Pacemaker configuration for an Oracle database and its listener

Preamble

In order to test a real life high availability scenario you might want to create an operating system cluster to simulate what you could have in production. Where I work the standard tool to manage OS cluster is Veritas Cluster Server (VCS). It’s a nice tool but its installation require a license key that is not easy to get to test the product.

A free alternative is anyway available and is called Pacemaker. In this blog post I will setup a completer cluster with a virtual IP address (192.168.56.99), a LVM volume group (vg01), a file system (/u01) and finally an Oracle database and its associated listener. The listener will obviously listen on the virtual IP address of the cluster.

For testing I have used two virtual machines running Oracle Linux Server release 7.2 64 bits and Oracle Enterprise edition 12cR2 (12.2.0.1.0) but any Oracle release can be used. The virtual servers are:

  • server2.domain.com using non routable IP address 192.168.56.102
  • server3.domain.com using non routable IP address 192.168.56.103

The command to control and manage Pacemaker is pcs.

Pacemaker installation

Install PCS that control and configure pacemaker and corosync with:

[root@server2 ~]# yum -y install pcs

Pacemaker and corosync will be installed as well:

Dependencies Resolved
 
===========================================================================================================================================================================================================
 Package                                                           Arch                                 Version                                             Repository                                Size
===========================================================================================================================================================================================================
Installing:
 pcs                                                               x86_64                               0.9.152-10.0.1.el7                                  ol7_latest                               5.0 M
Installing for dependencies:
 corosync                                                          x86_64                               2.4.0-4.el7                                         ol7_latest                               212 k
 corosynclib                                                       x86_64                               2.4.0-4.el7                                         ol7_latest                               125 k
 libqb                                                             x86_64                               1.0-1.el7                                           ol7_latest                                91 k
 libtool-ltdl                                                      x86_64                               2.4.2-22.el7_3                                      ol7_latest                                48 k
 libxslt                                                           x86_64                               1.1.28-5.0.1.el7                                    ol7_latest                               241 k
 libyaml                                                           x86_64                               0.1.4-11.el7_0                                      ol7_latest                                54 k
 nano                                                              x86_64                               2.3.1-10.el7                                        ol7_latest                               438 k
 net-snmp-libs                                                     x86_64                               1:5.7.2-24.el7_3.2                                  ol7_latest                               747 k
 pacemaker                                                         x86_64                               1.1.15-11.el7                                       ol7_latest                               441 k
 pacemaker-cli                                                     x86_64                               1.1.15-11.el7                                       ol7_latest                               319 k
 pacemaker-cluster-libs                                            x86_64                               1.1.15-11.el7                                       ol7_latest                                95 k
 pacemaker-libs                                                    x86_64                               1.1.15-11.el7                                       ol7_latest                               521 k
 perl-TimeDate                                                     noarch                               1:2.30-2.el7                                        ol7_latest                                51 k
 psmisc                                                            x86_64                               22.20-11.el7                                        ol7_latest                               140 k
 python-backports                                                  x86_64                               1.0-8.el7                                           ol7_latest                               5.2 k
 python-backports-ssl_match_hostname                               noarch                               3.4.0.2-4.el7                                       ol7_latest                                11 k
 python-clufter                                                    x86_64                               0.59.5-2.0.1.el7                                    ol7_latest                               349 k
 python-lxml                                                       x86_64                               3.2.1-4.el7                                         ol7_latest                               758 k
 python-setuptools                                                 noarch                               0.9.8-4.el7                                         ol7_latest                               396 k
 resource-agents                                                   x86_64                               3.9.5-82.el7                                        ol7_latest                               359 k
 ruby                                                              x86_64                               2.0.0.648-29.el7                                    ol7_latest                                68 k
 ruby-irb                                                          noarch                               2.0.0.648-29.el7                                    ol7_latest                                89 k
 ruby-libs                                                         x86_64                               2.0.0.648-29.el7                                    ol7_latest                               2.8 M
 rubygem-bigdecimal                                                x86_64                               1.2.0-29.el7                                        ol7_latest                                80 k
 rubygem-io-console                                                x86_64                               0.4.2-29.el7                                        ol7_latest                                51 k
 rubygem-json                                                      x86_64                               1.7.7-29.el7                                        ol7_latest                                76 k
 rubygem-psych                                                     x86_64                               2.0.0-29.el7                                        ol7_latest                                78 k
 rubygem-rdoc                                                      noarch                               4.0.0-29.el7                                        ol7_latest                               319 k
 rubygems                                                          noarch                               2.0.14.1-29.el7                                     ol7_latest                               215 k
 
Transaction Summary
===========================================================================================================================================================================================================

On all nodes:

[root@server2 ~]# systemctl start pcsd.service
[root@server2 ~]# systemctl enable pcsd.service
Created symlink from /etc/systemd/system/multi-user.target.wants/pcsd.service to /usr/lib/systemd/system/pcsd.service.

