Intercommunication

Managing your channels

Table 31 lists the tasks that you can perform to manage your channels, channel initiators, and listeners. It also gives the name of the relevant MQSC command, and points to the topic where each task is discussed.

Table 31. Channel tasks

Task to be performed	MQSC command	See topic
Define a channel	DEFINE CHANNEL	"Defining a channel"
Alter a channel definition	ALTER CHANNEL	"Altering a channel definition"
Display a channel definition	DISPLAY CHANNEL	"Displaying a channel definition"
Delete a channel definition	DELETE CHANNEL	"Deleting a channel definition"
Start a channel initiator	START CHINIT	"Starting a channel initiator"
Stop a channel initiator	STOP CHINIT	"Stopping a channel initiator"
Display channel initiator information	DISPLAY DQM	"Displaying information about DQM"
Start a channel listener	START LISTENER	"Starting a channel listener"
Stop a channel listener	STOP LISTENER	"Stopping a channel listener"
Start a channel	START CHANNEL	"Starting a channel"
Test a channel	PING CHANNEL	"Testing a channel"
Reset message sequence numbers for a channel	RESET CHANNEL	"Resetting message sequence numbers for a channel"
Resolve in-doubt messages on a channel	RESOLVE CHANNEL	"Resolving in-doubt messages on a channel"
Stop a channel	STOP CHANNEL	"Stopping a channel"
Display channel status	DISPLAY CHSTATUS	"Displaying channel status"
Display cluster channels	DISPLAY CLUSQMGR	"Displaying cluster channels"

Defining a channel

To define a channel using the MQSC commands, use DEFINE CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	2 (Define like)
Object type	channel type (for example SENDER) or CHANNEL
Name
Disposition	The location of the new object.

You are presented with some panels to complete with information about the name and attributes you want for the channel you are defining. They are initialized with the default attribute values. Change any you want before pressing Enter.

Note:: If you entered CHANNEL in the object type field, you are presented with the Select a Valid Channel Type panel first.

If you want to define a channel with the same attributes as an existing channel, put the name of the channel you want to copy in the Name field on the initial panel. The panels will be initialized with the attributes of the existing object.

For information about the channel attributes, see Chapter 6, Channel attributes

Notes:

If you are using distributed queuing with CICS as well, don't use any of the same channel names.
You are strongly recommended to name all the channels in your network uniquely. As shown in Table 1, including the source and target queue manager names in the channel name is a good way to do this.

Altering a channel definition

To alter a channel definition using the MQSC commands, use ALTER CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	3 (Alter)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.ALTER
Disposition	The location of the stored object.

You are presented with some panels containing information about the current attributes of the channel. Change any of the unprotected fields that you want by overtyping the new value, and then press Enter to change the channel definition.

For information about the channel attributes, see Chapter 6, Channel attributes.

Displaying a channel definition

To display a channel definition using the MQSC commands, use DISPLAY CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	1 (Display)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.DISPLAY
Disposition	The location of the object.

You are presented with some panels displaying information about the current attributes of the channel.

For information about the channel attributes, see Chapter 6, Channel attributes.

Deleting a channel definition

To delete a channel definition using the MQSC commands, use DELETE CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	4 (Manage)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.DELETE
Disposition	The location of the object.

You are presented with another panel. Select function type 1 on this panel.

Press Enter to delete the channel definition; you will be asked to confirm that you want to delete the channel definition by pressing Enter again.

Note:: The channel initiator has to be running before a channel definition can be deleted (except for client-connection channels).

Displaying information about DQM

To display information about the channel initiator using the MQSC commands, use DISPLAY DQM.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	1 (Display)
Object type	SYSTEM
Name	Blank

You are presented with another panel. Select function type 1 on this panel.

Notes:

Displaying distributed queuing information may take some time if you have lots of channels.
The channel initiator has to be running before you can display information about distributed queuing.

Starting a channel initiator

To start a channel initiator using the MQSC commands, use START CHINIT.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	6 (Start)
Object type	SYSTEM
Name	Blank

The Start a System Function panel is displayed. The text following the panel below explains what action you should take.:

Figure 39. Starting a system function

+--------------------------------------------------------------------------------+
|                            Start a System Function                             |
|                                                                                |
| Select function type, complete fields, then press Enter to start system        |
| function.                                                                      |
|                                                                                |
| Function type . . . . . . . . _     1. Channel initiator                       |
|                                     2. Channel listener                        |
| Action queue manager  . . . : MQ25                                             |
|                                                                                |
| Channel initiator                                                              |
|    Parameter module name  . . ________                                         |
|    JCL substitution . . . . . ________________________________________________ |
|                               ________________________________________________ |
|                                                                                |
|                                                                                |
| Channel listener                                                               |
|    Inbound disposition  . . . Q  G=Group,Q=Qmgr                                |
|    Transport type . . . . . . _  L=LU6.2,T=TCP/IP                              |
|    LU name (LU6.2)  . . . . . ________________                                 |
|    Port number (TCP/IP) . . . 1414                                             |
|    IP address (TCP/IP)  . . . ________________________________________________ |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F9=Swap     F10=Messages F12=Cancel    |
|                                                                                |
+--------------------------------------------------------------------------------+

Select function type 1 (channel initiator), and press Enter. The channel initiator parameter module name defaults to CSQXPARM. If you want to use a different parameter module, enter the name on the panel.

