diff --git a/doc/Pacemaker_Administration/en-US/Ch-Agents.txt b/doc/Pacemaker_Administration/en-US/Ch-Agents.txt
index ab82420f58..1cb2e252a3 100644
--- a/doc/Pacemaker_Administration/en-US/Ch-Agents.txt
+++ b/doc/Pacemaker_Administration/en-US/Ch-Agents.txt
@@ -1,337 +1,337 @@
= Resource Agents =
== OCF Resource Agents ==
=== Location of Custom Scripts ===
indexterm:[OCF Resource Agents]
OCF Resource Agents are found in +/usr/lib/ocf/resource.d/pass:[provider]+
When creating your own agents, you are encouraged to create a new
directory under +/usr/lib/ocf/resource.d/+ so that they are not
confused with (or overwritten by) the agents shipped by existing providers.
So, for example, if you choose the provider name of bigCorp and want
a new resource named bigApp, you would create a resource agent called
+/usr/lib/ocf/resource.d/bigCorp/bigApp+ and define a resource:
[source,XML]
----
----
=== Actions ===
All OCF resource agents are required to implement the following actions.
.Required Actions for OCF Agents
[width="95%",cols="3m,3,7",options="header",align="center"]
|=========================================================
|Action
|Description
|Instructions
|start
|Start the resource
|Return 0 on success and an appropriate error code otherwise. Must not
report success until the resource is fully active.
indexterm:[start,OCF Action]
indexterm:[OCF,Action,start]
|stop
|Stop the resource
|Return 0 on success and an appropriate error code otherwise. Must not
report success until the resource is fully stopped.
indexterm:[stop,OCF Action]
indexterm:[OCF,Action,stop]
|monitor
|Check the resource's state
|Exit 0 if the resource is running, 7 if it is stopped, and anything
else if it is failed.
indexterm:[monitor,OCF Action]
indexterm:[OCF,Action,monitor]
NOTE: The monitor script should test the state of the resource on the local machine only.
|meta-data
|Describe the resource
|Provide information about this resource as an XML snippet. Exit with 0.
indexterm:[meta-data,OCF Action]
indexterm:[OCF,Action,meta-data]
NOTE: This is _not_ performed as root.
|validate-all
|Verify the supplied parameters
|Return 0 if parameters are valid, 2 if not valid, and 6 if resource is not configured.
indexterm:[validate-all,OCF Action]
indexterm:[OCF,Action,validate-all]
|=========================================================
Additional requirements (not part of the OCF specification) are placed on
agents that will be used for advanced concepts such as clone resources.
.Optional Actions for OCF Resource Agents
[width="95%",cols="2m,6,3",options="header",align="center"]
|=========================================================
|Action
|Description
|Instructions
|promote
|Promote the local instance of a promotable clone resource to the master (primary) state.
|Return 0 on success
indexterm:[promote,OCF Action]
indexterm:[OCF,Action,promote]
|demote
|Demote the local instance of a promotable clone resource to the slave (secondary) state.
|Return 0 on success
indexterm:[demote,OCF Action]
indexterm:[OCF,Action,demote]
|notify
|Used by the cluster to send the agent pre- and post-notification
events telling the resource what has happened and will happen.
|Must not fail. Must exit with 0
indexterm:[notify,OCF Action]
indexterm:[OCF,Action,notify]
|=========================================================
One action specified in the OCF specs, +recover+, is not currently used by the
cluster. It is intended to be a variant of the +start+ action that tries to
recover a resource locally.
[IMPORTANT]
====
If you create a new OCF resource agent, use indexterm:[ocf-tester]`ocf-tester`
to verify that the agent complies with the OCF standard properly.
====
=== How are OCF Return Codes Interpreted? ===
The first thing the cluster does is to check the return code against
the expected result. If the result does not match the expected value,
then the operation is considered to have failed, and recovery action is
initiated.
There are three types of failure recovery:
.Types of recovery performed by the cluster
[width="95%",cols="1m,4,4",options="header",align="center"]
|=========================================================
|Type
|Description
|Action Taken by the Cluster
|soft
|A transient error occurred
|Restart the resource or move it to a new location
indexterm:[soft,OCF error]
indexterm:[OCF,error,soft]
|hard
|A non-transient error that may be specific to the current node occurred
|Move the resource elsewhere and prevent it from being retried on the current node
indexterm:[hard,OCF error]
indexterm:[OCF,error,hard]
|fatal
|A non-transient error that will be common to all cluster nodes (e.g. a bad configuration was specified)
|Stop the resource and prevent it from being started on any cluster node
indexterm:[fatal,OCF error]
indexterm:[OCF,error,fatal]
|=========================================================
[[s-ocf-return-codes]]
=== OCF Return Codes ===
The following table outlines the different OCF return codes and the type of
recovery the cluster will initiate when a failure code is received.
Although counterintuitive, even actions that return 0
(aka. +OCF_SUCCESS+) can be considered to have failed, if 0 was not
the expected return value.
.OCF Return Codes and their Recovery Types
-[width="95%",cols="1m,4 tmp.xml
# vi tmp.xml
# cibadmin --replace --xml-file tmp.xml
--------
======
Some of the better XML editors can make use of a Relax NG schema to
help make sure any changes you make are valid. The schema describing
the configuration can be found in +pacemaker.rng+, which may be
deployed in a location such as +/usr/share/pacemaker+ or
+/usr/lib/heartbeat+ depending on your operating system and how you
installed the software.
If you want to modify just one section of the configuration, you can
query and replace just that section to avoid modifying any others.
.Safely using an editor to modify only the resources section
======
--------
# cibadmin --query --scope resources > tmp.xml
# vi tmp.xml
# cibadmin --replace --scope resources --xml-file tmp.xml
--------
======
=== Quickly Deleting Part of the Configuration ===
Identify the object you wish to delete by XML tag and id. For example,
you might search the CIB for all STONITH-related configuration:
.Searching for STONITH-related configuration items
======
----
# cibadmin -Q | grep stonith
----
======
If you wanted to delete the +primitive+ tag with id +child_DoFencing+,
you would run:
----
# cibadmin --delete --xml-text ''
----
=== Updating the Configuration Without Using XML ===
Most tasks can be performed with one of the other command-line
tools provided with pacemaker, avoiding the need to read or edit XML.
To enable STONITH for example, one could run:
----
# crm_attribute --name stonith-enabled --update 1
----
Or, to check whether *somenode* is allowed to run resources, there is:
----
# crm_standby --query --node somenode
----
Or, to find the current location of *my-test-rsc*, one can use:
----
# crm_resource --locate --resource my-test-rsc
----
Examples of using these tools for specific cases will be given throughout this
document where appropriate.
[[s-config-sandboxes]]
== Making Configuration Changes in a Sandbox ==
Often it is desirable to preview the effects of a series of changes
before updating the configuration all at once. For this purpose, we
have created `crm_shadow` which creates a
"shadow" copy of the configuration and arranges for all the command
line tools to use it.
To begin, simply invoke `crm_shadow --create` with
the name of a configuration to create footnote:[Shadow copies are
identified with a name, making it possible to have more than one.],
and follow the simple on-screen instructions.
[WARNING]
====
Read this section and the on-screen instructions carefully; failure to do so could
result in destroying the cluster's active configuration!
====
.Creating and displaying the active sandbox
======
----
# crm_shadow --create test
Setting up shadow instance
Type Ctrl-D to exit the crm_shadow shell
shadow[test]:
shadow[test] # crm_shadow --which
test
----
======
From this point on, all cluster commands will automatically use the
shadow copy instead of talking to the cluster's active configuration.
Once you have finished experimenting, you can either make the
changes active via the `--commit` option, or discard them using the `--delete`
option. Again, be sure to follow the on-screen instructions carefully!
For a full list of `crm_shadow` options and
commands, invoke it with the `--help` option.
.Use sandbox to make multiple changes all at once, discard them, and verify real configuration is untouched
======
----
shadow[test] # crm_failcount -r rsc_c001n01 -G
scope=status name=fail-count-rsc_c001n01 value=0
shadow[test] # crm_standby --node c001n02 -v on
shadow[test] # crm_standby --node c001n02 -G
scope=nodes name=standby value=on
shadow[test] # cibadmin --erase --force
shadow[test] # cibadmin --query
shadow[test] # crm_shadow --delete test --force
Now type Ctrl-D to exit the crm_shadow shell
shadow[test] # exit
# crm_shadow --which
No active shadow configuration defined
# cibadmin -Q
----
======
[[s-config-testing-changes]]
== Testing Your Configuration Changes ==
We saw previously how to make a series of changes to a "shadow" copy
of the configuration. Before loading the changes back into the
cluster (e.g. `crm_shadow --commit mytest --force`), it is often
advisable to simulate the effect of the changes with +crm_simulate+.
For example:
----
# crm_simulate --live-check -VVVVV --save-graph tmp.graph --save-dotfile tmp.dot
----
This tool uses the same library as the live cluster to show what it
would have done given the supplied input. Its output, in addition to
a significant amount of logging, is stored in two files +tmp.graph+
and +tmp.dot+. Both files are representations of the same thing: the
cluster's response to your changes.
The graph file stores the complete transition from the existing cluster state
to your desired new state, containing a list of all the actions, their
parameters and their pre-requisites. Because the transition graph is not
terribly easy to read, the tool also generates a Graphviz
footnote:[Graph visualization software. See http://www.graphviz.org/ for details.]
dot-file representing the same information.
For information on the options supported by `crm_simulate`, use
its `--help` option.
