ODA Support - 12.2 RAC Database High "gc cr/current request" 'gc buffer busy acquire' and Locks On Hot Object SELECT SPARE6 FROM USER$ WHERE USER#=:1 After Upgrading from 11.2.0.4 Single Instance (Doc ID 2583711.1)

Last updated on JULY 20, 2024

Applies to:

Symptoms

Upgrade to 12.2 and now sessions are hanging and locking requiring manual killing of sessions.
Requires a RAC configuration as Single-Instance does not show the severity of the problem all other things being equal.
The queries and application had worked before an upgrade and / or migration to 12.2.

Wait events include:

• Hangs of application queries which had worked before te update to 12.2.x
• High 'gc cr/current request' Waits
• High 'gc buffer busy acquire'Waits
• Locks On Hot Object
• Possible query  SELECT SPARE6 FROM USER$ WHERE USER#=:1
• IPCLW:[0.0]{E}[WAIT]:RC: [1############] op zrcv   >>> failed with local protection error
• ORA-07445 [ipclw_free_cbuf()+114] [SIGSEGV] [ADDR:0x##] [PC:0x7F########] [Address not mapped to object] []
• ORA-07445: exception encountered: core dump [PC:0x7F#########] [SIGSEGV] [ADDR:0x1111111111] [PC:0x7F#########] [Address not mapped to object] []

Changes

 Upgrade of the Oracle Product using Linux to UEK4 with kernels older than 4.1.12-61.49.1.
  This includes Engineered Systems running UEK4 which are the default in many 12.2 versions of the product line.

Cause

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