pcmk-2 ~]# lvs +[root@pcmk-2 ~]# lvs   LV        VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert   drbd-demo VolGroup -wi-a- 1.00G                                         lv_root   VolGroup -wi-ao   7.30G                                         lv_swap   VolGroup -wi-ao 500.00M
Write the DRBD Config There is no series of commands for build a DRBD configuration, so simply copy the configuration below to /etc/drbd.conf Detailed information on the directives used in this configuration (and other alternatives) is available from http://www.drbd.org/users-guide/ch-configure.html Be sure to use the names and addresses of your nodes if they differ from the ones used in this guide. global {   usage-count yes; } common {   protocol C; } resource wwwdata {   meta-disk internal;   device    /dev/drbd1;   syncer {     verify-alg sha1;   }   net {     allow-two-primaries;   }   on pcmk-1 {     disk      /dev/mapper/VolGroup-drbd--demo;     address   192.168.122.101:7789;   }   on pcmk-2 {     disk      /dev/mapper/VolGroup-drbd--demo;     address   192.168.122.102:7789;   } } TODO: Explain the reason for the allow-two-primaries option
Initialize and Load DRBD With the configuration in place, we can now perform the DRBD initialization -[root@pcmk-1 drbd-8.3.6]# drbdadm create-md wwwdata +[root@pcmk-1 ~]# drbdadm create-md wwwdata md_offset 12578816 al_offset 12546048 bm_offset 12541952 Found some data  ==> This might destroy existing data! <== Do you want to proceed? [need to type 'yes' to confirm] yes Writing meta data... initializing activity log NOT initialized bitmap New drbd meta data block successfully created. success Now load the DRBD kernel module and confirm that everything is sane -[root@pcmk-1 drbd-8.3.6]# modprobe drbd -[root@pcmk-1 drbd-8.3.6]# drbdadm up wwwdata -[root@pcmk-1 drbd-8.3.6]# cat /proc/drbd +[root@pcmk-1 ~]# modprobe drbd +[root@pcmk-1 ~]# drbdadm up wwwdata +[root@pcmk-1 ~]# cat /proc/drbd version: 8.3.6 (api:88/proto:86-90) GIT-hash: f3606c47cc6fcf6b3f086e425cb34af8b7a81bbf build by root@pcmk-1, 2009-12-08 11:22:57 1: cs:WFConnection ro:Secondary/Unknown ds:Inconsistent/DUnknown C r----     ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:12248 -[root@pcmk-1 drbd-8.3.6]# +[root@pcmk-1 ~]# Repeat on the second node drbdadm --force create-md wwwdata modprobe drbd drbdadm up wwwdata cat /proc/drbd -[root@pcmk-2 ~]# drbdadm --force create-md wwwdata +[root@pcmk-2 ~]# drbdadm --force create-md wwwdata Writing meta data... initializing activity log NOT initialized bitmap New drbd meta data block successfully created. success -[root@pcmk-2 ~]# modprobe drbd +[root@pcmk-2 ~]# modprobe drbd WARNING: Deprecated config file /etc/modprobe.conf, all config files belong into /etc/modprobe.d/. -[root@pcmk-2 ~]# drbdadm up wwwdata -[root@pcmk-2 ~]# cat /proc/drbd +[root@pcmk-2 ~]# drbdadm up wwwdata +[root@pcmk-2 ~]# cat /proc/drbd version: 8.3.6 (api:88/proto:86-90) GIT-hash: f3606c47cc6fcf6b3f086e425cb34af8b7a81bbf build by root@pcmk-1, 2009-12-08 11:22:57 1: cs:Connected ro:Secondary/Secondary ds:Inconsistent/Inconsistent C r----     ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:12248 Now we need to tell DRBD which set of data to use. Since both sides contain garbage, we can run the following on pcmk-1: -[root@pcmk-1 ~]# drbdadm -- --overwrite-data-of-peer primary wwwdata -[root@pcmk-1 ~]# cat /proc/drbd +[root@pcmk-1 ~]# drbdadm -- --overwrite-data-of-peer primary wwwdata +[root@pcmk-1 ~]# cat /proc/drbd version: 8.3.6 (api:88/proto:86-90) GIT-hash: f3606c47cc6fcf6b3f086e425cb34af8b7a81bbf build by root@pcmk-1, 2009-12-08 11:22:57  1: cs:SyncSource ro:Primary/Secondary ds:UpToDate/Inconsistent C r----     ns:2184 nr:0 dw:0 dr:2472 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:10064         [=====>..............] sync'ed: 33.4% (10064/12248)K         finish: 0:00:37 speed: 240 (240) K/sec -[root@pcmk-1 ~]# cat /proc/drbd +[root@pcmk-1 ~]# cat /proc/drbd version: 8.3.6 (api:88/proto:86-90) GIT-hash: f3606c47cc6fcf6b3f086e425cb34af8b7a81bbf build by root@pcmk-1, 2009-12-08 11:22:57  1: cs:Connected ro:Primary/Secondary ds:UpToDate/UpToDate C r----     ns:12248 nr:0 dw:0 dr:12536 al:0 bm:1 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:0 pcmk-1 is now in the Primary state which allows it to be written to. Which means its a good point at which to create a filesystem and populate it with some data to serve up via our WebSite resource.
