WFM - NLB Issues

Hi,

I have an instance of WFM that runs without problems when going direct to the server where WFM Web resides. However, trying to access WFM Web via Cisco NLB fails. The following error is generated in the WFM Web logs. There isn’t an issues direct or via NLB when logging in as an Agent. The problem occurs when trying to login as a supervisor.

Error message:
Exception: com.genesyslabs.wfm70.LoginException: Invalid state of HTTP Session or WFM Session context.
at com.genesyslabs.wfm70.server.GenericWFM7Servlet.doPost(GenericWFM7Servlet.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:66)
at com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:168)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
at com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:168)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
at com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:168)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
at com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:118)
at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:117)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:877)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:594)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1675)
at java.lang.Thread.run(Thread.java:662)

Any help would be appreciated.

Thanks.

For the future just a little searching:

Session is unknown to the Web Server due to its restart Every time we start any applet (WFM Web Supervisor) it performs registration of its sessions on the Servers (Web Server, WFM Server and WFM DA in case of adherence view is being used). Every request from the Web Supervisor then uses these sessions IDs to communicate with the servers. WFM Web Supervisor also performs a ping of its session every 4 minutes so that this session does not expire.

Upon servers are restart, the session ids are lost. When WFM Supervisor applet is left open, it will continue to send the ping requests to the servers. But because of the restart, the server no longer recognizes the session id and issue the error message described above.

The error message indicates that some WFM Web Supervisor applet(s) that has been started before Web Server restart are still up and running, trying to reconnect to web server. The error message does not indicate any environment problems. Message will no longer appear in the log as the old WFM Web Supervisors applets are closed.

Session is unknown to the Web Server due to incorrect redirection by Load Balancer
In environments where hardware or software Load Balancer front server is in use, the session affinity should be enable and configured.

The session affinity means that front server should redirect every session to the same WFM Web (servlet runner) instance where it has been initially established. If the existed session will be redirected to another then original application instance, this instance will be unable to recognize it and issue described error message.

If the issue does not happens with direct servlet runner http port connection (login to the servlet runner directly), but occurring wile connection is establishing to front server, then session affinity configuration/possible defects of front server should be investigated.

For example, for F5 Load Balancer session affinity type needs to be change from “session cookies” to “source address persistence”

Fair enough.

Thanks for your help.