-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 János,
On 4/13/2011 1:01 PM, János Löbb wrote: > My problems are starting with the requirement of removing a server from the > cluster and adding it back to the cluster without affecting the users. I > know just three ways to take a server out from the cluster. I assume > "server" here means a tomcat instance. > - shut that tomcat down. > - comment out the <Cluster..../> tag and let tomcat re-read the config > change, although I do not know how to do that. I do not see any "graceful" > options. > - Change its multicast address and again re-read the config change > somehow. > Is there any command line or web based interface that can interact with the > running cluster and take a cluster member "out" and put it back later ? mod_jk has a life configuration screen ("jk status manager") that allows you to remove a member from the load-balancing portion of the cluster... that Tomcat will still communicate with the rest of the cluster for session distribution, though, and that might not work well in your environment: potentially lots of de-serialization issues. > If I just shut down the web application on one cluster member it > renders all the replicated sessions of the webapp on other tomcat > unreachable via the reverse proxy, I already tested that out. Really? I would be surprised if, in a distributed-session environment, the removal of a server expired all the sessions it initially created across the entire cluster. That would not be useful under any circumstances. Maybe I don't understand what you're trying to describe. I think you want to do something like this: 1. Disable the target server via jk-manager: this stops traffic from being sent to it. Now, you can safely stop the target server without interrupting any real users. 2. Stop the target server, remove the <Cluster> configuration, upgrade your webapp and re-start the server. 3. Direct your users to use a special URL that takes you directly to the target server and does /not/ use the jk-managed cluster. When you're ready to re-join the cluster: 4. Stop the target server, re-enabled the <Cluster> configuration, re-deploy the same version of the webapp that is available on the other cluster members, and start the server. 5. Re-enable the target server via jk-manager Everything else you said seems to be way-over-thinking things. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk2mClEACgkQ9CaO5/Lv0PAq9gCcDzK6VkJfO8gcQKu5BAs0+CX4 EhAAoLm6cTrkLUF5zrXLSUJvnj0l34dj =WsOP -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org