Channel attributes for MQSC keywords (N-R)

An alphabetical list of the channel attributes for MQSC keywords, starting with the letters N thru R.

NETPRTY (Network-connection priority)

The NETPRTY channel attribute specifies the priority for a CLUSRCVR channel. The value must be in the range 0-9, where 0 is the lowest priority and 9 is the highest.

Use the NETPRTY attribute to make one network the primary network, and another network the backup network. Given a set of equally ranked channels, clustering chooses the path with the highest priority when multiple paths are available.

A typical example of using the NETPRTY channel attribute is to differentiate between networks that have different costs or speeds and connect the same destinations.

Note: Specify this attribute on the cluster-receiver channel at the target queue manager. Any balancing you specify on the matching cluster-sender channel is likely to be ignored. See Cluster channels.

NPMSPEED (Nonpersistent message speed)

This attribute specifies the speed at which nonpersistent messages are to be sent.

Possible values are:

NORMAL: Nonpersistent messages on a channel are transferred within transactions.
FAST: Nonpersistent messages on a channel are not transferred within transactions.

The default is FAST. The advantage of this is that nonpersistent messages become available for retrieval far more quickly. The disadvantage is that because they are not part of a transaction, messages might be lost if there is a transmission failure or if the channel stops when the messages are in transit. See Safety of messages.

Notes:

If the active recovery logs for IBM® MQ for z/OS® are switching and archiving more frequently than expected, given that the messages being sent across a channel are non-persistent, setting NPMSPEED(FAST) on both the sending and receiving ends of the channel can minimize the SYSTEM.CHANNEL.SYNCQ updates.
If you are seeing high CPU usage relating to updates to the SYSTEM.CHANNEL.SYNCQ, setting NPMSPEED(FAST) can significantly reduce the CPU usage.

This attribute is valid for channel types of:

Sender
Server
Receiver
Requester
Cluster sender
Cluster receiver

PASSWORD (Password)

This attribute specifies a password that can be used by the MCA when attempting to initiate a secure LU 6.2 session with a remote MCA.

You can specify a password of maximum length 12 characters, although only the first 10 characters are used.

[z/OS] On IBM MQ for z/OS, this attribute is valid only for client connection channels.

On other platforms, this attribute is valid for channel types of:

Sender
Server
Requester
Client connection
Cluster sender

PORT (Port number)

Specify the port number that is used to connect the AMQP client.

The default port for AMQP 1.0 connections is 5672. If you are already using port 5672, you can specify a different port.

PUTAUT (PUT authority)

This attribute specifies the type of security processing to be carried out by the MCA.

Use this attribute to choose the type of security processing to be carried out by the MCA when executing:

An MQPUT command to the destination queue (for message channels), or
An MQI call (for MQI channels).

[z/OS] On z/OS, the user IDs that are checked, and how many user IDs are checked, depends on the setting of the MQADMIN RACF® class hlq.RESLEVEL profile. Depending on the level of access the user ID of the channel initiator has to hlq.RESLEVEL, zero, one or two user IDs are checked. To see how many user IDs are checked, see RESLEVEL and channel initiator connections. For more information about which user IDs are checked, see User IDs used by the channel initiator.

You can choose one of the following:

Process security, also called default authority (DEF)

The default user ID is used.

[UNIX, Linux, Windows, IBM i] On Multiplatforms, the user ID used to check open authority on the queue is that of the process or user running the MCA at the receiving end of the message channel.

[z/OS] On z/OS, both the user ID received from the network, and the user ID derived from MCAUSER might be used, depending on the number of user IDs that are to be checked.

The queues are opened with this user ID and the open option MQOO_SET_ALL_CONTEXT.

Context security (CTX)

The user ID from the context information associated with the message is used as an alternate user ID.

The UserIdentifier in the message descriptor is moved into the AlternateUserId field in the object descriptor. The queue is opened with the open options MQOO_SET_ALL_CONTEXT and MQOO_ALTERNATE_USER_AUTHORITY.

[UNIX, Linux, Windows, IBM i] On Multiplatforms, the user ID used to check open authority on the queue for MQOO_SET_ALL_CONTEXT and MQOO_ALTERNATE_USER_AUTHORITY is that of the process or user running the MCA at the receiving end of the message channel. The user ID used to check open authority on the queue for MQOO_OUTPUT is the UserIdentifier in the message descriptor.

