Skip to content
CA IDMS Reference - 19.0
Documentation powered by DocOps

DCMT DISPLAY LOCKS Command

Last update November 28, 2017

DCMT DISPLAY LOCKS displays information about various types of locks that are currently in effect.

This article describes the following information:

Syntax

►►─ DCMT ─┬───────────────────┬─ Display LOCks ─────────────────────────────►
          └─ broadcast-parms ─┘

 ►─┬─ AREa area-name ───────────────────────┬───────────────────────────────►◄
   ├─ Areas ────────────────────────────────┤
   ├─ Lterm lterm-name ─────────────────────┤
   ├─ Lterms ───────────────────────────────┤
   ├─ Statistics ───────────────────────────┤
   ├─ Stats ────────────────────────────────┤
   └─ RECord data ─┬──────────────────────┬─┘
                   └─ MEMber member-name ─┘

Parameters

  • broadcast-parms
    Indicates to execute the DCMT command on all or a list of data sharing group members.

    Note: For more information about broadcasting and broadcast-parms syntax, see the section How to Broadcast System Tasks.
  • Area
    Displays information for a specified area.
    • area-name
      Specified area name.
  • Areas
    Displays information for all areas currently in use.
  • Lterm
    Displays information for a specified LTERM.
    • lterm-name
      Specified LTERM name.
  • Lterms
    Displays information for all LTERMs currently in use.
  • Statistics/Stats
    Requests the display of statistical information associated with management of transaction locks.
  • RECord data
    Requests the display of record data entries held by a member of a data sharing group.
    • MEMber member-name
      Specifies the name of the member for which record data entries are to be displayed. If member-name is omitted, the record data entries held by the member on which the command is executed are displayed.

Usage

About Areas

The following fields describe information about areas:

Field Value
Area The area name.
Lterm The LTERM name currently using the area.
User The authorization ID of the user signed on to the LTERM.
Task The currently executing task name.
TR+N The number of transient locks plus null locks placed on the area.
IS The number of INTENT SHARE locks placed on the area.
IX The number of INTENT EXCLUSIVE locks placed on the area.
S The number of SHARE locks placed on the area.
U The number of UPDATE locks placed on the area.
UIX The number of UPDATE INTENT EXCLUSIVE locks placed on the area.
X The number of EXCLUSIVE locks placed on the area.

About Logical Terminals

The following fields describe information about LTERMs:

Field Value
Lterm The LTERM name.
User The authorization ID of the user signed on to the LTERM.
Task The currently executing task name.
Notfy The number of outstanding NOTIFY locks associated with the LTERM.
Share The number of outstanding LONGTERM SHARE locks associated with the LTERM.
Excl The number of outstanding LONGTERM SHARE locks associated with the LTERM.

Display for DCMT DISPLAY LOCK STATISTICS

The following information is displayed if the LOCK STATISTICS option is specified:

  • For each of local transaction locks, local page locks, global proxy locks and global resource locks, the following information:
    • The number of lock requests issued
    • The number of locks currently held
  • For each of local transaction locks, global proxy locks and global resource locks, the following information:
    • The number of record data entries held for global locks
    • The number of times a task waited on a lock request
    • The number of locks denied due to conflicts
  • For global proxy and resource locks, the following information:
    • The number of times the CA IDMS contention exit was invoked for a new contention situation
    • The number of times the CA IDMS contention exit was invoked to resolve contention
    • The number of times the CA IDMS notify exit was invoked to help resolve contention or to inform of DBMS activity for a record on which this system holds a notify lock
    • The number of times the CA IDMS notify exit downgraded a global lock in an effort to eliminate contention
    • The number of times the CA IDMS notify exit released a global lock in an effort to eliminate contention
    • The number of times the CA IDMS notify exit upgraded local locks on resources represented by a proxy to global local in order to provide a finer level of contention management
  • The number of notify, longterm exclusive and longterm share locks that have been acquired and that are currently held.
  • The number of cross-member notifications of DBMS activity that were issued by this system and that were received by this system as a result of notify locks placed on proxies and db-keys.
  • The number of proxy control blocks that were created, released, reused for the same proxy before being released, stolen from another proxy for which no lock was held.
  • The value of the SYSLOCKs sysgen parameter. This parameter influences the amount of storage initially allocated for a number of the lock-related control blocks.
  • Information on storage overflows for each of the following types of control blocks: session, lock class, resource, XES lock request block and proxy. The following statistics are displayed for each:
    • The number of times a new overflow situation occurred
    • The number of times storage was acquired to increase the available number of control blocks
    • The current amount of overflow storage in use
    • The maximum amount of overflow storage at any one time
  • The number of times a longterm or notify lock was upgraded to a new mode and of those, the number that occurred without internally acquiring a new lock and the number that were denied due to a deadlock situation.
  • The number of times the lock manager scanned all outstanding locks in order to locate and release those for a failing task.
  • The number of times the lock manager eliminated duplicate kept locks for a task.

