diff --git a/doc/sphinx/Pacemaker_Administration/agents.rst b/doc/sphinx/Pacemaker_Administration/agents.rst index 18e1c5ce13..fada66e34b 100644 --- a/doc/sphinx/Pacemaker_Administration/agents.rst +++ b/doc/sphinx/Pacemaker_Administration/agents.rst @@ -1,380 +1,405 @@ +.. index:: + single: resource agent + Resource Agents --------------- -Resource Agent Actions -###################### + +Action Completion +################# If one resource depends on another resource via constraints, the cluster will interpret an expected result as sufficient to continue with dependent actions. This may cause timing issues if the resource agent start returns before the service is not only launched but fully ready to perform its function, or if the resource agent stop returns before the service has fully released all its claims on system resources. At a minimum, the start or stop should not return before a status command would return the expected (started or stopped) result. + +.. index:: + single: OCF resource agent + single: resource agent; OCF + OCF Resource Agents ################### +.. index:: + single: OCF resource agent; location + Location of Custom Scripts __________________________ -.. index:: OCF resource agents - OCF Resource Agents are found in ``/usr/lib/ocf/resource.d/$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 big-corp and want a new resource named big-app, you would create a resource agent called ``/usr/lib/ocf/resource.d/big-corp/big-app`` and define a resource: .. code-block: xml + +.. index:: + single: OCF resource agent; action + Actions _______ All OCF resource agents are required to implement the following actions. .. table:: **Required Actions for OCF Agents** +--------------+-------------+------------------------------------------------+ | Action | Description | Instructions | +==============+=============+================================================+ - | start | Start the | Return 0 on success and an appropriate | - | | resource | error code otherwise. Must not report | + | start | Start the | .. index:: | + | | resource | single: OCF resource agent; start | + | | | single: start action | + | | | | + | | | Return 0 on success and an appropriate | + | | | error code otherwise. Must not report | | | | success until the resource is fully | | | | active. | - | | | | - | | | .. index:: | - | | | pair: start; OCF action | - | | | pair: start; action | +--------------+-------------+------------------------------------------------+ - | stop | Stop the | Return 0 on success and an appropriate | - | | resource | error code otherwise. Must not report | + | stop | Stop the | .. index:: | + | | resource | single: OCF resource agent; stop | + | | | single: stop action | + | | | | + | | | Return 0 on success and an appropriate | + | | | error code otherwise. Must not report | | | | success until the resource is fully | | | | stopped. | - | | | | - | | | .. index:: | - | | | pair: stop; OCF action | - | | | pair: stop; action | +--------------+-------------+------------------------------------------------+ - | monitor | Check the | Exit 0 if the resource is running, 7 | - | | resource's | if it is stopped, and any other OCF | - | | state | exit code if it is failed. NOTE: The | + | monitor | Check the | .. index:: | + | | resource's | single: OCF resource agent; monitor | + | | state | single: monitor action | + | | | | + | | | Exit 0 if the resource is running, 7 | + | | | if it is stopped, and any other OCF | + | | | exit code if it is failed. NOTE: The | | | | monitor script should test the state | | | | of the resource on the local machine | | | | only. | - | | | | - | | | .. index:: | - | | | pair: monitor; OCF action | - | | | pair: monitor; action | +--------------+-------------+------------------------------------------------+ - | meta-data | Describe | Provide information about this | - | | the | resource in the XML format defined by | - | | resource | the OCF standard. Exit with 0. NOTE: | + | meta-data | Describe | .. index:: | + | | the | single: OCF resource agent; meta-data | + | | resource | single: meta-data action | + | | | | + | | | Provide information about this | + | | | resource in the XML format defined by | + | | | the OCF standard. Exit with 0. NOTE: | | | | This is *not* required to be performed | | | | as root. | - | | | | - | | | .. index:: | - | | | pair: meta-data; OCF action | - | | | pair: meta-data; action | +--------------+-------------+------------------------------------------------+ - | validate-all | Verify the | Return 0 if parameters are valid, 2 if | - | | supplied | not valid, and 6 if resource is not | - | | parameters | configured. | + | validate-all | Verify the | .. index:: | + | | supplied | single: OCF resource agent; validate-all | + | | parameters | single: validate-all action | | | | | - | | | .. index:: | - | | | pair: validate-all; OCF action | - | | | pair: validate-all; action | + | | | Return 0 if parameters are valid, 2 if | + | | | not valid, and 6 if resource is not | + | | | configured. | +--------------+-------------+------------------------------------------------+ Additional requirements (not part of the OCF specification) are placed on agents that will be used for advanced concepts such as clone resources. .. table:: **Optional Actions for OCF Resource Agents** +--------------+-------------+------------------------------------------------+ | Action | Description | Instructions | +==============+=============+================================================+ - | promote | Promote the | Return 0 on success | - | | local | | - | | instance of | .. index:: | - | | a promotable| pair: promote; OCF action | - | | clone | pair: promote; action | + | promote | Promote the | .. index:: | + | | local | single: OCF resource agent; promote | + | | instance of | single: promote action | + | | a promotable| | + | | clone | Return 0 on success | | | resource to | | | | the master | | | | (primary) | | | | state. | | +--------------+-------------+------------------------------------------------+ - | demote | Demote the | Return 0 on success | - | | local | | - | | instance of | .. index:: | - | | a promotable| pair: demote; OCF action | - | | clone | pair: demote; action | + | demote | Demote the | .. index:: | + | | local | single: OCF resource agent; demote | + | | instance of | single: demote action | + | | a promotable| | + | | clone | Return 0 on success | | | resource to | | | | the slave | | | | (secondary) | | | | state. | | +--------------+-------------+------------------------------------------------+ - | notify | Used by the | Must not fail. Must exit with 0 | - | | cluster to | | - | | send | .. index:: | - | | the agent | pair: notify; OCF action | - | | pre- and | pair: notify; action | + | notify | Used by the | .. index:: | + | | cluster to | single: OCF resource agent; notify | + | | send | single: notify action | + | | the agent | | + | | pre- and | Must not fail. Must exit with 0 | | | post- | | | | notification| | | | events | | | | telling the | | | | resource | | | | what has | | | | happened and| | | | will happen.| | +--------------+-------------+------------------------------------------------+ 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 `ocf-tester` to verify that the agent complies with the OCF standard properly. -.. index:: ocf-tester + +.. index:: + single: OCF resource agent; return code 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: .. table:: **Types of recovery performed by the cluster** - +-------+------------------------------+--------------------------------------+ - | Type | Description | Action Taken by the Cluster | - +=======+==============================+======================================+ - | soft | A transient error occurred | Restart the resource or move it to a | - | | | new location | - | | .. index:: | | - | | pair: soft; OCF error | | - +-------+------------------------------+--------------------------------------+ - | hard | A non-transient error that | Move the resource elsewhere and | - | | may be specific to the | prevent it from being retried on the | - | | current node | current node | - | | | | - | | .. index:: | | - | | pair: hard; OCF error | | - +-------+------------------------------+--------------------------------------+ - | fatal | A non-transient error that | Stop the resource and prevent it | - | | will be common to all | from being started on any cluster | - | | cluster nodes (e.g. a bad | node | - | | configuration was specified) | | - | | | | - | | .. index:: | | - | | pair: fatal; OCF error | | - +-------+------------------------------+--------------------------------------+ + +-------+--------------------------------------------+--------------------------------------+ + | Type | Description | Action Taken by the Cluster | + +=======+============================================+======================================+ + | soft | .. index:: | Restart the resource or move it to a | + | | single: OCF resource agent; soft error | new location | + | | | | + | | A transient error occurred | | + +-------+--------------------------------------------+--------------------------------------+ + | hard | .. index:: | Move the resource elsewhere and | + | | single: OCF resource agent; hard error | prevent it from being retried on the | + | | | current node | + | | A non-transient error that | | + | | may be specific to the | | + | | current node | | + +-------+--------------------------------------------+--------------------------------------+ + | fatal | .. index:: | Stop the resource and prevent it | + | | single: OCF resource agent; fatal error | from being started on any cluster | + | | | node | + | | A non-transient error that | | + | | will be common to all | | + | | cluster nodes (e.g. a bad | | + | | configuration was specified) | | + +-------+--------------------------------------------+--------------------------------------+ .. _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. .. table:: **OCF Exit Codes and their Recovery Types** - +-------+-----------------------+---------------------------------------------+----------+ - | Exit | OCF Alias | Description | Recovery | - | Code | | | | - +=======+=======================+=============================================+==========+ - | 0 | OCF_SUCCESS | Success. The command completed successfully.