what's your best way to redeploy webapp with least amount of downtime?
Hello list, I have two instances of Tomcat running the same webapp behind a load balancer. My current redeployment method is just simply shut one instance down(undeploy), replace warfile, deploy latest war back online, and then proceed to the seond instance. This works most of the time, but for those users who are happens on the instances I shut down, they lost the session at best, and lost a form submission while middle of request at worst. Can you share your story of how you solve your redeployment problem to keep max availability of your webapp? Thanks, Zemian Deng
Re: what's your best way to redeploy webapp with least amount of downtime?
Zemian Deng wrote: Can you share your story of how you solve your redeployment problem to keep max availability of your webapp? 1. Write stateless apps and where you can't, use sticky sessions and clustering. 2. When upgrading. I: - disable worker1 - wait for all requests on Tomcat 1 to complete (LambdaProbe is great for monitoring this and a bunch of other stuff) - upgrade Tomcat 1 - enable worker 1 - repeat for worker 2 Using this approach I never had any downtime associated with an upgrade. There were plenty of other causes of downtime ;), but upgrade wasn't one of them. Mark - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: what's your best way to redeploy webapp with least amount of downtime?
Hi Mark, How do you - disable worker1 and still let Tomcat1 to process remaining requests? I guess I am not sure what worker1 is, where to disable that. Can you explain little more on this? Yes, I have heard of LambdaProbe. I will check this out in more detail later. Thanks for sharing. -Z On Fri, Mar 28, 2008 at 9:53 AM, Mark Thomas [EMAIL PROTECTED] wrote: Zemian Deng wrote: Can you share your story of how you solve your redeployment problem to keep max availability of your webapp? 1. Write stateless apps and where you can't, use sticky sessions and clustering. 2. When upgrading. I: - disable worker1 - wait for all requests on Tomcat 1 to complete (LambdaProbe is great for monitoring this and a bunch of other stuff) - upgrade Tomcat 1 - enable worker 1 - repeat for worker 2 Using this approach I never had any downtime associated with an upgrade. There were plenty of other causes of downtime ;), but upgrade wasn't one of them. Mark - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] -- Thanks, Zemian Deng
Re: what's your best way to redeploy webapp with least amount of downtime?
Zemian Deng wrote: Hi Mark, How do you - disable worker1 and still let Tomcat1 to process remaining requests? I guess I am not sure what worker1 is, where to disable that. Can you explain little more on this? I was assuming you were using httpd and mod_jk or mod_proxy_ajp to do the load balancing. These use the concept of workers to connect httpd and Tomcat which, when disabled allow existing requests to continue to completion. There is a special worker, the balancer-manager that you use to control worker state. See: http://tomcat.apache.org/connectors-doc/ http://httpd.apache.org/docs/2.2/mod/mod_proxy.html http://httpd.apache.org/docs/2.2/mod/mod_proxy_ajp.html http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html Mark - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
