How To Fix DB6120 - Too many exclusive lock escalations occur in the system

SAP Error Message - Details

• Message type: E = Error

• Message class: DB6 - DB6: Alert Monitoring and Alert Configuration

• Message number: 120

• Message text: Too many exclusive lock escalations occur in the system

What causes this issue?

As a transaction is exclusively accessing too many records in a table,
the system has locked the entire table. Other transactions can no
longer access any records in the table, even to read them.

System Response

The table-wide exclusive lock is significantly obstructing other
running transactions and should generally be avoided.

How to fix this error?

Increase the amount of memory available to an application to store
locks using the database parameters LOCKLIST and MAXLOCK.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message DB6120 - Too many exclusive lock escalations occur in the system ?

  The SAP error message DB6120 indicates that there are too many exclusive lock escalations occurring in the system. This typically happens when the database is trying to manage locks for transactions, and it is unable to do so efficiently, leading to performance issues and potential deadlocks.
  Cause:
  
  High Lock Contention: This can occur when multiple transactions are trying to access the same data simultaneously, leading to a situation where the database has to escalate from row-level locks to page-level or table-level locks.
  Insufficient Lock Resources: If the database is configured with insufficient resources to handle the number of locks being requested, it may lead to escalations.
  Long-Running Transactions: Transactions that hold locks for an extended period can contribute to lock contention and escalations.
  Poorly Designed Applications: Applications that do not manage locks efficiently can lead to excessive lock escalations.
  
  Solution:
  
  Analyze Lock Usage: Use transaction codes like SM12 (for lock entries) and SM21 (for system logs) to analyze lock contention and identify problematic transactions.
  Optimize Transactions: Review and optimize long-running transactions to ensure they hold locks for the shortest time possible. This may involve breaking down large transactions into smaller ones.
  Increase Lock Resources: Depending on the database being used, you may need to increase the configuration settings related to lock resources. This could involve adjusting parameters in the database configuration.
  Database Tuning: Perform database tuning to improve performance and reduce lock contention. This may include indexing strategies, query optimization, and adjusting isolation levels.
  Review Application Logic: Ensure that the application logic is designed to minimize lock contention. This may involve changing the way data is accessed or updated.
  Monitor and Adjust: Continuously monitor the system for lock escalations and adjust configurations as necessary.
  
  Related Information:
  
  SAP Notes: Check SAP Notes related to DB6120 for specific recommendations and patches that may address the issue.
  Database Documentation: Refer to the documentation for the specific database being used (e.g., Oracle, SQL Server, HANA) for best practices on managing locks and performance tuning.
  Performance Monitoring Tools: Utilize SAP's performance monitoring tools to gain insights into system performance and lock behavior.
  
  By addressing the underlying causes of lock escalations and optimizing the system, you can reduce the occurrence of the DB6120 error and improve overall system performance.