DCMT DISPLAY Commands › DCMT DISPLAY LOCKS Command › DCMT DISPLAY LOCKS Command Usage

DCMT DISPLAY LOCKS Command Usage

About Areas

The following fields describe information about areas:

About Logical Terminals

The following fields describe information about LTERMs:

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

More Information

• For more information about notify and longterm locks, see the Navigational DML Programming Guide.
• For more information about data sharing and global locking, see the Database Administration Guide.