1.1.22

ORA-00240 control file enqueue held for more than XXX seconds


ORA-00240 control file enqueue held for more than XXX seconds


Description： control file enqueue held for more than string seconds

Cause 1:-

 The current process did not release the control file enqueue within the maximum allowed time.

Cause 2:-

 This issue was  investigated in unpublished Bug  by oracle 7570453 - [3 RAC NODE] ORA-00240          WHEN STARTUP AFTER UPGRADE TO 10.2.0.4.0 which was closed as Not a Bug. The                    Developers confirmed that this is just a warning to let the DBA know that a CF enqueue is being held for more than 120 seconds.

This is not an error, and error will occur if a CF enqueue is held for more than 900 seconds (15 minutes) and this is not the case here. 

The message occurs when there are many datafiles in the database and  DBWriter  is taking too much time to release the CF enqueue due to having to open these  datafiles.

Action： 1. Reissue any commands that failed and contact Oracle Support Services with the incident information.

   2.  The recommendation will be to reduce this time by reducing the number of database files you have. It is more recommended having less but bigger datafiles  instead of smaller but lots of datafiles.

We aware to check alert log for sure. 

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Bug 20639511  ORA-00240: CONTROL FILE ENQUEUE HELD FOR MORE THAN 120 SECONDS


Description

RELEASE NOTES:
 
 The bug is know to cause issues while deleting large number of files from ASM dectory
 
Rediscovery Notes
 
 Server Process of asmcmd rm command with -rf option holds enqueues for long time.
 
Workaround
 
  Kill the ongoing asmcmd rm command with -rf option and delete files one by one


Flex: ORA-00240: Control File Enqueue Held for More Than 120 Seconds (Doc ID 2434297.1)


Cause - This is due to Bug 25445289 (FLEX: ORA-00240: CONTROL FILE ENQUEUE HELD FOR MORE THAN 120 SECONDS) and the bug 25445289 is closed as duplicate of Bug 25368979 
(FLEX: ASM STALLS IN ALTER DISKGROUP ALL MOUNT, ONLY 1 OF 3 COMPLETE IN 30 MIN)

Solution:- Bug 25368979 fixed in 18.1. Apply interim patch 25368979, if available for your platform and Oracle version.
If no patch exists for your version, please contact Oracle Support for a backport request. 

Source:- Oracle

Below by ChatGPT

The error message "ORA-00240 control file enqueue held for more than XXX seconds" in Oracle indicates that a process is waiting for a control file enqueue lock for an extended period of time. This can occur due to various reasons, such as high system load, contention, or issues with the control file itself. Here are some possible solutions to address this error:

  1. Check system load: Monitor the system load and resource usage. If the system is heavily loaded, you may need to reduce the workload or allocate more resources to alleviate the contention.

  2. Investigate contention: Identify if there are any other processes or transactions that might be causing contention for the control file enqueue lock. You can use Oracle's dynamic performance views, such as V$SESSION and V$LOCK, to identify the blocking sessions and take appropriate actions to resolve the contention.

  3. Verify control file accessibility: Ensure that the control file is accessible and not corrupted. Check the file permissions, disk space, and integrity of the control file. If necessary, restore a backup of the control file or recreate it.

  4. Increase resources: If the system consistently experiences high contention for the control file enqueue, consider increasing the number of control files in the Oracle database configuration. Having multiple control files can help distribute the load and reduce contention.

  5. Optimize database performance: Review the database performance and identify any potential bottlenecks or resource-intensive operations. Optimizing queries, tuning database parameters, and implementing appropriate indexing strategies can help improve overall performance and reduce contention.

  6. Restart the database: In some cases, restarting the database can help resolve temporary contention issues. However, ensure that all necessary precautions are taken, such as ensuring a clean shutdown and performing a thorough analysis of the underlying cause before resorting to a restart.

  7. Seek expert assistance: If the issue persists or you are unsure about the appropriate actions to take, consider involving a database administrator or Oracle support for further analysis and resolution.

It's important to note that the specific solution may vary depending on the underlying cause of the contention. Analyzing the system logs, and performance metrics, and consulting with experienced Oracle professionals can help in identifying and resolving the issue effectively. 


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