Problem: Database Lock ---------------------------------- Dear all I am working as a database administrator in a company. Our Database system is Postgresql-8.3.5 and Application server is Jboss used for our Adempiere ERP system. This is a web based ERP system. All servers are running on RHEL. Now our system is going to on-line and users are entering old data. So transactions are occurring very frequently. Now I am facing the problem is the application server just hangs at busy hour and it does not accept any new connection. When I restart the server (Adempiere, Jboss) it works fine for a few hours and problem occurs again. When this problem occurs the database server shows the following log LOG: process 19181 still waiting for ShareLock on transaction 18025221 after 1002.251 ms STATEMENT: SELECT CurrentNext, CurrentNextSys, IncrementNo, Prefix, Suffix, DecimalPattern, AD_Sequence_ID FROM AD_Sequence WHERE Name = $1 AND AD_Client_ID = $2 AND IsActive='Y' AND IsTableID='N' AND IsAutoSequence='Y' ORDER BY AD_Client_ID DESC FOR UPDATE OF AD_Sequence LOG: process 19181 acquired ShareLock on transaction 18025221 after 1298870.572 ms STATEMENT: SELECT CurrentNext, CurrentNextSys, IncrementNo, Prefix, Suffix, DecimalPattern, AD_Sequence_ID FROM AD_Sequence WHERE Name = $1 AND AD_Client_ID = $2 AND IsActive='Y' AND IsTableID='N' AND IsAutoSequence='Y' ORDER BY AD_Client_ID DESC FOR UPDATE OF AD_Sequence and the lock table informations are as following: adempiere=# select * from pg_locks where granted = 'y' and mode = 'ExclusiveLock'; locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted ---------------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-------+---------------+--------- transactionid | | | | | | 18386552 | | | | 39/1733 | 19196 | ExclusiveLock | t virtualxid | | | | | 24/1586 | | | | | 24/1586 | 19181 | ExclusiveLock | t transactionid | | | | | | 18386856 | | | | 24/1586 | 19181 | ExclusiveLock | t virtualxid | | | | | 39/1733 | | | | | 39/1733 | 19196 | ExclusiveLock | t transactionid | | | | | | 18386574 | | | | 39/1733 | 19196 | ExclusiveLock | t transactionid | | | | | | 18386563 | | | | 39/1733 | 19196 | ExclusiveLock | t transactionid | | | | | | 18386869 | | | | 24/1586 | 19181 | ExclusiveLock | t virtualxid | | | | | 50/20 | | | | | 50/20 | 19217 | ExclusiveLock | t transactionid | | | | | | 18386846 | | | | 24/1586 | 19181 | ExclusiveLock | t tuple | 250427 | 251989 | 209 | 7 | | | | | | 24/1586 | 19181 | ExclusiveLock | t (10 rows) adempiere=# select * from pg_locks where granted = 'f'; locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted ---------------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-------+-----------+--------- transactionid | | | | | | 18386574 | | | | 24/1586 | 19181 | ShareLock | f (1 row) *** Here you can see that process 19196 have ExclusiveLock on transaction 18386574 and process 19181 is waiting for ShareLock to the same transaction. When I monitor the Application server sessions from Jboss console normally I can see one of three stats R-Ready, K-Keep Alive and S-Service. When the application server hangs all sessions goes to Service mode. Please give me your appropriate and valuable solution in this regard. I am eagerly looking forward for your quick reply. Thanks in advance: --------------------------- Shohorab Hossain Send instant messages to your online friends http://uk.messenger.yahoo.com -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
