Identifying Blocked Processes and Blocking Processes

Find user processes that are blocked and the processes that are blocking them.

  1. In the Perspective Resources view, select the server to monitor, click the drop-down arrow, and select Monitor.
  2. In the left pane, select Processes.
  3. Click the All Processes tab.
  4. (Optional for cluster configurations) Click Select User Processes by. Choose All Instances to depict information for the entire cluster, or select a specific instance to see information for only the selected instance of the cluster.
  5. Check the table below the bar graph for rows highlighted in red, and with a lock icon, which indicate blocked processes.
    The Blocked by SPID column identifies the blocking process. Blocking processes are also shown in the table, highlighted in yellow.
  6. Click a red table row to display information about the blocked process in the Details, SQL, and Wait Events tabs at the bottom of the screen.
  7. Click the row for the blocking process (yellow) to display its information in the tabs.
    Note: Identifying the lock held by a blocking process is not always straightforward. For example, the blocking process does not necessarily hold a page lock; it might hold a table lock. For this reason, the lock request process that is blocking another process is shown, not the blocking lock.
  8. Click the Blocked Processes tab to display additional information about blocked processes, including details about the lock, the row number, the page number, and the lock configuration options.

    For nonclustered servers, the numbers of free locks, active locks, and maximum used locks are shown. For clustered servers, these values are shown on a per instance basis, and you must select Display Lock Configuration to display these values.

For information on handling blocked processes, see the locking reports chapter of the Performance and Tuning Series: Locking and Concurrency Control.
Related tasks
Displaying Wait Events for a Process
Displaying the SQL Query Associated with a Process
Identifying the Lead Blocker in a Chain
Identifying Resource-Intensive Processes
Terminating Blocking Processes
Related reference
Process Statistics and Details