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Imapd Memory Usage And Mmap() Syscall Bottleneck (Doc ID 2750785.1)

Last updated on NOVEMBER 02, 2023

Applies to:

Oracle Communications Messaging Server - Version 8.0.2 and later
Information in this document applies to any platform.


Using: Messaging Server 64bit (built Aug 26 2019)

This issue deals with an imapd memory usage and mmap() syscall bottleneck that has been seen over a long period of time. On a couple of systems, it was noted that the mmap() syscall performance degraded to the point where it was impacting the performance of the Messaging Server.  After restarting the Messaging Server, the problem disappeared which eluded to the issue of memory growth.

A a pstack was run on each of the Messaging Server processes which showed the number of imapd threads were high, due to the delay in mmap() syscall, not the other way around.

Due to this long-standing issue, the Messaging Server degrades/bottlenecks and the server must be restarted to correct it.




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