.Interpreting the Graphviz output
* Arrows indicate ordering dependencies
* Dashed arrows indicate dependencies that are not present in the transition graph
* Actions with a dashed border of any color do not form part of the transition graph
* Actions with a green border form part of the transition graph
* Actions with a red border are ones the cluster would like to execute but cannot run
* Actions with a blue border are ones the cluster does not feel need to be executed
* Actions with orange text are pseudo/pretend actions that the cluster uses to simplify the graph
* Actions with black text are sent to the LRM
* Resource actions have text of the form pass:[rsc]_pass:[action]_pass:[interval] pass:[node]
* Any action depending on an action with a red border will not be able to execute.
* Loops are _really_ bad. Please report them to the development team.
=== Small Cluster Transition ===
image::images/Policy-Engine-small.png["An example transition graph as represented by Graphviz",width="16cm",height="6cm",align="center"]
In the above example, it appears that a new node, *pcmk-2*, has come
online and that the cluster is checking to make sure *rsc1*, *rsc2*
and *rsc3* are not already running there (Indicated by the
*rscN_monitor_0* entries). Once it did that, and assuming the resources
were not active there, it would have liked to stop *rsc1* and *rsc2*
on *pcmk-1* and move them to *pcmk-2*. However, there appears to be
some problem and the cluster cannot or is not permitted to perform the
stop actions which implies it also cannot perform the start actions.
For some reason the cluster does not want to start *rsc3* anywhere.
=== Complex Cluster Transition ===
image::images/Policy-Engine-big.png["Another, slightly more complex, transition graph that you're not expected to be able to read",width="16cm",height="20cm",align="center"]
== Do I Need to Update the Configuration on All Cluster Nodes? ==
No. Any changes are immediately synchronized to the other active
members of the cluster.
To reduce bandwidth, the cluster only broadcasts the incremental
updates that result from your changes and uses MD5 checksums to ensure
that each copy is completely consistent.
== Working with CIB Properties ==
Although these fields can be written to by the user, in
most cases the cluster will overwrite any values specified by the
user with the "correct" ones.
To change the ones that can be specified by the user,
for example +admin_epoch+, one should use:
----
# cibadmin --modify --xml-text ''
----
A complete set of CIB properties will look something like this:
.Attributes set for a cib object
======
[source,XML]
-------
-------
======
== Querying and Setting Cluster Options ==
indexterm:[Querying,Cluster Option]
indexterm:[Setting,Cluster Option]
indexterm:[Cluster,Querying Options]
indexterm:[Cluster,Setting Options]
Cluster options can be queried and modified using the `crm_attribute` tool. To
get the current value of +cluster-delay+, you can run:
----
# crm_attribute --query --name cluster-delay
----
which is more simply written as
----
# crm_attribute -G -n cluster-delay
----
If a value is found, you'll see a result like this:
----
# crm_attribute -G -n cluster-delay
scope=crm_config name=cluster-delay value=60s
----
If no value is found, the tool will display an error:
----
# crm_attribute -G -n clusta-deway
scope=crm_config name=clusta-deway value=(null)
Error performing operation: No such device or address
----
To use a different value (for example, 30 seconds), simply run:
----
# crm_attribute --name cluster-delay --update 30s
----
To go back to the cluster's default value, you can delete the value, for example:
----
# crm_attribute --name cluster-delay --delete
Deleted crm_config option: id=cib-bootstrap-options-cluster-delay name=cluster-delay
----
=== When Options are Listed More Than Once ===
If you ever see something like the following, it means that the option you're modifying is present more than once.
.Deleting an option that is listed twice
=======
------
# crm_attribute --name batch-limit --delete
Multiple attributes match name=batch-limit in crm_config:
Value: 50 (set=cib-bootstrap-options, id=cib-bootstrap-options-batch-limit)
Value: 100 (set=custom, id=custom-batch-limit)
Please choose from one of the matches above and supply the 'id' with --id
-------
=======
In such cases, follow the on-screen instructions to perform the
requested action. To determine which value is currently being used by
the cluster, refer to the 'Rules' chapter of 'Pacemaker Explained'.
[[s-remote-connection]]
== Connecting from a Remote Machine ==
indexterm:[Cluster,Remote connection]
indexterm:[Cluster,Remote administration]
Provided Pacemaker is installed on a machine, it is possible to
connect to the cluster even if the machine itself is not in the same
cluster. To do this, one simply sets up a number of environment
variables and runs the same commands as when working on a cluster
node.
.Environment Variables Used to Connect to Remote Instances of the CIB
-[width="95%",cols="1m,1,3<",options="header",align="center"]
+[width="95%",cols="1m,1,<3",options="header",align="center"]
|=========================================================
|Environment Variable
|Default
|Description
|CIB_user
|$USER
|The user to connect as. Needs to be part of the +haclient+ group on
the target host.
indexterm:[Environment Variable,CIB_user]
|CIB_passwd
|
|The user's password. Read from the command line if unset.
indexterm:[Environment Variable,CIB_passwd]
|CIB_server
|localhost
|The host to contact
indexterm:[Environment Variable,CIB_server]
|CIB_port
|
|The port on which to contact the server; required.
indexterm:[Environment Variable,CIB_port]
|CIB_encrypted
|TRUE
|Whether to encrypt network traffic
indexterm:[Environment Variable,CIB_encrypted]
|=========================================================
So, if *c001n01* is an active cluster node and is listening on port 1234
for connections, and *someuser* is a member of the *haclient* group,
then the following would prompt for *someuser*'s password and return
the cluster's current configuration:
----
# export CIB_port=1234; export CIB_server=c001n01; export CIB_user=someuser;
# cibadmin -Q
----
For security reasons, the cluster does not listen for remote
connections by default. If you wish to allow remote access, you need
to set the +remote-tls-port+ (encrypted) or +remote-clear-port+
(unencrypted) CIB properties (i.e., those kept in the +cib+ tag, like
+num_updates+ and +epoch+).
.Extra top-level CIB properties for remote access
-[width="95%",cols="1m,1,3<",options="header",align="center"]
+[width="95%",cols="1m,1,<3",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|remote-tls-port
|_none_
|Listen for encrypted remote connections on this port.
indexterm:[remote-tls-port,Remote Connection Option]
indexterm:[Remote Connection,Option,remote-tls-port]
|remote-clear-port
|_none_
|Listen for plaintext remote connections on this port.
indexterm:[remote-clear-port,Remote Connection Option]
indexterm:[Remote Connection,Option,remote-clear-port]
|=========================================================
diff --git a/doc/Pacemaker_Explained/en-US/Ch-Advanced-Options.txt b/doc/Pacemaker_Explained/en-US/Ch-Advanced-Options.txt
index fbd992267d..c662c60a49 100644
--- a/doc/Pacemaker_Explained/en-US/Ch-Advanced-Options.txt
+++ b/doc/Pacemaker_Explained/en-US/Ch-Advanced-Options.txt
@@ -1,728 +1,728 @@
= Advanced Configuration =
[[s-recurring-start]]
== Specifying When Recurring Actions are Performed ==
By default, recurring actions are scheduled relative to when the
resource started. So if your resource was last started at 14:32 and
you have a backup set to be performed every 24 hours, then the backup
will always run in the middle of the business day -- hardly
desirable.
To specify a date and time that the operation should be relative to, set
the operation's +interval-origin+. The cluster uses this point to
calculate the correct +start-delay+ such that the operation will occur
at _origin + (interval * N)_.
So, if the operation's interval is 24h, its interval-origin is set to
02:00 and it is currently 14:32, then the cluster would initiate
the operation with a start delay of 11 hours and 28 minutes. If the
resource is moved to another node before 2am, then the operation is
cancelled.
The value specified for +interval+ and +interval-origin+ can be any
date/time conforming to the
http://en.wikipedia.org/wiki/ISO_8601[ISO8601 standard]. By way of
example, to specify an operation that would run on the first Monday of
2009 and every Monday after that, you would add:
.Specifying a Base for Recurring Action Intervals
=====
[source,XML]
=====
[[s-failure-handling]]
== Handling Resource Failure ==
By default, Pacemaker will attempt to recover failed resources by restarting
them. However, failure recovery is highly configurable.
=== Failure Counts ===
Pacemaker tracks resource failures for each combination of node, resource, and
operation (start, stop, monitor, etc.).
You can query the fail count for a particular node, resource, and/or operation
using the `crm_failcount` command. For example, to see how many times the
10-second monitor for +myrsc+ has failed on +node1+, run:
----
# crm_failcount --query -r myrsc -N node1 -n monitor -I 10s
----
If you omit the node, `crm_failcount` will use the local node. If you omit the
operation and interval, `crm_failcount` will display the sum of the fail counts
for all operations on the resource.
You can use `crm_resource --cleanup` or `crm_failcount --delete` to clear
fail counts. For example, to clear the above monitor failures, run:
----
# crm_resource --cleanup -r myrsc -N node1 -n monitor -I 10s
----
If you omit the resource, `crm_resource --cleanup` will clear failures for all
resources. If you omit the node, it will clear failures on all nodes. If you
omit the operation and interval, it will clear the failures for all operations
on the resource.
[NOTE]
====
Even when cleaning up only a single operation, all failed operations will
disappear from the status display. This allows us to trigger a re-check of the
resource's current status.
====
Higher-level tools may provide other commands for querying and clearing
fail counts.
The `crm_mon` tool shows the current cluster status, including any failed
operations. To see the current fail counts for any failed resources, call
`crm_mon` with the `--failcounts` option. This shows the fail counts per
resource (that is, the sum of any operation fail counts for the resource).
=== Failure Response ===
Normally, if a running resource fails, pacemaker will try to stop it and start
it again. Pacemaker will choose the best location to start it each time, which
may be the same node that it failed on.
