How To Fix WQENQ001 - Lock request expired after &1 milliseconds

SAP Error Message - Details

• Message type: E = Error

• Message class: WQENQ - Messages for priority queue processing

• Message number: 001

• Message text: Lock request expired after &1 milliseconds

What causes this issue?

A lock request for lock table &V2& expired after &V1& milliseconds. The
lock argument was &V3&.

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?

Check whether it is possible to increase the value of the
<DS:DE.WQENQ_MAX_WAIT_TIME>Maximum Waiting Time </> parameter, for
example, by using the
<DS:RE.RFWQENQ_ACTIVATE_QUEUE>Priority Queue for Lock Processing
</> report.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WQENQ001 - Lock request expired after &1 milliseconds ?

  Certainly! Here's a detailed explanation of the SAP error message WQENQ001: Lock request expired after &1 milliseconds:
  
  Error Message
  WQENQ001: Lock request expired after &1 milliseconds
  
  Cause
  This error occurs when an SAP enqueue (lock) request times out because the requested lock could not be obtained within the specified time limit. In SAP, enqueue locks are used to synchronize access to shared resources (such as database entries) to prevent data inconsistencies.
  Typical causes include:
  
  Long-running transactions or processes holding locks for an extended period.
  Deadlocks or lock contention where multiple processes are waiting for locks held by each other.
  High system load or performance issues causing delays in lock processing.
  Improperly terminated transactions that did not release locks.
  Enqueue server issues or communication problems between application servers and the enqueue server.
  
  
  Explanation
  When a program tries to lock an object (e.g., a database record), it sends a lock request to the enqueue server. If the lock is already held by another process, the requesting process waits for a certain timeout period. If the lock is not granted within this timeout, the system raises the WQENQ001 error indicating the lock request expired.
  
  Solution / Troubleshooting Steps
  
  
  Identify the locked object and locking session:
  
  Use transaction SM12 to check current locks.
  Look for locks related to the object or table involved in the error.
  Identify which user/session holds the lock.
  
  
  
  Analyze long-running or stuck transactions:
  
  Use SM50 or SM66 to check for long-running work processes.
  Check if any process is stuck or waiting for a lock.
  Investigate and terminate or resolve problematic sessions if necessary.
  
  
  
  Check for deadlocks:
  
  Review system logs (transaction SM21) for deadlock messages.
  Analyze enqueue trace files if enabled.
  
  
  
  Increase lock wait timeout (if appropriate):
  
  The timeout value can be adjusted in the enqueue parameters, but this is usually a last resort.
  Parameter: rdisp/enq_timeout (default is 120000 ms = 2 minutes).
  Increasing this value allows longer wait times but may delay error detection.
  
  
  
  Restart enqueue server (if necessary):
  
  If the enqueue server is unresponsive or has issues, restarting it can clear stale locks.
  Use transaction SM12 to check locks before and after restart.
  Coordinate with users to avoid data loss.
  
  
  
  Optimize application logic:
  
  Review custom code or standard processes to ensure locks are held for the shortest possible time.
  Avoid unnecessary locking or long transactions.
  
  
  
  Check system performance:
  
  High CPU or database load can delay lock processing.
  Monitor system performance and tune as needed.
  
  
  
  
  Related Information
  
  Transaction SM12: Display and manage lock entries.
  Transaction SM50 / SM66: Monitor work processes and system-wide processes.
  Transaction SM21: System log for error and warning messages.
  Enqueue Server: Central lock management in SAP.
  SAP Note references (search SAP Support Portal for WQENQ001 or enqueue lock timeout issues).
  Locking concepts in SAP: Understanding enqueue locks and their management.
  
  
  Summary
  
  
  
  Aspect
  Details
  
  
  
  
  Error
  WQENQ001: Lock request expired after &1 ms
  
  
  Cause
  Lock request timeout due to lock contention or long-held locks
  
  
  Solution
  Check locks (SM12), identify blocking sessions, resolve deadlocks, possibly increase timeout, optimize transactions, restart enqueue server if needed
  
  
  Tools
  SM12, SM50, SM66, SM21
  
  
  
  
  If you provide more context (e.g., which transaction or program triggered the error), I can help with more specific advice.