Thread activity: Locks/Claims causing a thread to wait

This panel shows information about the locks that cause a thread to wait. You can use this information to determine whether a selected thread is suspended and waiting because of a locking conflict.

When a thread is suspended, this panel provides the name of the lock/claim request causing the suspension. It also provides a list of all locks/claims currently held by other threads causing the thread to be suspended.

If accounting class 2 and class 3 are not available, N/A is displayed.

The locking information is divided into the following categories:

The name of the lock request causing the suspension.
A list of all locks which are causing the thread to wait.

HEX values are displayed for lock resources, if the resource is owned by a thread on a remote LPAR, and no OMPE task is available from that LPAR, or XCF is not setup correctly.


________________ ZLOCKW   VTM     O2       V550./I SN13 07/11/13 13:30:43   2 
> Help PF1               Back PF3               Up PF7                Down PF8 
                                                                               
>       THREAD INFORMATION:  Enter a selection letter on the top line.         
                                                                               
> A-THREAD DETAIL B-LOCK COUNTS *-LOCK WAITS     D-LOCKS OWNED  E-GLOBAL LOCKS 
> F-CURRENT SQL   G-SQL COUNTS  H-DISTRIBUTED    I-BUFFER POOL  J-GROUP BP     
> K-PACKAGES      L-RES LIMIT   M-PARALLEL TASKS N-UTILITY      O-OBJECTS      
> P-CANCEL THREAD Q-DB2 CONSOLE D-DSN ACTIVITY   S-APPL TRACE   T-ENCLAVE      
> U-LONG NAMES                  W-ACCEL ACTIVITY                               
===============================================================================
>                    LOCKS/CLAIMS CAUSING A THREAD TO WAIT                     
 PLAN                                                                          
+ Thread:  Plan=DSNBIND   Connid=BATCH    Corrid=HONGAZ91     Authid=HONG      
+ Attach:  BATCH          JOB Name=HONGAZ91                   JOB Asid=  56    
+ Luwid=DEIBMIPS.IPSASN13.CBA4B01943B3=5791                                    
 wait                                                                          
+      Thread Is Currently Suspended Waiting To Obtain The Following Lock      
+      Type=COLL  Level=X   Resource = Coll=KO2OM520                           
+                                                                              
+      Wait For Lock Time  =   10 Seconds     # to repeat lock timeout =    3  
+      IRLM Time Out Value =   60 Seconds                                      
+                                                                              
+      The Lock Being Waited On Is Owned By The Following User(s)              
+      Plan               Connid             Corrid                 Lvl        
+      --------           --------           ------------           ---        
+      DSNBIND            BATCH              HONGEZ91                 X        
===============================================================================

Highlighting

Highlighted fields indicate that an exception relating to that field is tripped.

To display the Exception Messages for Thread Exceptions panel, type E.A. On this panel, you can determine the exceptions that have tripped.

Table 1. Highlighted fields on Locks/Claims Causing a Thread to Wait panel
Field	Exception	Reason
Plan	ARCM	Backout requires an archive tape log mount.
	ETIM	This thread has reached the Elapsed Time threshold value.
	GETP	The Getpage to Read I/O ratio indicates poor read efficiency.
	INDB	The thread is indoubt and terminated.
	PREF	The Sequential Prefetch rate is high.
	RIO	The synchronous Read I/O rate is high.
	PGUP	The rate for system page updates is high.
	WTRE	The lock has been waiting for a resource for too long.

Navigation

For additional information about:

Locks that are owned by a thread, an SQL activity, a general thread activity, or a resource limit activity, or to go to the Db2 system console, type the appropriate option letter on the top line and press ENTER.
Related topics, select one of the options on the top of the panel.
Other topics, use the PF keys.

Fields

Thread identifier: This information identifies the thread to which the information in this panel applies.

Plan: The Db2 plan name of the active thread.
Connid: The Db2 connection identifier of the active thread.
Corrid: The Db2 correlation identifier of the active thread. If the correlation is not set, N/A is displayed.
Authid: The Db2 authorization identifier of the active thread.
Attach: Depending on the type of connection, the appropriate information is displayed.; Attach information is displayed only if the thread is a distributed allied thread (not for distributed database access threads).

Connection Type

Batch

The MVS jobname and ASID.

Note: For threads from remote Db2, the MVS job name is N/A.

CICS®

The CICS jobname, task name, task number, terminal ID, and thread type. The thread type is:

Pool: The thread in use is a pool thread.
Entry: The thread in use is a nonprotected entry thread.
Prot: The thread in use is a protected thread. Protected threads are defined in an RCT entry definition using the THRDS operand.

IMS

The IMS region number, transaction name, region name, and terminal ID (LTERM).

RRSAF

The MVS job name and ASID.

Note: For threads from remote Db2, the MVS job name is N/A.

System

The originating Db2 job name and the resource manager that is the source of the thread. An additional line below the Attach line identifies the user thread, if any, being served by the system thread.

TSO

The TSO user ID and region ASID.

Utility

No additional information.

Db2

The Db2 subsystem identifier.

MVS

The MVS system identifier.