| soft | - | | | This is the expected result for all start, | | - | | | stop, promote and demote commands. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_SUCCESS | | - | | | pair: return code; 0 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 1 | OCF_ERR_GENERIC | Generic "there was a problem" | soft | - | | | error code. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_GENERIC | | - | | | pair: return code; 1 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 2 | OCF_ERR_ARGS | The resource's configuration is not valid on| hard | - | | | this machine. E.g. it refers to a location | | - | | | not found on the node. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_ARGS | | - | | | pair: return code; 2 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 3 | OCF_ERR_UNIMPLEMENTED | The requested action is not | hard | - | | | implemented. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_UNIMPLEMENTED | | - | | | pair: return code; 3 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 4 | OCF_ERR_PERM | The resource agent does not have | hard | - | | | sufficient privileges to complete the task. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_PERM | | - | | | pair: return code; 4 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 5 | OCF_ERR_INSTALLED | The tools required by the resource are | hard | - | | | not installed on this machine. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_INSTALLED | | - | | | pair: return code; 5 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 6 | OCF_ERR_CONFIGURED | The resource's configuration is invalid. | fatal | - | | | E.g. required parameters are missing. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_ERR_CONFIGURED | | - | | | pair: return code; 6 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 7 | OCF_NOT_RUNNING | The resource is safely stopped. The cluster | N/A | - | | | will not attempt to stop a resource that | | - | | | returns this for any action. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_NOT_RUNNING | | - | | | pair: return code; 7 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 8 | OCF_RUNNING_MASTER | The resource is running in | soft | - | | | master mode. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_RUNNING_MASTER | | - | | | pair: return code; 8 | | - +-------+-----------------------+---------------------------------------------+----------+ - | 9 | OCF_FAILED_MASTER | The resource is in master mode but has | soft | - | | | failed. The resource will be demoted, | | - | | | stopped and then started (and possibly | | - | | | promoted) again. | | - | | | | | - | | | .. index:: | | - | | | pair: return code; OCF_FAILED_MASTER | | - | | | pair: return code; 9 | | - +-------+-----------------------+---------------------------------------------+----------+ - | other | *none* | Custom error code. | soft | - | | | | | - | | | .. index:: | | - | | | pair: return code; other | | - +-------+-----------------------+---------------------------------------------+----------+ + +-------+-----------------------+---------------------------------------------------+----------+ + | Exit | OCF Alias | Description | Recovery | + | Code | | | | + +=======+=======================+===================================================+==========+ + | 0 | OCF_SUCCESS | .. index:: | soft | + | | | single: OCF_SUCCESS | | + | | | single: OCF return code; OCF_SUCCESS | | + | | | pair: OCF return code; 0 | | + | | | | | + | | | Success. The command completed successfully. | | + | | | This is the expected result for all start, | | + | | | stop, promote and demote commands. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 1 | OCF_ERR_GENERIC | .. index:: | soft | + | | | single: OCF_ERR_GENERIC | | + | | | single: OCF return code; OCF_ERR_GENERIC | | + | | | pair: OCF return code; 1 | | + | | | | | + | | | Generic "there was a problem" error code. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 2 | OCF_ERR_ARGS | .. index:: | hard | + | | | single: OCF_ERR_ARGS | | + | | | single: OCF return code; OCF_ERR_ARGS | | + | | | pair: OCF return code; 2 | | + | | | | | + | | | The resource's configuration is not valid on | | + | | | this machine. E.g. it refers to a location | | + | | | not found on the node. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 3 | OCF_ERR_UNIMPLEMENTED | .. index:: | hard | + | | | single: OCF_ERR_UNIMPLEMENTED | | + | | | single: OCF return code; OCF_ERR_UNIMPLEMENTED | | + | | | pair: OCF return code; 3 | | + | | | | | + | | | The requested action is not implemented. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 4 | OCF_ERR_PERM | .. index:: | hard | + | | | single: OCF_ERR_PERM | | + | | | single: OCF return code; OCF_ERR_PERM | | + | | | pair: OCF return code; 4 | | + | | | | | + | | | The resource agent does not have | | + | | | sufficient privileges to complete the task. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 5 | OCF_ERR_INSTALLED | .. index:: | hard | + | | | single: OCF_ERR_INSTALLED | | + | | | single: OCF return code; OCF_ERR_INSTALLED | | + | | | pair: OCF return code; 5 | | + | | | | | + | | | The tools required by the resource are | | + | | | not installed on this machine. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 6 | OCF_ERR_CONFIGURED | .. index:: | fatal | + | | | single: OCF_ERR_CONFIGURED | | + | | | single: OCF return code; OCF_ERR_CONFIGURED | | + | | | pair: OCF return code; 6 | | + | | | | | + | | | The resource's configuration is invalid. | | + | | | E.g. required parameters are missing. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 7 | OCF_NOT_RUNNING | .. index:: | N/A | + | | | single: OCF_NOT_RUNNING | | + | | | single: OCF return code; OCF_NOT_RUNNING | | + | | | pair: OCF return code; 7 | | + | | | | | + | | | The resource is safely stopped. The cluster | | + | | | will not attempt to stop a resource that | | + | | | returns this for any action. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 8 | OCF_RUNNING_MASTER | .. index:: | soft | + | | | single: OCF_RUNNING_MASTER | | + | | | single: OCF return code; OCF_RUNNING_MASTER | | + | | | pair: OCF return code; 8 | | + | | | | | + | | | The resource is running in the master role. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | 9 | OCF_FAILED_MASTER | .. index:: | soft | + | | | single: OCF_FAILED_MASTER | | + | | | single: OCF return code; OCF_FAILED_MASTER | | + | | | pair: OCF return code; 9 | | + | | | | | + | | | The resource is in the master role but has | | + | | | failed. The resource will be demoted, | | + | | | stopped and then started (and possibly | | + | | | promoted) again. | | + +-------+-----------------------+---------------------------------------------------+----------+ + | other | *none* | Custom error code. | soft | + +-------+-----------------------+---------------------------------------------------+----------+ Exceptions to the recovery handling described above: * Probes (non-recurring monitor actions) that find a resource active (or in master mode) will not result in recovery action unless it is also found active elsewhere. * The recovery action taken when a resource is found active more than once is determined by the resource's ``multiple-active`` property. * Recurring actions that return ``OCF_ERR_UNIMPLEMENTED`` do not cause any type of recovery. +.. index:: + single: resource agent; LSB + single: LSB resource agent + single: init script + LSB Resource Agents (Init Scripts) ################################## LSB Compliance ______________ The relevant part of the `LSB specifications `_ includes a description of all the return codes listed here. Assuming `some_service` is configured correctly and currently inactive, the following sequence will help you determine if it is LSB-compatible: #. Start (stopped): .. code-block:: none # /etc/init.d/some_service start ; echo "result: $?" * Did the service start? * Did the echo command print ``result: 0`` (in addition to the init script's usual output)? #. Status (running): .. code-block:: none # /etc/init.d/some_service status ; echo "result: $?" * Did the script accept the command? * Did the script indicate the service was running? * Did the echo command print ``result: 0`` (in addition to the init script's usual output)? #. Start (running): .. code-block:: none # /etc/init.d/some_service start ; echo "result: $?" * Is the service still running? * Did the echo command print ``result: 0`` (in addition to the init script's