ARCHIVE LOG

 

Use ARCHIVE LOG as part of your backup procedure. It takes a copy of the current active log (or both logs if you are using dual logging).

In detail, it does the following:

  1. Truncates the current active log data sets.
  2. Continues logging, switching to the next active log data set.
  3. Starts a task to off-load the data sets.
  4. Archives previous active log data sets not yet archived.

If the MODE(QUIESCE) parameter is used, the ARCHIVE LOG command quiesces (suspends) all user update activity on the current active log before the off-load process. Once a system-wide point of consistency is reached (that is, when all currently active update users have reached a commit point), the current active log data set is immediately truncated, and the off-load process is initiated. The resulting point of consistency is captured in the current active log before it is off-loaded.

Normally, control returns to the user immediately, and the quiescing is done asynchronously. However, if the WAIT(YES) parameter is used, the quiescing is done synchronously, and control does not return to the user until it has finished.

Synonym: ARC LOG 

ARCHIVE LOG
 
>>-ARCHIVE LOG-------------------------------------------------->
 
>--+---------------------------------------------+-------------->
   |                               .-WAIT(NO)--. |
   +-MODE(QUIESCE)--+-----------+--+-----------+-+
   |                '-TIME(nnn)-'  '-WAIT(YES)-' |
   '-CANCEL OFFLOAD------------------------------'
 
   .-CMDSCOPE(' ')------------.
>--+--------------------------+--------------------------------><
   |                     (1)  |
   '-CMDSCOPE(qmgr-name)------'

Notes:

  1. Valid only on full function WebSphere MQ for z/OS when the queue manager is a member of a queue-sharing group.

 

Parameter descriptions

All the parameters are optional. If none are specified, the current active log data sets are switched and off-loaded immediately.

CANCEL OFFLOAD
Cancels any off-loading currently in progress and restarts the off-load process. The process starts with the oldest active log data set and proceeds through all the active data sets that need off-loading.

Use this command only if the off-load task does not appear to be working, or if you want to restart a previous off-load attempt that failed.

CMDSCOPE
This parameter specifies how the command is executed when the queue manager is a member of a queue-sharing group.

CMDSCOPE cannot be used for commands issued from the first initialization input data set CSQINP1.

' '
The command is executed on the queue manager on which it was entered. This is the default value.

qmgr-name
The command is executed on the queue manager you specify, providing the queue manager is active within the queue-sharing group.

You can specify a queue manager name, other than the queue manager on which the command was entered, only if you are using a queue-sharing group environment and if the command server is enabled.

MODE(QUIESCE)
Stops any new update activity on the queue manager, and brings all existing users to a point of consistency after a commit. When this state is reached, or the number of active users is zero, the current active log is archived.

The time that the queue manager waits to reach such a state is limited to the value specified by QUIESCE in the CSQ6ARVP system parameter macro. The value of QUIESCE can be overridden by the TIME parameter of this command. If activity has not quiesced in that time, the command fails; no off-load is done, and logging continues with the current active log data set.

TIME(nnn)
Overrides the quiesce time period specified by the QUIESCE value of the CSQ6ARVP system parameter macro.

nnn is the time, in seconds, in the range 001 through 999.

To specify the TIME parameter, also specify MODE(QUIESCE).

If you specify the TIME parameter, specify an appropriate value for the quiesce period. If you make the period too short or too long, one of the following problems might occur:

  • The quiesce might not be complete

  • WebSphere MQ lock contention might develop

  • A timeout might interrupt the quiesce

WAIT
Specifies whether WebSphere MQ is to wait until the quiesce process has finished before returning to the issuer of the ARCHIVE LOG command.

To specify the WAIT parameter, also specify MODE(QUIESCE).

NO
Specifies that control is returned to the issuer when the quiesce process starts. (The synonym is N.) This makes the quiesce process asynchronous to the issuer; you can issue further MQSC commands when the ARCHIVE LOG command returns control to you. This is the default.

YES
Specifies that control is returned to the issuer when the quiesce process finishes. (The synonym is Y.) This makes the quiesce process synchronous to the issuer; further MQSC commands are not processed until the ARCHIVE LOG command finishes.

 

Usage notes

  1. You cannot issue an ARCHIVE LOG command while a previous ARCHIVE LOG command is in progress.

  2. You cannot issue an ARCHIVE LOG command when the active log data set is the last available active log data set, because it would use all the available active log data set space, and WebSphere MQ would halt all processing until an off-load had been completed.

  3. You can issue an ARCHIVE LOG command without the MODE(QUIESCE) option when a STOP QMGR MODE(QUIESCE) is in progress, but not when a STOP QMGR MODE (FORCE) is in progress.

  4. You can issue a DISPLAY THREAD command to discover whether an ARCHIVE LOG command is active. If an ARCHIVE LOG command is active, the DISPLAY command returns message CSQV400I.

  5. You can issue an ARCHIVE LOG command even if archiving is not being used (that is, OFFLOAD is set to NO in the CSQ6LOGP system parameter macro), or dynamically using the SET LOG command. In this case, the current active log data sets are truncated and logging continues using the next active log data set, but there is no off-loading to archive data sets.

 

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IBM is a trademark of the IBM Corporation in the United States, other countries, or both.