DCMT DISPLAY LOCKS Command

DCMT DISPLAY LOCKS displays information about various types of locks that are currently in effect.
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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.
    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 "Administrating CA IDMS Database" information in the CA IDMS documentation.