Chapter 23. Pacemaker cluster properties
Chapter 23. Pacemaker cluster properties Cluster properties control how the cluster behaves when confronted with situations that might occur during cluster operation. 23.1. Summary of cluster properties and options The following table summaries the Pacemaker cluster properties, showing the default values of the properties and the possible values you can set for those properties. There are additional cluster properties that determine fencing behavior. For information about these properties, see the table of cluster properties that determine fencing behavior in General properties of fencing devices . Note In addition to the properties described in this table, there are additional cluster properties that are exposed by the cluster software. For these properties, it is recommended that you not change their values from their defaults. Table 23.1. Cluster Properties Option Default Description batch-limit 0 The number of resource actions that the cluster is allowed to execute in parallel. The "correct" value will depend on the speed and load of your network and cluster nodes. The default value of 0 means that the cluster will dynamically impose a limit when any node has a high CPU load. migration-limit -1 (unlimited) The number of migration jobs that the cluster is allowed to execute in parallel on a node. no-quorum-policy stop What to do when the cluster does not have quorum. Allowed values: * ignore - continue all resource management * freeze - continue resource management, but do not recover resources from nodes not in the affected partition * stop - stop all resources in the affected cluster partition * suicide - fence all nodes in the affected cluster partition * demote - if a cluster partition loses quorum, demote any promoted resources and stop all other resources symmetric-cluster true Indicates whether resources can run on any node by default. cluster-delay 60s Round trip delay over the network (excluding action execution). The "correct" value will depend on the speed and load of your network and cluster nodes. dc-deadtime 20s How long to wait for a response from other nodes during startup. The "correct" value will depend on the speed and load of your network and the type of switches used. stop-orphan-resources true Indicates whether deleted resources should be stopped. stop-orphan-actions true Indicates whether deleted actions should be canceled. start-failure-is-fatal true Indicates whether a failure to start a resource on a particular node prevents further start attempts on that node. When set to false , the cluster will decide whether to try starting on the same node again based on the resource's current failure count and migration threshold. For information about setting the migration-threshold option for a resource, see Configuring resource meta options . Setting start-failure-is-fatal to false incurs the risk that this will allow one faulty node that is unable to start a resource to hold up all dependent actions. This is why start-failure-is-fatal defaults to true. The risk of setting start-failure-is-fatal=false can be mitigated by setting a low migration threshold so that other actions can proceed after that many failures. pe-error-series-max -1 (all) The number of scheduler inputs resulting in ERRORs to save. Used when reporting problems. pe-warn-series-max -1 (all) The number of scheduler inputs resulting in WARNINGs to save. Used when reporting problems. pe-input-series-max -1 (all) The number of "normal" scheduler inputs to save. Used when reporting problems. cluster-infrastructure The messaging stack on which Pacemaker is currently running. Used for informational and diagnostic purposes; not user-configurable. dc-version Version of Pacemaker on the cluster's Designated Controller (DC). Used for diagnostic purposes; not user-configurable. cluster-recheck-interval 15 minutes Pacemaker is primarily event-driven, and looks ahead to know when to recheck the cluster for failure timeouts and most time-based rules. Pacemaker will also recheck the cluster after the duration of inactivity specified by this property. This cluster recheck has two purposes: rules with date-spec are guaranteed to be checked this often, and it serves as a fail-safe for some kinds of scheduler bugs. A value of 0 disables this polling; positive values indicate a time interval. maintenance-mode false Maintenance Mode tells the cluster to go to a "hands off" mode, and not start or stop any services until told otherwise. When maintenance mode is completed, the cluster does a sanity check of the current state of any services, and then stops or starts any that need it. shutdown-escalation 20min The time after which to give up trying to shut down gracefully and just exit. Advanced use only. stop-all-resources false Should the cluster stop all resources. enable-acl false Indicates whether the cluster can use access control lists, as set with the pcs acl command. placement-strategy default Indicates whether and how the cluster will take utilization attributes into account when determining resource placement on cluster nodes. node-health-strategy none When used in conjunction with a health resource agent, controls how Pacemaker responds to changes in node health. Allowed values: * none - Do not track node health. * migrate-on-red - Resources are moved off any node where a health agent has determined that the node's status is red , based on the local conditions that the agent monitors. * only-green - Resources are moved off any node where a health agent has determined that the node's status is yellow or red , based on the local conditions that the agent monitors. * progressive , custom - Advanced node health strategies that offer finer-grained control over the cluster's response to health conditions according to the internal numeric values of health attributes. 23.2. Setting and removing cluster properties To set the value of a cluster property, use the following pcs command. For example, to set the value of symmetric-cluster to false , use the following command. You can remove a cluster property from the configuration with the following command. Alternately, you can remove a cluster property from a configuration by leaving the value field of the pcs property set command blank. This restores that property to its default value. For example, if you have previously set the symmetric-cluster property to false , the following command removes the value you have set from the configuration and restores the value of symmetric-cluster to true , which is its default value. 23.3. Querying cluster property settings In most cases, when you use the pcs command to display values of the various cluster components, you can use pcs list or pcs show interchangeably. In the following examples, pcs list is the format used to display an entire list of all settings for more than one property, while pcs show is the format used to display the values of a specific property. To display the values of the property settings that have been set for the cluster, use the following pcs command. To display all of the values of the property settings for the cluster, including the default values of the property settings that have not been explicitly set, use the following command. To display the current value of a specific cluster property, use the following command. For example, to display the current value of the cluster-infrastructure property, execute the following command: For informational purposes, you can display a list of all of the default values for the properties, whether they have been set to a value other than the default or not, by using the following command. 23.4. Exporting cluster properties as pcs commands As of Red Hat Enterprise Linux 9.3, you can display the pcs commands that can be used to re-create configured cluster properties on a different system using the --output-format=cmd option of the pcs property config command. The following command sets the migration-limit cluster property to 10. After you set the cluster property, the following command displays the pcs command you can use to set the cluster property on a different system.
pcs property set property = value pcs property set symmetric-cluster=false pcs property unset property pcs property set symmetic-cluster= pcs property list pcs property list --all pcs property show property pcs property show cluster-infrastructure Cluster Properties: cluster-infrastructure: cman pcs property [list|show] --defaults pcs property set migration-limit=10 pcs property config --output-format=cmd pcs property set --force -- migration-limit=10 placement-strategy=minimal