Connection timeouts in default trace log

[Former Member]

Hi,

We have performance issues in our Estonian site running SAP ME 5.2.4.7.

When looking in the default trace log there is several lines with a connection timeout error.

We have tried restarting the servers but it only helps temporarily.

What can these connection timeouts be? Could it be the reason of the perfomance issues?

Br,

Johan Nordebrink

#2.0 #2011 03 28 15:51:09:132#+0300#Error#com.sap.engine.services.connector.jca.ConnectionHashSet#

#BC-JAS-TRH#connector#0025B3E1D6F400710000000000001FE8#8615050000000004#sap.com/me~ear#com.sap.engine.services.connector.jca.ConnectionHashSet#UMEUser#15#SAP J2EE Engine JTA Transaction : [0ffffff8374ffffff8a0063ffffffa4]#17B06698592711E0C5CC00000083748A#c1e6829d593911e0b18a00000083748a#c1e6829d593911e0b18a00000083748a#0#Thread[HTTP Worker [@1001335214],5,Dedicated_Application_Thread]#Plain##

ConnectionHashSet, Exception:

[EXCEPTION]

com.sap.engine.services.connector.exceptions.BaseResourceException: Cannot get connection for 120 seconds. Possible reasons: 1) Connections are cached within SystemThread(can be any server service or any code invoked within SystemThread in the SAP J2EE Engine) or they are allocated from a non transactional ConnectionFactory. In case of transactional ConnectionFactory used from Application Thread there is an automatic mechanism which detects unclosed connections, 2)The pool size of adapter "DefaultXATopicConnectionFactory" is not enough according to the current load of the system . In case 1) the solution is to check for cached connections using the Connector Service list_conns command or in case 2), to increase the size of the pool.

at com.sap.engine.services.connector.jca.ConnectionHashSet.match(ConnectionHashSet.java:341)

at com.sap.engine.services.connector.jca.ConnectionManagerImpl.allocateConnection(ConnectionManagerImpl.java:343)

at com.sap.engine.services.connector.jca.ShareableConnectionManager.allocateConnection(ShareableConnectionManager.java:54)

at com.sap.engine.services.jmsconnector.cci.TopicConnectionImpl.createTopicSession(TopicConnectionImpl.java:141)

at com.sap.me.frame.JMSClient.getTopicSession(JMSClient.java:269)

at com.sap.me.frame.JMSClient.buildTopicObjectMessage(JMSClient.java:90)

at com.sap.me.demand.SFCBOMRemoveWorker.removeComponent(SFCBOMRemoveWorker.java:496)

at com.sap.me.demand.SFCBOMBOBean.removeComponent(SFCBOMBOBean.java:1152)

at sun.reflect.GeneratedMethodAccessor325.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:592)

at com.sap.engine.services.ejb3.runtime.impl.RequestInvocationContext.proceedFinal(RequestInvocationContext.java:46)

at com.sap.engine.services.ejb3.runtime.impl.AbstractInvocationContext.proceed(AbstractInvocationContext.java:166)

at com.sap.engine.services.ejb3.runtime.impl.Interceptors_StatesTransition.invoke(Interceptors_StatesTransition.java:19)

at com.sap.engine.services.ejb3.runtime.impl.AbstractInvocationContext.proceed(AbstractInvocationContext.java:177)

at com.sap.engine.services.ejb3.runtime.impl.Interceptors_Resource.invoke(Interceptors_Resource.java:71)

at com.sap.engine.services.ejb3.runtime.impl.AbstractInvocationContext.proceed(AbstractInvocationContext.java:177)

at com.sap.engine.services.ejb3.runtime.impl.Interceptors_Transaction.doWorkWithAttribute

[alexander_teslyuk · Accepted solution]

Hi Johan,

I would try to increase transaction timeout value. According to the installation guide it should be set to 300 sec, but you can set bigger value.

Regards,

Alex.

[Former Member · Accepted solution]

Hi Alex,

Thank you for the answer. Can you just explain a little bit more why I should change?

Will we not suffer even more by setting a larger timeout value than 120 seconds?

What could be the reasons for getting these timeouts?

Br,

Johan

[alexander_teslyuk · Accepted solution]

Johan,

Please refer to the section 4.1.15 in installation guide according to which the transaction timeout is set. In case it is set to 120 in your production environment, I would suggest increasing it at least to 300 as it is recommended.

Connection timeout errors could be caused by high production load. So, the system must be adjusted according to your production needs.

Best regards,

Alex.

[Former Member · Accepted solution]

Hi again Alex,

I have checked the ts transaction timeout value and it is actually already set to 300.

Br,

Johan

[alexander_teslyuk · Accepted solution]

Johan,

Can you identify the exact scenario which causes the problem? Do you have any Events configured? Please note that we faced before some JMS problems against Event notifications.

Regards,

Alex.

[Former Member · Accepted solution]

Hi Alex,

There is no exact scenario. It seems to occurr randomly.

Yes, events is used. An email is sent every time an Xchange XML message fails.

Br,

Johan

[former_member182330 · Accepted solution]

Johan,

Looking at the stack trace, system cannot establish connection to jms queue. In configtool find jmsconnector service and try to play with maxConnections and timeToWaitForConnection parameters.

Regards,

Konstantin

[Former Member · Accepted solution]

Hi Konstantin,

Before I start to play around in the production system. How can I check how many connections

is in use and know if that is the reason to the error?

Br,

Johan

[former_member182330 · Accepted solution]

Check out this link:

http://wiki.sdn.sap.com/wiki/display/TechTSG/%28JSTSG%29%28Telnet%29JMSProviderCommands

Konstantin

[Former Member · Accepted solution]

From the stacktrace it looks like it happens on component removal (probably from asbuilt).

If the number of components to be removed is high (>100 ), then this could be a known issue in NW which we hope will be fixed at some point (it might have been addressed in 7.3 though).

NW 7.11 does not use a transaction scope caching of JMS sessions (connections). Because of that the number of objects that can be operated transactionally directly depends on the maxConnections settings on jmsconnector node in config tool (as was described).

Regards

[Former Member · Accepted solution]

Hi,

Problem is now solved. It was indeed problems when scrapping panels with many locations and components.

I changed the MaxConnections to 500 in Java Config Tool for JMSConnector service.

Thank you for your help!

Br,

Johan