However, if a resource fails repeatedly, it is possible that there is an
underlying problem on that node, and you might desire trying a different node
in such a case. Pacemaker allows you to set your preference via the
+migration-threshold+ resource meta-attribute.
footnote:[
The naming of this option was perhaps unfortunate as it is easily
confused with live migration, the process of moving a resource from
one node to another without stopping it. Xen virtual guests are the
most common example of resources that can be migrated in this manner.
]
If you define +migration-threshold=pass:[N]+ for a
resource, it will be banned from the original node after 'N' failures.
[NOTE]
====
The +migration-threshold+ is per 'resource', even though fail counts are
tracked per 'operation'. The operation fail counts are added together
to compare against the +migration-threshold+.
====
By default, fail counts remain until manually cleared by an administrator
using `crm_resource --cleanup` or `crm_failcount --delete` (hopefully after
first fixing the failure's cause). It is possible to have fail counts expire
automatically by setting the +failure-timeout+ resource meta-attribute.
[IMPORTANT]
====
A successful operation does not clear past failures. If a recurring monitor
operation fails once, succeeds many times, then fails again days later, its
fail count is 2. Fail counts are cleared only by manual intervention or
falure timeout.
====
For example, a setting of +migration-threshold=2+ and +failure-timeout=60s+
would cause the resource to move to a new node after 2 failures, and
allow it to move back (depending on stickiness and constraint scores) after one
minute.
[NOTE]
====
+failure-timeout+ is measured since the most recent failure. That is, older
failures do not individually time out and lower the fail count. Instead, all
failures are timed out simultaneously (and the fail count is reset to 0) if
there is no new failure for the timeout period.
====
There are two exceptions to the migration threshold concept:
when a resource either fails to start or fails to stop.
If the cluster property +start-failure-is-fatal+ is set to +true+ (which is the
default), start failures cause the fail count to be set to +INFINITY+ and thus
always cause the resource to move immediately.
Stop failures are slightly different and crucial. If a resource fails
to stop and STONITH is enabled, then the cluster will fence the node
in order to be able to start the resource elsewhere. If STONITH is
not enabled, then the cluster has no way to continue and will not try
to start the resource elsewhere, but will try to stop it again after
the failure timeout.
[IMPORTANT]
Please read <> to understand how timeouts work
before configuring a +failure-timeout+.
== Moving Resources ==
indexterm:[Moving,Resources]
indexterm:[Resource,Moving]
=== Moving Resources Manually ===
There are primarily two occasions when you would want to move a
resource from its current location: when the whole node is under
maintenance, and when a single resource needs to be moved.
==== Standby Mode ====
Since everything eventually comes down to a score, you could create
constraints for every resource to prevent them from running on one
node. While pacemaker configuration can seem convoluted at times, not even
we would require this of administrators.
Instead, one can set a special node attribute which tells the cluster
"don't let anything run here". There is even a helpful tool to help
query and set it, called `crm_standby`. To check the standby status
of the current machine, run:
----
# crm_standby -G
----
A value of +on+ indicates that the node is _not_ able to host any
resources, while a value of +off+ says that it _can_.
You can also check the status of other nodes in the cluster by
specifying the `--node` option:
----
# crm_standby -G --node sles-2
----
To change the current node's standby status, use `-v` instead of `-G`:
----
# crm_standby -v on
----
Again, you can change another host's value by supplying a hostname with `--node`.
==== Moving One Resource ====
When only one resource is required to move, we could do this by creating
location constraints. However, once again we provide a user-friendly
shortcut as part of the `crm_resource` command, which creates and
modifies the extra constraints for you. If +Email+ were running on
+sles-1+ and you wanted it moved to a specific location, the command
would look something like:
----
# crm_resource -M -r Email -H sles-2
----
Behind the scenes, the tool will create the following location constraint:
[source,XML]
It is important to note that subsequent invocations of `crm_resource
-M` are not cumulative. So, if you ran these commands
----
# crm_resource -M -r Email -H sles-2
# crm_resource -M -r Email -H sles-3
----
then it is as if you had never performed the first command.
To allow the resource to move back again, use:
----
# crm_resource -U -r Email
----
Note the use of the word _allow_. The resource can move back to its
original location but, depending on +resource-stickiness+, it might
stay where it is. To be absolutely certain that it moves back to
+sles-1+, move it there before issuing the call to `crm_resource -U`:
----
# crm_resource -M -r Email -H sles-1
# crm_resource -U -r Email
----
Alternatively, if you only care that the resource should be moved from
its current location, try:
----
# crm_resource -B -r Email
----
Which will instead create a negative constraint, like
[source,XML]
This will achieve the desired effect, but will also have long-term
consequences. As the tool will warn you, the creation of a
+-INFINITY+ constraint will prevent the resource from running on that
node until `crm_resource -U` is used. This includes the situation
where every other cluster node is no longer available!
In some cases, such as when +resource-stickiness+ is set to
+INFINITY+, it is possible that you will end up with the problem
described in <>. The tool can detect
some of these cases and deals with them by creating both
positive and negative constraints. E.g.
+Email+ prefers +sles-1+ with a score of +-INFINITY+
+Email+ prefers +sles-2+ with a score of +INFINITY+
which has the same long-term consequences as discussed earlier.
=== Moving Resources Due to Connectivity Changes ===
You can configure the cluster to move resources when external connectivity is
lost in two steps.
==== Tell Pacemaker to Monitor Connectivity ====
First, add an *ocf:pacemaker:ping* resource to the cluster. The
*ping* resource uses the system utility of the same name to a test whether
list of machines (specified by DNS hostname or IPv4/IPv6 address) are
reachable and uses the results to maintain a node attribute called +pingd+
by default.
footnote:[
The attribute name is customizable, in order to allow multiple ping groups to be defined.
]
[NOTE]
===========
Older versions of Pacemaker used a different agent *ocf:pacemaker:pingd* which
is now deprecated in favor of *ping*. If your version of Pacemaker does not
contain the *ping* resource agent, download the latest version from
https://github.com/ClusterLabs/pacemaker/tree/master/extra/resources/ping
===========
Normally, the ping resource should run on all cluster nodes, which means that
you'll need to create a clone. A template for this can be found below
along with a description of the most interesting parameters.
.Common Options for a 'ping' Resource
-[width="95%",cols="1m,4<",options="header",align="center"]
+[width="95%",cols="1m,<4",options="header",align="center"]
|=========================================================
|Field
|Description
|dampen
|The time to wait (dampening) for further changes to occur. Use this
to prevent a resource from bouncing around the cluster when cluster
nodes notice the loss of connectivity at slightly different times.
indexterm:[dampen,Ping Resource Option]
indexterm:[Ping Resource,Option,dampen]
|multiplier
|The number of connected ping nodes gets multiplied by this value to
get a score. Useful when there are multiple ping nodes configured.
indexterm:[multiplier,Ping Resource Option]
indexterm:[Ping Resource,Option,multiplier]
|host_list
|The machines to contact in order to determine the current
connectivity status. Allowed values include resolvable DNS host
names, IPv4 and IPv6 addresses.
indexterm:[host_list,Ping Resource Option]
indexterm:[Ping Resource,Option,host_list]
|=========================================================
.An example ping cluster resource that checks node connectivity once every minute
=====
[source,XML]
------------
------------
=====
[IMPORTANT]
===========
You're only half done. The next section deals with telling Pacemaker
how to deal with the connectivity status that +ocf:pacemaker:ping+ is
recording.
===========
==== Tell Pacemaker How to Interpret the Connectivity Data ====
[IMPORTANT]
======
Before attempting the following, make sure you understand
<>.
======
There are a number of ways to use the connectivity data.
The most common setup is for people to have a single ping
target (e.g. the service network's default gateway), to prevent the cluster
from running a resource on any unconnected node.
.Don't run a resource on unconnected nodes
=====
[source,XML]
-------
-------
=====
A more complex setup is to have a number of ping targets configured.
You can require the cluster to only run resources on nodes that can
connect to all (or a minimum subset) of them.
.Run only on nodes connected to three or more ping targets.
=====
[source,XML]
-------
...
...
...
-------
=====
Alternatively, you can tell the cluster only to _prefer_ nodes with the best
connectivity. Just be sure to set +multiplier+ to a value higher than
that of +resource-stickiness+ (and don't set either of them to
+INFINITY+).
.Prefer the node with the most connected ping nodes
=====
[source,XML]
-------
-------
=====
It is perhaps easier to think of this in terms of the simple
constraints that the cluster translates it into. For example, if
*sles-1* is connected to all five ping nodes but *sles-2* is only
connected to two, then it would be as if you instead had the following
constraints in your configuration:
.How the cluster translates the above location constraint
=====
[source,XML]
-------
-------
=====
The advantage is that you don't have to manually update any
constraints whenever your network connectivity changes.
You can also combine the concepts above into something even more
complex. The example below shows how you can prefer the node with the
most connected ping nodes provided they have connectivity to at least
three (again assuming that +multiplier+ is set to 1000).
.A more complex example of choosing a location based on connectivity
=====
[source,XML]
-------
-------
=====
[[s-migrating-resources]]
=== Migrating Resources ===
Normally, when the cluster needs to move a resource, it fully restarts
the resource (i.e. stops the resource on the current node
and starts it on the new node).
However, some types of resources, such as Xen virtual guests, are able to move to
another location without loss of state (often referred to as live migration
or hot migration). In pacemaker, this is called resource migration.
Pacemaker can be configured to migrate a resource when moving it,
rather than restarting it.
Not all resources are able to migrate; see the Migration Checklist
below, and those that can, won't do so in all situations.
Conceptually, there are two requirements from which the other
prerequisites follow:
* The resource must be active and healthy at the old location; and
* everything required for the resource to run must be available on
both the old and new locations.
The cluster is able to accommodate both 'push' and 'pull' migration models
by requiring the resource agent to support two special actions:
+migrate_to+ (performed on the current location) and +migrate_from+
(performed on the destination).
