RESET CHANNEL (reset message sequence number for a channel)

Using MQSC commands

For information on how you use MQSC commands, see Performing local administration tasks using MQSC commands.

Usage notes

1. On z/OS, the command server and channel initiator must be running.
2. This command can be issued to a channel of any type except SVRCONN and CLNTCONN channels, (including those that have been defined automatically). However, if it is issued to a sender or server channel, then in addition to resetting the value at the end at which the command is issued, the value at the other (receiver or requester) end is also reset to the same value the next time this channel is initiated (and resynchronized if necessary). Issuing this command on a cluster-sender channel might reset the message sequence number at either end of the channel. However, this is not significant because the sequence numbers are not checked on clustering channels.
3. If the command is issued to a receiver, requester, or cluster-receiver channel, the value at the other end is not reset as well; this must be done separately if necessary.
4. Where there is both a locally defined channel and an auto-defined cluster-sender channel of the same name, the command applies to the locally defined channel. If there is no locally defined channel but more than one auto-defined cluster-sender channel, the command applies to the channel that was last added to the local queue manager's repository.
5. If the message is non-persistent, and the RESET CHANNEL command is issued to the sender channel, reset data is sent and flows every time the channel starts.

Parameter descriptions for RESET CHANNEL

(channel-name)

The name of the channel to be reset. This is required.

CHLDISP

This parameter applies to z/OS only and can take the values of:

• DEFAULT
• PRIVATE
• SHARED

If this parameter is omitted, then the DEFAULT value applies. This is taken from the default channel disposition attribute, DEFCDISP, of the channel object.

In conjunction with the various values of the CMDSCOPE parameter, this parameter controls two types of channel:

SHARED

A receiving channel is shared if it was started in response to an inbound transmission directed to the queue sharing group.

A sending channel is shared if its transmission queue has a disposition of SHARED.

PRIVATE

A receiving channel is private if it was started in response to an inbound transmission directed to the queue manager.

A sending channel is private if its transmission queue has a disposition other than SHARED.

Note: This disposition is not related to the disposition set by the disposition of the queue sharing group of the channel definition.

The combination of the CHLDISP and CMDSCOPE parameters also controls from which queue manager the channel is operated. The possible options are:

• On the local queue manager where the command is issued.
• On another specific named queue manager in the group.

The various combinations of CHLDISP and CMDSCOPE are summarized in the following table:

Table 1. CHLDISP and CMDSCOPE for RESET CHANNEL

CHLDISP	CMDSCOPE( ) or CMDSCOPE (local-qmgr)	CMDSCOPE (qmgr-name)
PRIVATE	Reset private channel on the local queue manager	Reset private channel on the named queue manager
SHARED	Reset a shared channel on all active queue managers. This might automatically generate a command using CMDSCOPE and send it to the appropriate queue managers. If there is no definition for the channel on the queue managers to which the command is sent, or if the definition is unsuitable for the command, the action fails there. The definition of a channel on the queue manager where the command is entered might be used to determine the target queue manager where the command is actually run. Therefore, it is important that channel definitions are consistent. Inconsistent channel definitions might result in unexpected command behavior.	Not permitted

CMDSCOPE

This parameter applies to z/OS only and specifies how the command runs when the queue manager is a member of a queue sharing group.

If CHLDISP is set to SHARED, CMDSCOPE must be blank or the local queue manager.

' '

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

qmgr-name

The command runs on the queue manager you specify, providing the queue manager is active within the queue sharing group.

You can specify a queue manager name only if you are using a queue sharing group environment and if the command server is enabled.

SEQNUM( integer )

The new message sequence number, which must be in the range 1 through 999 999 999. This is optional.