PQ45585: PROBLEM STARTING CLONES SIMULTANIOUSLY


APAR

APAR status
Closed as program error.

Error description
Cant start clones silmultaniously, meaning that if you start
the model it will fail because all clones will be started at the
same time.
.
When trying to start the model we get:
[00.12.14 13:41:53:102 EST] 1101523 DBMgr         W Exception on
database update: "update wasadmin.MODEL_TABLE set N
AME = ? ,CLONE_INTF_CLASS = ? ,IF_STARTED = ? ,START_TIME = ?,
CONFIG_NO = ? , NUM_CLONES = ?  where INSTANCE
_ID = ?" java.sql.SQLException: ORA-08177: can't serialize
access for this transaction.
When trying to start the model we get:[00.12.14 13:41:53:102 EST], 1101523 DBMgr W Exception ondatabase update: "update wasadmin.MODEL_TABLE set NAME = ? ,CLONE_INTF_CLASS = ? ,IF_STARTED = ? ,START_TIME = ?,CONFIG_NO = ? , NUM_CLONES = ? where INSTANCE_ID = ?" java.sql.SQLException: ORA-08177: can't serializeaccess for this transaction.
Local fix
Problem summary
models/clones.  The problem was traced to Oracle's behavior when
serialized transactions are involved.
Basically, if two serialized transactions (transactions with
isolation (TRANSACTION_SERIALIZABLE) run concurrently, the
transaction that started second (but before the first one
committed) will fail with ORA-08177. All admin beans have
TRANSACTION_SERIALIZABLE as their isolation levels.
Problem conclusion
solution was used.
Adminserver currently has a mechanism to lock repository using
the SQL "LOCK TABLE <tblname> IN EXCLUSIVE MODE".   This
operation obtains a global mutex and all of Admin servers
transactions are serialized.  Therefore it is possible to relax
isolation level to READ_COMMITTED for Admin server beans.  This
is to add support for Connection manager.
Code in the following files were changed to implement
this fix:
com/ibm/ejs/cm/DataSourceImpl.java
com/ibm/ejs/cm/SMDataSource.java
com/ibm/ejs/cm/pool/ConnectionPool.java
com/ibm/ejs/cm/pool/ConnectO.java
com/ibm/ejs/cm/pool/JTAConnectO.java
com/ibm/ejs/cm/pool/OnePhaseConnectO.java
com/ibm/ejs/cm/portability/PortableDataSource.java
com/ibm/ejs/cm/MirrorDataSource.java
this fix:com/ibm/ejs/cm/DataSourceImpl.javacom/ibm/ejs/cm/SMDataSource.javacom/ibm/ejs/cm/pool/ConnectionPool.javacom/ibm/ejs/cm/pool/ConnectO.javacom/ibm/ejs/cm/pool/JTAConnectO.javacom/ibm/ejs/cm/pool/OnePhaseConnectO.javacom/ibm/ejs/cm/portability/PortableDataSource.javacom/ibm/ejs/cm/MirrorDataSource.java
Temporary fix
Comments
APAR information
APAR numberPQ45585
Reported component nameWAS ADVANCED SU
Reported component ID5648C8402
Reported release350
StatusCLOSED PER
PENoPE
HIPERNoHIPER
Submitted date2001-01-29
Closed date2001-02-07
Last modified date2001-02-07

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:APAR is sysrouted FROM one or more of the following:


Modules/Macros
EJS
APAR is sysrouted TO one or more of the following:Modules/Macros

Fix information
Fixed component nameWAS ADVANCED SU
Fixed component ID5648C8402

Applicable component levels
R350 PSYUP











Document Information

Product categories: Software, Application Servers, Distributed Application & Web Servers, WebSphere Application Server, General
Software version: 350
Reference #: PQ45585
IBM Group: Software Group
Modified date: 2001-02-07