Multiple instance Job

[sb_akarmarkar]

Hi all,

Can any one tell me what exactly allow mutiple instance will do ?
will it copy code and run apart from other ?
If multiple instance job start at same time what will happen will it abort one or ...?


Thanks,
Anupam

[Kirtikumar]

When multi-instance enabled job is executed - it needs an instance name say Z. Now if the job is executed say JobRead, then its execution is started and the while executing the process(es) running for the jobs are identified as JobRead.Z.
If job is executing with instance name Z, then another instance can be started with instance name Y, but not with same name.
The two instances executing at the same times have diff memory usage and also diff processes are created for execution of the jobs. So say JobREad.Z will have seperate memory & unix processes and JobRead.Y will have seperate memorty and & unix processes.

Now as the multi-instance jobs have same executable code, while building these jobs, we need to make sure that when they perform any write or update operations, they job will not corrupt the target. E.g. if job writes to seq file then seq file name, used during each instance execution, should be different. If Database is used, transaction settings should be such that there will be no deadlock. and so on....

Multiple instances should have diff instance names while executing and then both will run OK.

[kumar_s]

Hi,
It is the same as the other programing languages (if you are aware of). Source Code will remain same and single, it is intastantiated multiple time. If it is enalbed with "Allow mutiple instance" you will be given an option to feed in a invocation id while calling the job. And hence if you call the job with multiple invocation id at the same time, you can find multiple jobs running at the time.
Read the manual and do a search, you can find more informations.

[ray.wurlod]

Source code is not multiply instantiated. Only the executable program is. The invocation ID ensures that each instance is uniquely identifiable. They run as completely independent process (that is, not as multiple threads in the same process).

[sb_akarmarkar]

Thanks all for your reply.... :D

Thanks,
Anupam