Question & Answer
Question
How to avoid OOM due to JVM fragmentation in IBM JRE
Cause
Answer
IBM JRE throws OOM exception if it can not allocate required amout of
(usually huge memory) in one single chunk. This solution explains how to avoid
JVM fragmentation and avoid OOM due to the fragmentation.
A.
1. -Xk15000 - This value will accommodate more pinned objects in reserved
location.
2. -Xp50000K,25000K
3. -Xloratio0.3 -
Object > 64K is large per IBM's definition of large object. So, we think that
about 30 - 40% of heap should be reserved for large objects.
Above configuration helped Customer.
Pl refer to links below for
complete understanding of the IBM bug and the corresponding recommendations -
http://www-1.ibm.com/support/docview.wss?uid=swg21176363 -
solution to avoid jvm fragmentation
http://www-1.ibm.com/support/docview.wss?uid=swg21236509 - New param in SR1
-Xloratio0.2
http://www-1.ibm.com/support/docview.wss?rs=180&uid=swg24010272 - This is fix
http://www-1.ibm.com/support/docview.wss?uid=swg21236523 - How to find
java thread ..
Historical Number
PRI49719
Product Synonym
[<p><b>]Fact[</b><p>];
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Document Information
Modified date:
16 June 2018
UID
swg21521888