In push migration, the process on the current location transfers the
resource to the new location where is it later activated. In this
scenario, most of the work would be done in the +migrate_to+ action
and, if anything, the activation would occur during +migrate_from+.
Conversely for pull, the +migrate_to+ action is practically empty and
+migrate_from+ does most of the work, extracting the relevant resource
state from the old location and activating it.
There is no wrong or right way for a resource agent to implement migration,
as long as it works.
.Migration Checklist
* The resource may not be a clone.
* The resource must use an OCF style agent.
* The resource must not be in a failed or degraded state.
* The resource agent must support +migrate_to+ and
+migrate_from+ actions, and advertise them in its metadata.
* The resource must have the +allow-migrate+ meta-attribute set to
+true+ (which is not the default).
If an otherwise migratable resource depends on another resource
via an ordering constraint, there are special situations in which it will be
restarted rather than migrated.
For example, if the resource depends on a clone, and at the time the resource
needs to be moved, the clone has instances that are stopping and instances
that are starting, then the resource will be restarted. The scheduler is not
yet able to model this situation correctly and so takes the safer (if less
optimal) path.
Also, if a migratable resource depends on a non-migratable resource, and both
need to be moved, the migratable resource will be restarted.
[[s-node-health]]
== Tracking Node Health ==
A node may be functioning adequately as far as cluster membership is concerned,
and yet be "unhealthy" in some respect that makes it an undesirable location
for resources. For example, a disk drive may be reporting SMART errors, or the
CPU may be highly loaded.
Pacemaker offers a way to automatically move resources off unhealthy nodes.
=== Node Health Attributes ===
Pacemaker will treat any node attribute whose name starts with +#health+ as an
indicator of node health. Node health attributes may have one of the following
values:
.Allowed Values for Node Health Attributes
-[width="95%",cols="1,3<",options="header",align="center"]
+[width="95%",cols="1,<3",options="header",align="center"]
|=========================================================
|Value
|Intended significance
|+red+
|This indicator is unhealthy
indexterm:[Node health,red]
|+yellow+
|This indicator is becoming unhealthy
indexterm:[Node health,yellow]
|+green+
|This indicator is healthy
indexterm:[Node health,green]
|'integer'
|A numeric score to apply to all resources on this node
(0 or positive is healthy, negative is unhealthy)
indexterm:[Node health,score]
|=========================================================
=== Node Health Strategy ===
Pacemaker assigns a node health score to each node, as the sum of the values of
all its node health attributes. This score will be used as a location
constraint applied to this node for all resources.
The +node-health-strategy+ cluster option controls how Pacemaker responds to
changes in node health attributes, and how it translates +red+, +yellow+, and
+green+ to scores.
Allowed values are:
.Node Health Strategies
-[width="95%",cols="1m,3<",options="header",align="center"]
+[width="95%",cols="1m,<3",options="header",align="center"]
|=========================================================
|Value
|Effect
|none
|Do not track node health attributes at all.
indexterm:[Node health,none]
|migrate-on-red
|Assign the value of +-INFINITY+ to +red+, and 0 to +yellow+ and +green+.
This will cause all resources to move off the node if any attribute is +red+.
indexterm:[Node health,migrate-on-red]
|only-green
|Assign the value of +-INFINITY+ to +red+ and +yellow+, and 0 to +green+.
This will cause all resources to move off the node if any attribute is +red+
or +yellow+.
indexterm:[Node health,only-green]
|progressive
|Assign the value of the +node-health-red+ cluster option to +red+, the value
of +node-health-yellow+ to +yellow+, and the value of +node-health-green+ to
+green+. Each node is additionally assigned a score of +node-health-base+
(this allows resources to start even if some attributes are +yellow+). This
strategy gives the administrator finer control over how important each value
is.
indexterm:[Node health,progressive]
|custom
|Track node health attributes using the same values as +progressive+ for
+red+, +yellow+, and +green+, but do not take them into account.
The administrator is expected to implement a policy by defining rules
(see <>) referencing node health attributes.
indexterm:[Node health,custom]
|=========================================================
=== Measuring Node Health ===
Since Pacemaker calculates node health based on node attributes,
any method that sets node attributes may be used to measure node
health. The most common ways are resource agents or separate daemons.
Pacemaker provides examples that can be used directly or as a basis for
custom code. The +ocf:pacemaker:HealthCPU+ and +ocf:pacemaker:HealthSMART+
resource agents set node health attributes based on CPU and disk parameters.
The +ipmiservicelogd+ daemon sets node health attributes based on IPMI
values (the +ocf:pacemaker:SystemHealth+ resource agent can be used to manage
the daemon as a cluster resource).
== Reloading Services After a Definition Change ==
The cluster automatically detects changes to the definition of
services it manages. The normal response is to stop the
service (using the old definition) and start it again (with the new
definition). This works well, but some services are smarter and can
be told to use a new set of options without restarting.
To take advantage of this capability, the resource agent must:
. Accept the +reload+ operation and perform any required actions.
_The actions here depend completely on your application!_
+
.The DRBD agent's logic for supporting +reload+
=====
[source,Bash]
-------
case $1 in
start)
drbd_start
;;
stop)
drbd_stop
;;
reload)
drbd_reload
;;
monitor)
drbd_monitor
;;
*)
drbd_usage
exit $OCF_ERR_UNIMPLEMENTED
;;
esac
exit $?
-------
=====
. Advertise the +reload+ operation in the +actions+ section of its metadata
+
.The DRBD Agent Advertising Support for the +reload+ Operation
=====
[source,XML]
-------
1.1
Master/Slave OCF Resource Agent for DRBD
...
-------
=====
. Advertise one or more parameters that can take effect using +reload+.
+
Any parameter with the +unique+ set to 0 is eligible to be used in this way.
+
.Parameter that can be changed using reload
=====
[source,XML]
-------
Full path to the drbd.conf file.Path to drbd.conf
-------
=====
Once these requirements are satisfied, the cluster will automatically
know to reload the resource (instead of restarting) when a non-unique
field changes.
[NOTE]
======
Metadata will not be re-read unless the resource needs to be started. This may
mean that the resource will be restarted the first time, even though you
changed a parameter with +unique=0+.
======
[NOTE]
======
If both a unique and non-unique field are changed simultaneously, the
resource will still be restarted.
======
diff --git a/doc/Pacemaker_Explained/en-US/Ch-Advanced-Resources.txt b/doc/Pacemaker_Explained/en-US/Ch-Advanced-Resources.txt
index 345ccaa042..4c401d1dd1 100644
--- a/doc/Pacemaker_Explained/en-US/Ch-Advanced-Resources.txt
+++ b/doc/Pacemaker_Explained/en-US/Ch-Advanced-Resources.txt
@@ -1,1454 +1,1454 @@
= Advanced Resource Types =
[[group-resources]]
== Groups - A Syntactic Shortcut ==
indexterm:[Group Resources]
indexterm:[Resource,Groups]
One of the most common elements of a cluster is a set of resources
that need to be located together, start sequentially, and stop in the
reverse order. To simplify this configuration, we support the concept
of groups.
.A group of two primitive resources
======
[source,XML]
-------
-------
======
Although the example above contains only two resources, there is no
limit to the number of resources a group can contain. The example is
also sufficient to explain the fundamental properties of a group:
* Resources are started in the order they appear in (+Public-IP+
first, then +Email+)
* Resources are stopped in the reverse order to which they appear in
(+Email+ first, then +Public-IP+)
If a resource in the group can't run anywhere, then nothing after that
is allowed to run, too.
* If +Public-IP+ can't run anywhere, neither can +Email+;
* but if +Email+ can't run anywhere, this does not affect +Public-IP+
in any way
The group above is logically equivalent to writing:
.How the cluster sees a group resource
======
[source,XML]
-------
-------
======
Obviously as the group grows bigger, the reduced configuration effort
can become significant.
Another (typical) example of a group is a DRBD volume, the filesystem
mount, an IP address, and an application that uses them.
=== Group Properties ===
.Properties of a Group Resource
-[width="95%",cols="3m,5<",options="header",align="center"]
+[width="95%",cols="3m,<5",options="header",align="center"]
|=========================================================
|Field
|Description
|id
|A unique name for the group
indexterm:[id,Group Resource Property]
indexterm:[Resource,Group Property,id]
|=========================================================
=== Group Options ===
Groups inherit the +priority+, +target-role+, and +is-managed+ properties
from primitive resources. See <> for information about
those properties.
=== Group Instance Attributes ===
Groups have no instance attributes. However, any that are set for the group
object will be inherited by the group's children.
=== Group Contents ===
Groups may only contain a collection of cluster resources (see
<>). To refer to a child of a group resource, just use
the child's +id+ instead of the group's.
=== Group Constraints ===
Although it is possible to reference a group's children in
constraints, it is usually preferable to reference the group itself.
.Some constraints involving groups
======
[source,XML]
-------
-------
======
=== Group Stickiness ===
indexterm:[resource-stickiness,Groups]
Stickiness, the measure of how much a resource wants to stay where it
is, is additive in groups. Every active resource of the group will
contribute its stickiness value to the group's total. So if the
default +resource-stickiness+ is 100, and a group has seven members,
five of which are active, then the group as a whole will prefer its
current location with a score of 500.
[[s-resource-clone]]
== Clones - Resources That Can Have Multiple Active Instances ==
indexterm:[Clone Resources]
indexterm:[Resource,Clones]
'Clone' resources are resources that can have more than one copy active at the
same time. This allows you, for example, to run a copy of a daemon on every
node. You can clone any primitive or group resource.
footnote:[
Of course, the service must support running multiple instances.
]
=== Anonymous versus Unique Clones ===
A clone resource is configured to be either 'anonymous' or 'globally unique'.