usual output)? #. Stop (running): .. code-block:: none # /etc/init.d/some_service stop ; echo "result: $?" * Was the service stopped? * Did the echo command print ``result: 0`` (in addition to the init script's usual output)? #. Status (stopped): .. code-block:: none # /etc/init.d/some_service status ; echo "result: $?" * Did the script accept the command? * Did the script indicate the service was not running? * Did the echo command print ``result: 3`` (in addition to the init script's usual output)? #. Stop (stopped): .. code-block:: none # /etc/init.d/some_service stop ; echo "result: $?" * Is the service still stopped? * Did the echo command print ``result: 0`` (in addition to the init script's usual output)? #. Status (failed): This step is not readily testable and relies on manual inspection of the script. The script can use one of the error codes (other than 3) listed in the LSB spec to indicate that it is active but failed. This tells the cluster that before moving the resource to another node, it needs to stop it on the existing one first. If the answer to any of the above questions is no, then the script is not LSB-compliant. Your options are then to either fix the script or write an OCF agent based on the existing script. diff --git a/doc/sphinx/Pacemaker_Administration/cluster.rst b/doc/sphinx/Pacemaker_Administration/cluster.rst index 26da9e5c68..069121f042 100644 --- a/doc/sphinx/Pacemaker_Administration/cluster.rst +++ b/doc/sphinx/Pacemaker_Administration/cluster.rst @@ -1,64 +1,71 @@ +.. index:: + single: cluster layer + The Cluster Layer ----------------- Pacemaker and the Cluster Layer ############################### Pacemaker utilizes an underlying cluster layer for two purposes: * obtaining quorum * messaging between nodes Currently, only Corosync 2 and later is supported for this layer. +.. index:: + single: cluster layer; Corosync + single: Corosync + Managing Nodes in a Corosync-Based Cluster ########################################## +.. index:: + pair: Corosync; add cluster node + Adding a New Corosync Node __________________________ -.. index:: - pair: corosync; add cluster node - To add a new node: #. Install Corosync and Pacemaker on the new host. #. Copy ``/etc/corosync/corosync.conf`` and ``/etc/corosync/authkey`` (if it exists) from an existing node. You may need to modify the ``mcastaddr`` option to match the new node's IP address. #. Start the cluster software on the new host. If a log message containing "Invalid digest" appears from Corosync, the keys are not consistent between the machines. +.. index:: + pair: Corosync; remove cluster node + Removing a Corosync Node ________________________ -.. index:: - pair: corosync; remove cluster node - Because the messaging and membership layers are the authoritative source for cluster nodes, deleting them from the CIB is not a complete solution. First, one must arrange for corosync to forget about the node (**pcmk-1** in the example below). #. Stop the cluster on the host to be removed. How to do this will vary with your operating system and installed versions of cluster software, for example, ``pcs cluster stop`` if you are using pcs for cluster management. #. From one of the remaining active cluster nodes, tell Pacemaker to forget about the removed host, which will also delete the node from the CIB: .. code-block:: none # crm_node -R pcmk-1 +.. index:: + pair: Corosync; replace cluster node + Replacing a Corosync Node _________________________ -.. index:: - pair: corosync; replace cluster node - To replace an existing cluster node: #. Make sure the old node is completely stopped. #. Give the new machine the same hostname and IP address as the old one. #. Follow the procedure above for adding a node. diff --git a/doc/sphinx/Pacemaker_Administration/configuring.rst b/doc/sphinx/Pacemaker_Administration/configuring.rst index b0321f1909..d3e638d67b 100644 --- a/doc/sphinx/Pacemaker_Administration/configuring.rst +++ b/doc/sphinx/Pacemaker_Administration/configuring.rst @@ -1,264 +1,278 @@ +.. index:: + single: configuration + single: CIB + Configuring Pacemaker --------------------- Pacemaker's configuration, the CIB, is stored in XML format. Cluster administrators have multiple options for modifying the configuration either via the XML, or at a more abstract (and easier for humans to understand) level. Pacemaker reacts to configuration changes as soon as they are saved. Pacemaker's command-line tools and most higher-level tools provide the ability to batch changes together and commit them at once, rather than make a series of small changes, which could cause avoid unnecessary actions as Pacemaker responds to each change individually. Pacemaker tracks revisions to the configuration and will reject any update older than the current revision. Thus, it is a good idea to serialize all changes to the configuration. Avoid attempting simultaneous changes, whether on the same node or different nodes, and whether manually or using some automated configuration tool. .. note:: It is not necessary to update the configuration on all cluster nodes. Pacemaker immediately synchronizes changes to all active members of the cluster. To reduce bandwidth, the cluster only broadcasts the incremental updates that result from your changes and uses checksums to ensure that each copy is consistent. Configuration Using Higher-level Tools ______________________________________ Most users will benefit from using higher-level tools provided by projects separate from Pacemaker. Some of the most commonly used include the crm shell, hawk, and pcs. [#]_ See those projects' documentation for details on how to configure Pacemaker using them. Configuration Using Pacemaker's Command-Line Tools __________________________________________________ Pacemaker provides lower-level, command-line tools to manage the cluster. Most configuration tasks can be performed with these tools, without needing any XML knowledge. To enable STONITH for example, one could run: .. code-block:: none # crm_attribute --name stonith-enabled --update 1 Or, to check whether **node1** is allowed to run resources, there is: .. code-block:: none # crm_standby --query --node node1 Or, to change the failure threshold of **my-test-rsc**, one can use: .. code-block:: none # crm_resource -r my-test-rsc --set-parameter migration-threshold --parameter-value 3 --meta Examples of using these tools for specific cases will be given throughout this document where appropriate. See the man pages for further details. See :ref:`cibadmin` for how to edit the CIB using XML. See :ref:`crm_shadow` for a way to make a series of changes, then commit them all at once to the live cluster. +.. index:: + single: configuration; CIB properties + single: CIB; properties + single: CIB property + 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: .. code-block:: none # cibadmin --modify --xml-text '' A complete set of CIB properties will look something like this: .. topic:: XML attributes set for a cib element .. code-block:: xml +.. index:: + single: configuration; cluster options + Querying and Setting Cluster Options #################################### -.. index:: - pair: cluster option; querying - pair: cluster option; setting - Cluster options can be queried and modified using the ``crm_attribute`` tool. To get the current value of ``cluster-delay``, you can run: .. code-block:: none # crm_attribute --query --name cluster-delay which is more simply written as .. code-block:: none # crm_attribute -G -n cluster-delay If a value is found, you'll see a result like this: .. code-block:: none # 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: .. code-block:: none # 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: .. code-block:: none # crm_attribute --name cluster-delay --update 30s To go back to the cluster's default value, you can delete the value, for example: .. code-block:: none # 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. .. topic:: Deleting an option that is listed twice .. code-block:: none # 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*. +.. index:: + single: configuration; remote + .. _remote_connection: Connecting from a Remote Machine ################################ -.. index:: - pair: cluster; remote connection - pair: 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. .. table:: **Environment Variables Used to Connect to Remote Instances of the CIB** - +----------------------+-----------+----------------------------------------------+ - | Environment Variable | Default | Description | - +======================+===========+==============================================+ - | CIB_user | $USER | The user to connect as. Needs to be | - | | | part of the ``haclient`` group on | - | | | the target host. | - | | | | - | | | .. index:: | - | | | pair: environment variable; CIB_user | - +----------------------+-----------+----------------------------------------------+ - | CIB_passwd | | The user's password. Read from the | - | | | command line if unset. | - | | | | - | | | .. index:: | - | | | pair: environment variable; CIB_passwd | - +----------------------+-----------+----------------------------------------------+ - | CIB_server | localhost | The host to contact | - | | | | - | | | .. index:: | - | | | pair: environment variable; CIB_server | - +----------------------+-----------+----------------------------------------------+ - | CIB_port | | The port on which to contact the server; | - | | | required. | - | | | | - | | | .. index:: | - | | | pair: environment variable; CIB_port | - +----------------------+-----------+----------------------------------------------+ - | CIB_encrypted | TRUE | Whether to encrypt network traffic | - | | | | - | | | .. index:: | - | | | pair: environment variable; CIB_encrypted | - +----------------------+-----------+----------------------------------------------+ + +----------------------+-----------+------------------------------------------------+ + | Environment Variable | Default | Description | + +======================+===========+================================================+ + | CIB_user | $USER | .. index:: | + | | | single: CIB_user | + | | | single: environment variable; CIB_user | + | | | | + | | | The user to connect as. Needs to be | + | | | part of the ``haclient`` group on | + | | | the target host. | + +----------------------+-----------+------------------------------------------------+ + | CIB_passwd | | .. index:: | + | | | single: CIB_passwd | + | | | single: environment variable; CIB_passwd | + | | | | + | | | The user's password. Read from the | + | | | command line if unset. | + +----------------------+-----------+------------------------------------------------+ + | CIB_server | localhost | .. index:: | + | | | single: CIB_server | + | | | single: environment variable; CIB_server | + | | | | + | | | The host to contact | + +----------------------+-----------+------------------------------------------------+ + | CIB_port | | .. index:: | + | | | single: CIB_port | + | | | single: environment variable; CIB_port | + | | | | + | | | The port on which to contact the server; | + | | | required. | + +----------------------+-----------+------------------------------------------------+ + | CIB_encrypted | TRUE | .. index:: | + | | | single: CIB_encrypted | + | | | single: environment variable; CIB_encrypted | + | | | | + | | | Whether to encrypt network traffic | + +----------------------+-----------+------------------------------------------------+ 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: .. code-block:: none # 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``). .. table:: **Extra top-level CIB properties for remote access** +----------------------+-----------+------------------------------------------------------+ | CIB Property | Default | Description | +======================+===========+======================================================+ - | remote-tls-port | | Listen for encrypted remote connections | - | | | on this port. | + | remote-tls-port | | .. index:: | + | | | single: remote-tls-port | + | | | single: CIB property; remote-tls-port | | | | | - | | | .. index:: | - | | | pair: remote connection option; remote-tls-port | - +----------------------+-----------+------------------------------------------------------+ - | remote-clear-port | | Listen for plaintext remote connections | + | | | Listen for encrypted remote connections | | | | on this port. | + +----------------------+-----------+------------------------------------------------------+ + | remote-clear-port | | .. index:: | + | | | single: remote-clear-port | + | | | single: CIB property; remote-clear-port | | | | | - | | | .. index:: | - | | | pair: remote connection option; remote-clear-port | + | | | Listen for plaintext remote connections | + | | | on this port. | +----------------------+-----------+------------------------------------------------------+ .. important:: The Pacemaker version on the administration host must be the same or greater than the version(s) on the cluster nodes. Otherwise, it may not have the schema files necessary to validate the CIB. .. rubric:: Footnotes .. [#] For a list, see "Configuration Tools" at https://clusterlabs.org/components.html diff --git a/doc/sphinx/Pacemaker_Administration/installing.rst b/doc/sphinx/Pacemaker_Administration/installing.rst index 334a06ca88..179f4fe665 100644 --- a/doc/sphinx/Pacemaker_Administration/installing.rst +++ b/doc/sphinx/Pacemaker_Administration/installing.rst @@ -1,107 +1,112 @@ Installing Cluster Software --------------------------- +.. index:: installation + Installing the Software ####################### Most major Linux distributions have pacemaker packages in their standard package repositories, or the software can be built from source code. See the `Install wiki page `_ for details. Enabling Pacemaker ################## +.. index:: + pair: configuration; Corosync + Enabling Pacemaker For Corosync version 2 and greater _____________________________________________________ High-level cluster management tools are available that can configure corosync for you. This document focuses on the lower-level details if you want to configure corosync yourself. Corosync configuration is normally located in ``/etc/corosync/corosync.conf``. .. topic:: Corosync configuration file for two nodes **myhost1** and **myhost2** .. code-block:: none totem { version: 2 secauth: off cluster_name: mycluster transport: udpu } nodelist { node { ring0_addr: myhost1 nodeid: 1 } node { ring0_addr: myhost2 nodeid: 2 } } quorum { provider: corosync_votequorum two_node: 1 } logging { to_syslog: yes } .. topic:: Corosync configuration file for three nodes **myhost1**, **myhost2** and **myhost3** .. code-block:: none totem { version: 2 secauth: off cluster_name: mycluster transport: udpu } nodelist { node { ring0_addr: myhost1 nodeid: 1 } node { ring0_addr: myhost2 nodeid: 2 } node { ring0_addr: myhost3 nodeid: 3 } } quorum { provider: corosync_votequorum } logging { to_syslog: yes } In the above examples, the ``totem`` section defines what protocol version and options (including encryption) to use, [#]_ and gives the cluster a unique name (``mycluster`` in these examples). The ``node`` section lists the nodes in this cluster. The ``quorum`` section defines how the cluster uses quorum. The important thing is that two-node clusters must be handled specially, so ``two_node: 1`` must be defined for two-node clusters (it will be ignored for clusters of any other size). The ``logging`` section should be self-explanatory. .. rubric:: Footnotes .. [#] Please consult the Corosync website (http://www.corosync.org/) and documentation for details on enabling encryption and peer authentication for the cluster. diff --git a/doc/sphinx/Pacemaker_Administration/tools.rst b/doc/sphinx/Pacemaker_Administration/tools.rst index aff767d9e9..64fd4789ae 100644 --- a/doc/sphinx/Pacemaker_Administration/tools.rst +++ b/doc/sphinx/Pacemaker_Administration/tools.rst @@ -1,553 +1,570 @@ +.. index:: command-line tool + Using Pacemaker Command-Line Tools ---------------------------------- +.. index:: + single: command-line tool; output format + .. _cmdline_output: Controlling Command Line Output ############################### Some of the pacemaker command line utilities have been converted to a new output system. Among these tools are ``crm_mon`` and ``stonith_admin``. This is an ongoing project, and more tools will be converted over time. This system lets you control the formatting of output with ``--output-as=`` and the destination of output with ``--output-to=``. The available formats vary by tool, but at least plain text and XML are supported by all tools that use the new system. The default format is plain text. The default destination is stdout but can be redirected to any file. Some formats support command line options for changing the style of the output. For instance: .. code-block:: none # crm_mon --help-output Usage: crm_mon [OPTION?] Provides a summary of cluster's current state. Outputs varying levels of detail in a number of different formats. Output Options: --output-as=FORMAT Specify output format as one of: console (default), html, text, xml --output-to=DEST Specify file name for output (or "-" for stdout) --html-cgi Add text needed to use output in a CGI program --html-stylesheet=URI Link to an external CSS stylesheet --html-title=TITLE Page title --text-fancy Use more highly formatted output +.. index:: + single: crm_mon + single: command-line tool; crm_mon + .. _crm_mon: Monitor a Cluster with crm_mon ############################## -.. index:: - pair: command-line tool; crm_mon - The ``crm_mon`` utility displays the current state of an active cluster. It can show the cluster status organized by node or by resource, and can be used in either single-shot or dynamically updating mode. It can also display operations performed and information about failures. Using this tool, you can examine the state of the cluster for irregularities, and see how it responds when you cause or simulate failures. See the manual page or the output of ``crm_mon --help`` for a full description of its many options. .. topic:: Sample output from crm_mon -1 .. code-block:: none Cluster Summary: * Stack: corosync * Current DC: node2 (version 2.0.0-1) - partition with quorum * Last updated: Mon Jan 29 12:18:42 2018 * Last change: Mon Jan 29 12:18:40 2018 by root via crm_attribute on node3 * 5 nodes configured * 2 resources configured Node List: * Online: [ node1 node2 node3 node4 node5 ] * Active resources: * Fencing (stonith:fence_xvm): Started node1 * IP (ocf:heartbeat:IPaddr2): Started node2 .. topic:: Sample output from crm_mon -n -1 .. code-block:: none Cluster Summary: * Stack: corosync * Current DC: node2 (version 2.0.0-1) - partition with quorum * Last updated: Mon Jan 29 12:21:48 2018 * Last change: Mon Jan 29 12:18:40 2018 by root via crm_attribute on node3 * 5 nodes configured * 2 resources configured * Node List: * Node node1: online * Fencing (stonith:fence_xvm): Started * Node node2: online * IP (ocf:heartbeat:IPaddr2): Started * Node node3: online * Node node4: online * Node node5: online As mentioned in an earlier chapter, the DC is the node is where decisions are made. The cluster elects a node to be DC as needed. The only significance of the choice of DC to an administrator is the fact that its logs will have the most information about why decisions were made. -.. _crm_mon_css: - -Styling crm_mon output -______________________ - .. index:: pair: crm_mon; CSS +.. _crm_mon_css: + +Styling crm_mon HTML output +___________________________ + Various parts of ``crm_mon``'s HTML output have a CSS class associated with them. Not everything does, but some of the most interesting portions do. In the following example, the status of each node has an ``online`` class and the details of each resource have an ``rsc-ok`` class. .. code-block:: html

