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EM 13c : Row Lock Contention experienced for MGMT_USER_CONTEXT table (Doc ID 2825701.1)

Last updated on DECEMBER 02, 2021

Applies to:

Enterprise Manager Base Platform - Version 13.4.0.0.0 and later
Information in this document applies to any platform.

Symptoms

In Enterprise Manager (EM) Cloud Control, MGMT_USER_CONTEXT table locks the table when the cache is rebuilt, hence parallel threads will wait for the row to unlock.

Observing serious locking issues on queries like:

SELECT QUEUE_ID, ACTIVE, ENABLED FROM MGMT_JOB_QUEUES WHERE QUEUE_NAME = :B1 FOR UPDATE

SELECT CLIENT_IDENTIFIER FROM MGMT_USER_CONTEXT WHERE CLIENT_IDENTIFIER = :B2 AND ATTRIBUTE = :B1 FOR UPDATE

SQL> select sid, con_id, chain_id, num_waiters, in_wait_secs, osid, blocker_osid, wait_event_text from v$wait_chains where wait_event_text like '%row lock%';

  SID CON_ID CHAIN_ID NUM_WAITERS IN_WAIT_SECS OSID BLOCKER_OSID WAIT_EVENT_TEXT
---------- ---------- ---------- ----------- ------------ -------- ------------ ----------------------------------------------------------------
  47 0 1 0 55 98902 22990 enq: TX - row lock contention
  237 0 2 0 20 35291 60713 enq: TX - row lock contention
  48 0 3 0 55 98999 22990 enq: TX - row lock contention
  223 0 4 0 55 67635 22990 enq: TX - row lock contention
  245 0 5 0 55 22986 22990 enq: TX - row lock contention
  407 0 6 0 55 34497 22990 enq: TX - row lock contention
  419 0 7 0 55 67933 22990 enq: TX - row lock contention

 

Cause

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In this Document
Symptoms
Cause
Solution
References


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