When running Post in MTP mode, you see the following messages repeat over and over:
06/27/07 15:45 Notice: Oracle env - TRNPROD:/oracle/product/10.2.0/Db_1 [sp_cnc(pdb)/10119]
[1] 06/27/07 15:39 Notice: FindAllLocks: Object "TRN2"."PERSON_CLASS_EXTRA_CERT" locked by user
"SPLEX",session(1078), command(No co
mmand), type(1078), mode(Table Lock), request(Row-S (RS)), blocking(NONE), block(No Block), row(41045)
[sp_opst_mt(osp)/7328]
.
The Post is running very slow while this is occurring.
Blocking in MTP and consequent writing activity in event log slows down Post.
WORKAROUND:
This sometimes occurs when the Post is running in MTP mode. Two things can slow Post down. One is the blocking sessions themselves and the increased writing activity in event log due to blocking session warning notices as shown above. One quick workaround is to let Post run in single-threaded mode. This should most likely resolve the blocking issue which can be due to a number of reasons. To set Post in single-threaded mode, you may have to do the following:
1. sp_ctrl>stop post
After this, keep issuing "status" command from sp_ctrl till you see that status is "stopped by user" and not "stopping". There are times when it will not do so for long periods which could be due to Post sessions being rolled back at the database level. You may have to check the v$session view of the database to make sure that all sessions belonging to Shareplex users do not show up anymore and are not just marked "killed". At times this may be a long wait. Also make sure that there are no sessions belonging to the post process (named sp_opst) at the OS level. Then you can proceed to the following steps.
2. sp_ctrl>set post single
3. sp_ctrl>start post
At a later time when you can switch the Post back to MTP mode and let it run in MTP if the problem does not show up anymore. The reason being that MTP will usually have a better performance than single-threaded Post. To do this:
1. sp_ctrl>stop post (make sure that it stops gracefully and if not, do the steps shown in para 1 above)
2. sp_ctrl>set post multi
3. sp_ctrl>start post
STATUS:
Waiting for fix in a future release of Shareplex for Oracle.
Starting with SharePlex 6.x, the single-threaded Post is deprecated. So all references about switching from single-threaded and multi-threaded Post and vice versa will not be applicable in current versions as Post only runs in multi-threaded mode.
There is a performance problem with the query that displays the locks in database when MTP encounters deadlock problem.
