ERS (Enqueue Replication Service): How to Perform Lock Table Copy?

[Former Member]

Hi All,

The set-up for Standalone Enqueue (ASCS) depends highly on the ERS (Enqueu Replication Service) to protect the locking-table.

Without ERS, locking table will be gone during ASCS failure, and after ASCS recover (started) again, the same object can be edited by 2 different people.

This is easily reproduced by opening SU01 and edit a user, shutdown ASCS, start ASCS again, and edit the same user. No locking mechanism seems to be working.

When ERS is running, it holds a copy of the locking table as the standby enqueue. But it needs to be activated.

Question is:

How to manually activate the ERS to become ASCS with still holding the previous locking-table. Because if we start ASCS, then the lock-table is refreshed and the new one is created.

Note: Once correctly configure, HA solution like cluster system provide this automatically, but what is really happened behind? What if the cluster system is failing and we need to perform it manually?

In SAP Documentation in this URL: http://help.sap.com/saphelp_nw70/helpdata/en/33/5cfd37a4e08e14e10000009b38f842/content.htm

Said:

The standby server runs a replicated enqueue server that can be activated if the primary enqueue server fails, using the enqueue table copy.

But I cannot yet found the way to perform it.

Thank you

Edited by: Shadowdancer on Jan 5, 2012 2:27 AM

[Former Member · Accepted solution]

Hi,

Try settings up these parameters in ASCS and ERS profiles.

enque/server/replication = true

enque/deque_wait_answer = TRUE

Regards,

Sonia

[Former Member · Accepted solution]

Hi,

Thank you all for your link and knowledge sharing.

I think I will close this thread because the discussion has gone very long time.

Have a nice day

[mercedes_fernandez]

hello,

in this case the enqueue table copy you mentioned refers to the replication table

See this page of the online help that would clarify the mechanism:

http://help.sap.com/saphelp_nw73/helpdata/en/47/e01bb686983c85e10000000a42189c/frameset.htm

kind regards,

Mercedes

[Former Member]

Hi Mercendes,

Sorry, I've been a while away from SDN.

I have checked your link, it helps, although I didn't yet find the solution to activate ERS become ASCS

Thank you

[Former Member]

Hello,

I'm not sure about it, but my understanding is this:

ERS will never ever become ASCS. But it will provide the lock table to a new ASCS that will have to be started, either by the cluster software, or perhaps manually.

regards