[ClusterLabs] Issues with DB2 HADR Resource Agent

[Ondrej Famera]

On 02/01/2018 05:57 PM, Dileep V Nair wrote:
> Now the second issue I am facing is that when I crash the node were DB
> is primary, the STANDBY DB is not getting promoted to PRIMARY. I could
> fix that by adding below lines in db2_promote()
> 
> 773 *)
> 774 # must take over forced
> 775 force="by force"
> 776
> 777 ;;
> 
> But I am not sure of the implications that this can cause.
> 
> Can someone suggest whether what I am doing is correct OR will this lead
> to any Data loss.


Hi Dileep,

As for the 'by force' implications you may check the documentation on
what it brings. In short: the data can get corrupted.

https://www.ibm.com/support/knowledgecenter/SSEPGG_11.1.0/com.ibm.db2.luw.admin.cmd.doc/doc/r0011553.html#r0011553__byforce

The original 'by force peer window only' is limiting the takeover to
period when DB2 is within PEER_WINDOW which gives a bit more safety.
(the table in link above also explains how much safer it is)

Instead of changing the resource agent I would rather suggest checking
the PEER_WINDOW and HADR_TIMEOUT variables in DB2. They determine how
long it is possible to do takeover 'by force peer window only'.

-- 
Ondrej Faměra
@Red Hat