Multi-threading in servlets

[gurneeraj singh]

We know that when new client request comes for a servlet then container calls the service method from a new thread.

And service method always calls the get or post method.

So, my question is if we synchronize the get or post method and when client is working on that servlet then other client has to wait or not because of synchronization issues?

[Antonio Tercero]

If you synchronize service(), doGet() or doPost() methods, only one client request can be processed at a time.
So that's bad ...

[Kunal Jag]

So, my question is if we synchronize the get or post method and when client is working on that servlet then other client has to wait or not because of synchronization issues?

Absolutely, Synchronizing the entire service(), doGet() or doPost() method will kill concurrency. Doing so will cause extra delays and performance penalty. It's always advisable to use short synchronized blocks.

Regards,

[Amit Prakash Singh]

Hi,

synchronizing the service method kills the concurrency. So no other thread can run at the same time for the same servlet instance. However, I would like to add one note here :

If you are using STM for the synchronization, then, how your container vendor has implemetend the STM is important. Either a single servlet instance and make a queue for each request. Or multiple instance of the servlet and each handling the request seperately. Read Chap5 of HFSJ.

[Deepak Bala]

Anyone using the Single threaded model should be smeared with bile fluid.

As for synchronization problems, synchronizing service() is pretty much the same as using STM. Synchronizing doPost() or doGet() is a little less worse, but worse never the less (assuming you sync doPost() but not doGet() or something like that).