Populate DRBD with Data -[root@pcmk-1 ~]# mkfs.ext4 /dev/drbd1 +[root@pcmk-1 ~]# mkfs.ext4 /dev/drbd1 mke2fs 1.41.4 (27-Jan-2009) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) 3072 inodes, 12248 blocks 612 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=12582912 2 block groups 8192 blocks per group, 8192 fragments per group 1536 inodes per group Superblock backups stored on blocks:         8193 Writing inode tables: done                             Creating journal (1024 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 26 mounts or 180 days, whichever comes first.  Use tune2fs -c or -i to override. Now mount the newly created filesystem so we can create our index file mount /dev/drbd1 /mnt/ cat <<-END >/mnt/index.html <html> <body>My Test Site - drbd</body> </html> END umount /dev/drbd1 -[root@pcmk-1 ~]# mount /dev/drbd1 /mnt/ -[root@pcmk-1 ~]# cat <<-END >/mnt/index.html +[root@pcmk-1 ~]# mount /dev/drbd1 /mnt/ +[root@pcmk-1 ~]# cat <<-END >/mnt/index.html > <html> > <body>My Test Site - drbd</body> > </html> > END -[root@pcmk-1 ~]# umount /dev/drbd1 - - - And finally, confirm the data is in sync between the two nodes - - -[root@pcmk-1 ~]# drbdadm verify wwwdata -[root@pcmk-1 ~]# echo $? -0 +[root@pcmk-1 ~]# umount /dev/drbd1
Configure the Cluster for DRBD One handy feature of the crm shell is that you can use it in interactive mode to make several changes atomically. First we launch the shell. The prompt will change to indicate you’re in interactive mode. -[root@pcmk-1 ~]# crm +[root@pcmk-1 ~]# crm cib crm(live)# Next we must create a working copy or the current configuration. This is where all our changes will go. The cluster will not see any of them until we say its ok. Notice again how the prompt changes, this time to indicate that we’re no longer looking at the live cluster. -cib new drbd -cib crm(live)# cib new drbd +cib crm(live)# cib new drbd INFO: drbd shadow CIB created crm(drbd)# Now we can create our DRBD clone and display the revised configuration. -configure primitive wwwdrbd ocf:linbit:drbd params drbd_resource=wwwdata op monitor interval=60s -configure ms WebData wwwdrbd meta master-max=1 master-node-max=1 \ -        clone-max=2 clone-node-max=1 notify=true -configure show -crm(drbd)# configure primitive ocf:linbit:drbd WebData params drbd_resource=wwwdata op monitor interval=60s -crm(drbd)# configure ms WebDataClone WebData meta master-max=1 master-node-max=1 \ -        clone-max=2 clone-node-max=1 notify=true -crm(drbd)# configure show +crm(drbd)# configure primitive ocf:linbit:drbd WebData params drbd_resource=wwwdata \ +        op monitor interval=60s +crm(drbd)# configure ms WebDataClone WebData meta master-max=1 master-node-max=1 \ +        clone-max=2 clone-node-max=1 notify=true +crm(drbd)# configure show node pcmk-1 node pcmk-2 primitive WebData ocf:linbit:drbd \ params drbd_resource="wwwdata" \ op monitor interval="60s" primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" ms WebDataClone WebData \ meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" location prefer-pcmk-1 WebSite 50: pcmk-1 colocation website-with-ip inf: WebSite ClusterIP order apache-after-ip inf: ClusterIP WebSite property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes=”2” \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness=”100” Once we’re happy with the changes, we can tell the cluster to start using them and use crm_mon to check everything is functioning. -crm(drbd)# cib commit drbd +crm(drbd)# cib commit drbd INFO: commited 'drbd' shadow CIB to the cluster -crm(drbd)# quit +crm(drbd)# quit bye -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Tue Sep  1 09:37:13 2009 Stack: openais Current DC: pcmk-1 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 3 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 WebSite (ocf::heartbeat:apache):        Started pcmk-1 Master/Slave Set: WebDataClone Masters: [ pcmk-2 ] Slaves: [ pcmk-1 ] Include details on adding a second DRBD resource Now that DRBD is functioning we can configure a Filesystem resource to use it. In addition to the filesystem’s definition, we also need to tell the cluster where it can be located (only on the DRBD Primary) and when it is allowed to start (after the Primary was promoted). Once again we’ll use the shell’s interactive mode -[root@pcmk-1 ~]# crm -crm(live)# cib new fs +[root@pcmk-1 ~]# crm +crm(live)# cib new fs INFO: fs shadow CIB created -crm(fs)# configure primitive WebFS ocf:heartbeat:Filesystem params device="/dev/mapper/VolGroup-drbd--demo" directory="/var/www/html" fstype="ext4" -crm(fs)# configure colocation fs_on_drbd inf: WebFS WebDataClone:Master -crm(fs)# configure order WebFS-after-WebData inf: WebDataClone:promote WebFS:start +crm(fs)# configure primitive WebFS ocf:heartbeat:Filesystem \ +        params device="/dev/mapper/VolGroup-drbd--demo" directory="/var/www/html" fstype="ext4" +crm(fs)# configure colocation fs_on_drbd inf: WebFS WebDataClone:Master +crm(fs)# configure order WebFS-after-WebData inf: WebDataClone:promote WebFS:start We also need to tell the cluster that Apache needs to run on the same machine as the filesystem and that it must be active before Apache can start. -crm(fs)# configure colocation WebSite-with-WebFS inf: WebSite WebFS -crm(fs)# configure order WebSite-after-WebFS inf: WebFS WebSite -[root@pcmk-1 ~]# crm configure show +crm(fs)# configure colocation WebSite-with-WebFS inf: WebSite WebFS +crm(fs)# configure order WebSite-after-WebFS inf: WebFS WebSite + + + Time to review the updated configuration: + + +[root@pcmk-1 ~]# crm configure show node pcmk-1 node pcmk-2 primitive WebData ocf:linbit:drbd \         params drbd_resource="wwwdata" \         op monitor interval="60s" primitive WebFS ocf:heartbeat:Filesystem \         params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4" primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip="192.168.122.101" cidr_netmask="32" \         op monitor interval="30s" ms WebDataClone WebData \         meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" location prefer-pcmk-1 WebSite 50: pcmk-1 colocation WebSite-with-WebFS inf: WebSite WebFS colocation fs_on_drbd inf: WebFS WebDataClone:Master colocation website-with-ip inf: WebSite ClusterIP order WebFS-after-WebData inf: WebDataClone:promote WebFS:start order WebSite-after-WebFS inf: WebFS WebSite order apache-after-ip inf: ClusterIP WebSite property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes=”2” \         stonith-enabled="false" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness=”100” After reviewing the new configuration, we again upload it and watch the cluster put it into effect. -crm(fs)# cib commit fs +crm(fs)# cib commit fs INFO: commited 'fs' shadow CIB to the cluster -crm(fs)# quit +crm(fs)# quit bye -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm_mon ============ Last updated: Tue Sep  1 10:08:44 2009 Stack: openais Current DC: pcmk-1 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 4 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1 WebSite (ocf::heartbeat:apache): Started pcmk-1 Master/Slave Set: WebDataClone         Masters: [ pcmk-1 ]         Slaves: [ pcmk-2 ] WebFS (ocf::heartbeat:Filesystem): Started pcmk-1
Testing Migration We could shut down the active node again, but another way to safely simulate recovery is to put the node into what is called “standby mode”. Nodes in this state tell the cluster that they are not allowed to run resources. Any resources found active there will be moved elsewhere. This feature can be particularly useful when updating the resources’ packages. Put the local node into standby mode and observe the cluster move all the resources to the other node. Note also that the node’s status will change to indicate that it can no longer host resources. -[root@pcmk-1 ~]# crm node standby -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm node standby +[root@pcmk-1 ~]# crm_mon ============ Last updated: Tue Sep  1 10:09:57 2009 Stack: openais Current DC: pcmk-1 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 4 Resources configured. ============ Node pcmk-1: standby Online: [ pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 WebSite (ocf::heartbeat:apache):        Started pcmk-2 Master/Slave Set: WebDataClone         Masters: [ pcmk-2 ]         Stopped: [ WebData:1 ] WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2 Once we’ve done everything we needed to on pcmk-1 (in this case nothing, we just wanted to see the resources move), we can allow the node to be a full cluster member again. -[root@pcmk-1 ~]# crm node online -[root@pcmk-1 ~]# crm_mon +[root@pcmk-1 ~]# crm node online +[root@pcmk-1 ~]# crm_mon ============ Last updated: Tue Sep  1 10:13:25 2009 Stack: openais Current DC: pcmk-1 - partition with quorum Version: 1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7 2 Nodes configured, 2 expected votes 4 Resources configured. ============ Online: [ pcmk-1 pcmk-2 ] ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2 WebSite (ocf::heartbeat:apache):        Started pcmk-2 Master/Slave Set: WebDataClone         Masters: [ pcmk-2 ]         Slaves: [ pcmk-1 ] WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2 Notice that our resource stickiness settings prevent the services from migrating back to pcmk-1.
diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Stonith.xml b/doc/Clusters_from_Scratch/en-US/Ch-Stonith.xml index 4cade893d7..f0ed47e962 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Stonith.xml +++ b/doc/Clusters_from_Scratch/en-US/Ch-Stonith.xml @@ -1,161 +1,161 @@ %BOOK_ENTITIES; ]> Configure STONITH
Why You Need STONITH STONITH is an acronym for Shoot-The-Other-Node-In-The-Head and it protects your data from being corrupted by rouge nodes or concurrent access. Just because a node is unresponsive, this doesn’t mean it isn’t accessing your data. The only way to be 100% sure that your data is safe, is to use STONITH so we can be certain that the node is truly offline, before allowing the data to be accessed from another node. STONITH also has a role to play in the event that a clustered service cannot be stopped. In this case, the cluster uses STONITH to force the whole node offline, thereby making it safe to start the service elsewhere.
What STONITH Device Should You Use It is crucial that the STONITH device can allow the cluster to differentiate between a node failure and a network one. The biggest mistake people make in choosing a STONITH device is to use remote power switch (such as many onboard IMPI controllers) that shares power with the node it controls. In such cases, the cluster cannot be sure if the node is really offline, or active and suffering from a network fault. Likewise, any device that relies on the machine being active (such as SSH-based “devices” used during testing) are inappropriate.
