7.2 Optional Configuration for Hang Manager

You can adjust the sensitivity, and control the size and number of the log files used by Hang Manager.

Sensitivity

If Hang Manager detects a hang, then Hang Manager waits for a certain threshold time period to ensure that the sessions are hung. Change threshold time period by using DBMS_HANG_MANAGER to set the sensitivity parameter to either Normal or High. If the sensitivity parameter is set to Normal, then Hang Manager waits for the default time period. However, if the sensitivity is set to High, then the time period is reduced by 50%.

By default, the sensitivity parameter is set to Normal. To set Hang Manager sensitivity, run the following commands in SQL*Plus as SYS user:

  • To set the sensitivity parameter to Normal: 
    exec dbms_hang_manager.set(dbms_hang_manager.sensitivity, dbms_hang_manager.sensitivity_normal);
  • To set the sensitivity parameter to High: 
    exec dbms_hang_manager.set(dbms_hang_manager.sensitivity, dbms_hang_manager.sensitivity_high);

Size of the Trace Log File

The Hang Manager logs detailed diagnostics of the hangs in the trace files with _base_ in the file name. Change the size of the trace files in bytes with the base_file_size_limit parameter. Run the following command in SQL*Plus, for example, to set the trace file size limit to 100 MB: 
exec dbms_hang_manager.set(dbms_hang_manager.base_file_size_limit, 104857600);

Number of Trace Log Files

The base Hang Manager trace files are part of a trace file set. Change the number of trace files in trace file set with the base_file_set_count  parameter. Run the following command in SQL*Plus, for example, to set the number of trace files in trace file set to 6: 
exec dbms_hang_manager.set(dbms_hang_manager.base_file_set_count,6);

By default, base_file_set_count parameter is set to 5.