Hi, > We want to run a large number of tomcat instances on the same server > without virtualization or containerization. Each instance is executed from > its own folder tree and listens on its own unique TCP port. Each instance > will run code that connects to a backend database server to send queries > that are triggered by JSP calls from users. We've done this successfully > with up to 120 instances of tomcat running on the same server while > avoiding the overhead of virtualization and the complexity of containers. > Based on our experience over the past decade, we know that we could > potentially host 500 or more separate tomcat instances on the same server > without running into performance problems. So now we want to make it 500 > parallel instances. > > > Here's the problem. When tomcat initiates an outbound connection (for > example, with Connector/J to query a backend database) it establishes a > socket, and the socket has a client port. With thousands of users making > requests that require the tomcat services to query back end databases, the > OS can easily run out of available client ports to allocate to sockets. To > avoid that problem, we can assign multiple IPs to the server and use the > localSocketAddress property of Connector/J to group tomcats such that only > a subset of them each use the same source IP. Then each group will have > its own range of 64,000-ish client ports. I've tested this and it works. > > > > My question is, is there a better way?
I guess the database is not on the Tomcat host, otherwise you could connect via unix domain socket to avoid the limitations of TCP port numbers. Otherwise I think you could run a db proxy where your Tomcat clients connect locally via unix domain socket and the proxy relays the queries to the db backend. Regards, Simon --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
