CODEWITHSUNDEEP
javatomcat
ihavprobs
ihavprobs

Reputation: 1492

Tomcat's behaviour when two simultaneous requests come from same ip

When i try to run 2 wget commands simultaneously to my server (http://myserver), looks like tomcat allocates two threads to process them. But i believe when tomcat receives two simultaneously from same ip address, it will not create a new thread for processing the second request as it considers both the requests come from same session.

If i want to check if both the threads are same or different, is using thread.getId() the only way? I think this id may be reused for new threads. Is there any unique property of the thread existing to check its identity other than threadid?

Upvotes: 3

Views: 3151

Answers (3)

Joshua Fox
Joshua Fox

Reputation: 19675

Web servers will almost always assign multiple threads (or processes) to multiple simultaneous requests, since the client can work faster when it does not have to wait for each response.

Newer servers may use asynchronous IO (nio), however, and a single thread can simultaneously serve many clients.

Yes, Thread.getId() is a way of identifying threads.

Session IDs are the mechanism used to identify requests from a single client.

The IP address is not a good way to do that, since multiple machines can expose the same IP when hiding behind a NAT.

Upvotes: 1

mindas
mindas

Reputation: 26723

I suggest to never rely on threads to identify their source. There are no Servlet spec guarantees about threads, and newer Servlet spec implementations make use of NIO. You are skating on a thin ice.

Upvotes: 2

anirvan
anirvan

Reputation: 4877

I believe Tomcat will always create a new thread of execution irrespective of whether it comes from the same IP or not. In case, the client application running on the particular IP has a mechanism to send across the session-id, then Tomcat will simply associate the same session context with the request thread [making it stateful].

in your case, you'll need to customise wget to hold on to the session-id [the Tomcat web-app might send it across through a cookie or as a url parameter - jsessionid]. wget will then need to send it back with the subsequent requests [url rewrite and include the jsessionid parameter, or exchange cookies]. this way Tomcat will be able to treat each request coming from a unique client instance and associate a state with it.

Upvotes: 0

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