Identifying the Lead Blocker in a Chain

Find a process that is blocking several other processes.

When Process A blocks Process B, which blocks Process C—and so on—the blocking processes form a chain.

  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 Blocked Processes.
    You see a table with information about blocked and blocking processes, including the lock requests on the basis of which processes are blocked.
  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. The table on the Blocked Processes tab has an entry for each lead blocker; click the arrow to expand the entry and show all the blocked processes in the chain.
    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.
  6. Select a process to populate the tabs at the bottom of the screen with information about that process.
  7. Click the tabs to see:
    Option Description
    Details Details about the selected process, including the initiating program, transaction information, and network statistics
    SQL The SQL statement and query plan for the selected process
    Wait Events Information about wait events for the selected process, including number of waits, wait times, and wait descriptions
  8. (Optional) Click the All Processes tab at the top of the window.
    In the table below the bar graph, rows that are highlighted in yellow indicate blocking processes. Rows that are highlighted in red indicate blocked processes.
For information on handling blocked processes, see the Performance and Tuning Series: Locking and Concurrency Control. You can find SAP Adaptive Server Enterprise documentation on the SAP Product Documents Web site at
Related tasks
Displaying Wait Events for a Process
Displaying the SQL Query Associated with a Process
Identifying Resource-Intensive Processes
Identifying Blocked Processes and Blocking Processes
Terminating Blocking Processes
Related reference
Process Statistics and Details