Question about Multithreading !

**Jack_Tauson_Sr** · 03-27-2014, 12:35 AM

Suppose I am running 10 threads to grab a data(1000) from a database table located at one
IP Address and Insert it into another database located at different IP address.So how does this
multithreading decide the number of records each thread will carry out of 1000 records in the database?

**jim829** · 03-27-2014, 01:28 AM

That is pretty much up to you. Threads are just programs that run concurrently. So you need to instruct each thread how and when to do network I/O to and from a database. There's no point in each thread reading the same records because it's inefficient. And I presume writing them concurrently to a DB could cause problems but I guess that depends on the DB. You need to sync their behavior so they don't clobber each other. And you also have to decide how many threads, if any, will improve the overall performance of the system, since that is usually the overall goal.

Caveat: I am a retired network engineer with a degree in CS who has minimal experience with data base management.

Regards,
Jim

**Jack_Tauson_Sr** · 03-27-2014, 01:51 AM

Thanks for your answer. By any chance you know how to decide the number of threads I should use for best performance?

Also, is there a way in Netbeans to check the performance of my application based on the number of threads I use?

Originally Posted by jim829

That is pretty much up to you. Threads are just programs that run concurrently. So you need to instruct each thread how and when to do network I/O to and from a database. There's no point in each thread reading the same records because it's inefficient. And I presume writing them concurrently to a DB could cause problems but I guess that depends on the DB. You need to sync their behavior so they don't clobber each other. And you also have to decide how many threads, if any, will improve the overall performance of the system, since that is usually the overall goal.

Caveat: I am a retired network engineer with a degree in CS who has minimal experience with data base management.

Regards,
Jim

**jim829** · 03-27-2014, 03:12 AM

I really don't know. I can assume it depends on a lot of factors. How many concurrent writes can you do? What's the B/W of the network path? It's sort of like if you can't completely empty one bucket before a second is full, then you only need two buckets. That's a very simplified analogy so others in this forum may offer some better guidance. And as far as profiling on Netbeans, I don't use that IDE.

Regards,
Jim