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Solaris RDS Performance Impacted by kmem_flags Settting after SuperCluster Patched to Q2 2019 QFSDP (11.4) (Doc ID 2611945.1)

Last updated on MARCH 26, 2021

Applies to:

Solaris Operating System - Version 11.4 and later
Information in this document applies to any platform.

Symptoms

An M7-8 SuperCluster exerienced a serious performance degradation after patching with the 2019 Q2 QFSDP (Quarterly Full Stack Download Patch).  

The patch upgraded the Solaris OS from 11.3.36.7.0 to 11.4.5.3.0.

When under a database load, latency and throughput of RDS traffic was severely impacted. 

These are qperf values - using the qperf rds_lat and rds_bw tests, while under a substantial database workload:

While under DB workload - with kmem_flags=0x7

  Patch/OS version       RDS bandwidth      RDS latency
  Q1 2019 11.3.36.7.0    151 MBytes/sec     65.9 microseconds
  Q2 2019 11.4.5.3.0     691 KBytes/sec     3.86 milliseconds

 We can see that the Q1 (11.3.46.7.0) performance is not what is generally considered good, but the Q2 (11.4.5.3.0) perfromance is far behind.     

Cause

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In this Document
Symptoms
Cause
Solution
References


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