This is a text-only version of the following page on https://raymii.org: --- Title : Corosync Notes Author : Remy van Elst Date : 02-11-2013 URL : https://raymii.org/s/snippets/Corosync_Notes.html Format : Markdown/HTML --- What are all the components?

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* Pacemaker: Resource manager * Corosync: Messaging layer * Heartbeat: Also a messaging layer * Resource Agents: Scripts that know how to control various services Pacemaker is the thing that starts and stops services (like your database or mail server) and contains logic for ensuring both that they are running, and that they are only running in one location (to avoid data corruption). But it cant do that without the ability to talk to instances of itself on the other node(s), which is where Heartbeat and/or Corosync come in. Think of Heartbeat and Corosync as dbus but between nodes. Somewhere that any node can throw messages on and know that they'll be received by all its peers. This bus also ensures that everyone agrees who is (and is not) connected to the bus and tells Pacemaker when that list changes. If you want to make sure that the commands below execute on all cluster nodes, append the `-w` parameter to the crm command, it stands for `wait`. Like so: `crm -w resource stop virtual-ip`. #### Get corosync cluster status crm_mon --one-shot -V or crm status #### Put node on standby Execute on node you want to put in standby. crm node standby Put node online again (after standby) Execute on node you want to put online again. crm node online If you want to put a node online or in standby from another cluster node, append the node name to the commands above, like so: crm node standby NODENAME #### Disable stonith (shoot the other node in the head) crm configure property stonith-enabled=false #### Add a simple shared IP resource crm configure primitive failover-ip ocf:heartbeat:IPaddr2 params ip=10.0.2.10 cidr_netmask=32 op monitor interval=10s This tells Pacemaker three things about the resource you want to add. The first field, ocf, is the standard to which the resource script conforms to and where to find it. The second field is specific to OCF resources and tells the cluster which namespace to find the resource script in, in this case heartbeat. The last field indicates the name of the resource script. ##### View all available resource classes crm ra classes Output: heartbeat lsb ocf / heartbeat pacemaker stonith ##### View all the OCF resource agents provided by Pacemaker and Heartbeat crm ra list ocf pacemaker Output: ClusterMon Dummy HealthCPU HealthSMART Stateful SysInfo SystemHealth controld o2cb ping pingd For Heartbeat: crm ra list ocf heartbeat Output: AoEtarget AudibleAlarm CTDB ClusterMon Delay Dummy EvmsSCC Evmsd Filesystem ICP IPaddr IPaddr2 IPsrcaddr IPv6addr LVM LinuxSCSI MailTo ManageRAID ManageVE Pure-FTPd Raid1 Route SAPDatabase SAPInstance SendArp ServeRAID SphinxSearchDaemon Squid Stateful SysInfo VIPArip VirtualDomain WAS WAS6 WinPopup Xen Xinetd anything apache conntrackd db2 drbd eDir88 ethmonitor exportfs fio iSCSILogicalUnit iSCSITarget ids iscsi jboss ldirectord lxc mysql mysql-proxy nfsserver nginx oracle oralsnr pgsql pingd portblock postfix proftpd rsyncd scsi2reservation sfex symlink syslog-ng tomcat vmware #### Add simple apache resource crm configure primitive apache-ha ocf:heartbeat:apache params configfile=/etc/apache2/apachd2.conf op monitor interval=1min #### Make sure Apache and the Virtual IP are on the same node crm configure colocation apache-with-ip inf: apache-ha failover-ip #### Make sure that when either one crashes they both are recovered on another node: crm configure order apache-after-ip mandatory: failover-ip apache-ha #### Stop a resource crm resource stop $`RESOURCENAME #### Delete a resource crm configure delete $RESOURCENAME #### Remove a node from the cluster crm node delete $NODENAME #### Stop all cluster resources crm configure property stop-all-resources=true #### Clean up warnings and errors for a resource crm resource cleanup $RESOURCENAME #### Erase entire config crm configure erase #### Disable quorum (when using only two nodes) crm configure property no-quorum-policy=ignore #### Let the shared IP go back to the primary node when it is up after failover crom configure rsc_defaults resource-stickiness=100 #### sysctl In order to be able to bind on a IP which is not yet defined on the system, we need to enable non local binding at the kernel level. Temporary: echo 1 > /proc/sys/net/ipv4/ip_nonlocal_bind Permanent: Add this to `/etc/sysctl.conf`: net.ipv4.ip_nonlocal_bind = 1 Enable with: sysctl -p ### Sources * [http://clusterlabs.org/doc/en-US/Pacemaker/1.1-crmsh/html-single/Clusters _from_ Scratch/index.html][2] * * * * [1]: https://www.digitalocean.com/?refcode=7435ae6b8212 [2]: http://clusterlabs.org/doc/en-US/Pacemaker/1.1-crmsh/html-single/Clusters_from_Scratch/index.html --- License: All the text on this website is free as in freedom unless stated otherwise. This means you can use it in any way you want, you can copy it, change it the way you like and republish it, as long as you release the (modified) content under the same license to give others the same freedoms you've got and place my name and a link to this site with the article as source. This site uses Google Analytics for statistics and Google Adwords for advertisements. You are tracked and Google knows everything about you. 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