Change hacluster password on all nodes:

[root@server3 ~]# echo secure_password | passwd --stdin hacluster
Changing password for user hacluster.
passwd: all authentication tokens updated successfully.

Set authentication for pcs:

[root@server3 ~]# pcs cluster auth server2.domain.com server3.domain.com
Username: hacluster
Password:
server3.domain.com: Authorized
server2.domain.com: Authorized

Create your cluster (cluster01) on your two nodes with:

[root@server2 ~]# pcs cluster setup --start --name cluster01 server2.domain.com server3.domain.com
Destroying cluster on nodes: server2.domain.com, server3.domain.com...
server2.domain.com: Stopping Cluster (pacemaker)...
server3.domain.com: Stopping Cluster (pacemaker)...
server2.domain.com: Successfully destroyed cluster
server3.domain.com: Successfully destroyed cluster
 
Sending cluster config files to the nodes...
server2.domain.com: Succeeded
server3.domain.com: Succeeded
 
Starting cluster on nodes: server2.domain.com, server3.domain.com...
server2.domain.com: Starting Cluster...
server3.domain.com: Starting Cluster...
 
Synchronizing pcsd certificates on nodes server2.domain.com, server3.domain.com...
server3.domain.com: Success
server2.domain.com: Success
 
Restarting pcsd on the nodes in order to reload the certificates...
server3.domain.com: Success
server2.domain.com: Success

Check it with:

[root@server2 ~]# pcs status
Cluster name: cluster01
WARNING: no stonith devices and stonith-enabled is not false
Stack: unknown
Current DC: NONE
Last updated: Wed Apr 19 10:01:02 2017          Last change: Wed Apr 19 10:00:47 2017 by hacluster via crmd on server2.domain.com
 
2 nodes and 0 resources configured
 
Node server2.domain.com: UNCLEAN (offline)
Node server3.domain.com: UNCLEAN (offline)
 
No resources
 
 
Daemon Status:
  corosync: active/disabled
  pacemaker: active/disabled
  pcsd: active/enabled

Notice the WARNING above about missing stonish device…

Enable cluster with:

[root@server2 ~]# pcs cluster enable --all
server2.domain.com: Cluster Enabled
server3.domain.com: Cluster Enabled
[root@server2 ~]# pcs cluster status
Cluster Status:
 Stack: corosync
 Current DC: server2.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
 Last updated: Wed Apr 19 10:02:02 2017         Last change: Wed Apr 19 10:01:08 2017 by hacluster via crmd on server2.domain.com
 2 nodes and 0 resources configured
 
PCSD Status:
  server2.domain.com: Online
  server3.domain.com: Online

As documentation says:

STONITH is an acronym for “Shoot The Other Node In The Head” and it protects your data from being corrupted by rogue nodes or concurrent access.

This is also known as split brain, this simply allow multiple nodes to access same resource (like writing to a filesystem) at same time and simple goal is to avoid corruption… As the aim is to build something simple I will disable fencing with:

[root@server2 ~]# pcs property set stonith-enabled=false
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server2.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 10:02:53 2017          Last change: Wed Apr 19 10:02:49 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 0 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
No resources
 
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Pacemaker resources creation

To create a new resource you might want to know what are available ones in Pacemaker:

