IFCID 002 - Data Sharing Locking Data

This topic shows detailed information about "Record Trace - IFCID 002 - Data Sharing Locking Data".

Record trace - IFCID 002 - Data Sharing Locking Data

The field labels shown in the following sample layout of "Record Trace - IFCID 002 - Data Sharing Locking Data" are described in the following section.

                                               DATA SHARING LOCKING DATA
LOCK REQ (P-LOCKS)                68965   SYNCH.XES - LOCK REQ             608641   SUSPENDS - IRLM GLBL CONT        5099
UNLOCK REQ (P-LOCKS)              65415   SYNCH.XES - CHANGE REQ            22225   SUSPENDS - XES GLBLL CONT         228
CHANGE REQ (P-LOCKS)               2288   SYNCH.XES - UNLOCK REQ           632660    
NOTIFY MESSAGES SENT              18566   ASYNCH.XES - RESOURCES              662   INCOMPAT RETAINED LOCK              0
NOTIFY MESSAGES RECEIVED          36866   P-LOCK/NOTIFY EXITS ENGINES         500   P-LOCK/NFY EX.ENGINE N/A            0
PSET/PART P-LOCK NEGOTIAT.         2207   PAGE P-LOCK NEGOTIAT.                 3   OTHER P-LOCK NEGOTIAT .          1321
P-LOCK CHANGE DURING NEG.          2433   FALSE CONTENTIONS                  2007
SYNC-ASYNC XES CONV               37563   FLMG COUNTS PER                  SUBSYS   NO DELAY LOCK REQ REJECTS           0

LOCK REQ (P-LOCKS)

The number of lock requests for P-locks.

Field Name: QTGSLPLK

SYNCH.XES - LOCK REQ

The number of P/L-lock requests propagated to z/OS XES synchronously.

This number is not incremented if the request is suspended before going to XES.

Field Name: QTGSLSLM

SUSPENDS - IRLM GLBL CONT

The number of suspensions due to IRLM global resource contention. All IRLM lock states were in conflict on the same resource.

Global contention requires intersystem communication to resolve the lock conflict whereas local contention does not.

Field Name: QTGSIGLO

UNLOCK REQ (P-LOCKS)

The number of unlock requests for P-locks.

Field Name: QTGSUPLK

SYNCH.XES - CHANGE REQ

The number of change requests propagated to z/OS XES synchronously, including logical and physical locks.

This number is not incremented if the request is suspended before going to XES.

Field Name: QTGSCSLM

SUSPENDS - XES GLBLL CONT

The number of suspensions due to z/OS XES global resource contention. The z/OS XES lock states were in conflict but the IRLM lock states were not.

IRLM has many lock states but XES is only aware of the exclusive and shared lock states.

Field Name: QTGSSGLO

CHANGE REQ (P-LOCKS)

The number of change requests for P-locks.

Field Name: QTGSCPLK

SYNCH.XES - UNLOCK REQ

The number of unlock requests propagated to z/OS XES synchronously, including logical and physical locks.

This number is not incremented if the request is suspended before going to XES.

Field Name: QTGSUSLM

NOTIFY MESSAGES SENT

The number of notify messages sent.

Field Name: QTGSNTFY

ASYNCH.XES - RESOURCES

The number of resources propagated by IRLM to z/OS XES asynchronously, including logical and physical locks.

This can happen when new inter-DB2 interest occurs on a parent resource or when a request completes after the requester's execution unit was suspended.

Field Name: QTGSKIDS

INCOMPAT RETAINED LOCK

The number of global lock or change requests denied or suspended due to an incompatible retained lock.

Field Name: QTGSDRTA

NOTIFY MESSAGES RECEIVED

The number of notify messages received.

Field Name: QTGSNTFR

P-LOCK/NOTIFY EXITS ENGINES

The maximum number of engines available for physical lock exit or notify exit requests.

Field Name: QTGSPEMX

P-LOCK/NFY EX.ENGINE N/A

The number of times an engine is not available for physical lock exit or notify exit requests.

Field Name: QTGSPEQW

PSET/PART P-LOCK NEGOTIAT.

The number of times this DB2 was driven to negotiate a partition or page set physical lock due to changing inter-DB2 interest levels on the partition or page set.

Field Name: QTGSPPPE

PAGE P-LOCK NEGOTIAT.

The number of times this DB2 negotiated a page physical lock because of physical lock contention within DB2.

Field Name: QTGSPGPE

OTHER P-LOCK NEGOTIAT .

The number of times this DB2 was driven to negotiate a physical lock type other than page set, partition, or page.

Field Name: QTGSOTPE

P-LOCK CHANGE DURING NEG.

The number of times a physical lock change request was issued during physical lock negotiation.

Field Name: QTGSCHNP

FALSE CONTENTIONS

The total number of false contentions for LOCK and UNLOCK requests. A false contention occurs when different resource names hash to the same entry in the coupling facility (CF) lock table. The CF detects contention within the hash entry, and XES uses intersystem messaging to determine that no actual resource contention exists.

Note: The QTGSFCON flag indicates whether the false contention is reported at subsystem(=1) or LPAR level (=0).

Field Name: QTGSFLMG

SYNC-ASYNC XES CONV

The number of synchronous to asynchronous heuristic conversions for LOCK requests in XES. This conversion is done when XES determines that it is more efficient to drive the request asynchronously to the coupling facility (CF).

Field Name: QTGSFLSE

FLMG COUNTS PER

Flags describing QTGS counters:

ON: QTGSFLMG counts per subsystem (SUBSYS)
OFF: QTGSFLMG counts per LPAR

Field Name: QTGSFLGS

NO DELAY LOCK REQ REJECTS

The total number of failed DB2 lock requests to XES to process without delay. XES rejects the lock request because it could not process it synchronously.

Field Name: QTGSCREJ

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