ORIGAUTH

The original (primary) Db2 authorization identifier of the thread. This field displays only when the original identifier is different from the Authid.

Package identifier: This information identifies the package to which the information in this panel applies.

Package: The Db2 package name of the active thread. Up to 18 characters of the package name are returned.
Collection: The package collection identifier. This field is displayed only if a package is being used.

Distributed thread identifier: The following fields are displayed when the thread has a distributed relationship with a remote Db2 subsystem.

Type

The distributed thread type.

Distributed Allied: A requesting thread; one that has issued an SQL call to a remote Db2® location.
Database Access: A responding thread; one that is serving a remote Db2 location by responding to an SQL call.

Luwid

This value consists of two parts: the logical unit-of-work ID (luw-id) and a token. The token can be used in place of the luw-id in any Db2 command that accepts luw-id as input. Format:


luw-id=token

The luw-id consists of the network name, the originating VTAM® LUNAME, and a unique identifier (separated by periods). Thus, the Luwid field displays data such as the following:


USCACO01.O2D22A.A1FE8E04B9D4=8

Drain information:

Type

The type of object being drained. Possible object types are:

TS: Tablespace
TS PART: Data Partition
IX: Indexspace
IX PART: Index Partition

Class

The drain class. Possible classes are:

CS: Drain all CS read access to object.
RR: Drain all RR access to object.
Write: Drain all write access to object.

Resource

The name of the resource being drained. This includes the database name, pageset name, and the partition number (if any).

Claim information:

Plan

The planname of the thread claiming the resource.

Connid

The connection identifier of the thread claiming the resource.

Corrid

The correlation identifier of the thread claiming the resource.

Class

The claim class. Possible classes are:

CS: Cursor Stability
RR: Repeatable Read
Write: Write access

Lock wait information:

Type

The lock type on which the thread is waiting.

Level

The level or state (mode) of the lock request. This information describes the level of resource access demanded by the lock request.

Resource

The resource for which the user is waiting. The content of the Resource field is dependent on lock type.

The resource varies depending upon the type of lock held. This field displays the following resources:

Lock Type: Resource
ALBP: BP=buffer pool ID
BIND: COLL=collection ID PKG=package name
BMBA: BMC_MBAO or BMC_MBAR
BPPS: BP=buffer pool ID, DB=database name, PS=pageset name
CDRN: DB=database name PS=pageset name PT=partition
COLL: COLL=collection ID
DBEX: DB=database name PS=pageset name PT=partition
DBXU: HASH CLASS=class number
DGTT: URID=unit of recovery ID
DPAG: DB=database name PS=pageset name PG=page
DSET: DB=database name PS=pageset name PT=partition
DTBS: DB=database name
GRBP: BP=buffer pool ID
HASH: DB=database name PS=pageset name PG=page
IEOF: DB=database name PS=pageset name PT=partition
IPAG: DB=database name PS=pageset name PG=page
LBLK: DB=database name PS=pageset name
MDEL: DB=database name PS=pageset name
PALK: DB=database name PS=pageset name PT=partition
PBPC: BP=buffer pool ID
PCDB: DB=database name
PDBD: DB=database name
PDSO: DB=database name PS=pageset name
PITR: DB=database name PS=pageset name PT=partition
PPAG: DB=database name PS=pageset name PG=page
PPSC: DB=database name PS=pageset name PT=partition
PPSP: DB=database name PS=pageset name PT=partition
PRLF: DB=database name PS=pageset name PT=partition
PSET: DB=database name PS=pageset name
PSPI: DB=dataset name PS=pageset name
RDRN: DB=dataset name PS=pageset name PT=partition
RGDA: DB=database name PS=pageset name PG=page
ROW: DB=database name PS=pageset name PG=page
RSTR: BMC-RSTP
SDBA: DB=dataset name PS=pageset name
SKCT: PLAN=plan name
SKPT: TOKEN is the consistency token (CONTOKEN) column from SYSIBM.SYSPACKAGE. Token=token
SPRC: SYS_PITR
SREC: DB=database name TS=tablespace name
TABL: DB=database name PS=pageset name
UNDT: Resource ID (in hexadecimal)
UTEX: UTEXEC
UTID: UID=utility identifier
UTOB: DB=database name PS=pageset name PT=partition
UTSE: UTSERIAL
WDRN: DB=database name PS=pageset name PT=partition

Note: DB=database name can be represented as a DBID=identifier, which is the decimal identifier of the database. PSID=identifier can be represented as PSID=identifier, which is the decimal identifier of the table space or index space.

Wait For Lock Time

The time that Db2 has been waiting for the locked resource.

# To Repeat Lock Timeout

The number of times Db2 repeats the lock timeout.

IRLM Time Out Value

The maximum time that Db2 waits for a locked resource. When Db2 reaches the maximum value, it rolls back the unit of work.

Level

The level or state (mode) of the lock request. This information describes the level of resource access demanded by the lock request.

Lock owner information:

Plan: The Db2 plan name of the active thread.
Connid: The Db2 connection identifier of the active thread.
Corrid: The Db2 correlation identifier of the active thread.
Lvl: The lock level owned.