[root@server2 ~]# pcs resource list ocf:heartbeat
ocf:heartbeat:CTDB - CTDB Resource Agent
ocf:heartbeat:Delay - Waits for a defined timespan
ocf:heartbeat:Dummy - Example stateless resource agent
ocf:heartbeat:Filesystem - Manages filesystem mounts
ocf:heartbeat:IPaddr - Manages virtual IPv4 and IPv6 addresses (Linux specific version)
ocf:heartbeat:IPaddr2 - Manages virtual IPv4 and IPv6 addresses (Linux specific version)
ocf:heartbeat:IPsrcaddr - Manages the preferred source address for outgoing IP packets
ocf:heartbeat:LVM - Controls the availability of an LVM Volume Group
ocf:heartbeat:MailTo - Notifies recipients by email in the event of resource takeover
ocf:heartbeat:Route - Manages network routes
ocf:heartbeat:SendArp - Broadcasts unsolicited ARP announcements
ocf:heartbeat:Squid - Manages a Squid proxy server instance
ocf:heartbeat:VirtualDomain - Manages virtual domains through the libvirt virtualization framework
ocf:heartbeat:Xinetd - Manages a service of Xinetd
ocf:heartbeat:apache - Manages an Apache Web server instance
ocf:heartbeat:clvm - clvmd
ocf:heartbeat:conntrackd - This resource agent manages conntrackd
ocf:heartbeat:db2 - Resource Agent that manages an IBM DB2 LUW databases in Standard role as primitive or in HADR roles as master/slave configuration. Multiple partitions are supported.
ocf:heartbeat:dhcpd - Chrooted ISC DHCP server resource agent.
ocf:heartbeat:docker - Docker container resource agent.
ocf:heartbeat:ethmonitor - Monitors network interfaces
ocf:heartbeat:exportfs - Manages NFS exports
ocf:heartbeat:galera - Manages a galara instance
ocf:heartbeat:garbd - Manages a galera arbitrator instance
ocf:heartbeat:iSCSILogicalUnit - Manages iSCSI Logical Units (LUs)
ocf:heartbeat:iSCSITarget - iSCSI target export agent
ocf:heartbeat:iface-vlan - Manages VLAN network interfaces.
ocf:heartbeat:mysql - Manages a MySQL database instance
ocf:heartbeat:nagios - Nagios resource agent
ocf:heartbeat:named - Manages a named server
ocf:heartbeat:nfsnotify - sm-notify reboot notifications
ocf:heartbeat:nfsserver - Manages an NFS server
ocf:heartbeat:nginx - Manages an Nginx web/proxy server instance
ocf:heartbeat:oracle - Manages an Oracle Database instance
ocf:heartbeat:oralsnr - Manages an Oracle TNS listener
ocf:heartbeat:pgsql - Manages a PostgreSQL database instance
ocf:heartbeat:portblock - Block and unblocks access to TCP and UDP ports
ocf:heartbeat:postfix - Manages a highly available Postfix mail server instance
ocf:heartbeat:rabbitmq-cluster - rabbitmq clustered
ocf:heartbeat:redis - Redis server
ocf:heartbeat:rsyncd - Manages an rsync daemon
ocf:heartbeat:slapd - Manages a Stand-alone LDAP Daemon (slapd) instance
ocf:heartbeat:symlink - Manages a symbolic link
ocf:heartbeat:tomcat - Manages a Tomcat servlet environment instance

Virtual Ip address

Add resource, a virtual IP, to test your cluster. I have chosen to use the Host-only Virtualbox adapter as it is cluster nodes communication so eth0 on all my nodes. We have seen how to configure this with Oracle Enterprise Linux or Redhat:

[root@server2 ~]# pcs resource create virtualip IPaddr2 ip=192.168.56.99 cidr_netmask=24 nic=eth0 op monitor interval=10s
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server2.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 10:03:50 2017          Last change: Wed Apr 19 10:03:36 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 1 resource configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server2.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

You can check at OS level it has been done with:

[root@server2 ~]# ping -c 1 192.168.56.99
PING 192.168.56.99 (192.168.56.99) 56(84) bytes of data.
64 bytes from 192.168.56.99: icmp_seq=1 ttl=64 time=0.025 ms
 
--- 192.168.56.99 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.025/0.025/0.025/0.000 ms
[root@server2 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:47:54:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.102/24 brd 192.168.56.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 192.168.56.99/24 brd 192.168.56.255 scope global secondary eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::a00:27ff:fe47:5407/64 scope link
       valid_lft forever preferred_lft forever

Move virtual IP on server3.domain.com:

[root@server3 ~]# pcs resource move virtualip server3.domain.com
[root@server3 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server2.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 10:24:59 2017          Last change: Wed Apr 19 10:06:21 2017 by root via crm_resource on server3.domain.com
 
2 nodes and 1 resource configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

We see the IP address has been transferred to server3.domain.com:

[root@server3 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:b4:9d:bf brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.103/24 brd 192.168.56.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 192.168.56.99/24 brd 192.168.56.255 scope global secondary eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::a00:27ff:feb4:9dbf/64 scope link
       valid_lft forever preferred_lft forever

Volume group

I create a volume group (vg01) on a shared disk, I also mount the logical volume but this part is not yet required:

[root@server2 ~]# vgcreate vg01 /dev/sdb
  Physical volume "/dev/sdb" successfully created.
  Volume group "vg01" successfully created
[root@server2 ~]# lvcreate -n lvol01 -L 5G vg01
  Logical volume "lvol01" created.
[root@server2 ~]# mkfs -t xfs /dev/vg01/lvol01
meta-data=/dev/vg01/lvol01       isize=256    agcount=4, agsize=327680 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0, sparse=0
data     =                       bsize=4096   blocks=1310720, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@server2 ~]# mkdir /u01
[root@server2 ~]# systemctl daemon-reload
[root@server2 /]# mount -t xfs /dev/vg01/lvol01 /u01
[root@server2 /]# df /u01
Filesystem              1K-blocks  Used Available Use% Mounted on
/dev/mapper/vg01-lvol01   5232640 32928   5199712   1% /u01

I add the LVM resource to Pacemaker, I deliberately create it on server2.domain.com:

[root@server2 /]# pcs resource create vg01 LVM volgrpname=vg01
[root@server2 /]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 15:27:28 2017          Last change: Wed Apr 19 15:27:24 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server2.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

I try to move vg01 volume group to server3.domain.com:

[root@server2 ~]# pcs resource move vg01 server3.domain.com
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 15:31:17 2017          Last change: Wed Apr 19 15:31:04 2017 by root via crm_resource on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   FAILED server2.domain.com (blocked)
 
Failed Actions:
* vg01_stop_0 on server2.domain.com 'unknown error' (1): call=12, status=complete, exitreason='LVM: vg01 did not stop correctly',
    last-rc-change='Wed Apr 19 15:31:04 2017', queued=1ms, exec=10526ms
 
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

All this to show that it is not so easy and it requires a bit more of modification. I start by removing the volume group resource:

[root@server2 ~]# pcs resource delete vg01
Deleting Resource - vg01

On all nodes:

[root@server2 ~]# lvmconf --enable-halvm --services --startstopservices
Warning: Stopping lvm2-lvmetad.service, but it can still be activated by:
  lvm2-lvmetad.socket
Removed symlink /etc/systemd/system/sysinit.target.wants/lvm2-lvmetad.socket.
[root@server2 ~]# ps -ef | grep lvm
root     31974  9198  0 15:58 pts/1    00:00:00 grep --color=auto lvm

In /etc/lvm/lvm.conf file of all nodes I add:

volume_list = [ "vg00" ]

Execute below command on each node, this is not supporting kernel upgrade. The annoying thing is that each time you have a new kernel you have to issue the command on new kernel BEFORE rebooting or you need to reboot two times:

[root@server3 ~]# dracut -H -f /boot/initramfs-$(uname -r).img $(uname -r)

Recreate the volume group resource with exclusive option (parameter to ensure that only the cluster is capable of activating the LVM logical volume):

[root@server2 ~]# pcs resource create vg01 LVM volgrpname=vg01 exclusive=true
[root@server2 ~]# pcs resource show
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server2.domain.com
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:10:53 2017          Last change: Wed Apr 19 17:10:43 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server2.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

The volume group move is now working fine:

[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:10:53 2017          Last change: Wed Apr 19 17:10:43 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server2.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled
[root@server2 ~]# pcs resource move vg01 server3.domain.com
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:12:20 2017          Last change: Wed Apr 19 17:11:06 2017 by root via crm_resource on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Filesystem

Create the file system based on a logical volume:

[root@server2 ~]# pcs resource create u01 Filesystem device="/dev/vg01/lvol01" directory="/u01" fstype="xfs"
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:13:51 2017          Last change: Wed Apr 19 17:13:47 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 3 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 virtualip      (ocf::heartbeat:IPaddr2):       Started server3.domain.com
 vg01   (ocf::heartbeat:LVM):   Started server3.domain.com
 u01    (ocf::heartbeat:Filesystem):    Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

To collocate resources I create a group, this can also be done with constraints but a group is more logic in our case (the order you choose will be starting order):

[root@server3 u01]# pcs resource group add oracle virtualip vg01 u01
[root@server3 u01]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:36:10 2017          Last change: Wed Apr 19 17:36:07 2017 by root via cibadmin on server3.domain.com
 