Node List

  • Node: cluster01 online
    • ping (ocf::pacemaker:ping): Started
  • Node: cluster02 online
    • ping (ocf::pacemaker:ping): Started
By default, a stylesheet for styling these classes is included in the head of the HTML output. The relevant portions of this stylesheet that would be used in the above example is: .. code-block:: css If you want to override some or all of the styling, simply create your own stylesheet, place it on a web server, and pass ``--html-stylesheet=`` to ``crm_mon``. The link is added after the default stylesheet, so your changes take precedence. You don't need to duplicate the entire default. Only include what you want to change. +.. index:: + single: cibadmin + single: command-line tool; cibadmin + .. _cibadmin: Edit the CIB XML with cibadmin ############################## -.. index:: - pair: command-line tool; cibadmin - The most flexible tool for modifying the configuration is Pacemaker's ``cibadmin`` command. With ``cibadmin``, you can query, add, remove, update or replace any part of the configuration. All changes take effect immediately, so there is no need to perform a reload-like operation. The simplest way of using ``cibadmin`` is to use it to save the current configuration to a temporary file, edit that file with your favorite text or XML editor, and then upload the revised configuration. .. topic:: Safely using an editor to modify the cluster configuration .. code-block:: none # cibadmin --query > 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`` depending on your operating system distribution 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. .. topic:: Safely using an editor to modify only the resources section .. code-block:: none # cibadmin --query --scope resources > tmp.xml # vi tmp.xml # cibadmin --replace --scope resources --xml-file tmp.xml To quickly delete a 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: .. topic:: Searching for STONITH-related configuration items .. code-block:: none # cibadmin --query | grep stonith If you wanted to delete the ``primitive`` tag with id ``child_DoFencing``, you would run: .. code-block:: none # cibadmin --delete --xml-text '' See the cibadmin man page for more options. .. warning:: Never edit the live ``cib.xml`` file directly. Pacemaker will detect such changes and refuse to use the configuration. +.. index:: + single: crm_shadow + single: command-line tool; crm_shadow + .. _crm_shadow: Batch Configuration Changes with crm_shadow ########################################### -.. index:: - pair: command-line tool; crm_shadow - Often, it is desirable to preview the effects of a series of configuration changes before updating the live configuration all at once. For this purpose, ``crm_shadow`` 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 a name of your choice, and follow the simple on-screen instructions. Shadow copies are identified with a name to make it possible to have more than one. .. warning:: Read this section and the on-screen instructions carefully; failure to do so could result in destroying the cluster's active configuration! .. topic:: Creating and displaying the active sandbox .. code-block:: none # 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. .. topic:: Use sandbox to make multiple changes all at once, discard them, and verify real configuration is untouched .. code-block:: none 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 See the next section, :ref:`crm_simulate`, for how to test your changes before committing them to the live cluster. +.. index:: + single: crm_simulate + single: command-line tool; crm_simulate + .. _crm_simulate: Simulate Cluster Activity with crm_simulate ########################################### -.. index:: - pair: command-line tool; crm_simulate - The command-line tool `crm_simulate` shows the results of the same logic the cluster itself uses to respond to a particular cluster configuration and status. As always, the man page is the primary documentation, and should be consulted for further details. This section aims for a better conceptual explanation and practical examples. Replaying cluster decision-making logic _______________________________________ At any given time, one node in a Pacemaker cluster will be elected DC, and that node will run Pacemaker's scheduler to make decisions. Each time decisions need to be made (a "transition"), the DC will have log messages like "Calculated transition ... saving inputs in ..." with a file name. You can grab the named file and replay the cluster logic to see why particular decisions were made. The file contains the live cluster configuration at that moment, so you can also look at it directly to see the value of node attributes, etc., at that time. The simplest usage is (replacing $FILENAME with the actual file name): .. topic:: Simulate cluster response to a given CIB .. code-block:: none # crm_simulate --simulate --xml-file $FILENAME That will show the cluster state when the process started, the actions that need to be taken ("Transition Summary"), and the resulting cluster state if the actions succeed. Most actions will have a brief description of why they were required. The transition inputs may be compressed. ``crm_simulate`` can handle these compressed files directly, though if you want to edit the file, you'll need to uncompress it first. You can do the same simulation for the live cluster configuration at the current moment. This is useful mainly when using ``crm_shadow`` to create a sandbox version of the CIB; the ``--live-check`` option will use the shadow CIB if one is in effect. .. topic:: Simulate cluster response to current live CIB or shadow CIB .. code-block:: none # crm_simulate --simulate --live-check Why decisions were made _______________________ To get further insight into the "why", it gets user-unfriendly very quickly. If you add the ``--show-scores`` option, you will also see all the scores that went into the decision-making. The node with the highest cumulative score for a resource will run it. You can look for ``-INFINITY`` scores in particular to see where complete bans came into effect. You can also add ``-VVVV`` to get more detailed messages about what's happening under the hood. You can add up to two more V's even, but that's usually useful only if you're a masochist or tracing through the source code. Visualizing the action sequence _______________________________ Another handy feature is the ability to generate a visual graph of the actions needed, using the ``--dot-file`` option. This relies on the separate Graphviz [#]_ project. .. topic:: Generate a visual graph of cluster actions from a saved CIB .. code-block:: none # crm_simulate --simulate --xml-file $FILENAME --dot-file $FILENAME.dot # dot $FILENAME.dot -Tsvg > $FILENAME.svg ``$FILENAME.dot`` will contain a GraphViz representation of the cluster's response to your changes, including all actions with their ordering dependencies. ``$FILENAME.svg`` will be the same information in a standard graphical format that you can view in your browser or other app of choice. You could, of course, use other ``dot`` options to generate other formats. How to interpret the graphical output: * Bubbles indicate actions, and arrows indicate ordering dependencies * Resource actions have text of the form ``__ `` indicating that the specified action will be executed for the specified resource on the specified node, once if interval is 0 or at specified recurring interval otherwise * Actions with black text will be sent to the executor (that is, the appropriate agent will be invoked) * Actions with orange text are "pseudo" actions that the cluster uses internally for ordering but require no real activity * Actions with a solid green border are part of the transition (that is, the cluster will attempt to execute them in the given order -- though a transition can be interrupted by action failure or new events) * Dashed arrows indicate dependencies that are not present in the transition graph * Actions with a dashed border will not be executed. If the dashed border is blue, the cluster does not feel the action needs to be executed. If the dashed border is red, the cluster would like to execute the action but cannot. Any actions depending on an action with a dashed border will not be able to