Ping Channel

The Ping Channel (MQCMD_PING_CHANNEL) command tests a channel by sending data as a special message to the remote message queue manager and checking that the data is returned. The data is generated by the local queue manager.

This command can only be used for channels with a ChannelType value of MQCHT_SENDER, MQCHT_SERVER, or MQCHT_CLUSSDR.

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 last channel added to the repository on the local queue manager.

The command is not valid if the channel is running; however it is valid if the channel is stopped or in retry mode.

Required parameters

ChannelName (MQCFST): Channel name (parameter identifier: MQCACH_CHANNEL_NAME).
The name of the channel to be tested. The maximum length of the string is MQ_CHANNEL_NAME_LENGTH.

Optional parameters

DataCount (MQCFIN)

Data count (parameter identifier: MQIACH_DATA_COUNT).

Specifies the length of the data.

Specify a value in the range 16 through 32 768. The default value is 64 bytes.

CommandScope (MQCFST)

Command scope (parameter identifier: MQCACF_COMMAND_SCOPE). This parameter applies to z/OS only. Specifies how the command is executed when the queue manager is a member of a queue sharing group. We can specify one of the following:

blank (or omit the parameter altogether). The command is processed on the queue manager on which it was entered.
a queue manager name. The command is processed on the queue manager you specify, providing it is active within the queue sharing group. If you specify a queue manager name other than the queue manager on which it was entered, we must be using a queue sharing group environment, and the command server must be enabled.
an asterisk (*). The command is processed on the local queue manager and is also passed to every active queue manager in the queue sharing group.

The maximum length is MQ_QSG_NAME_LENGTH.

ChannelDisposition (MQCFIN)

Channel disposition (parameter identifier: MQIACH_CHANNEL_DISP). This parameter applies to z/OS only.

Specifies the disposition of the channels to be tested.

If this parameter is omitted, then the value for the channel disposition is taken from the default channel disposition attribute of the channel object.

The value can be any of the following values:

MQCHLD_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 MQQSGD_SHARED.
MQCHLD_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 MQQSGD_SHARED.
MQCHLD_FIXSHARED: Tests shared channels, tied to a specific queue manager.

The combination of the ChannelDisposition and CommandScope 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.
On the most suitable queue manager in the group, determined automatically by the queue manager itself.

The various combinations of ChannelDisposition and CommandScope are summarized in Table 1

ChannelDisposition	CommandScope blank or local-qmgr	CommandScope qmgr-name	CommandScope(*)
MQCHLD_PRIVATE	Ping private channel on the local queue manager	Ping private channel on the named queue manager	Ping private channel on all active queue managers
MQCHLD_SHARED	Ping a shared channel on the most suitable queue manager in the group MQCHLD_SHARED might automatically generate a command using CommandScope and send it to the appropriate queue manager. If there is no definition for the channel on the queue manager to which the command is sent, or if the definition is unsuitable for the command, the command fails. 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 run. Therefore, it is important that channel definitions are consistent. Inconsistent channel definitions might result in unexpected command behavior.	Not permitted	Not permitted
MQCHLD_FIXSHARED	Ping a shared channel on the local queue manager	Ping a shared channel on the named queue manager	Not permitted

ChannelDisposition

CommandScope blank or local-qmgr

CommandScope qmgr-name

CommandScope(*)

MQCHLD_PRIVATE

Ping private channel on the local queue manager

Ping private channel on the named queue manager

Ping private channel on all active queue managers

MQCHLD_SHARED

Ping a shared channel on the most suitable queue manager in the group

MQCHLD_SHARED might automatically generate a command using CommandScope and send it to the appropriate queue manager. If there is no definition for the channel on the queue manager to which the command is sent, or if the definition is unsuitable for the command, the command fails.

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 run. Therefore, it is important that channel definitions are consistent. Inconsistent channel definitions might result in unexpected command behavior.

Not permitted

MQCHLD_FIXSHARED

Ping a shared channel on the local queue manager

Ping a shared channel on the named queue manager

Not permitted

Error codes

This command might return the following error codes in the response format header, in addition to the values shown in Error codes applicable to all commands.

Reason (MQLONG)

The value can be any of the following values:

MQRCCF_ALLOCATE_FAILED: Allocation failed.
MQRCCF_BIND_FAILED: Bind failed.
MQRCCF_CCSID_ERROR: Coded character-set identifier error.
MQRCCF_CHANNEL_CLOSED: Channel closed.
MQRCCF_CHANNEL_IN_USE: Channel in use.
MQRCCF_CHANNEL_NOT_FOUND: Channel not found.
MQRCCF_CHANNEL_TYPE_ERROR: Channel type not valid.
MQRCCF_CONFIGURATION_ERROR: Configuration error.
MQRCCF_CONNECTION_CLOSED: Connection closed.
MQRCCF_CONNECTION_REFUSED: Connection refused.
MQRCCF_DATA_TOO_LARGE: Data too large.
MQRCCF_ENTRY_ERROR: Connection name not valid.
MQRCCF_HOST_NOT_AVAILABLE: Remote system not available.
MQRCCF_NO_COMMS_MANAGER: Communications manager not available.
MQRCCF_PING_DATA_COMPARE_ERROR: Ping Channel command failed.
MQRCCF_PING_DATA_COUNT_ERROR: Data count not valid.
MQRCCF_PING_ERROR: Ping error.
MQRCCF_RECEIVE_FAILED: Receive failed.
MQRCCF_RECEIVED_DATA_ERROR: Received data error.
MQRCCF_REMOTE_QM_TERMINATING: Remote queue manager terminating.
MQRCCF_REMOTE_QM_UNAVAILABLE: Remote queue manager not available.
MQRCCF_SEND_FAILED: Send failed.
MQRCCF_STRUCTURE_TYPE_ERROR: Structure type not valid.
MQRCCF_TERMINATED_BY_SEC_EXIT: Channel terminated by security exit.
MQRCCF_UNKNOWN_REMOTE_CHANNEL: Remote channel not known.
MQRCCF_USER_EXIT_NOT_AVAILABLE: User exit not available.

Parent topic: Definitions of the Programmable Command Formats