LCK_M_IU_ABORT_BLOCKERS SQL Server Wait Type

Wait Type LCK_M_IU_ABORT_BLOCKERS

The wait type LCK_M_IU_ABORT_BLOCKERS is ranked #207 by Stedman Solutions and Database Health Monitor.

Wait statistics, in the context of SQL Server, refer to the amount of time that a query spends waiting to access data in the database. When a client application requests data from the database, the request is placed in a queue and the client application must wait for its turn to access the data. The time that the query spends waiting is called a "wait" and is tracked by SQL Server. This information can be used to identify potential performance bottlenecks and optimize the performance of the database. Wait statistics are commonly used by database administrators to diagnose and troubleshoot performance issues in SQL Server.


In SQL Server, locks are critical for ensuring data consistency during concurrent operations. However, certain locks can result in waits that impact performance, such as LCK_M_IU_ABORT_BLOCKERS. Understanding this wait type can help you resolve contention issues and keep your database running smoothly.

What is LCK_M_IU_ABORT_BLOCKERS?

The LCK_M_IU_ABORT_BLOCKERS wait type occurs when a session is waiting to acquire an Intent Update (IU) lock, but the requested lock is blocked by other transactions. SQL Server waits for the blocking transactions to finish or be aborted before granting the lock. IU locks are typically used when a transaction intends to modify data but hasn’t yet done so, ensuring that no other conflicting operations occur in the meantime.

In simpler terms, this wait type means SQL Server is pausing a transaction while it waits for other processes to release their locks or complete their tasks. While some waits are expected, frequent or prolonged waits can indicate underlying contention or inefficiencies in your database workload.

Why Does LCK_M_IU_ABORT_BLOCKERS Happen?

Several factors can lead to LCK_M_IU_ABORT_BLOCKERS waits, including:

  • Long-running transactions holding incompatible locks on the target data.
  • High contention for resources, such as specific tables, rows, or indexes.
  • Inefficient queries that create longer lock durations.
  • Concurrency issues during peak usage times, leading to overlapping transactions.
  • Heavy workloads with a mix of read and write operations causing lock conflicts.

Understanding and addressing these factors can help reduce contention and improve database performance.

How to Monitor LCK_M_IU_ABORT_BLOCKERS Waits

Monitoring LCK_M_IU_ABORT_BLOCKERS waits is essential for identifying their impact on your system. The Database Health Monitor is a powerful tool for tracking this wait type. Its Historic Waits Monitoring feature allows you to observe when these waits occur, how often they happen, and their impact on system performance.

Using Database Health Monitor, you can identify patterns in these waits and determine whether they are caused by inefficient queries, resource contention, or workload imbalances, enabling you to take corrective actions to optimize your SQL Server environment.

What Can You Do About LCK_M_IU_ABORT_BLOCKERS Waits?

If you notice frequent or prolonged LCK_M_IU_ABORT_BLOCKERS waits, consider these actions:

  • Analyze blocking chains using tools like Extended Events or Activity Monitor to identify and resolve transactions causing delays.
  • Optimize queries to reduce lock durations and improve efficiency.
  • Ensure indexes are properly designed to minimize contention and speed up data retrieval.
  • Adjust transaction isolation levels to balance concurrency and data consistency.
  • Partition large tables to limit the scope of locks and reduce contention.
  • Break large or long-running transactions into smaller operations to reduce the likelihood of blocking.
  • Schedule intensive tasks, such as bulk updates, during off-peak hours to avoid conflicts with other operations.

Implementing these strategies can help reduce contention and improve the overall performance of your SQL Server database.

Why Use Database Health Monitor?

The Database Health Monitor is an essential tool for tracking SQL Server wait types, including LCK_M_IU_ABORT_BLOCKERS. Its Historic Waits Monitoring feature provides actionable insights into wait trends, helping you identify and address performance bottlenecks. With Database Health Monitor, you can maintain a high-performing and reliable SQL Server environment.

Start using Database Health Monitor today to monitor and optimize your SQL Server’s performance, ensuring efficient and reliable database operations!


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Applies to

    Related Waits

    LCK_M_BU
    LCK_M_BU_ABORT_BLOCKERS
    LCK_M_BU_LOW_PRIORITY
    LCK_M_IS
    LCK_M_IS_ABORT_BLOCKERS
    LCK_M_IS_LOW_PRIORITY
    LCK_M_IU
    LCK_M_IU_LOW_PRIORITY
    LCK_M_IX
    LCK_M_IX_ABORT_BLOCKERS
    LCK_M_IX_LOW_PRIORITY
    LCK_M_RIn_NL
    LCK_M_RIn_NL_ABORT_BLOCKERS
    LCK_M_RIn_NL_LOW_PRIORITY
    LCK_M_RIn_S
    LCK_M_RIn_S_ABORT_BLOCKERS
    LCK_M_RIn_S_LOW_PRIORITY
    LCK_M_RIn_U
    LCK_M_RIn_U_ABORT_BLOCKERS
    LCK_M_RIn_U_LOW_PRIORITY
    LCK_M_RIn_X
    LCK_M_RIn_X_ABORT_BLOCKERS
    LCK_M_RIn_X_LOW_PRIORITY
    LCK_M_RS_S
    LCK_M_RS_S_ABORT_BLOCKERS
    LCK_M_RS_S_LOW_PRIORITY
    LCK_M_RS_U
    LCK_M_RS_U_ABORT_BLOCKERS
    LCK_M_RS_U_LOW_PRIORITY
    LCK_M_RX_S
    LCK_M_RX_S_ABORT_BLOCKERS
    LCK_M_RX_S_LOW_PRIORITY
    LCK_M_RX_U
    LCK_M_RX_U_ABORT_BLOCKERS
    LCK_M_RX_U_LOW_PRIORITY
    LCK_M_RX_X
    LCK_M_RX_X_ABORT_BLOCKERS
    LCK_M_RX_X_LOW_PRIORITY
    LCK_M_S
    LCK_M_S_ABORT_BLOCKERS
    LCK_M_S_LOW_PRIORITY
    LCK_M_SCH_M
    LCK_M_SCH_M_ABORT_BLOCKERS
    LCK_M_SCH_M_LOW_PRIORITY
    LCK_M_SCH_S
    LCK_M_SCH_S_ABORT_BLOCKERS
    LCK_M_SCH_S_LOW_PRIORITY
    LCK_M_SIU
    LCK_M_SIU_ABORT_BLOCKERS
    LCK_M_SIU_LOW_PRIORITY
    LCK_M_SIX
    LCK_M_SIX_ABORT_BLOCKERS
    LCK_M_SIX_LOW_PRIORITY
    LCK_M_U
    LCK_M_U_ABORT_BLOCKERS
    LCK_M_U_LOW_PRIORITY
    LCK_M_UIX
    LCK_M_UIX_ABORT_BLOCKERS
    LCK_M_UIX_LOW_PRIORITY
    LCK_M_X
    LCK_M_X_ABORT_BLOCKERS
    LCK_M_X_LOW_PRIORITY

    See Also


    All Wait Types
    LCK_M_IU_ABORT_BLOCKERS SQL Server Wait Type