2 nodes and 3 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server3.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server3.domain.com
     u01        (ocf::heartbeat:Filesystem):    Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

At that stage you can test already created resources are moving from one cluster node to the other with something like:

[root@server3 u01]# pcs cluster standby server3.domain.com
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:45:45 2017          Last change: Wed Apr 19 17:45:37 2017 by root via crm_resource on server2.domain.com
 
2 nodes and 3 resources configured
 
Node server3.domain.com: standby
Online: [ server2.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server2.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server2.domain.com
     u01        (ocf::heartbeat:Filesystem):    Started server2.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

And be back in initial situation with (they are back on server3.domain.com because I have also played with preferred node but this is not mandatory):

[root@server3 ~]# pcs node unstandby server3.domain.com
[root@server3 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Wed Apr 19 17:48:05 2017          Last change: Wed Apr 19 17:48:03 2017 by root via crm_attribute on server3.domain.com
 
2 nodes and 3 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server3.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server3.domain.com
     u01        (ocf::heartbeat:Filesystem):    Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Oracle database

[root@server2 ~]# pcs resource describe oracle
ocf:heartbeat:oracle - Manages an Oracle Database instance
 
Resource script for oracle. Manages an Oracle Database instance
as an HA resource.
 
Resource options:
  sid (required): The Oracle SID (aka ORACLE_SID).
  home: The Oracle home directory (aka ORACLE_HOME). If not specified, then the SID along with its home should be listed in /etc/oratab.
  user: The Oracle owner (aka ORACLE_OWNER). If not specified, then it is set to the owner of file $ORACLE_HOME/dbs/*${ORACLE_SID}.ora. If this does not work for you, just set it explicitely.
  monuser: Monitoring user name. Every connection as sysdba is logged in an audit log. This can result in a large number of new files created. A new user is created (if it doesn't exist) in the start action and subsequently used in monitor. It should have very limited rights. Make sure that the password for this user does not expire.
  monpassword: Password for the monitoring user. Make sure that the password for this user does not expire.
  monprofile: Profile used by the monitoring user. If the profile does not exist, it will be created with a non-expiring password.
  ipcrm: Sometimes IPC objects (shared memory segments and semaphores) belonging to an Oracle instance might be left behind which prevents the instance from starting. It is not easy to figure out which shared segments belong to which instance, in particular when more instances are running as same user. What we use here is the "oradebug" feature and its "ipc" trace utility. It is not optimal to parse the debugging information, but I am not aware of any other way to find out about the IPC information. In case the format or wording of the trace report changes, parsing might fail. There are some precautions, however, to prevent stepping on other peoples toes. There is also a dumpinstipc option which will make us print the IPC objects which belong to the instance. Use it to see if we parse the trace file correctly. Three settings are possible: - none: don't mess with IPC and hope for the best (beware: you'll probably be out of luck, sooner or later) - instance: try to figure out the IPC stuff which belongs to the instance and remove only those (default; should be safe) - orauser: remove all IPC belonging to the user which runs the instance (don't use this if you run more than one instance as same user or if other apps running as this user use IPC) The default setting "instance" should be safe to use, but in that case we cannot guarantee that the instance will start. In case IPC objects were already left around, because, for instance, someone mercilessly killing Oracle processes, there is no way any more to find out which IPC objects should be removed. In that case, human intervention is necessary, and probably _all_ instances running as same user will have to be stopped. The third setting, "orauser", guarantees IPC objects removal, but it does that based only on IPC objects ownership, so you should use that only if every instance runs as separate user. Please report any problems. Suggestions/fixes welcome.
  clear_backupmode: The clear of the backup mode of ORACLE.
  shutdown_method: How to stop Oracle is a matter of taste it seems. The default method ("checkpoint/abort") is: alter system checkpoint; shutdown abort; This should be the fastest safe way bring the instance down. If you find "shutdown abort" distasteful, set this attribute to "immediate" in which case we will shutdown immediate; If you still think that there's even better way to shutdown an Oracle instance we are willing to listen.

I have then installed Oracle on server3.domain.com where is mounted /u01 filesystem. I have also copied /etc/oratab, /usr/local/bin/coraenv, /usr/local/bin/dbhome and /usr/local/bin/oraenv to server2.domain.com. This step is not mandatory but it will ease Oracle usage on both nodes.

