> -----Original Message----- > From: Shawn Heisey <apa...@elyograg.org> > Sent: Saturday, June 26, 2021 8:09 PM > To: users@tomcat.apache.org > Subject: Re: 500 instances of tomcat on the same server > > On 6/25/2021 8:58 PM, Eric Robinson wrote: > > We can run 75 to 125 instances of tomcat on a single Linux server with 12 > cores and 128GB RAM. It works great. CPU is around 25%, our JVMs are not > throwing OOMEs, iowait is minimal, and network traffic is about 30Mbps. > We're happy with the results. > > > > Now we're upping the ante. We have a 48-core server with 1TB RAM, and > we're planning to run 600+ tomcat instances on it simultaneously. What > caveats or pitfalls should we watch out for? Are there any hard limits that > would prevent this from working as expected? > > I'm a lurker here. I have some experience with Tomcat, but most of my > experience is with other Apache projects. > > I'm hoping that my question mirrors what the experienced folks around here > are thinking: > > For something like this ... why are you running so many multiple instances? > Why not run one instance, or a few of them, and have each one handle many > many webapps? I bet you'll find that the overall memory requirements go > way down, because there will be far fewer instances of Java running. > > Maybe you've got good reasons for the architecture you have chosen ... > but it seems like a complete waste of resources to me. > > Thanks, > Shawn
Hi Shawn -- We architected it that way many years ago and have always been happy with our early decisions. By running separate tomcats, each from a separate folder and listening on a unique port, we are able to perform maintenance on individual customer's instances, stop and start services, etc., without impacting other customers. We can customize tomcat settings and configurations to customer needs, fine-tune per-customer memory usage, run different versions of tomcat and JDK, create customer-specific security sandboxes, per-customer filesystem permissions, samba shares, etc., and move entire instances around the farm to distribute load as needed. Errors and problems are easier to track down because the tomcat and webapps logs are in separate folders unique to each instance. If Customer A is having an issue with their application, we know that everything associated with their application, including all settings and logs, are in a folder dedicated to them. -Eric Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
