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JVM processes are not getting memory allocation as soon as started

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# 1  
Old 09-19-2017
Java JVM processes are not getting memory allocation as soon as started
Hi,

i have this scenario, when i start about 20 java processes simultaneously in unix and run ps -eaf command i can see that processes are running but memory is not getting allocated to them immediately and it stays ideal for at least 10-15 min.
Meanwhile i run free command to check the RAM, it stays available and nothing is allocated to those processes.
RAM is about 24 GB and each java process i am starting at min and max 1024MB.
could someone please let me know is there any way to start them fast.

Thanks in advance!

Regards,
Vishal
# 2  
Old 09-19-2017
What is the issue you are trying to solve and what do you means "it stays ideal for at least 10-15 min"?
# 3  
Old 09-20-2017
I think the o/p means "stays idle".
# 4  
Old 09-20-2017
Ah, that makes sense now.

@Vishal Allocating (i.e. reserving memory) is almost instantaneous and doesn't show up in RAM usage until the memory is actually used. The problem is probably elsewhere, in the java code or elsewhere.

During the 10-15 minutes delay, what processes, if any, are using the CPU? Are there significant I/Os during this period?
# 5  
Old 09-21-2017
@Jilliagre - Processes neither using CPU nor RAM. RAM is getting allocated process by process but it is very slow. RAM allocation is not instantaneous in this case.
All the processes are java processes.
# 6  
Old 09-21-2017
The JVM doesn't allocates RAM, it has no power to do so.

It allocates virtual memory. Allocating virtual memory is always essentially instantaneous. The fact you see memory allocation growing slowly is possibly a consequence of the slow start issue, not its root cause.

Please post the commands you run and their output to help figuring out what you are actually measuring.

Also, you didn't even tell what OS you are running.
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