Configuring STONITH Find the correct driver: stonith -L Since every device is different, the parameters needed to configure it will vary. To find out the parameters required by the device: stonith -t {type} -n Hopefully the developers chose names that make sense, if not you can query for some additional information by finding an active cluster node and running: lrmadmin -M stonith {type} pacemaker The output should be XML formatted text containing additional parameter descriptions Create a file called stonith.xml containing a primitive resource with a class of stonith, a type of {type} and a parameter for each of the values returned in step 2 Create a clone from the primitive resource if the device can shoot more than one node and supports multiple simultaneous connections. Upload it into the CIB using cibadmin: cibadmin -C -o resources --xml-file stonith.xml
Example Assuming we have an IBM BladeCenter containing our two nodes and the management interface is active on 192.168.122.31, then we would chose the external/ibmrsa driver in step 2 and obtain the following list of parameters stonith -t external/ibmrsa -n -[root@pcmk-1 ~]# stonith -t external/ibmrsa -n +[root@pcmk-1 ~]# stonith -t external/ibmrsa -n hostname  ipaddr  userid  passwd  type Assuming we know the username and password for the management interface, we would create a STONITH resource with the shell -[root@pcmk-1 ~]# crm -crm(live)# cib new stonith +[root@pcmk-1 ~]# crm +crm(live)# cib new stonith INFO: stonith shadow CIB created -crm(stonith)# configure primitive rsa-fencing stonith::external/ibmrsa \ -        params hostname=”pcmk-1 pcmk-2" ipaddr=192.168.122.31 userid=mgmt passwd=abc123 type=ibm \ -        op monitor interval="60s" -crm(stonith)# configure clone Fencing rsa-fencing +crm(stonith)# configure primitive rsa-fencing stonith::external/ibmrsa \ +        params hostname=”pcmk-1 pcmk-2" ipaddr=192.168.122.31 userid=mgmt passwd=abc123 type=ibm \ +        op monitor interval="60s" +crm(stonith)# configure clone Fencing rsa-fencing And finally, since we disabled it earlier, we need to re-enable STONITH -crm(stonith)# configure property stonith-enabled="true" -crm(stonith)# configure show +crm(stonith)# configure property stonith-enabled="true" +crm(stonith)# configure show node pcmk-1 node pcmk-2 primitive WebData ocf:linbit:drbd \         params drbd_resource="wwwdata" \         op monitor interval="60s" primitive WebFS ocf:heartbeat:Filesystem \         params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2” primitive WebSite ocf:heartbeat:apache \         params configfile="/etc/httpd/conf/httpd.conf" \         op monitor interval="1min" primitive ClusterIP ocf:heartbeat:IPaddr2 \         params ip=”192.168.122.101” cidr_netmask=”32” clusterip_hash=”sourceip” \         op monitor interval="30s" primitive dlm ocf:pacemaker:controld \         op monitor interval="120s" primitive gfs-control ocf:pacemaker:controld \    params daemon=”gfs_controld.pcmk” args=”-g 0” \         op monitor interval="120s" primitive rsa-fencing stonith::external/ibmrsa \ params hostname=”pcmk-1 pcmk-2" ipaddr=192.168.122.31 userid=mgmt passwd=abc123 type=ibm \ op monitor interval="60s" ms WebDataClone WebData \         meta master-max="2" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" clone Fencing rsa-fencing clone WebFSClone WebFS clone WebIP ClusterIP  \         meta globally-unique=”true” clone-max=”2” clone-node-max=”2” clone WebSiteClone WebSite clone dlm-clone dlm \         meta interleave="true" clone gfs-clone gfs-control \         meta interleave="true" colocation WebFS-with-gfs-control inf: WebFSClone gfs-clone colocation WebSite-with-WebFS inf: WebSiteClone WebFSClone colocation fs_on_drbd inf: WebFSClone WebDataClone:Master colocation gfs-with-dlm inf: gfs-clone dlm-clone colocation website-with-ip inf: WebSiteClone WebIP order WebFS-after-WebData inf: WebDataClone:promote WebFSClone:start order WebSite-after-WebFS inf: WebFSClone WebSiteClone order apache-after-ip inf: WebIP WebSiteClone order start-WebFS-after-gfs-control inf: gfs-clone WebFSClone order start-gfs-after-dlm inf: dlm-clone gfs-clone property $id="cib-bootstrap-options" \         dc-version="1.0.5-462f1569a43740667daf7b0f6b521742e9eb8fa7" \         cluster-infrastructure="openais" \         expected-quorum-votes=”2” \         stonith-enabled="true" \         no-quorum-policy="ignore" rsc_defaults $id="rsc-options" \         resource-stickiness=”100”
diff --git a/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml b/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml index 1d49ecf9f9..fee4c564d8 100644 --- a/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml +++ b/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml @@ -1,25 +1,24 @@ %BOOK_ENTITIES; ]> -