[z/OS] On z/OS, the user ID received from the network or that derived from MCAUSER might be used, as well as the user ID from the context information in the message descriptor, depending on the number of user IDs that are to be checked.

Context security (CTX) is not supported on server-connection channels.

Only Message Channel Agent security (ONLYMCA)

The user ID derived from MCAUSER is used.

Queues are opened with the open option MQOO_SET_ALL_CONTEXT.

This value only applies to z/OS.

Alternate Message Channel Agent security (ALTMCA)

The user ID from the context information (the UserIdentifier field) in the message descriptor might be used, as well as the user ID derived from MCAUSER, depending on the number of user IDs that are to be checked.

This value only applies to z/OS.

Further details about context fields and open options can be found in Controlling context information.

More information about security can be found here:

This attribute is valid for channel types of:

Receiver
Requester
Server connection ( z/OS only)
Cluster receiver

QMNAME (Queue manager name)

his attribute specifies the name of the queue manager or queue manager group to which an IBM MQ MQI client application can request connection.

This attribute is valid for channel types of:

Client connection

QSGDISP (Disposition)

This attribute specifies the disposition of the channel in a queue sharing group. It is valid on z/OS only.

Values are:

QMGR: The channel is defined on the page set of the queue manager that executes the command. This value is the default.
GROUP: The channel is defined in the shared repository. This value is allowed only if there is a shared queue manager environment. When a channel is defined with QSGDISP(GROUP), the command DEFINE CHANNEL(name) NOREPLACE QSGDISP(COPY) is generated automatically and sent to all active queue managers to cause them to make local copies on page set 0. For queue managers which are not active, or which join the queue sharing group at a later date, the command is generated when the queue manager starts.
COPY: The channel is defined on the page set of the queue manager that executes the command, copying its definition from the QSGDISP(GROUP) channel of the same name. This value is allowed only if there is a shared queue manager environment.

This attribute is valid for all channel types.

RCVDATA (Receive exit user data)

This attribute specifies user data that is passed to the receive exit.

You can run a sequence of receive exits. The string of user data for a series of exits must be separated by a comma, spaces, or both. For example:

RCVDATA(exit1_data exit2_data)
MSGDATA(exit1_data,exit2_data)
SENDDATA(exit1_data, exit2_data)

[AIX, Linux, Windows] In IBM MQ for UNIX systems, and Windows systems, the length of the string of exit names and strings of user data is limited to 500 characters.

[IBM i] In IBM MQ for IBM i, you can specify up to 10 exit names and the length of user data for each is limited to 32 characters.

[z/OS] In IBM MQ for z/OS, you can specify up to eight strings of user data each of length 32 characters.

This attribute is valid for all channel types.

RCVEXIT (Receive exit name)

This attribute specifies the name of the user exit program to be run by the channel receive user exit.

This attribute can be a list of names of programs that are to be run in succession. Leave it blank if no channel receive user exit is in effect.

The format and maximum length of this attribute depend on the platform:

On z/OS it is a load module name, maximum length 8 characters, except for client-connection channels where the maximum length is 128 characters.
On IBM i, it is of the form:
```
libname/progname
```
when specified in CL commands.
When specified in IBM MQ Commands (MQSC) it has the form:
```
progname libname
```
where progname occupies the first 10 characters, and libname the second 10 characters (both blank-padded to the right if necessary). The maximum length of the string is 20 characters.
On AIX and Linux, it is of the form:
```
libraryname(functionname)
```
The maximum length of the string is 40 characters.
On Windows, it is of the form:
```
dllname(functionname)
```
where dllname is specified without the suffix .DLL. The maximum length of the string is 40 characters.

[z/OS] During cluster sender channel auto-definition on z/OS, channel exit names are converted to z/OS format. If you want to control how exit names are converted, you can write a channel auto-definition exit. For more information, see Channel auto-definition exit program.

You can specify a list of receive, send, or message exit program names. The names must be separated by a comma, a space, or both. For example:

RCVEXIT(exit1 exit2)
MSGEXIT(exit1,exit2)
SENDEXIT(exit1, exit2)

The total length of the string of exit names and strings of user data for a particular type of exit is limited to 500 characters.

On IBM MQ for IBM i, you can list up to 10 exit names.
On IBM MQ for z/OS, you can list up to eight exit names.

This attribute is valid for all channel types.