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7.  After restarting the WCS, the gc-core.log log files show the periodic operation of the garbage collector. To understand the working model of Z Garbage Collector, you can see this presentation.

Physical memory allocation tuning on system level

When server is under a high load, there can be not enough a physical memory map areas which are avalable to a proccess in system by default. This can lead to JVM crash due to lack of native memory. In this case, crash log contains the following comment:

Code Block
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 12288 bytes for committing reserved memory.
# Possible reasons:
#   The system is out of physical RAM or swap space

To prevent such crashes, increase memory map areas count available to a procces with the following system parameter

Code Block
sysctl -w vm.max_map_count=131072

and restart WCS.