Anonymous clones are the simplest. These behave completely identically
everywhere they are running. Because of this, there can be only one instance of
an anonymous clone active per node.
The instances of globally unique clones are distinct entities. All instances
are launched identically, but one instance of the clone is not identical to any
other instance, whether running on the same node or a different node. As an
example, a cloned IP address can use special kernel functionality such that
each instance handles a subset of requests for the same IP address.
[[s-resource-promotable]]
=== Promotable clones ===
indexterm:[Promotable Clone Resources]
indexterm:[Resource,Promotable]
If a clone is 'promotable', its instances can perform a special role that
Pacemaker will manage via the +promote+ and +demote+ actions of the resource
agent.
Services that support such a special role have various terms for the special
role and the default role: primary and secondary, master and replica,
controller and worker, etc. Pacemaker uses the terms 'master' and 'slave',
footnote:[
These are historical terms that will eventually be replaced, but the extensive
use of them and the need for backward compatibility makes it a long process.
You may see examples using a +master+ tag instead of a +clone+ tag with the
+promotable+ meta-attribute set to +true+; the +master+ tag is supported, but
deprecated, and will be removed in a future version. You may also see such
services referred to as 'multi-state' or 'stateful'; these means the same thing
as 'promotable'.
]
but is agnostic to what the service calls them or what they do.
All that Pacemaker cares about is that an instance comes up in the default role
when started, and the resource agent supports the +promote+ and +demote+ actions
to manage entering and exiting the special role.
=== Clone Properties ===
.Properties of a Clone Resource
-[width="95%",cols="3m,5<",options="header",align="center"]
+[width="95%",cols="3m,<5",options="header",align="center"]
|=========================================================
|Field
|Description
|id
|A unique name for the clone
indexterm:[id,Clone Property]
indexterm:[Clone,Property,id]
|=========================================================
=== Clone Options ===
<> inherited from primitive resources:
+priority, target-role, is-managed+
.Clone-specific configuration options
-[width="95%",cols="1m,1,3<",options="header",align="center"]
+[width="95%",cols="1m,1,<3",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|globally-unique
|false
|If +true+, each clone instance performs a distinct function
indexterm:[globally-unique,Clone Option]
indexterm:[Clone,Option,globally-unique]
|clone-max
|number of nodes in cluster
|The maximum number of clone instances that can be started across the entire
cluster
indexterm:[clone-max,Clone Option]
indexterm:[Clone,Option,clone-max]
|clone-node-max
|1
|If +globally-unique+ is +true+, the maximum number of clone instances that can
be started on a single node
indexterm:[clone-node-max,Clone Option]
indexterm:[Clone,Option,clone-node-max]
|clone-min
|0
|Require at least this number of clone instances to be runnable before allowing
resources depending on the clone to be runnable. A value of 0 means require
all clone instances to be runnable.
indexterm:[clone-min,Clone Option]
indexterm:[Clone,Option,clone-min]
|notify
|false
|Call the resource agent's +notify+ action for all active instances, before and
after starting or stopping any clone instance. The resource agent must support
this action. Allowed values: +false+, +true+
indexterm:[notify,Clone Option]
indexterm:[Clone,Option,notify]
|ordered
|false
|If +true+, clone instances must be started sequentially instead of in parallel
Allowed values: +false+, +true+
indexterm:[ordered,Clone Option]
indexterm:[Clone,Option,ordered]
|interleave
|false
|When this clone is ordered relative to another clone, if this option is
+false+ (the default), the ordering is relative to 'all' instances of the
other clone, whereas if this option is +true+, the ordering is relative only
to instances on the same node.
Allowed values: +false+, +true+
indexterm:[interleave,Clone Option]
indexterm:[Clone,Option,interleave]
|promotable
|false
|If +true+, clone instances can perform a special role that Pacemaker will
manage via the resource agent's +promote+ and +demote+ actions. The resource
agent must support these actions.
Allowed values: +false+, +true+
indexterm:[promotable,Clone Option]
indexterm:[Clone,Option,promotable]
|promoted-max
|1
|If +promotable+ is +true+, the number of instances that can be promoted at one
time across the entire cluster
indexterm:[promoted-max,Clone Option]
indexterm:[Clone,Option,promoted-max]
|promoted-node-max
|1
|If +promotable+ is +true+ and +globally-unique+ is +false+, the number of
clone instances can be promoted at one time on a single node
indexterm:[promoted-node-max,Clone Option]
indexterm:[Clone,Option,promoted-node-max]
|=========================================================
For backward compatibility, +master-max+ and +master-node-max+ are accepted as
aliases for +promoted-max+ and +promoted-node-max+, but are deprecated since
2.0.0, and support for them will be removed in a future version.
=== Clone Contents ===
Clones must contain exactly one primitive or group resource.
.A clone that runs a web server on all nodes
====
[source,XML]
----
----
====
[WARNING]
You should never reference the name of a clone's child (the primitive or group
resource being cloned). If you think you need to do this, you probably need to
re-evaluate your design.
=== Clone Instance Attributes ===
Clones have no instance attributes; however, any that are set here will be
inherited by the clone's child.
=== Clone Constraints ===
In most cases, a clone will have a single instance on each active cluster
node. If this is not the case, you can indicate which nodes the
cluster should preferentially assign copies to with resource location
constraints. These constraints are written no differently from those
for primitive resources except that the clone's +id+ is used.
.Some constraints involving clones
======
[source,XML]
-------
-------
======
Ordering constraints behave slightly differently for clones. In the
example above, +apache-stats+ will wait until all copies of +apache-clone+
that need to be started have done so before being started itself.
Only if _no_ copies can be started will +apache-stats+ be prevented
from being active. Additionally, the clone will wait for
+apache-stats+ to be stopped before stopping itself.
Colocation of a primitive or group resource with a clone means that
the resource can run on any node with an active instance of the clone.
The cluster will choose an instance based on where the clone is running and
the resource's own location preferences.
Colocation between clones is also possible. If one clone +A+ is colocated
with another clone +B+, the set of allowed locations for +A+ is limited to
nodes on which +B+ is (or will be) active. Placement is then performed
normally.
==== Promotable Clone Constraints ====
For promotable clone resources, the +first-action+ and/or +then-action+ fields
for ordering constraints may be set to +promote+ or +demote+ to constrain the
master role, and colocation constraints may contain +rsc-role+ and/or
+with-rsc-role+ fields.
.Additional colocation constraint options for promotable clone resources
-[width="95%",cols="1m,1,3<",options="header",align="center"]
+[width="95%",cols="1m,1,<3",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|rsc-role
|Started
|An additional attribute of colocation constraints that specifies the
role that +rsc+ must be in. Allowed values: +Started+, +Master+,
+Slave+.
indexterm:[rsc-role,Ordering Constraints]
indexterm:[Constraints,Ordering,rsc-role]
|with-rsc-role
|Started
|An additional attribute of colocation constraints that specifies the
role that +with-rsc+ must be in. Allowed values: +Started+,
+Master+, +Slave+.
indexterm:[with-rsc-role,Ordering Constraints]
indexterm:[Constraints,Ordering,with-rsc-role]
|=========================================================
.Constraints involving promotable clone resources
======
[source,XML]
-------
-------
======
In the example above, +myApp+ will wait until one of the database
copies has been started and promoted to master before being started
itself on the same node. Only if no copies can be promoted will +myApp+ be
prevented from being active. Additionally, the cluster will wait for
+myApp+ to be stopped before demoting the database.
Colocation of a primitive or group resource with a promotable clone
resource means that it can run on any node with an active instance of
the promotable clone resource that has the specified role (+master+ or
+slave+). In the example above, the cluster will choose a location based on
where database is running as a +master+, and if there are multiple
+master+ instances it will also factor in +myApp+'s own location
preferences when deciding which location to choose.
Colocation with regular clones and other promotable clone resources is also
possible. In such cases, the set of allowed locations for the +rsc+
clone is (after role filtering) limited to nodes on which the
+with-rsc+ promotable clone resource is (or will be) in the specified role.
Placement is then performed as normal.
==== Using Promotable Clone Resources in Colocation Sets ====
.Additional colocation set options relevant to promotable clone resources
-[width="95%",cols="1m,1,6<",options="header",align="center"]
+[width="95%",cols="1m,1,<6",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|role
|Started
|The role that 'all members' of the set must be in. Allowed values: +Started+, +Master+,
+Slave+.
indexterm:[role,Ordering Constraints]
indexterm:[Constraints,Ordering,role]
|=========================================================
In the following example +B+'s master must be located on the same node as +A+'s master.
Additionally resources +C+ and +D+ must be located on the same node as +A+'s
and +B+'s masters.
.Colocate C and D with A's and B's master instances
======
[source,XML]
-------
-------
======
==== Using Promotable Clone Resources in Ordered Sets ====
.Additional ordered set options relevant to promotable clone resources
-[width="95%",cols="1m,1,3<",options="header",align="center"]
+[width="95%",cols="1m,1,<3",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|action
|value of +first-action+
|An additional attribute of ordering constraint sets that specifies the
action that applies to 'all members' of the set. Allowed
values: +start+, +stop+, +promote+, +demote+.
indexterm:[action,Ordering Constraints]
indexterm:[Constraints,Ordering,action]
|=========================================================
.Start C and D after first promoting A and B
======
[source,XML]
-------
-------
======
In the above example, +B+ cannot be promoted to a master role until +A+ has
been promoted. Additionally, resources +C+ and +D+ must wait until +A+ and +B+
have been promoted before they can start.
