PQ41628: WEBSPHERE PERFORMANCE DEGRADES WHEN THE EJB WORKLOAD INCREASES FROM 100 TO 3000 CLIENTS ( THREADS )


APAR

APAR status
Closed as program error.

Error description
WebSphere performance degrades significantly (compared to
an OEM app server) when the EJB workload increases: from
100 clients (threads) to 3000 clients (threads).
Samples of test results are following:
                        Millis per request
        (excluding remote interface creation times)
Clients (Threads)    WebSphere                 OEM app server
50                 1.101890949                 2.815162319
100                3.885422061                 0.69762901
150               14.48816997                  0.629110343
250               72.48309179                  1.234753086
500               277.8611111                  1.766710817
1000              189.9050633                  1.650061856
1500              666.7777778                  1.780743905
2000              937.625                      1.709939321
3000              30004                        2.148378785
defect is 86689
Samples of test results are following:Millis per request(excluding remote interface creation times)Clients (Threads) WebSphere OEM app server50 1.101890949 2.815162319100 3.885422061 0.69762901150 14.48816997 0.629110343250 72.48309179 1.234753086500 277.8611111 1.7667108171000 189.9050633 1.6500618561500 666.7777778 1.7807439052000 937.625 1.7099393213000 30004 2.148378785defect is 86689
Local fix
pq41628.jar
Problem summary
share a single IIOPConnection.
Problem conclusion
IIOPConnection.writeLock() because writeUnlock() does a
signalAll() which wakes up all the threads and each thread does
some checks to see if it can get the write lock even though
only one thread will get the lock.  IIOPConnection.writeUnlock
was modified to do signal() in the case where the connection
is ESTABLISHED rather than signalAll (signalAll is still done
for other connection states).
Temporary fix
com.ibm.CORBA.iiop.IIOPConnection.class.  The readme file also
noted that property com.ibm.CORBA.OptimizeMutipleThreads=true
had to be set to enable the fix.  The e-fix was built on top
of WSAE 3.5.1 (aka 3.5 PTF-A), orbs3.5 build level ptfa0036.01
Comments
APAR information
APAR numberPQ41628
Reported component nameWAS ADVANCED AI
Reported component ID5648C8400
Reported release350
StatusCLOSED PER
PENoPE
HIPERNoHIPER
Submitted date2000-09-18
Closed date2000-11-24
Last modified date2000-11-24

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

Fix information
Fixed component nameWAS ADVANCED AI
Fixed component ID5648C8400

Applicable component levels
R350 PSYUP











Document Information

Product categories: Software, Application Servers, Distributed Application & Web Servers, WebSphere Application Server, General
Software version: 350
Reference #: PQ41628
IBM Group: Software Group
Modified date: 2000-11-24