Its not that the memory replication didnt work, it worked very well just seemed to 
have exteme problems with it under load, there may have been other factors though.

Using clustering and in-memory replication we on fairly regular occasion saw the load 
of one or more members of the cluster rise so high that the machine became unusable. 
Turning off the clustering completly but keeping the load balancing seems to have 
sorted this.

One thing I saw in the logs, which i'm unsure is the cause or a symptom, is that all 
member periodically saw other members of the cluster leaving then rejoining again 1 
second later. I'm not sure what would cause this but I suppose too much network 
traffic from the in-memory session replication could cause a hold up, although I find 
it hard to believe that it would be over 3 seconds. Or as a cause of the problems, 
every time a member rejoins, all of the active sessions will have to be shared between 
the members so increased network traffic there.

If you have any ideas on that i'd be grateful.

My intended course of action was to retain the clustering and write the sessions to a 
shared disk to avoid the network traffic associated. My 1 question would be here, is 
that say I have 2 tomcats TomcatA and TomcatB, and they write their sessions to a 
shared file system using PersistenceManager, will each of them know about the sessions 
belonging to the other tomcat?

Ta
Matt


> persist sessions in a clustered environmentuse the PersistenceManager instead of the 
> clustering if all you want is to write sessions to a file system.
> http://jakarta.apache.org/tomcat/tomcat-5.0-doc/config/manager.html

> Did you need any help figuring out why in memory replication didn't work?
> Filip

  ----- Original Message ----- 
  From: Dale, Matt 
  To: Tomcat Users List (E-mail) 
  Sent: Monday, June 07, 2004 4:03 PM
  Subject: persist sessions in a clustered environment


  Hi, 

  We have been experiencing problems with our cluster using in-memory replication so 
we are looking into other ways in which to replicate the sessions. Our first step will 
be to switch to asynchronous mode for the replication from pooled but what i'm stuck 
with is replicating sessions to a shared file system. Basically I want to know how to 
do it or if someone can point me towards examples. 

  Ta 
  Matt 





------------------------------------------------------------------------------


  ---------------------------------------------------------------------
  To unsubscribe, e-mail: [EMAIL PROTECTED]
  For additional commands, e-mail: [EMAIL PROTECTED]
Any opinions expressed in this E-mail may be those of the individual and not 
necessarily the company. This E-mail and any files transmitted with it are 
confidential and solely for the use of the intended recipient. If you are not the 
intended recipient or the person responsible for delivering to the intended recipient, 
be advised that you have received this E-mail in error and that any use or copying is 
strictly prohibited. If you have received this E-mail in error please notify the 
beCogent postmaster at [EMAIL PROTECTED]
Unless expressly stated, opinions in this email are those of the individual sender and 
not beCogent Ltd. You must take full responsibility for virus checking this email and 
any attachments.
Please note that the content of this email or any of its attachments may contain data 
that falls within the scope of the Data Protection Acts and that you must ensure that 
any handling or processing of such data by you is fully compliant with the terms and 
provisions of the Data Protection Act 1984 and 1998.


---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to