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user53864
Asked: 2012-02-04 04:57:31 +0800 CST

Pacemaker Active/Active haproxy load balancing

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I am using Haproxy to load balance replicated mysql master servers. I am also using Heartbeat and Pacemaker for Active/Active ip failover with two virtual ips on the two load balancers for web server high availability. I used location in pacemaker to stay VIPs one on each load balancer and I'm using round-robin DNS domains pointing to VIPs to load balance the load balancers. Everything looks fine so far!

|LB1: | Round-Robin -->| 1.2.3.4 | Heartbeat Pacemaker | Haproxy | 192.168.1.1

          |           |           |             |         |

|LB2: | Round-Robin -->| 5.6.7.8 | Heartbeat Pacemaker | Haproxy | 192.168.1.2

crm configure show

node $id="394647e0-0a08-451f-a5bf-6c568854f8d1" lb1
node $id="9e95dc4f-8a9a-4727-af5a-40919ac902ba" lb2
primitive vip1 ocf:heartbeat:IPaddr2 \
    params ip="1.2.3.4" cidr_netmask="255.255.255.0" nic="eth0:0" \
    op monitor interval="40s" timeout="20s"
primitive vip2 ocf:heartbeat:IPaddr2 \
    params ip="5.6.7.8" cidr_netmask="255.255.255.0" nic="eth0:1" \
    op monitor interval="40s" timeout="20s"
location vip1_pref vip1 100: lb1
location vip2_pref vip2 100: lb2
property $id="cib-bootstrap-options" \
    dc-version="1.0.8-042548a451fce8400660f6031f4da6f0223dd5dd" \
    cluster-infrastructure="Heartbeat" \
    stonith-enabled="false" \
    no-quorum-policy="ignore" \
    expected-quorum-votes="1"

How to configure Pacemaker so that if Haproxy on any load balancer is corrupted, it should still work either using haproxy on another lb or moving both the vips to working haproxy lb node. I DON'T want Active/Passive BUT Active/Active configuration as running haproxy on both the lbs responding to mysql requests.

Is it possible to do with Pacemaker? Anybody know?

Any help is greatly appreciated!. Thanks!

Update 1

That was a nice hint by @Arek B. using clone. I appended below line to pacemaker configuration but still couldn't exactly get what is actually required. I checked stopping haproxy on both the LBs and it's automatically started by pacemaker but when I checked permanently stopping it(/etc/defaults/haproxy, enabled=0), haproxy failed to start and in those case when it couldn't start haproxy, I want the resource(ipaddr2) to be moved to another running haproxy lb. Any more hint?

primitive mysql_proxy lsb:haproxy \
        op monitor interval="10s"
clone clone_mysql_proxy mysql_proxy \
        meta clone-max="2" clone-node-max="1"
location mysql_proxy_pref1 clone_mysql_proxy 100: lb1
location mysql_proxy_pref2 clone_mysql_proxy 50: lb2
mysql load-balancing failover pacemaker haproxy

1 Answers

  1. I have active-active 2*virtIP cluster

    For CRM config:
    I'm using two virtual IPs as primitive IPaddr2 services
    and for the service which should run on both nodes:

    1. create primitive for it, you'll then use it's ID
    2. make "clone" from it like:
      clone any_name_of_the_clone your_primitive_service_id \
      meta clone-max="2" clone-node-max="1"

    You may add order (to start virt IP after starting clone - NOT primitive, after you create clone you should not use it's child's ID)

    It is working, failover works (assigning 2 IPs on one node when other fails).
    However I have problem how to make colocation - I mean to have contrained services: I cannot have virtIP on node with subservice failed.
    It is OK when the service is down - cluster brings it up but when starting fails (e.g. broken config for the service) - cluster notes error but brings IP up.

    Anyone knows what's the cause?
    - Is it a matter of bad monitoring/start/stop control or it is a matter of configuring constraints?

    EDIT:
    I have added to Primitive option to 'op start': on-fail="standby". Now when my service (the only primitive in clone) cannot start the node looses also virtIP
    This seems to solve my problem now.

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