execute. * Loops should not happen, and should be reported as a bug if found. .. topic:: Small Cluster Transition .. image:: ../../shared/en-US/images/Policy-Engine-small.png :alt: An example transition graph as represented by Graphviz :height: 325 :width: 1161 :scale: 75 % :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. .. topic:: Complex Cluster Transition .. image:: ../../shared/en-US/images/Policy-Engine-big.png :alt: Complex transition graph that you're not expected to be able to read :width: 1455 :height: 1945 :scale: 75 % :align: center What-if scenarios _________________ You can make changes to the saved or shadow CIB and simulate it again, to see how Pacemaker would react differently. You can edit the XML by hand, use command-line tools such as ``cibadmin`` with either a shadow CIB or the ``CIB_file`` environment variable set to the filename, or use higher-level tool support (see the man pages of the specific tool you're using for how to perform actions on a saved CIB file rather than the live CIB). You can also inject node failures and/or action failures into the simulation; see the ``crm_simulate`` man page for more details. This capability is useful when using a shadow CIB to edit the configuration. Before committing the changes to the live cluster with ``crm_shadow --commit``, you can use ``crm_simulate`` to see how the cluster will react to the changes. .. _attrd_updater: .. _crm_attribute: +.. index:: + single: attrd_updater + single: command-line tool; attrd_updater + single: crm_attribute + single: command-line tool; crm_attribute + Manage Node Attributes, Cluster Options and Defaults with crm_attribute and attrd_updater ######################################################################################### -.. index:: - pair: command-line tool; attrd_updater - pair: command-line tool; crm_attribute - ``crm_attribute`` and ``attrd_updater`` are confusingly similar tools with subtle differences. ``attrd_updater`` can query and update node attributes. ``crm_attribute`` can query and update not only node attributes, but also cluster options, resource defaults, and operation defaults. To understand the differences, it helps to understand the various types of node attribute. .. table:: **Types of Node Attributes** +-----------+----------+-------------------+------------------+----------------+----------------+ | Type | Recorded | Recorded in | Survive full | Manageable by | Manageable by | | | in CIB? | attribute manager | cluster restart? | crm_attribute? | attrd_updater? | | | | memory? | | | | +===========+==========+===================+==================+================+================+ | permanent | yes | no | yes | yes | no | +-----------+----------+-------------------+------------------+----------------+----------------+ | transient | yes | yes | no | yes | yes | +-----------+----------+-------------------+------------------+----------------+----------------+ | private | no | yes | no | no | yes | +-----------+----------+-------------------+------------------+----------------+----------------+ As you can see from the table above, ``crm_attribute`` can manage permanent and transient node attributes, while ``attrd_updater`` can manage transient and private node attributes. The difference between the two tools lies mainly in *how* they update node attributes: ``attrd_updater`` always contacts the Pacemaker attribute manager directly, while ``crm_attribute`` will contact the attribute manager only for transient node attributes, and will instead modify the CIB directly for permanent node attributes (and for transient node attributes when unable to contact the attribute manager). By contacting the attribute manager directly, ``attrd_updater`` can change an attribute's "dampening" (whether changes are immediately flushed to the CIB or after a specified amount of time, to minimize disk writes for frequent changes), set private node attributes (which are never written to the CIB), and set attributes for nodes that don't yet exist. By modifying the CIB directly, ``crm_attribute`` can set permanent node attributes (which are only in the CIB and not managed by the attribute manager), and can be used with saved CIB files and shadow CIBs. However a transient node attribute is set, it is synchronized between the CIB and the attribute manager, on all nodes. +.. index:: + single: crm_failcount + single: command-line tool; crm_failcount + single: crm_node + single: command-line tool; crm_node + single: crm_report + single: command-line tool; crm_report + single: crm_standby + single: command-line tool; crm_standby + single: crm_verify + single: command-line tool; crm_verify + single: stonith_admin + single: command-line tool; stonith_admin + Other Commonly Used Tools ######################### Other command-line tools include: -.. index:: - pair: command-line tool; crm_failcount - pair: command-line tool; crm_node - pair: command-line tool; crm_report - pair: command-line tool; crm_standby - pair: command-line tool; crm_verify - pair: command-line tool; stonith_admin - * ``crm_failcount``: query or delete resource fail counts * ``crm_node``: manage cluster nodes * ``crm_report``: generate a detailed cluster report for bug submissions * ``crm_resource``: manage cluster resources * ``crm_standby``: manage standby status of nodes * ``crm_verify``: validate a CIB * ``stonith_admin``: manage fencing devices See the manual pages for details. .. rubric:: Footnotes .. [#] Graph visualization software. See http://www.graphviz.org/ for details. diff --git a/doc/sphinx/Pacemaker_Administration/troubleshooting.rst b/doc/sphinx/Pacemaker_Administration/troubleshooting.rst index 53970a0f94..c740361e9a 100644 --- a/doc/sphinx/Pacemaker_Administration/troubleshooting.rst +++ b/doc/sphinx/Pacemaker_Administration/troubleshooting.rst @@ -1,67 +1,73 @@ +.. index:: troubleshooting + Troubleshooting Cluster Problems -------------------------------- +.. index:: logging, pacemaker.log + Logging ####### Pacemaker by default logs messages of notice severity and higher to the system log, and messages of info severity and higher to the detail log, which by default is ``/var/log/pacemaker/pacemaker.log``. Logging options can be controlled via environment variables at Pacemaker start-up. Where these are set varies by operating system (often ``/etc/sysconfig/pacemaker`` or ``/etc/default/pacemaker``). Because cluster problems are often highly complex, involving multiple machines, cluster daemons, and managed services, Pacemaker logs rather verbosely to provide as much context as possible. It is an ongoing priority to make these logs more user-friendly, but by necessity there is a lot of obscure, low-level information that can make them difficult to follow. The default log rotation configuration shipped with Pacemaker (typically installed in ``/etc/logrotate.d/pacemaker``) rotates the log when it reaches 100MB in size, or weekly, whichever comes first. If you configure debug or (Heaven forbid) trace-level logging, the logs can grow enormous quite quickly. Because rotated logs are by default named with the year, month, and day only, this can cause name collisions if your logs exceed 100MB in a single day. You can add ``dateformat -%Y%m%d-%H`` to the rotation configuration to avoid this. +.. index:: transition + Transitions ########### A key concept in understanding how a Pacemaker cluster functions is a *transition*. A transition is a set of actions that need to be taken to bring the cluster from its current state to the desired state (as expressed by the configuration). Whenever a relevant event happens (a node joining or leaving the cluster, a resource failing, etc.), the controller will ask the scheduler to recalculate the status of the cluster, which generates a new transition. The controller then performs the actions in the transition in the proper order. Each transition can be identified in the logs by a line like: .. code-block: none notice: Calculated transition 19, saving inputs in /var/lib/pacemaker/pengine/pe-input-1463.bz2 The file listed as the "inputs" is a snapshot of the cluster configuration and state at that moment (the CIB). This file can help determine why particular actions were scheduled. The ``crm_simulate`` command, described in :ref:`crm_simulate`, can be used to replay the file. Further Information About Troubleshooting ######################################### Andrew Beekhof wrote a series of articles about troubleshooting in his blog, `The Cluster Guy `_: * `Debugging Pacemaker `_ * `Debugging the Policy Engine `_ * `Pacemaker Logging `_ The articles were written for an earlier version of Pacemaker, so many of the specific names and log messages to look for have changed, but the concepts are still valid. diff --git a/doc/sphinx/Pacemaker_Administration/upgrading.rst b/doc/sphinx/Pacemaker_Administration/upgrading.rst index 1d6f0f68ad..b31cb24567 100644 --- a/doc/sphinx/Pacemaker_Administration/upgrading.rst +++ b/doc/sphinx/Pacemaker_Administration/upgrading.rst @@ -1,485 +1,505 @@ +.. index:: upgrade + Upgrading a Pacemaker Cluster ----------------------------- +.. index:: version + Pacemaker Versioning #################### Pacemaker has an overall release version, plus separate version numbers for certain internal components. +.. index:: + single: version; release + * **Pacemaker release version:** This version consists of three numbers (*x.y.z*). The major