12.3 Hang Manager Diagnostics and Logging
Hang Manager autonomously resolves hangs and continuously logs the resolutions in the database alert logs and the diagnostics in the trace files.
Hang Manager logs the resolutions in the database alert logs as Automatic Diagnostic Repository (ADR) incidents with incident code ORA–32701
.
You also get detailed diagnostics about the hang detection in the trace files. Trace files and alert logs have file names starting with database instance_dia0_
.
-
The trace files are stored in the
$ ADR_BASE/diag/rdbms/database name/database instance/incident/incdir_xxxxxx
directory -
The alert logs are stored in the
$ ADR_BASE/diag/rdbms/database name/database instance/trace
directory
Example 12-1 Hang Manager Trace File for a Local Instance
This example shows an example of the output you see for Hang Manager for the local database instance
Trace Log File .../oracle/log/diag/rdbms/hm1/hm11/incident/incdir_111/hm11_dia0_11111_i111.trc
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
...
*** 2016-07-16T12:39:02.715475-07:00
HM: Hang Statistics - only statistics with non-zero values are listed
current number of active sessions 3
current number of hung sessions 1
instance health (in terms of hung sessions) 66.67%
number of cluster-wide active sessions 9
number of cluster-wide hung sessions 5
cluster health (in terms of hung sessions) 44.45%
*** 2016-07-16T12:39:02.715681-07:00
Resolvable Hangs in the System
Root Chain Total Hang
Hang Hang Inst Root #hung #hung Hang Hang Resolution
ID Type Status Num Sess Sess Sess Conf Span Action
----- ---- -------- ---- ----- ----- ----- ------ ------ -------------------
1 HANG RSLNPEND 3 44 3 5 HIGH GLOBAL Terminate Process
Hang Resolution Reason: Although hangs of this root type are typically
self-resolving, the previously ignored hang was automatically resolved.
kjznshngtbldmp: Hang's QoS Policy and Multiplier Checksum 0x0
Inst Sess Ser Proc Wait
Num ID Num OSPID Name Event
----- ------ ----- --------- ----- -----
1 111 1234 34567 FG gc buffer busy acquire
1 22 12345 34568 FG gc current request
3 44 23456 34569 FG not in wait
Example 12-2 Error Message in the Alert Log Indicating a Hung Session
This example shows an example of a Hang Manager alert log on the master instance
2016-07-16T12:39:02.616573-07:00
Errors in file .../oracle/log/diag/rdbms/hm1/hm1/trace/hm1_dia0_i1111.trc (incident=1111):
ORA-32701: Possible hangs up to hang ID=1 detected
Incident details in: .../oracle/log/diag/rdbms/hm1/hm1/incident/incdir_1111/hm1_dia0_11111_i1111.trc
2016-07-16T12:39:02.674061-07:00
DIA0 requesting termination of session sid:44 with serial # 23456 (ospid:34569) on instance 3
due to a GLOBAL, HIGH confidence hang with ID=1.
Hang Resolution Reason: Although hangs of this root type are typically
self-resolving, the previously ignored hang was automatically resolved.
DIA0: Examine the alert log on instance 3 for session termination status of hang with ID=1.
Example 12-3 Error Message in the Alert Log Showing a Session Hang Resolved by Hang Manager
This example shows an example of a Hang Manager alert log on the local instance for resolved hangs
2016-07-16T12:39:02.707822-07:00
Errors in file .../oracle/log/diag/rdbms/hm1/hm11/trace/hm11_dia0_11111.trc (incident=169):
ORA-32701: Possible hangs up to hang ID=1 detected
Incident details in: .../oracle/log/diag/rdbms/hm1/hm11/incident/incdir_169/hm11_dia0_30676_i169.trc
2016-07-16T12:39:05.086593-07:00
DIA0 terminating blocker (ospid: 30872 sid: 44 ser#: 23456) of hang with ID = 1
requested by master DIA0 process on instance 1
Hang Resolution Reason: Although hangs of this root type are typically
self-resolving, the previously ignored hang was automatically resolved.
by terminating session sid:44 with serial # 23456 (ospid:34569)
...
DIA0 successfully terminated session sid:44 with serial # 23456 (ospid:34569) with status 0.
Parent topic: Resolving Database and Database Instance Hangs