Error
Error Code:
146
SAP S/4HANA Error 146: Transaction Lock Acquisition Failure
Description
Error 146 indicates that a transaction failed to acquire a necessary lock on a resource (e.g., a database table row or object) because the resource was already in use by another process. This occurs when the system is configured not to wait for the lock to become available, leading to immediate failure rather than a delay.
Error Message
ERR_TX_LOCK_ACQUISITION_FAIL: Resource busy and NOWAIT specified
Known Causes
4 known causesHigh Transaction Concurrency
Multiple users or automated processes are simultaneously attempting to access and modify the same critical data records or system resources.
Long-Running Transactions
An existing business transaction or report is holding a lock on the required resource for an extended duration, blocking other operations.
Suboptimal Application Logic
Inefficient custom developments or application logic are acquiring locks unnecessarily or holding them for longer than required by the business process.
Conflicting Batch Jobs
Scheduled background jobs or reports are accessing and locking the same resources that foreground transactions require at the same time.
Solutions
3 solutions available1. Identify and Release Blocking Transactions medium
Locate and terminate the transaction that is holding the lock.
1
Access the SAP system's transaction monitor (SM12).
2
Filter the lock entries to identify the resource that is currently locked. Look for entries related to the transaction or object that is causing the error.
3
Identify the user and program associated with the blocking lock entry.
4
If the blocking transaction is not critical or is hung, you can attempt to delete the lock entry. **Caution:** This can lead to data inconsistencies if done incorrectly. Only proceed if you understand the implications and have a rollback plan.
5
Alternatively, contact the user of the blocking transaction to ask them to complete or cancel their process.
2. Optimize Application Logic to Avoid NOWAIT advanced
Modify the application code to handle lock contention more gracefully.
1
Analyze the application code that is triggering the error. Identify where the `NOWAIT` option is being used in database operations or SAP enqueue mechanisms.
2
If possible, replace `NOWAIT` with a mechanism that allows for retries with a short delay or a more robust error handling strategy. This might involve using SAP's enqueue server functionalities with appropriate timeout parameters.
Example pseudo-code for a retry mechanism:
abap
DO 5 TIMES.
TRY.
CALL FUNCTION 'ENQUEUE_E_LOCK_OBJECT' ...
IF sy-subrc = 0.
" Lock acquired successfully
EXIT.
ENDIF.
CATCH cx_sy_lock_error.
" Lock not acquired, wait and retry
WAIT UP TO 2 SECONDS.
ENDTRY.
ENDDO.
IF sy-subrc <> 0.
" Handle persistent lock failure
ENDIF.
3
For critical transactions, consider implementing optimistic locking strategies where appropriate, although this requires significant application redesign.
3. Increase System Resources and Performance Tuning medium
Address underlying system performance issues that might be causing transactions to linger.
1
Monitor system performance metrics using SAP transaction ST03N and operating system tools. Look for high CPU utilization, excessive I/O, or memory pressure.
2
Review database performance. For HANA, use tools like HANA Cockpit or SQL queries to identify slow-running queries or inefficient table scans.
Example SQL query to find long-running statements (adjust table/view names based on your HANA version):
sql
SELECT TOP 100 * FROM M_STATEMENTS WHERE EXECUTION_COUNT > 0 ORDER BY ELAPSED_TIME DESC;
3
Optimize database indexes and statistics. Ensure that the database is configured with sufficient memory and processing power for the workload.
4
Check SAP application server performance. Ensure adequate work processes are available and configured correctly.