Display for DCMT DISPLAY LOCK RECORD DATA

The following information is displayed if the RECORD DATA option is specified:

  • For each record data entry held on behalf of the specified member, the following information:
    • The lock structure connect id assigned to the member by the operating system
    • The version of the lock structure connection assigned by the operating system
    • The type of resource represented by the record data entry: a "P" indicates a proxy, an "R" indicates an area or db-key
    • The resource identifier of the resource represented by the record data entry
    • The lock mode held by the member on the resource
    • A logical deletion indication. A "Y" in this field indicates that the record data entry is logically deleted
    • The CA IDMS/DC task identifier that resulted in the record data entry being created

Example

DCMT DISPLAY LOCKS AREAS

      DISPLAY LOCKS AREAS
     *** Area Locks ***
AREA                        LTERM    USER     TASK   TR+N IS IX  S  U UIX  X
AEDB.AE-AREA                *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AE-AREA2               *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AE-AREA3               *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AE-AREA4               *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AE-INDEX-AREA          *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AE-INDEX-AREA2         *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-A1IX-REGION       *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-A2IX-REGION       *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-A3IX-REGION       *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-A4IX-REGION       *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-A5IX-REGION       *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-PIX-REGION        *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AEQC-REC-REGION        *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDB.AETEST-AREA            *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDICT.DDLDCLOD             *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
AEDICT.DDLDML               *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
ASFDICT.DDLDCLOD            *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
ASFDICT.DDLDML              *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
ASFDICT.IDMSR-AREA          *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
ASFDICT.IDMSR-AREA2         *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0
              PAGE 001 - NEXT PAGE:

DCMT DISPLAY LOCKS LTERMS

      DISPLAY LOCKS LTERMS
     *** Notify/Longterm Locks by Lterm ***
LTERM    USER               TASK     NOTFY SHARE  EXCL
CONSOLE                     *SYSTEM*     0     0     0
LCCIQ301                    *SYSTEM*     0     0     0
LCCIQ302                    *SYSTEM*     0     0     0
LCCIQ303                    *SYSTEM*     0     0     0
LCCIQ304                    *SYSTEM*     0     0     0
LCCIQ305                    *SYSTEM*     0     0     0
UCFLT01                     *SYSTEM*     0     0     0
UCFLT02                     *SYSTEM*     0     0     0
UCFLT03                     *SYSTEM*     0     0     0
UCFLT04                     *SYSTEM*     0     0     0
UCFLT07                     *SYSTEM*     0     0     0
UCFLT08                     *SYSTEM*     0     0     0
VL10301                     *SYSTEM*     0     0     0
VL10302                     *SYSTEM*     0     0     0
VL10303                     DCMT         0     0     0
VL10304                     *SYSTEM*     0     0     0
VL10305                     *SYSTEM*     0     0     0
VL10306                     *SYSTEM*     0     0     0
VL10307                     *SYSTEM*     0     0     0
VL10308                     *SYSTEM*     0     0     0
              PAGE 001 - NEXT PAGE:

DCMT DISPLAY LOCKS AREA area-name

      DISPLAY LOCKS AREA EMPDICT.DDLDML
     *** Area Locks ***
AREA                        LTERM    USER     TASK   TR+N IS IX  S  U UIX  X
EMPDICT.DDLDML              *NONE*   *NONE*   *NONE*    0  0  0  0  0   0  0

DCMT DISPLAY LOCKS LTERM lterm-name

      DISPLAY LOCKS LTERM VL10310
     *** Notify/Longterm Locks by Lterm ***
LTERM    USER               TASK     NOTFY SHARE  EXCL
VL10310                     *SYSTEM*     0     0     0

DCMT DISPLAY LOCKS STATS

DISPLAY LOCK STATS

                       *** Transaction Lock Statistics ***

                   Local Trans      Local Page    Global Proxy Global Resource

Lock Requests           101393            7666           15567           14237

Locks Held                  12             666            1085               0

Rec Data Held                                              802               0

Waits                        0                            5245            5869

Locks Denied                46                               0              35

New Contention                                            1026             403

Contention Xit                                            3905            1463

Notify Xit                                                 850             650

 Downgrades                                                103             306

 Releases                                                   86             101

 Upgrade Posts                                             340

                    - - - -  Notify/Longterm Stats - - - -

                            Notify        Longterm Share       Longterm Update

Acquired                     36129                     0                     0

Held                             0                     0                     0

Global Notifies                Out                    In

          Proxy                  0                     0

       Resource                 48                    40

                    - - - - -  Proxy Management  - - - - -

                       Created           Freed          Reused   Stolen

                          2748            1743             501     7141

                    - - - - - Storage Management - - - - -

SYSLOCKs value:           5000

                  # Times Ovfl   # Ovfl Getstg  Curr Ovfl Size   Ovfl Size HWM

Overall:                     1              13          189184          189184

   Session:                  0               0               0               0

     Class:                  0               0               0               0

  Resource:                  1               7          136192          136192

  XES Reqs:                  0               0               0               0

     Proxy:                  1               6           52992           52992

                    - - - - - -  Miscellaneous - - - - - -

Upgrade Reqs:        31405    In Place:       26481     Denied:   35

Cleanup Calls:           0    Compression Calls:                   7

DCMT DISPLAY LOCK RECORD DATA

      DISPLAY LOCK RECORD DATA
Record data entries for: SYSTEM74
 ID   Version   Type         Resid         Mode  Ldel    Task
 02   00020CD5    P    00000008 000124FF    X+                99
 02   00020CD5    P    000F0008 000A8E4F    X+               144
 02   00020CD5    P    000F0008 000A7103    X+               144

More Information

  • For more information about notify and longterm locks, see the Navigational DML Administrating section.
  • For more information about data sharing and global locking, see the Database Administration Guide.
Was this helpful?

Please log in to post comments.