How To Fix RT177 - Subtree: enqueue

SAP Error Message - Details

• Message type: E = Error

• Message class: RT - Monitoring infrastructure MSG and alert texts

• Message number: 177

• Message text: Subtree: enqueue

What causes this issue?

This monitoring tree element (MTE) provides information on the
performance of the enqueue service in an SAP system. The enqueue
service lets applications lock data for exclusive use. Locking data
while it is being used prevents changes to the data in parallel, which
would result in inconsistencies in the data.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message RT177 - Subtree: enqueue ?

  The SAP error message RT177, which states "Subtree: enqueue," typically occurs in the context of SAP's enqueue mechanism, which is used to manage locks on objects in the system. This error can arise when there is an issue with the locking mechanism, often related to the way data is being accessed or modified in the system.
  Cause:
  
  Lock Conflicts: The most common cause of this error is that a lock is already held on the subtree (a hierarchical structure of data) that you are trying to access. This can happen if another transaction is currently using the data.
  Long-Running Transactions: If a transaction takes too long to complete, it can hold locks longer than necessary, leading to conflicts with other transactions trying to access the same data.
  Incorrect Configuration: Sometimes, the configuration of the enqueue server or the way locks are managed in the system can lead to issues.
  System Performance Issues: High load on the system or performance bottlenecks can also lead to delays in releasing locks.
  
  Solution:
  
  Identify Lock Holders: Use transaction code SM12 to check for existing locks. You can identify which user or transaction is holding the lock and take appropriate action, such as waiting for the transaction to complete or terminating it if necessary.
  Review Long-Running Transactions: Analyze the transactions that are taking a long time to complete. If possible, optimize these transactions to reduce their execution time.
  Check Configuration: Ensure that the enqueue server is properly configured and that there are no issues with the SAP system's locking mechanism.
  System Monitoring: Monitor system performance and load. If the system is under heavy load, consider scaling resources or optimizing processes to improve performance.
  Restart Enqueue Server: In some cases, restarting the enqueue server can resolve temporary issues related to locks.
  
  Related Information:
  
  Transaction Codes:
  
  SM12: To view and manage locks.
  SM21: To check system logs for any related errors or warnings.
  SM37: To monitor background jobs that may be causing locks.
  
  
  SAP Notes: Check SAP Notes for any specific patches or updates related to enqueue issues. SAP frequently releases notes that address known issues and provide solutions.
  Documentation: Review SAP documentation on the enqueue mechanism and locking to better understand how it works and how to manage locks effectively.
  
  If the problem persists after trying the above solutions, it may be necessary to consult with SAP support for further assistance.