LMHB Trace Files Report Confusing Information About Memory Metrics (Doc ID 1993208.1)

Last updated on FEBRUARY 14, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Information in this document applies to any platform.

Symptoms

LMHB trace file keeps reporting low free memory, which is misleading as there enough memory available at OS level.

We see the following message in lmhb trace file even if there is no load at the memory level

From LMHB trace file

*** 2014-07-01 00:00:49.116
kjgcr_StatCheckMEM: memory is low, free memory 52M, average 61M
kjgcr_Main: KJGCR_METRICS: Local metric memory load check, id 10 failed
kjgcr_Main: KJGCR_METRICS: Local metric memory threshold check, id 14 failed
kjgcr_SlaveReqBegin: message queued to slave
kjgcr_Main: KJGCR_ACTION - id 2
Memory is high.  Top oracle users listed below:
    Session           Serial         PGA_MEMORY
    387                 1           62278120
      5                 1           46090728
    1443                 1           44976616
    195                 1           44976616
    676                 1           36391400
kjgcr_Main: KJGCR_ACTION - id 18
kjgcr_Main: KJGCR_ACTION - id 19

*** 2014-07-01 00:00:54.119
kjgcr_StatCheckMEM: memory is low, free memory 52M, average 61M
kjgcr_Main: KJGCR_METRICS: Local metric memory load check, id 10 failed
kjgcr_Main: KJGCR_METRICS: Local metric memory threshold check, id 14 failed
kjgcr_SlaveReqBegin: message queued to slave
kjgcr_Main: KJGCR_ACTION - id 2
Memory is high.  Top oracle users listed below:
    Session           Serial         PGA_MEMORY
    387                 1           62278120
      5                 1           46090728
    1443                 1           44976616
    195                 1           44976616
    676                 1           36391400
kjgcr_Main: KJGCR_ACTION - id 18
kjgcr_Main: KJGCR_ACTION - id 19

 

 OS Watcher Top Output does not show any issue

zzz ***Tue Jul 1 00:00:49 BST 2014
top - 00:00:51 up  9:32,  1 user,  load average: 6.22, 6.16, 6.11
Tasks: 944 total,   1 running, 943 sleeping,   0 stopped,   0 zombie
Cpu(s):  1.5%us,  0.9%sy,  0.0%ni, 96.9%id,  0.6%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  132145600k total, 49070468k used, 83075132k free,   177360k buffers
Swap: 102399992k total,        0k used, 102399992k free, 41973320k cached

...

zzz ***Tue Jul 1 00:01:49 BST 2014
top - 00:01:51 up  9:33,  1 user,  load average: 6.08, 6.13, 6.10
Tasks: 934 total,   2 running, 932 sleeping,   0 stopped,   0 zombie
Cpu(s):  1.9%us,  0.9%sy,  0.0%ni, 96.2%id,  0.9%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  132145600k total, 48800464k used, 83345136k free,   177496k buffers
Swap: 102399992k total,        0k used, 102399992k free, 41973628k cached 

 

 

 

Cause

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