[[s-clone-stickiness]]
=== Clone Stickiness ===
indexterm:[resource-stickiness,Clones]
To achieve a stable allocation pattern, clones are slightly sticky by
default. If no value for +resource-stickiness+ is provided, the clone
will use a value of 1. Being a small value, it causes minimal
disturbance to the score calculations of other resources but is enough
to prevent Pacemaker from needlessly moving copies around the cluster.
[NOTE]
====
For globally unique clones, this may result in multiple instances of the
clone staying on a single node, even after another eligible node becomes
active (for example, after being put into standby mode then made active again).
If you do not want this behavior, specify a +resource-stickiness+ of 0
for the clone temporarily and let the cluster adjust, then set it back
to 1 if you want the default behavior to apply again.
====
=== Clone Resource Agent Requirements ===
Any resource can be used as an anonymous clone, as it requires no
additional support from the resource agent. Whether it makes sense to
do so depends on your resource and its resource agent.
==== Resource Agent Requirements for Globally Unique Clones ====
Globally unique clones require additional support in the resource agent. In
particular, it must only respond with +$\{OCF_SUCCESS}+ if the node has that
exact instance active. All other probes for instances of the clone should
result in +$\{OCF_NOT_RUNNING}+ (or one of the other OCF error codes if
they are failed).
Individual instances of a clone are identified by appending a colon and a
numerical offset, e.g. +apache:2+.
Resource agents can find out how many copies there are by examining
the +OCF_RESKEY_CRM_meta_clone_max+ environment variable and which
instance it is by examining +OCF_RESKEY_CRM_meta_clone+.
The resource agent must not make any assumptions (based on
+OCF_RESKEY_CRM_meta_clone+) about which numerical instances are active. In
particular, the list of active copies will not always be an unbroken
sequence, nor always start at 0.
==== Resource Agent Requirements for Promotable Clones ====
Promotable clone resources require two extra actions, +demote+ and +promote+,
which are responsible for changing the state of the resource. Like +start+ and
+stop+, they should return +$\{OCF_SUCCESS}+ if they completed successfully or
a relevant error code if they did not.
The states can mean whatever you wish, but when the resource is
started, it must come up in the mode called +slave+. From there the
cluster will decide which instances to promote to +master+.
In addition to the clone requirements for monitor actions, agents must
also _accurately_ report which state they are in. The cluster relies
on the agent to report its status (including role) accurately and does
not indicate to the agent what role it currently believes it to be in.
.Role implications of OCF return codes
-[width="95%",cols="1,1<",options="header",align="center"]
+[width="95%",cols="1,<1",options="header",align="center"]
|=========================================================
|Monitor Return Code
|Description
|OCF_NOT_RUNNING
|Stopped
indexterm:[Return Code,OCF_NOT_RUNNING]
|OCF_SUCCESS
|Running (Slave)
indexterm:[Return Code,OCF_SUCCESS]
|OCF_RUNNING_MASTER
|Running (Master)
indexterm:[Return Code,OCF_RUNNING_MASTER]
|OCF_FAILED_MASTER
|Failed (Master)
indexterm:[Return Code,OCF_FAILED_MASTER]
|Other
|Failed (Slave)
|=========================================================
==== Clone Notifications ====
If the clone has the +notify+ meta-attribute set to +true+, and the resource
agent supports the +notify+ action, Pacemaker will call the action when
appropriate, passing a number of extra variables which, when combined with
additional context, can be used to calculate the current state of the cluster
and what is about to happen to it.
.Environment variables supplied with Clone notify actions
-[width="95%",cols="5,3<",options="header",align="center"]
+[width="95%",cols="5,<3",options="header",align="center"]
|=========================================================
|Variable
|Description
|OCF_RESKEY_CRM_meta_notify_type
|Allowed values: +pre+, +post+
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,type]
indexterm:[type,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_operation
|Allowed values: +start+, +stop+
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,operation]
indexterm:[operation,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_start_resource
|Resources to be started
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,start_resource]
indexterm:[start_resource,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_stop_resource
|Resources to be stopped
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,stop_resource]
indexterm:[stop_resource,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_active_resource
|Resources that are running
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,active_resource]
indexterm:[active_resource,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_inactive_resource
|Resources that are not running
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,inactive_resource]
indexterm:[inactive_resource,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_start_uname
|Nodes on which resources will be started
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,start_uname]
indexterm:[start_uname,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_stop_uname
|Nodes on which resources will be stopped
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,stop_uname]
indexterm:[stop_uname,Notification Environment Variable]
|OCF_RESKEY_CRM_meta_notify_active_uname
|Nodes on which resources are running
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,active_uname]
indexterm:[active_uname,Notification Environment Variable]
|=========================================================
The variables come in pairs, such as
+OCF_RESKEY_CRM_meta_notify_start_resource+ and
+OCF_RESKEY_CRM_meta_notify_start_uname+ and should be treated as an
array of whitespace-separated elements.
+OCF_RESKEY_CRM_meta_notify_inactive_resource+ is an exception as the
matching +uname+ variable does not exist since inactive resources
are not running on any node.
Thus in order to indicate that +clone:0+ will be started on +sles-1+,
+clone:2+ will be started on +sles-3+, and +clone:3+ will be started
on +sles-2+, the cluster would set
.Notification variables
======
[source,Bash]
-------
OCF_RESKEY_CRM_meta_notify_start_resource="clone:0 clone:2 clone:3"
OCF_RESKEY_CRM_meta_notify_start_uname="sles-1 sles-3 sles-2"
-------
======
==== Interpretation of Notification Variables ====
.Pre-notification (stop):
* Active resources: +$OCF_RESKEY_CRM_meta_notify_active_resource+
* Inactive resources: +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
.Post-notification (stop) / Pre-notification (start):
* Active resources
** +$OCF_RESKEY_CRM_meta_notify_active_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Inactive resources
** +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources that were started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources that were stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
.Post-notification (start):
* Active resources:
** +$OCF_RESKEY_CRM_meta_notify_active_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Inactive resources:
** +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources that were started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources that were stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
==== Extra Notifications for Promotable Clones ====
.Extra environment variables supplied for promotable clones
-[width="95%",cols="5,3<",options="header",align="center"]
+[width="95%",cols="5,<3",options="header",align="center"]
|=========================================================
|_OCF_RESKEY_CRM_meta_notify_master_resource_
|Resources that are running in +Master+ mode
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,master_resource]
indexterm:[master_resource,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_slave_resource_
|Resources that are running in +Slave+ mode
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,slave_resource]
indexterm:[slave_resource,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_promote_resource_
|Resources to be promoted
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,promote_resource]
indexterm:[promote_resource,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_demote_resource_
|Resources to be demoted
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,demote_resource]
indexterm:[demote_resource,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_promote_uname_
|Nodes on which resources will be promoted
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,promote_uname]
indexterm:[promote_uname,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_demote_uname_
|Nodes on which resources will be demoted
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,demote_uname]
indexterm:[demote_uname,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_master_uname_
|Nodes on which resources are running in +Master+ mode
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,master_uname]
indexterm:[master_uname,Notification Environment Variable]
|_OCF_RESKEY_CRM_meta_notify_slave_uname_
|Nodes on which resources are running in +Slave+ mode
indexterm:[Environment Variable,OCF_RESKEY_CRM_meta_notify_,slave_uname]
indexterm:[slave_uname,Notification Environment Variable]
|=========================================================
==== Interpretation of Promotable Notification Variables ====
.Pre-notification (demote):
* +Active+ resources: +$OCF_RESKEY_CRM_meta_notify_active_resource+
* +Master+ resources: +$OCF_RESKEY_CRM_meta_notify_master_resource+
* +Slave+ resources: +$OCF_RESKEY_CRM_meta_notify_slave_resource+
* Inactive resources: +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources to be demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
.Post-notification (demote) / Pre-notification (stop):
* +Active+ resources: +$OCF_RESKEY_CRM_meta_notify_active_resource+
* +Master+ resources:
** +$OCF_RESKEY_CRM_meta_notify_master_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* +Slave+ resources: +$OCF_RESKEY_CRM_meta_notify_slave_resource+
* Inactive resources: +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources to be demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources that were demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
.Post-notification (stop) / Pre-notification (start)
* +Active+ resources:
** +$OCF_RESKEY_CRM_meta_notify_active_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* +Master+ resources:
** +$OCF_RESKEY_CRM_meta_notify_master_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* +Slave+ resources:
** +$OCF_RESKEY_CRM_meta_notify_slave_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Inactive resources:
** +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources to be demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources that were demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources that were stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
.Post-notification (start) / Pre-notification (promote)
* +Active+ resources:
** +$OCF_RESKEY_CRM_meta_notify_active_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* +Master+ resources:
** +$OCF_RESKEY_CRM_meta_notify_master_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* +Slave+ resources:
** +$OCF_RESKEY_CRM_meta_notify_slave_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Inactive resources:
** +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources to be demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources that were started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources that were demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources that were stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
.Post-notification (promote)
* +Active+ resources:
** +$OCF_RESKEY_CRM_meta_notify_active_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* +Master+ resources:
** +$OCF_RESKEY_CRM_meta_notify_master_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_demote_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* +Slave+ resources:
** +$OCF_RESKEY_CRM_meta_notify_slave_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_start_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Inactive resources:
** +$OCF_RESKEY_CRM_meta_notify_inactive_resource+
** plus +$OCF_RESKEY_CRM_meta_notify_stop_resource+
** minus +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources to be promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources to be demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources to be stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
* Resources that were started: +$OCF_RESKEY_CRM_meta_notify_start_resource+
* Resources that were promoted: +$OCF_RESKEY_CRM_meta_notify_promote_resource+
* Resources that were demoted: +$OCF_RESKEY_CRM_meta_notify_demote_resource+
* Resources that were stopped: +$OCF_RESKEY_CRM_meta_notify_stop_resource+
=== Monitoring Promotable Clone Resources ===
The usual monitor actions are insufficient to monitor a promotable clone
resource, because Pacemaker needs to verify not only that the resource is
active, but also that its actual role matches its intended one.
