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How do you move resources in a Pacemaker?
You can use the pcs resource relocate run command to move a resource to its preferred node, as determined by current cluster status, constraints, location of resources and other settings. For information on this command, see Section 7.1. 2, “Moving a Resource to its Preferred Node”.
How do I restart computer resources?
Service Management Quick Start pcs resource restart resource_name to restart a running resource. pcs resource move resource_name to move a running resource to a new node. find_service resource_name to find which node a resource is on. find_service is a home-built wrapper for pcs commands.
What is resource stickiness?
For complex services such as databases, this period can be quite long. To address this, Pacemaker has the concept of resource stickiness, which controls how strongly a service prefers to stay running where it is. You may like to think of it as the “cost” of any downtime.
How do you remove a node from a pacemaker cluster?
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.
- 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:
What is Pacemaker log?
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.
What are order constraints?
Order constraints determine the order in which the resources run. You can configure an order constraint to determine the order in which resources start and stop.
Why is node 1 important in a pacemaker cluster?
The complexity arises in that the node chosen by the cluster also takes into effect the location preferences of resources with which the resource is collocated. If resource A must be collocated with resource B, and B can only run on node1, then it doesn’t matter that A prefers node2.
How to build a high available failover cluster with pacemaker?
Just assume that this is what you have to open: Open UDP-ports 5404 and 5405 for Corosync: Save the changes you made to iptables: When testing the cluster, you could temporarily disable the firewall to be sure that blocked ports aren’t causing unexpected problems.
How are location constraints used in pacemaker cluster?
Location constraints, which control the nodes on which resources or resource groups may run. Colocation constraints, which control whether two resources or resource groups may run on the same node. Resource groups are the easiest way to set constraints on resources.
Which is CentOS 7 OS does pacemaker work on?
The example is based on CentOS 7 but should work without modifications on basically all el6 and el7 platforms and with some minor modifications on other Linux distributions as well.