Search Postgresql Archives

Re: FW: Java Memory Issue while Loading Postgres library

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 29/04/2010 8:48 PM, A.Bhattacharya@xxxxxxxxxxx wrote:

Your understanding is slightly incorrect. Actually we required to uses a
special library from postgres.

That mystery library being? From "postgres"? Do you mean a library supplied by the PostgreSQL project its self? Libpq? If not, what?

C'mon, specifics. Please. Try to read your message after you have written it while pretending you are somebody who does not work with your code and does not know the things you know about it. Try to notice assumptions and clarify them.

For this we write a wrapper around the
library and composed a dll out of it (which uses ECPG to communicate to
postgres). From the application front (Java) we make a JDBC call to
postgres function.  This postgres function then makes call to the dll.

This does not make sense. Your earlier mail said that the DLL is loaded into the Java runtime.

How does a "postgres function" make a call to a DLL running in the JRE? You can't make a call from the postgresql backend to code on a client connected to ecpg.

Please be SPECIFIC. What is a "postgres function?" How does it "make a call to the dll?" Etc. Provide links to PostgreSQL and Java documentation for the APIs you use, use the precise terms for those APIs, and generally be SPECIFIC and DETAILED. Post diagrams or code samples if you have to!

But the strange thing we observed that at runtime, somehow the execution
of dll is attached with java.exe. In other words, when we monitor the
performance of the application we realized that the execution of dll is
consuming java heap memory and is shown as a thread in java.exe process.
We expected that it should be linked with postgres.exe.

Ah, ok, so you are TRYING to load code a C extension to PostgreSQL into the server backend?

If so, why are you using ECPG? Or are you in fact *not* using ECPG, but the PostgreSQL backend extension interface?

How is the dll "shown as a thread in [the] java.exe process" ? Using a Java debugger attached to the JRE? Using Process Explorer or a C-level debugger examining the loaded DLL list of the JRE? Using the Java monitoring APIs?

I really do not understand what you are doing, or what you are trying to do. I doubt anybody can help you without a much more detailed and specific explanation of what you're doing.

I think it'd be a really good idea for you to write a minimalist test case for this and post it. Either you'll figure out what's wrong in the process of making the test case, or you'll have something to post that people can play with to see what you are trying to do.

--
Craig Ringer

--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux