When to use -Xms and -Xmx?

[Ahmed Moustafa]

I allocate memory to my app using -Xmx. When would I need to use -Xms?

Thanks in advance!

 

[Tris Orendorff]

I allocate memory to my app using -Xmx. When would I need to use -Xms?

Thanks in advance!

"-Xms" can be used when you know your app uses few memory resources and you
want to make the app's footprint as small as possible.

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[Mark Thornton]

I allocate memory to my app using -Xmx. When would I need to use -Xms?

Thanks in advance!

When you know you are going to use at least some minimum amount of
memory. Doing so then avoids a lot of heap expansion (and garbage
collection cycles). Try allocating say 250MB in 64K chunks (ensuring
that you keep a reference to each chunk). You will probably find it much
faster if -Xms is set to 250MB than if the default is used. The default
value for -Xms is quite low and it is rarely worthwhile setting a
smaller value.


Mark Thornton

 

[Ahmed Moustafa]

When you know you are going to use at least some minimum amount of
memory. Doing so then avoids a lot of heap expansion (and garbage
collection cycles). Try allocating say 250MB in 64K chunks (ensuring
that you keep a reference to each chunk). You will probably find it much
faster if -Xms is set to 250MB than if the default is used. The default
value for -Xms is quite low and it is rarely worthwhile setting a
smaller value.

So, it makes more sense to allocate the required memory by -Xms rather
than -Xmx, right?