I have also, obviously, changed the listener to make it listening on my virtual IP i.e. 192.168.56.99.

Create the oracle resource:

[root@server3 ~]# pcs resource create orcl oracle sid="orcl" --group=oracle
[root@server3 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Thu Apr 20 18:18:41 2017          Last change: Thu Apr 20 18:18:38 2017 by root via cibadmin on server3.domain.com
 
2 nodes and 4 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server3.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server3.domain.com
     u01        (ocf::heartbeat:Filesystem):    Started server3.domain.com
     orcl       (ocf::heartbeat:oracle):        Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

You must create monitoring user (default is OCFMON) and profile (default is OCFMONPROFILE) or you will get below error message:

* orcl_start_0 on server2.domain.com 'unknown error' (1): call=268, status=complete, exitreason='monprofile must start with C## for container databases',
    last-rc-change='Fri Apr 21 15:17:06 2017', queued=0ms, exec=17138ms

Please note that container databases is also taken into account and the account must be created on container with C## option as a global account. I have chosen not to create the required profile but I must take it into account when creating the resource:

SQL> CREATE USER c##ocfmon IDENTIFIED BY "secure_password";
 
USER created.
 
SQL> GRANT CONNECT TO c##ocfmon;
 
GRANT succeeded.

I create the Oracle database Pacemaker resource:

[root@server2 ~]# pcs resource update orcl monpassword="secure_password" monuser="c##ocfmon" monprofile="default"
[root@server2 ~]# pcs resource show orcl
 Resource: orcl (class=ocf provider=heartbeat type=oracle)
  Attributes: sid=orcl monpassword=secure_password monuser=c##ocfmon monprofile=default
  Operations: start interval=0s timeout=120 (orcl-start-interval-0s)
              stop interval=0s timeout=120 (orcl-stop-interval-0s)
              monitor interval=120 timeout=30 (orcl-monitor-interval-120)

To have my pluggable database automatically opened as instance startup I have used a nice 12cR2 new feature called pluggable database default state:

SQL> SELECT * FROM dba_pdb_saved_states;
 
no rows selected
 
SQL> set lines 150
SQL> col name for a20
SQL> SELECT name, open_mode FROM v$pdbs;
 
NAME                 OPEN_MODE
-------------------- ----------
PDB$SEED             READ ONLY
PDB1                 MOUNTED
 
SQL> alter pluggable database pdb1 open;
 
Pluggable database altered.
 
SQL> alter pluggable database pdb1 save state;
 
Pluggable database altered.
 
SQL> col con_name for a20
SQL> SELECT con_name, state FROM dba_pdb_saved_states;
 
CON_NAME             STATE
-------------------- --------------
PDB1                 OPEN

Oracle listener

Create the Oracle listener resource with:

[root@server3 ~]# pcs resource create listener_orcl oralsnr sid="orcl" listener="listener_orcl" --group=oracle
[root@server3 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Thu Apr 20 18:21:05 2017          Last change: Thu Apr 20 18:21:02 2017 by root via cibadmin on server3.domain.com
 
2 nodes and 5 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server3.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server3.domain.com
     u01        (ocf::heartbeat:Filesystem):    Started server3.domain.com
     orcl       (ocf::heartbeat:oracle):        Started server3.domain.com
     listener_orcl      (ocf::heartbeat:oralsnr):       Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Pacemaker graphical interface

You can go on any node of your cluster in https on port 2224 and get a very nice graphical interface where you can do apparently all the required modification of your cluster. Including the stop/start of resources. Overall this graphical interface is of great help when you want to know which options are available for resources:

pcs01
pcs01
pcs02
pcs02

Issues encountered

LVM volume group creation

If for any reason you must re-create or simply create the LVM volume group once you have done the configuration to forbid kernel to activate any volume outside of the root one (vg00 in my case) you must use below trick to escape from all LVM error messages.

The error messages you will get are:

[root@server2 ~]# vgcreate vg01 /dev/sdb
  Physical volume "/dev/sdb" successfully created.
  Volume group "vg01" successfully created
[root@server2 ~]# lvcreate -L 500m -n lvol01 vg01
  Volume "vg01/lvol01" is not active locally.
  Aborting. Failed to wipe start of new LV.

