DevHeads.net

Reply to comment

"proxy_balancer" | stickysession

Dear mailing list,

currently, we use the Apache2 version:
- Apache2 2.2.16 64bit
- standard "mod_proxy_balancer" module

with the following V-HOST configuration including a proxy balancer directive (with two Apache Tomcat instances behind):
<Proxy balancer://fs4server>
BalancerMember ajp://rb-wcmstc1.xx.xxxxx.xxx:8009 loadfactor=100 retry=10 route=rb-wcmstc1
BalancerMember ajp://rb-wcmstc2.xx.xxxxx.xxx:8009 loadfactor=100 retry=10 route=rb-wcmstc2

ProxySet stickysession=JSESSIONID
ProxySet lbmethod=byrequests
#ProxySet nofailover=On
ProxySet timeout=30
</Proxy>

In production environment, we discover connection switches from "rb-wcmstc1" to "rb-wcmstc2" and vice versa (documented in the Tomcat-Logs) for the same Session-ID:

"rb-wcmstc1"
tomcat@<rb-wcmstc1>:/opt/tomcat/logs $ grep -i "5893975846599935313" *
log4j-catalina.log.13:TRACE 29.09.2010 14:16:58 (de.espirit.firstspirit.io.servlet.ClientIOServlet): Opening connection to 10.35.32.123, id=5893975846599935313
log4j-catalina.log.13:TRACE 29.09.2010 14:16:58 (de.espirit.firstspirit.io.servlet.ClientIOServlet): Server call from 10.35.32.123, id=5893975846599935313, clientLength=82, serverLength=79, serverResponseLength=1, 455 ms

"rb-wcmstc2"
DEBUG 29.09.2010 14:16:58 (de.espirit.firstspirit.io.servlet.ClientIOServlet): IO error with 10.35.32.123, port=1088, host=rb-wcmsfs4.de.bosch.com - java.
lang.IllegalStateException: Connection '5893975846599935313' not found
java.lang.IllegalStateException: Connection '5893975846599935313' not found
at de.espirit.firstspirit.io.servlet.ClientIOServlet.callServer(ClientIOServlet.java:194)
at de.espirit.firstspirit.io.servlet.ClientIOServlet.doPost(ClientIOServlet.java:117)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

Although, the "stickysession" attribute is set properly using the "JSESSIONID" cookie name and the Apache-Tomcat instances are up and running, the connection SWITCHES. Why?

Reply