Thread: Out of memory work around for a java application (please help!)

I am working on a java application(Batch Process) and we have to use some third party API's (No Option to change it) related to the Database.It is causing out of memory after every 25000 updates and the total records are 5 million or so. I used the JProfiler to find out that the out of memory is caused by the third party API only.Since the application is in the production already we really cannot risk to change that third party API at any cost so we have to do some work around.

What is the best work around in this scenario? I am thinking to create separate thread in the below mentioned code which will do the first 20000 updates and as soon as this thread dies all the objects associated with this will also die and hence the new thread will be a fresh start and again the new thread will do 20000 updates or something like that.

If you have encountered such kind of problem in the past please help me and if possible write a pseudo code or sample code for it.

my current code looks like this which I am thinking to add the java threads:

public static void main(String [] args){

*ResultSet* rs (rs has all the records e.g. 5 millions)
long count=0;
while (rs.next()){

doUpdate();

count++;
*//the code fails if the count reaches to 25000*

}


}

Have you tried to increase the JVM default heap size? I believe the default Heap size is 128mb, but you can increase the max size into the GB if needed (using the -Xmx(max mem size) command line argument). However this doesn't fix any underlying problem. If you are creating new objects in the while loop and keeping references to them, then you might want to consider writing them out to a file rather than keeping a reference (if at all possible).

Thanks for your quick reply. I have already tried to use max and min memory setting, its not working. The other thing is The third party API does all the stuff and they only have provided .jar files so really I cannot change anything(e.g. writing the obj into the file etc.). So the only option I have is somehow I have to start the process again with the new records in the same JVM. So that I can have a fresh start. I dont know how to achieve this.

Are you getting the data from the database and loading the ResultSet? If so, you can change how you load the data and batch the resultsets... but if the 3rd party API is creating the resultset... then you might have to go with the hack...
One other thing... is the 3rd part a class you pass a record at a time and only at the 25000 record it hoses? If that the case load/unload the 3rd party class every 20000 records...
Hope this helps!
------------------------------
Mike

Are you closing your database properly? This sounds like a leak to me.

// Json