version number (the *x* in *x.y.z*) increases when at least some rolling upgrades are not possible from the previous major version. For example, a rolling upgrade from 1.0.8 to 1.1.15 should always be supported, but a rolling upgrade from 1.0.8 to 2.0.0 may not be possible. The minor version (the *y* in *x.y.z*) increases when there are significant changes in cluster default behavior, tool behavior, and/or the API interface (for software that utilizes Pacemaker libraries). The main benefit is to alert you to pay closer attention to the release notes, to see if you might be affected. The release counter (the *z* in *x.y.z*) is increased with all public releases of Pacemaker, which typically include both bug fixes and new features. +.. index:: + single: feature set + single: version; feature set + * **CRM feature set:** This version number applies to the communication between full cluster nodes, and is used to avoid problems in mixed-version clusters. The major version number increases when nodes with different versions would not work (rolling upgrades are not allowed). The minor version number increases when mixed-version clusters are allowed only during rolling upgrades. The minor-minor version number is ignored, but allows resource agents to detect cluster support for various features. [#]_ Pacemaker ensures that the longest-running node is the cluster's DC. This ensures new features are not enabled until all nodes are upgraded to support them. +.. index:: + single: version; Pacemaker Remote protocol + * **Pacemaker Remote protocol version:** This version applies to communication between a Pacemaker Remote node and the cluster. It increases when an older cluster node would have problems hosting the connection to a newer Pacemaker Remote node. To avoid these problems, Pacemaker Remote nodes will accept connections only from cluster nodes with the same or newer Pacemaker Remote protocol version. Unlike with CRM feature set differences between full cluster nodes, mixed Pacemaker Remote protocol versions between Pacemaker Remote nodes and full cluster nodes are fine, as long as the Pacemaker Remote nodes have the older version. This can be useful, for example, to host a legacy application in an older operating system version used as a Pacemaker Remote node. +.. index:: + single: version; XML schema + * **XML schema version:** Pacemaker’s configuration syntax — what's allowed in the Configuration Information Base (CIB) — has its own version. This allows the configuration syntax to evolve over time while still allowing clusters with older configurations to work without change. + +.. index:: + single: upgrade; methods + Upgrading Cluster Software ########################## There are three approaches to upgrading a cluster, each with advantages and disadvantages. .. table:: **Upgrade Methods** +---------------------------------------------------+----------+----------+--------+---------+----------+----------+ | Method | Available| Can be | Service| Service | Exercises| Allows | | | between | used with| outage | recovery| failover | change of| | | all | Pacemaker| during | during | logic | messaging| | | versions | Remote | upgrade| upgrade | | layer | | | | nodes | | | | [#]_ | +===================================================+==========+==========+========+=========+==========+==========+ | Complete cluster shutdown | yes | yes | always | N/A | no | yes | - | | | | | | | | - | .. index:: | | | | | | | - | pair: cluster; upgrade with shutdown | | | | | | | - | pair: upgrade; upgrade with shutdown | | | | | | | +---------------------------------------------------+----------+----------+--------+---------+----------+----------+ | Rolling (node by node) | no | yes | always | yes | yes | no | | | | | [#]_ | | | | - | | | | | | | | - | .. index:: | | | | | | | - | pair: cluster; rolling upgrade | | | | | | | - | pair: upgrade; rolling upgrade | | | | | | | +---------------------------------------------------+----------+----------+--------+---------+----------+----------+ | Detach and reattach | yes | no | only | no | no | yes | | | | | due to | | | | | | | | failure| | | | - | | | | | | | | - | .. index:: | | | | | | | - | pair: cluster; upgrade with detach and reattach| | | | | | | - | pair: upgrade; upgrade with detach and reattach| | | | | | | +---------------------------------------------------+----------+----------+--------+---------+----------+----------+ + +.. index:: + single: upgrade; shutdown + Complete Cluster Shutdown _________________________ In this scenario, one shuts down all cluster nodes and resources, then upgrades all the nodes before restarting the cluster. #. On each node: a. Shutdown the cluster software (pacemaker and the messaging layer). #. Upgrade the Pacemaker software. This may also include upgrading the messaging layer and/or the underlying operating system. #. Check the configuration with the ``crm_verify`` tool. #. On each node: a. Start the cluster software. Currently, only Corosync version 2 and greater is supported as the cluster layer, but if another stack is supported in the future, the stack does not need to be the same one before the upgrade. One variation of this approach is to build a new cluster on new hosts. This allows the new version to be tested beforehand, and minimizes downtime by having the new nodes ready to be placed in production as soon as the old nodes are shut down. + +.. index:: + single: upgrade; rolling upgrade + Rolling (node by node) ______________________ In this scenario, each node is removed from the cluster, upgraded, and then brought back online, until all nodes are running the newest version. Special considerations when planning a rolling upgrade: * If you plan to upgrade other cluster software -- such as the messaging layer -- at the same time, consult that software's documentation for its compatibility with a rolling upgrade. * If the major version number is changing in the Pacemaker version you are upgrading to, a rolling upgrade may not be possible. Read the new version's release notes (as well the information here) for what limitations may exist. * If the CRM feature set is changing in the Pacemaker version you are upgrading to, you should run a mixed-version cluster only during a small rolling upgrade window. If one of the older nodes drops out of the cluster for any reason, it will not be able to rejoin until it is upgraded. * If the Pacemaker Remote protocol version is changing, all cluster nodes should be upgraded before upgrading any Pacemaker Remote nodes. See the ClusterLabs wiki's `release calendar `_ to figure out whether the CRM feature set and/or Pacemaker Remote protocol version changed between the the Pacemaker release versions in your rolling upgrade. To perform a rolling upgrade, on each node in turn: #. Put the node into standby mode, and wait for any active resources to be moved cleanly to another node. (This step is optional, but allows you to deal with any resource issues before the upgrade.) #. Shutdown the cluster software (pacemaker and the messaging layer) on the node. #. Upgrade the Pacemaker software. This may also include upgrading the messaging layer and/or the underlying operating system. #. If this is the first node to be upgraded, check the configuration with the ``crm_verify`` tool. #. Start the messaging layer. This must be the same messaging layer (currently only Corosync version 2 and greater is supported) that the rest of the cluster is using. .. note:: Even if a rolling upgrade from the current version of the cluster to the newest version is not directly possible, it may be possible to perform a rolling upgrade in multiple steps, by upgrading to an intermediate version first. .. table:: **Version Compatibility Table** +-------------------------+---------------------------+ | Version being Installed | Oldest Compatible Version | +=========================+===========================+ | Pacemaker 2.y.z | Pacemaker 1.1.11 [#]_ | +-------------------------+---------------------------+ | Pacemaker 1.y.z | Pacemaker 1.0.0 | +-------------------------+---------------------------+ | Pacemaker 0.7.z | Pacemaker 0.6.z | +-------------------------+---------------------------+ +.. index:: + single: upgrade; detach and reattach + Detach and Reattach ___________________ The reattach method is a variant of a complete cluster shutdown, where the resources are left active and get re-detected when the cluster is restarted. This method may not be used if the cluster contains any Pacemaker Remote nodes. #. Tell the cluster to stop managing services. This is required to allow the services to remain active after the cluster shuts down. .. code-block:: none # crm_attribute --name maintenance-mode --update true #. On each node, shutdown the cluster software (pacemaker and the messaging layer), and upgrade the Pacemaker software. This may also include upgrading the messaging layer. While the underlying operating system may be upgraded at the same time, that will be more likely to cause outages in the detached services (certainly, if a reboot is required). #. Check the configuration with the ``crm_verify`` tool. #. On each node, start the cluster software. Currently, only Corosync version 2 and greater is supported as the cluster layer, but if another stack is supported in the future, the stack does not need to be the same one before the upgrade. #. Verify that the cluster re-detected all resources correctly. #. Allow the cluster to resume managing resources again: .. code-block:: none # crm_attribute --name maintenance-mode --delete .. note:: While the goal of the detach-and-reattach method is to avoid disturbing running services, resources may still move after the upgrade if any resource's location is governed by a rule based on transient node attributes. Transient node attributes are erased when the node leaves the cluster. A common example is using the ``ocf:pacemaker:ping`` resource to set a node attribute used to locate other resources. +.. index:: + pair: upgrade; CIB + Upgrading the Configuration ########################### -.. index:: - pair: upgrading; configuration - The CIB schema version can change from one Pacemaker version to another. After cluster software is upgraded, the cluster will continue to use the older schema version that it was previously using. This can be useful, for example, when administrators have written tools that modify the configuration, and are based on the older syntax. [#]_ However, when using an older syntax, new features may be unavailable, and there is a performance impact, since the cluster must do a non-persistent configuration upgrade before each transition. So while using the old syntax is possible, it is not advisable to continue using it indefinitely. Even if you wish to continue using the old syntax, it is a good idea to follow the upgrade procedure outlined below, except for the last step, to ensure that the new software has no problems with your existing configuration (since it will perform much the same task internally). If you are brave, it is sufficient simply to run ``cibadmin --upgrade``. A more cautious approach would proceed like this: #. Create a shadow copy of the configuration. The later commands will automatically operate on this copy, rather than the live configuration. .. code-block:: none # crm_shadow --create shadow +.. index:: + single: configuration; verify + #. Verify the configuration is valid with the new software (which may be stricter about syntax mistakes, or may have dropped support for deprecated features): - .. index:: - pair: verify; configuration - .. code-block:: none # crm_verify --live-check #. Fix any errors or warnings. #. Perform the upgrade: .. code-block:: none # cibadmin --upgrade #. If this step fails, there are three main possibilities: a. The configuration was not valid to start with (did you do steps 2 and 3?). #. The transformation failed; `report a bug `_. #. The transformation was successful but produced an invalid result. If the result of the transformation is invalid, you may see a number of errors from the validation library. If these are not helpful, visit the `Validation FAQ wiki page `_ and/or try the manual upgrade procedure described below. #. Check the changes: .. code-block:: none # crm_shadow --diff If at this point there is anything about the upgrade that you wish to fine-tune (for example, to change some of the automatic IDs), now is the time to do so: .. code-block:: none # crm_shadow --edit This will open the configuration in your favorite editor (whichever is specified by the standard ``$EDITOR`` environment variable). #. Preview how the cluster will react: .. code-block:: none # crm_simulate --live-check --save-dotfile shadow.dot -S # dot -Tsvg shadow.dot -o shadow.svg You can then view shadow.svg with any compatible image viewer or web browser. Verify that either no resource actions will occur or that you are happy with any that are scheduled. If the output contains actions you do not expect (possibly due to changes to the score calculations), you may need to make further manual changes. See :ref:`crm_simulate` for further details on how to interpret the output of ``crm_simulate`` and ``dot``. #. Upload the changes: .. code-block:: none # crm_shadow --commit shadow --force In the unlikely event this step fails, please report a bug. .. note:: It is also possible to perform the configuration upgrade steps manually: #. Locate the ``upgrade*.xsl`` conversion scripts provided with the source code. These will often be installed in a location such as ``/usr/share/pacemaker``, or may be obtained from the `source repository `_. #. Run the conversion scripts that apply to your older version, for example: .. code-block:: none # xsltproc /path/to/upgrade06.xsl config06.xml > config10.xml #. Locate the ``pacemaker.rng`` script (from the same location as the xsl files). #. Check the XML validity: .. code-block:: none # xmllint --relaxng /path/to/pacemaker.rng config10.xml The advantage of this method is that it can be performed without the cluster running, and any validation errors are often more informative. What Changed in 2.0 ################### The main goal of the 2.0 release was to remove support for deprecated syntax, along with some small changes in default configuration behavior and tool behavior. Highlights: * Only Corosync version 2 and greater is now supported as the underlying cluster layer. Support for Heartbeat and Corosync 1 (including CMAN) is removed. * The Pacemaker detail log file is now stored in ``/var/log/pacemaker/pacemaker.log`` by default. * The record-pending cluster property now defaults to true, which allows status tools such as crm_mon to show operations that are in progress. * Support for a number of deprecated build options, environment variables, and configuration settings has been removed. * The ``master`` tag has been deprecated in favor of using the ``clone`` tag with the new ``promotable`` meta-attribute set to ``true``. "Master/slave" clone resources are now referred to as "promotable" clone resources, though it will take longer for the full terminology change to be completed. * The public API for Pacemaker libraries that software applications can use has changed significantly. For a detailed list of changes, see the release notes and the `Pacemaker 2.0 Changes `_ page on the ClusterLabs wiki. What Changed in 1.0 ################### New ___ * Failure timeouts. * New section for resource and operation defaults. * Tool for making offline configuration changes. * ``Rules``, ``instance_attributes``, ``meta_attributes`` and sets of operations can be defined once and referenced in multiple places. * The CIB now accepts XPath-based create/modify/delete operations. See ``cibadmin --help``. * Multi-dimensional colocation and ordering constraints. * The ability to connect to the CIB from non-cluster machines. * Allow recurring actions to be triggered at known times. Changed _______ * Syntax * All resource and cluster options now use dashes (-) instead of underscores (_) * ``master_slave`` was renamed to ``master`` * The ``attributes`` container tag was removed * The operation field ``pre-req`` has been renamed ``requires`` * All operations must have an ``interval``, ``start``/``stop`` must have it set to zero * The ``stonith-enabled`` option now defaults to true. * The cluster will refuse to start resources if ``stonith-enabled`` is true (or unset) and no STONITH resources have been defined * The attributes of colocation and ordering constraints were renamed for clarity. * ``resource-failure-stickiness`` has been replaced by ``migration-threshold``. * The parameters for command-line tools have been made consistent * Switched to 'RelaxNG' schema validation and 'libxml2' parser * id fields are now XML IDs which have the following limitations: * id's cannot contain colons (:) * id's cannot begin with a number * id's must be globally unique (not just unique for that tag) * Some fields (such as those in constraints that refer to resources) are IDREFs. This means that they must reference existing resources or objects in order for the configuration to be valid. Removing an object which is referenced elsewhere will therefore fail. * The CIB representation, from which a MD5 digest is calculated to verify CIBs on the nodes, has changed. This means that every CIB update will require a full refresh on any upgraded nodes until the cluster is fully upgraded to 1.0. This will result in significant performance degradation and it is therefore highly inadvisable to run a mixed 1.0/0.6 cluster for any longer than absolutely necessary. * Ping node information no longer needs to be added to ``ha.cf``. Simply include the lists of hosts in your ping resource(s). Removed _______ * Syntax * It is no longer possible to set resource meta options as top-level attributes. Use meta-attributes instead. * Resource and operation defaults are no longer read from ``crm_config``. .. rubric:: Footnotes .. [#] Before CRM feature set 3.1.0 (Pacemaker 2.0.0), the minor-minor version number was treated the same as the minor version. .. [#] Currently, Corosync version 2 and greater is the only supported cluster stack, but other stacks have been supported by past versions, and may be supported by future versions. .. [#] Any active resources will be moved off the node being upgraded, so there will be at least a brief outage unless all resources can be migrated "live". .. [#] Rolling upgrades from Pacemaker 1.1.z to 2.y.z are possible only if the cluster uses corosync version 2 or greater as its messaging layer, and the Cluster Information Base (CIB) uses schema 1.0 or higher in its ``validate-with`` property. .. [#] As of Pacemaker 2.0.0, only schema versions pacemaker-1.0 and higher are supported (excluding pacemaker-1.1, which was an experimental schema now known as pacemaker-next).