Hello,
I've been trying to setup pacemaker to get a HA system for a web
application but I am having a hard time with DRBD. I have two nodes and
drbd is configured in single primary mode. The issue I am facing is that
I always end up with the two nodes being secondary/slaves, no node gets
promoted to primary/master. I don't have that issue when using drbd by
itself, without pacemaker.
I mainly followed this documentation:
http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Clusters_from_Scratch/index.html
Note that I am running on an up-to-date CentOS 7.2.1511 with all
packages coming from the repos (some from epel):
drbd 8.9.5
pacemaker 1.1.13
pcs 0.9.143
corosync 2.3.4
########################################################################
Here is the configuration I used:
########################################################################
pcs cluster cib webapp_cfg
# VIP
pcs -f webapp_cfg resource create vip ocf:heartbeat:IPaddr2 \
ip=10.5.200.30 cidr_netmask=24 op monitor interval=30s
pcs -f webapp_cfg constraint location vip prefers billing-primary=INFINITY
pcs -f webapp_cfg resource move vip billing-primary-sync
# DRBD
pcs -f webapp_cfg resource create drbd ocf:linbit:drbd \
drbd_resource=drbd0 \
op monitor interval=60s
pcs -f webapp_cfg resource master drbd-master drbd \
master-max=1 master-node-max=1 clone-max=2 clone-node-max=1 notify=true
pcs -f webapp_cfg constraint location drbd-master prefers
billing-primary=INFINITY
pcs -f webapp_cfg constraint colocation add drbd-master with vip
INFINITY with-rsc-role=Master
pcs -f webapp_cfg constraint order promote vip then promote drbd-master
pcs cluster cib-push webapp_cfg
########################################################################
Status
########################################################################
# pcs status
Cluster name: billing-cluster
Last updated: Tue Jun 14 08:59:57 2016 Last change: Tue Jun 14
08:46:41 2016 by root via cibadmin on billing-primary-sync
Stack: corosync
Current DC: billing-primary-sync (version 1.1.13-10.el7_2.2-44eb2dd) -
partition with quorum
2 nodes and 3 resources configured
Online: [ billing-backup-sync billing-primary-sync ]
Full list of resources:
vip (ocf::heartbeat:IPaddr2): Started billing-primary-sync
Master/Slave Set: drbd-master [drbd]
Slaves: [ billing-backup-sync billing-primary-sync ]
PCSD Status:
billing-primary-sync: Online
billing-backup-sync: Online
Daemon Status:
corosync: active/disabled
pacemaker: active/disabled
pcsd: active/enabled
########################################################################
Constraints
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# pcs constraint
Location Constraints:
Resource: drbd-master
Enabled on: billing-primary (score:INFINITY)
Enabled on: billing-primary-sync (score:INFINITY)
Resource: vip
Enabled on: billing-primary (score:INFINITY)
Enabled on: billing-primary-sync (score:INFINITY) (role: Started)
Ordering Constraints:
promote vip then promote drbd-master (kind:Mandatory)
Colocation Constraints:
drbd-master with vip (score:INFINITY) (with-rsc-role:Master)
########################################################################
I found some logs related to the issue in /var/log/messages:
error: drbd:1 and vip are both allocated but to different nodes:
billing-backup-sync vs. billing-primary-sync
notice: Promote drbd:0#011(Slave -> Master billing-primary-sync - blocked)
Full logs:
https://zerobin.net/?de9ecb3b7052f6dd#gc1f4j9Z+NqaiYYowA9xiOLCDAMJqmfW1uQpr0d2VpA=
I didn't see anything suspect in other log files but since it is the
first time I use pacemaker maybe I missed something so if you need other
logs, please ask me and I will provide them.
If you have any idea about what can be wrong with my configuration, I
would love to hear it :)
Thanks
Best regards,
--
Kevin THIERRY
IT System Engineer
CIT Lao Ltd. – A.T.M.
PO Box 10082
Vientiane Capital – Lao P.D.R.
Cell : +856 (0)20 2221 8623
kevin.thierry.cit...@gmail.com
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