Define two monitoring actions: the usual one will cover the slave role,
and an additional one with +role="master"+ will cover the master role.
.Monitoring both states of a promotable clone resource
======
[source,XML]
-------
-------
======
[IMPORTANT]
===========
It is crucial that _every_ monitor operation has a different interval!
Pacemaker currently differentiates between operations
only by resource and interval; so if (for example) a promotable clone resource
had the same monitor interval for both roles, Pacemaker would ignore the
role when checking the status -- which would cause unexpected return
codes, and therefore unnecessary complications.
===========
[[s-promotion-scores]]
=== Determining Which Instance is Promoted ===
Pacemaker can choose a promotable clone instance to be promoted in one of two
ways:
* Promotion scores: These are node attributes set via the `crm_master` utility,
which generally would be called by the resource agent's start action if it
supports promotable clones. This tool automatically detects both the resource
and host, and should be used to set a preference for being promoted. Based on
this, +promoted-max+, and +promoted-node-max+, the instance(s) with the
highest preference will be promoted.
* Constraints: Location constraints can indicate which nodes are most preferred
as masters.
.Explicitly preferring node1 to be promoted to master
======
[source,XML]
-------
-------
======
[[s-resource-bundle]]
== Bundles - Isolated Environments ==
indexterm:[bundle]
indexterm:[Resource,bundle]
indexterm:[Docker,bundle]
indexterm:[rkt,bundle]
Pacemaker supports a special syntax for launching a
https://en.wikipedia.org/wiki/Operating-system-level_virtualization[container]
with any infrastructure it requires: the 'bundle'.
Pacemaker bundles support https://www.docker.com/[Docker] and
https://coreos.com/rkt/[rkt] container technologies.
footnote:[Docker is a trademark of Docker, Inc. No endorsement by or
association with Docker, Inc. is implied.]
.A bundle for a containerized web server
====
[source,XML]
----
----
====
=== Bundle Properties ===
.Properties of a Bundle
-[width="95%",cols="3m,5<",options="header",align="center"]
+[width="95%",cols="3m,<5",options="header",align="center"]
|=========================================================
|Field
|Description
|id
|A unique name for the bundle (required)
indexterm:[id,bundle]
indexterm:[bundle,Property,id]
|description
|Arbitrary text (not used by Pacemaker)
indexterm:[description,bundle]
indexterm:[bundle,Property,description]
|=========================================================
A bundle must contain exactly one ++ or ++ element.
=== Docker Properties ===
Before configuring a Docker bundle in Pacemaker, the user must install Docker
and supply a fully configured Docker image on every node allowed to run the
bundle.
Pacemaker will create an implicit +ocf:heartbeat:docker+ resource to manage
a bundle's Docker container. The user must ensure that resource agent is
installed on every node allowed to run the bundle.
.Properties of a Bundle's Docker Element
-[width="95%",cols="3m,4,5<",options="header",align="center"]
+[width="95%",cols="3m,4,<5",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|image
|
|Docker image tag (required)
indexterm:[image,Docker]
indexterm:[Docker,Property,image]
|replicas
|Value of +promoted-max+ if that is positive, else 1
|A positive integer specifying the number of container instances to launch
indexterm:[replicas,Docker]
indexterm:[Docker,Property,replicas]
|replicas-per-host
|1
|A positive integer specifying the number of container instances allowed to run
on a single node
indexterm:[replicas-per-host,Docker]
indexterm:[Docker,Property,replicas-per-host]
|promoted-max
|0
|A non-negative integer that, if positive, indicates that the containerized
service should be treated as a promotable service, with this many replicas
allowed to run the service in the master role
indexterm:[promoted-max,Docker]
indexterm:[Docker,Property,promoted-max]
|network
|
|If specified, this will be passed to +docker run+ as the
https://docs.docker.com/engine/reference/run/#network-settings[network setting]
for the Docker container.
indexterm:[network,Docker]
indexterm:[Docker,Property,network]
|run-command
|`/usr/sbin/pacemaker-remoted` if bundle contains a +primitive+, otherwise none
|This command will be run inside the container when launching it ("PID 1"). If
the bundle contains a +primitive+, this command 'must' start pacemaker-remoted
(but could, for example, be a script that does other stuff, too). If the
container image has a pre-2.0.0 version of Pacemaker, set this to
+/usr/sbin/pacemaker_remoted+ (note the underbar instead of dash).
indexterm:[run-command,Docker]
indexterm:[Docker,Property,run-command]
|options
|
|Extra command-line options to pass to `docker run`
indexterm:[options,Docker]
indexterm:[Docker,Property,options]
|=========================================================
For backward compatibility, +masters+ is accepted as an alias for
+promoted-max+, but is deprecated since 2.0.0, and support for it will be
removed in a future version.
=== rkt Properties ===
Before configuring a rkt bundle in Pacemaker, the user must install rkt
and supply a fully configured container image on every node allowed to run the
bundle.
Pacemaker will create an implicit +ocf:heartbeat:rkt+ resource to manage
a bundle's rkt container. The user must ensure that resource agent is
installed on every node allowed to run the bundle.
.Properties of a Bundle's rkt Element
-[width="95%",cols="3m,4,5<",options="header",align="center"]
+[width="95%",cols="3m,4,<5",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|image
|
|Container image tag (required)
indexterm:[image,rkt]
indexterm:[rkt,Property,image]
|replicas
|Value of +promoted-max+ if that is positive, else 1
|A positive integer specifying the number of container instances to launch
indexterm:[replicas,rkt]
indexterm:[rkt,Property,replicas]
|replicas-per-host
|1
|A positive integer specifying the number of container instances allowed to run
on a single node
indexterm:[replicas-per-host,rkt]
indexterm:[rkt,Property,replicas-per-host]
|promoted-max
|0
|A non-negative integer that, if positive, indicates that the containerized
service should be treated as a promotable service, with this many replicas
allowed to run the service in the master role
indexterm:[promoted-max,rkt]
indexterm:[rkt,Property,promoted-max]
|network
|
|If specified, this will be passed to +rkt run+ as the
network setting for the rkt container.
indexterm:[network,rkt]
indexterm:[rkt,Property,network]
|run-command
|`/usr/sbin/pacemaker-remoted` if bundle contains a +primitive+, otherwise none
|This command will be run inside the container when launching it ("PID 1"). If
the bundle contains a +primitive+, this command 'must' start pacemaker-remoted
(but could, for example, be a script that does other stuff, too). If the
container image has a pre-2.0.0 version of Pacemaker, set this to
+/usr/sbin/pacemaker_remoted+ (note the underbar instead of dash).
indexterm:[run-command,rkt]
indexterm:[rkt,Property,run-command]
|options
|
|Extra command-line options to pass to `rkt run`
indexterm:[options,rkt]
indexterm:[rkt,Property,options]
|=========================================================
For backward compatibility, +masters+ is accepted as an alias for
+promoted-max+, but is deprecated since 2.0.0, and support for it will be
removed in a future version.
=== Bundle Network Properties ===
A bundle may optionally contain one ++ element.
indexterm:[bundle,network]
.Properties of a Bundle's Network Element
-[width="95%",cols="2m,1,4<",options="header",align="center"]
+[width="95%",cols="2m,1,<4",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|add-host
|TRUE
|If TRUE, and +ip-range-start+ is used, Pacemaker will automatically ensure
that +/etc/hosts+ inside the containers has entries for each
<> and its assigned IP.
indexterm:[add-host,network]
indexterm:[network,Property,add-host]
|ip-range-start
|
|If specified, Pacemaker will create an implicit +ocf:heartbeat:IPaddr2+
resource for each container instance, starting with this IP address,
using up to +replicas+ sequential addresses. These addresses can be used
from the host's network to reach the service inside the container, though
it is not visible within the container itself. Only IPv4 addresses are
currently supported.
indexterm:[ip-range-start,network]
indexterm:[network,Property,ip-range-start]
|host-netmask
|32
|If +ip-range-start+ is specified, the IP addresses are created with this
CIDR netmask (as a number of bits).
indexterm:[host-netmask,network]
indexterm:[network,Property,host-netmask]
|host-interface
|
|If +ip-range-start+ is specified, the IP addresses are created on this
host interface (by default, it will be determined from the IP address).
indexterm:[host-interface,network]
indexterm:[network,Property,host-interface]
|control-port
|3121
|If the bundle contains a +primitive+, the cluster will use this integer TCP
port for communication with Pacemaker Remote inside the container. Changing
this is useful when the container is unable to listen on the default port,
for example, when the container uses the host's network rather than
+ip-range-start+ (in which case +replicas-per-host+ must be 1), or when the
bundle may run on a Pacemaker Remote node that is already listening on the
default port. Any PCMK_remote_port environment variable set on the host or in
the container is ignored for bundle connections.
indexterm:[control-port,network]
indexterm:[network,Property,control-port]
|=========================================================
[[s-resource-bundle-note-replica-names]]
[NOTE]
====
Replicas are named by the bundle id plus a dash and an integer counter starting
with zero. For example, if a bundle named +httpd-bundle+ has +replicas=2+, its
containers will be named +httpd-bundle-0+ and +httpd-bundle-1+.
