Chapter 53. Pacemaker cluster properties
Cluster properties control how the cluster behaves when confronted with situations that might occur during cluster operation.
53.1. 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.
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.
| Option | Default | Description |
|---|---|---|
|
| 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. |
|
| -1 (unlimited) | The number of migration jobs that the cluster is allowed to execute in parallel on a node. |
|
| 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 |
|
| true | Indicates whether resources can run on any node by default. |
|
| 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. |
|
| 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. |
|
| true | Indicates whether deleted resources should be stopped. |
|
| true | Indicates whether deleted actions should be canceled. |
|
| true |
Indicates whether a failure to start a resource on a particular node prevents further start attempts on that node. When set to
Setting |
|
| -1 (all) | The number of scheduler inputs resulting in ERRORs to save. Used when reporting problems. |
|
| -1 (all) | The number of scheduler inputs resulting in WARNINGs to save. Used when reporting problems. |
|
| -1 (all) | The number of "normal" scheduler inputs to save. Used when reporting problems. |
|
| The messaging stack on which Pacemaker is currently running. Used for informational and diagnostic purposes; not user-configurable. | |
|
| Version of Pacemaker on the cluster’s Designated Controller (DC). Used for diagnostic purposes; not user-configurable. | |
|
| 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 |
|
| 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. |
|
| 20min | The time after which to give up trying to shut down gracefully and just exit. Advanced use only. |
|
| false | Should the cluster stop all resources. |
|
| false |
Indicates whether the cluster can use access control lists, as set with the |
|
| default | Indicates whether and how the cluster will take utilization attributes into account when determining resource placement on cluster nodes. |
|
| none | When used in conjunction with a health resource agent, controls how Pacemaker responds to changes in node health. Allowed values:
*
*
*
* |
53.2. Setting and removing cluster properties
To set the value of a cluster property, use the following pcs command.
pcs property set property=value
For example, to set the value of symmetric-cluster to false, use the following command.
# pcs property set symmetric-cluster=falseYou can remove a cluster property from the configuration with the following command.
pcs property unset property
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.
# pcs property set symmetic-cluster=53.3. 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.
pcs property list
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.
pcs property list --all
To display the current value of a specific cluster property, use the following command.
pcs property show property
For example, to display the current value of the cluster-infrastructure property, execute the following command:
# pcs property show cluster-infrastructure
Cluster Properties:
cluster-infrastructure: cmanFor 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.
pcs property [list|show] --defaults
53.4. Exporting cluster properties as pcs commands
As of Red Hat Enterprise Linux 8.9, 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.
# pcs property set migration-limit=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 config --output-format=cmd
pcs property set --force -- \
migration-limit=10 \
placement-strategy=minimal