Trying to activate the volume group is not changing anything:

[root@server2 ~]# vgchange -a y vg01
  0 logical volume(s) in volume group "vg01" now active

To overcome the problem use below sequence:

[root@server2 ~]# lvscan
  ACTIVE            '/dev/vg00/lvol00' [10.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol03' [500.00 MiB] inherit
  ACTIVE            '/dev/vg00/lvol01' [4.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol02' [4.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol20' [5.00 GiB] inherit
[root@server2 ~]# vgcreate vg01 /dev/sdb --addtag pacemaker --config 'activation { volume_list = [ "@pacemaker" ] }'
  Volume group "vg01" successfully created
[root@server2 ~]# lvcreate --addtag pacemaker -L 15g -n lvol01 vg01 --config 'activation { volume_list = [ "@pacemaker" ] }'
  Logical volume "lvol01" created.
[root@server2 ~]# lvs
  LV     VG   Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  lvol00 vg00 -wi-ao----  10.00g
  lvol01 vg00 -wi-ao----   4.00g
  lvol02 vg00 -wi-ao----   4.00g
  lvol03 vg00 -wi-ao---- 500.00m
  lvol20 vg00 -wi-ao----   5.00g
  lvol01 vg01 -wi-a-----  15.00g
[root@server2 ~]# lvscan
  ACTIVE            '/dev/vg01/lvol01' [15.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol00' [10.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol03' [500.00 MiB] inherit
  ACTIVE            '/dev/vg00/lvol01' [4.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol02' [4.00 GiB] inherit
  ACTIVE            '/dev/vg00/lvol20' [5.00 GiB] inherit
[root@server2 ~]# lvchange -an vg01/lvol01 --deltag pacemaker
  Logical volume vg01/lvol01 changed.
[root@server2 ~]# vgchange -an vg01 --deltag pacemaker
  Volume group "vg01" successfully changed
  0 logical volume(s) in volume group "vg01" now active
[root@server2 ~]# pcs resource create vg01 LVM volgrpname=vg01 exclusive=true --group oracle
[root@server2 ~]# pcs status
Cluster name: cluster01
Stack: corosync
Current DC: server3.domain.com (version 1.1.15-11.el7-e174ec8) - partition with quorum
Last updated: Thu Apr 20 17:16:37 2017          Last change: Thu Apr 20 17:16:34 2017 by root via cibadmin on server2.domain.com
 
2 nodes and 2 resources configured
 
Online: [ server2.domain.com server3.domain.com ]
 
Full list of resources:
 
 Resource Group: oracle
     virtualip  (ocf::heartbeat:IPaddr2):       Started server3.domain.com
     vg01       (ocf::heartbeat:LVM):   Started server3.domain.com
 
Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Resources constraints

Display resources constraints with:

[root@server2 ~]# pcs constraint show --full
Location Constraints:
  Resource: oracle
    Enabled on: server3.domain.com (score:INFINITY) (role: Started) (id:cli-prefer-oracle)
  Resource: virtualip
    Enabled on: server3.domain.com (score:INFINITY) (role: Started) (id:cli-prefer-virtualip)
Ordering Constraints:
Colocation Constraints:
Ticket Constraints:

If you want to remove location contraint (currently set to server3.domain.com):

[root@server2 ~]# pcs constraint location remove cli-prefer-oracle
[root@server2 ~]# pcs constraint show --full
Location Constraints:
  Resource: virtualip
    Enabled on: server3.domain.com (score:INFINITY) (role: Started) (id:cli-prefer-virtualip)
Ordering Constraints:
Colocation Constraints:
Ticket Constraints:
[root@server2 ~]# pcs constraint location remove cli-prefer-virtualip
[root@server2 ~]# pcs constraint show --full
Location Constraints:
Ordering Constraints:
Colocation Constraints:
Ticket Constraints:

If for example you want to colocate two resources without creating a group use something like:

[root@server2 ~]# pcs constraint colocation set virtualip vg01
[root@server2 ~]# pcs constraint show
Location Constraints:
Ordering Constraints:
Colocation Constraints:
  Resource Sets:
    set virtualip vg01 setoptions score=INFINITY
Ticket Constraints:
[root@server2 ~]# pcs constraint colocation show --full
Colocation Constraints:
  Resource Sets:
    set virtualip vg01 (id:pcs_rsc_set_virtualip_vg01) setoptions score=INFINITY (id:pcs_rsc_colocation_set_virtualip_vg01)
[root@server2 ~]# pcs constraint remove pcs_rsc_colocation_set_virtualip_vg01

References

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>