====
Additionally, a ++ element may optionally contain one or more
++ elements.
indexterm:[bundle,network,port-mapping]
.Properties of a Bundle's Port-Mapping Element
-[width="95%",cols="2m,1,4<",options="header",align="center"]
+[width="95%",cols="2m,1,<4",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|id
|
|A unique name for the port mapping (required)
indexterm:[id,port-mapping]
indexterm:[port-mapping,Property,id]
|port
|
|If this is specified, connections to this TCP port number on the host network
(on the container's assigned IP address, if +ip-range-start+ is specified)
will be forwarded to the container network. Exactly one of +port+ or +range+
must be specified in a +port-mapping+.
indexterm:[port,port-mapping]
indexterm:[port-mapping,Property,port]
|internal-port
|value of +port+
|If +port+ and this are specified, connections to +port+ on the host's network
will be forwarded to this port on the container network.
indexterm:[internal-port,port-mapping]
indexterm:[port-mapping,Property,internal-port]
|range
|
|If this is specified, connections to these TCP port numbers (expressed as
'first_port'-'last_port') on the host network (on the container's assigned IP
address, if +ip-range-start+ is specified) will be forwarded to the same ports
in the container network. Exactly one of +port+ or +range+ must be specified
in a +port-mapping+.
indexterm:[range,port-mapping]
indexterm:[port-mapping,Property,range]
|=========================================================
[NOTE]
====
If the bundle contains a +primitive+, Pacemaker will automatically map the
+control-port+, so it is not necessary to specify that port in a
+port-mapping+.
====
=== Bundle Storage Properties ===
A bundle may optionally contain one ++ element. A ++ element
has no properties of its own, but may contain one or more ++
elements.
indexterm:[bundle,storage,storage-mapping]
.Properties of a Bundle's Storage-Mapping Element
-[width="95%",cols="2m,1,4<",options="header",align="center"]
+[width="95%",cols="2m,1,<4",options="header",align="center"]
|=========================================================
|Field
|Default
|Description
|id
|
|A unique name for the storage mapping (required)
indexterm:[id,storage-mapping]
indexterm:[storage-mapping,Property,id]
|source-dir
|
|The absolute path on the host's filesystem that will be mapped into the
container. Exactly one of +source-dir+ and +source-dir-root+ must be specified
in a +storage-mapping+.
indexterm:[source-dir,storage-mapping]
indexterm:[storage-mapping,Property,source-dir]
|source-dir-root
|
|The start of a path on the host's filesystem that will be mapped into the
container, using a different subdirectory on the host for each container
instance. The subdirectory will be named the same as the
<>.
Exactly one of +source-dir+ and +source-dir-root+ must be specified in a
+storage-mapping+.
indexterm:[source-dir-root,storage-mapping]
indexterm:[storage-mapping,Property,source-dir-root]
|target-dir
|
|The path name within the container where the host storage will be mapped
(required)
indexterm:[target-dir,storage-mapping]
indexterm:[storage-mapping,Property,target-dir]
|options
|
|File system mount options to use when mapping the storage
indexterm:[options,storage-mapping]
indexterm:[storage-mapping,Property,options]
|=========================================================
[NOTE]
====
Pacemaker does not define the behavior if the source directory does not already
exist on the host. However, it is expected that the container technology and/or
its resource agent will create the source directory in that case.
====
[NOTE]
====
If the bundle contains a +primitive+,
Pacemaker will automatically map the equivalent of
+source-dir=/etc/pacemaker/authkey target-dir=/etc/pacemaker/authkey+
and +source-dir-root=/var/log/pacemaker/bundles target-dir=/var/log+ into the
container, so it is not necessary to specify those paths in a
+storage-mapping+.
====
[IMPORTANT]
====
The +PCMK_authkey_location+ environment variable must not be set to anything
other than the default of `/etc/pacemaker/authkey` on any node in the cluster.
====
=== Bundle Primitive ===
A bundle may optionally contain one ++ resource
(see <>). The primitive may have operations,
instance attributes and meta-attributes defined, as usual.
If a bundle contains a primitive resource, the container image must include
the Pacemaker Remote daemon, and at least one of +ip-range-start+ or
+control-port+ must be configured in the bundle. Pacemaker will create an
implicit +ocf:pacemaker:remote+ resource for the connection, launch
Pacemaker Remote within the container, and monitor and manage the primitive
resource via Pacemaker Remote.
If the bundle has more than one container instance (replica), the primitive
resource will function as an implicit clone (see <>) --
a promotable clone if the bundle has +masters+ greater than zero
(see <>).
[IMPORTANT]
====
Containers in bundles with a +primitive+ must have an accessible networking
environment, so that Pacemaker on the cluster nodes can contact
Pacemaker Remote inside the container. For example, the Docker option
`--net=none` should not be used with a +primitive+. The default (using a
distinct network space inside the container) works in combination with
+ip-range-start+. If the Docker option `--net=host` is used (making the
container share the host's network space), a unique +control-port+ should be
specified for each bundle. Any firewall must allow access to the
+control-port+.
====
[[s-bundle-attributes]]
=== Bundle Node Attributes ===
If the bundle has a +primitive+, the primitive's resource agent may want to set
node attributes such as <>. However, with
containers, it is not apparent which node should get the attribute.
If the container uses shared storage that is the same no matter which node the
container is hosted on, then it is appropriate to use the promotion score on the
bundle node itself.
On the other hand, if the container uses storage exported from the underlying host,
then it may be more appropriate to use the promotion score on the underlying host.
Since this depends on the particular situation, the
+container-attribute-target+ resource meta-attribute allows the user to specify
which approach to use. If it is set to +host+, then user-defined node attributes
will be checked on the underlying host. If it is anything else, the local node
(in this case the bundle node) is used as usual.
This only applies to user-defined attributes; the cluster will always check the
local node for cluster-defined attributes such as +#uname+.
If +container-attribute-target+ is +host+, the cluster will pass additional
environment variables to the primitive's resource agent that allow it to set
node attributes appropriately: +CRM_meta_container_attribute_target+ (identical
to the meta-attribute value) and +CRM_meta_physical_host+ (the name of the
underlying host).
[NOTE]
====
When called by a resource agent, the attrd_updater and crm_attribute commands
will automatically check those environment variables and set attributes
appropriately.
====
=== Bundle Meta-Attributes ===
Any meta-attribute set on a bundle will be inherited by the bundle's
primitive and any resources implicitly created by Pacemaker for the bundle.
This includes options such as +priority+, +target-role+, and +is-managed+. See
<> for more information.
=== Limitations of Bundles ===
Restarting pacemaker while a bundle is unmanaged or the cluster is in
maintenance mode may cause the bundle to fail.
Bundles may not be explicitly cloned or included in groups. This includes the
bundle's primitive and any resources implicitly created by Pacemaker for the
bundle. (If +replicas+ is greater than 1, the bundle will behave like a clone
implicitly.)
Bundles do not have instance attributes, utilization attributes, or operations,
though a bundle's primitive may have them.
A bundle with a primitive can run on a Pacemaker Remote node only if the bundle
uses a distinct +control-port+.
diff --git a/doc/Pacemaker_Explained/en-US/Ch-Alerts.txt b/doc/Pacemaker_Explained/en-US/Ch-Alerts.txt
index afc6d1b553..34daeece5f 100644
--- a/doc/Pacemaker_Explained/en-US/Ch-Alerts.txt
+++ b/doc/Pacemaker_Explained/en-US/Ch-Alerts.txt
@@ -1,423 +1,423 @@
= Alerts =
////
We prefer [[ch-alerts]], but older versions of asciidoc don't deal well
with that construct for chapter headings
////
anchor:ch-alerts[Chapter 7, Alerts]
indexterm:[Resource,Alerts]
'Alerts' may be configured to take some external action when a cluster event
occurs (node failure, resource starting or stopping, etc.).
== Alert Agents ==
As with resource agents, the cluster calls an external program (an
'alert agent') to handle alerts. The cluster passes information about the event
to the agent via environment variables. Agents can do anything
desired with this information (send an e-mail, log to a file,
update a monitoring system, etc.).
.Simple alert configuration
=====
[source,XML]
-----
-----
=====
In the example above, the cluster will call +my-script.sh+ for each event.
Multiple alert agents may be configured; the cluster will call all of them for
each event.
Alert agents will be called only on cluster nodes. They will be called for
events involving Pacemaker Remote nodes, but they will never be called _on_
those nodes.
== Alert Recipients ==
Usually alerts are directed towards a recipient. Thus each alert may be additionally configured with one or more recipients.
The cluster will call the agent separately for each recipient.
.Alert configuration with recipient
=====
[source,XML]
-----
-----
=====
In the above example, the cluster will call +my-script.sh+ for each event,
passing the recipient +some-address+ as an environment variable.
The recipient may be anything the alert agent can recognize --
an IP address, an e-mail address, a file name, whatever the particular
agent supports.
== Alert Meta-Attributes ==
As with resource agents, meta-attributes can be configured for alert agents
to affect how Pacemaker calls them.
.Meta-Attributes of an Alert
-[width="95%",cols="m,1,2
-----
=====
In the above example, the +my-script.sh+ will get called twice for each event,
with each call using a 15-second timeout. One call will be passed the recipient
+someuser@example.com+ and a timestamp in the format +%D %H:%M+, while the
other call will be passed the recipient +otheruser@example.com+ and a timestamp
in the format +%c+.
== Alert Instance Attributes ==
As with resource agents, agent-specific configuration values may be configured
as instance attributes. These will be passed to the agent as additional
environment variables. The number, names and allowed values of these
instance attributes are completely up to the particular agent.
.Alert configuration with instance attributes
=====
[source,XML]
-----
-----
=====
== Alert Filters ==
By default, an alert agent will be called for node events, fencing events, and
resource events. An agent may choose to ignore certain types of events, but
there is still the overhead of calling it for those events. To eliminate that
overhead, you may select which types of events the agent should receive.
.Alert configuration to receive only node events and fencing events
=====
[source,XML]
-----
-----
=====
The possible options within +