Here is short description of what I was doing at work among other things for last 10 days.

The idea was simple – fix Linux cluster, which crashed after switching to other node. This cluster consists only of two nodes with following software running on:

• Apache webserver
• postgreSQL
• ActianX client
• HVR

After reviewing this installation we found out that resources for ActianX and HVR was misconfigured as well as network settings for this cluster.

Here is short description on how it should be done in proper way to avoid 3 days of searching for Root cause:):

1. install cluster and apache resource on Centos (follow all of the steps, triple check whether you haven’t missed anything):

How To Configure High-Availability Cluster on CentOS 7 / RHEL 7

2. install postgreSQL in cluster:

https://www.howtoforge.com/how-to-set-up-an-active-passive-postgresql-cluster-with-pacemaker-corosync-and-drbd-centos-5.5#-installing-prerequisites-and-cluster-packages

3. install ActianX on shared device and configure it for usage in cluster:

https://docs.actian.com/actianx/11.1/index.html#page/Install%2FInstall_the_Cluster_Service_Script.htm%23wwconnect_header

4. install HVR and configure it for usage in cluster (add to systemctl):

https://www.hvr-software.com/docs/configuring-hvr/auto-starting-hvr-scheduler-after-unix-or-linux-boot