Note:: If you are using Interlink TCP, this must be started before you start the channel initiator. If you are using IBM TCP, you can start the channel initiator first but, unless you are using OE sockets, you will need to restart the channel initiator after you have started TCP, in order to establish communication. If you are using LU 6.2, this can be started before or after the channel initiator.

Stopping a channel initiator

To stop a channel initiator using the MQSC commands, use STOP CHINIT.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	7 (Stop)
Object type	SYSTEM
Name	Blank

The Stop a System Function panel is displayed. The text following the panel explains how you should use this panel:

Figure 40. Stopping a function control

+--------------------------------------------------------------------------------+
|                             Stop a System Function                             |
|                                                                                |
| Select function type, complete fields, then press Enter to stop system         |
| function.                                                                      |
|                                                                                |
| Function type . . . . . . . . _     1. Channel initiator                       |
|                                     2. Channel listener                        |
| Action queue manager  . . . : MQ25                                             |
|                                                                                |
| Channel initiator                                                              |
|    Restart shared channels    Y  Y=Yes,N=No                                    |
|                                                                                |
| Channel listener                                                               |
|    Inbound disposition  . . . Q  G=Group,Q=Qmgr                                |
|    Transport type . . . . . . _  L=LU6.2,T=TCP/IP                              |
|                                                                                |
|    Port number (TCP/IP) . . . _____                                            |
|    IP address (TCP/IP)  . . . ________________________________________________ |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F9=Swap     F10=Messages F12=Cancel    |
|                                                                                |
+--------------------------------------------------------------------------------+

Select function type 1 (channel initiator) and press Enter.

The channel initiator will wait for all running channels to stop in quiesce mode before it stops.

Note:: If some of the channels are receiver or requester channels that are running but not active, a stop request issued to either the receiver's or sender's channel initiator will cause it to stop immediately.

However, if messages are flowing, the channel initiator waits for the current batch of messages to complete before it stops.

Starting a channel listener

To start a channel listener using the MQSC commands, use START LISTENER.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	6 (Start)
Object type	SYSTEM
Name	Blank

The Start a System Function panel is displayed (see Figure 39).

Select function type 2 (channel listener). Select Inbound disposition. Select Transport type. If the Transport type is L, select LU name. If the Transport type is T, select Port number and (optionally) IP address. Press Enter.

Note:: For the TCP/IP listener, you can start multiple combinations of Port and IP address.

Stopping a channel listener

To stop a channel listener using the MQSC commands, use STOP LISTENER.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	7 (Stop)
Object type	SYSTEM
Name	Blank

The Stop a System Function panel is displayed (see Figure 40).

Select function type 2 (channel listener). Select Inbound disposition. Select Transport type. If the transport type is 'T', select Port number and (optionally) IP address. Press Enter.

Note:: For a TCP/IP listener, you can stop specific combinations of Port and IP address, or you can stop all combinations.

Starting a channel

To start a channel using the MQSC commands, use START CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	6 (Start)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.USE
Disposition	The disposition of the object.

The Start a Channel panel is displayed. The text following the panel explains how to use the panel.:

Figure 41. Starting a channel

+--------------------------------------------------------------------------------+
|                                Start a Channel                                 |
|                                                                                |
| Select disposition, then press Enter to start channel.                         |
|                                                                                |
|                                                                                |
| Channel name  . . . . . . . : CHANNEL.TO.USE                                   |
| Channel type  . . . . . . . : SENDER                                           |
| Description . . . . . . . . : Description of CHANNEL.TO.USE                    |
|                                                                                |
|                                                                                |
| Disposition . . . . . . . . . P     P=Private on MQ25                          |
|                                     S=Shared on MQ25                           |
|                                     A=Shared on any queue manager              |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F9=Swap     F10=Messages F12=Cancel    |
|                                                                                |
+--------------------------------------------------------------------------------+

Select the disposition of the channel instance and on which queue manager it is to be started.

Press Enter to start the channel.

Starting a shared channel

To start a shared channel, and keep it on a nominated channel initiator, use disposition = S (on the START CHANNEL command, specify CHLDISP(FIXSHARED)).

When you start a channel in this way, the following rules apply to that channel:

You can stop the channel from any queue manager in the queue-sharing group. You can do this even if the channel initiator on which it was started is not running at the time you issue the stop-channel request. When the channel has stopped, you can restart it by specifying disposition = S (CHLDISP(FIXSHARED)) on the same, or another, channel initiator. You can also start it by specifying disposition = A (CHLDISP(SHARED)).
If the channel is in the starting or retry state, you can restart it by specifying disposition = S (CHLDISP(FIXSHARED)) on the same or a different channel initiator. You can also start it by specifying disposition = A (CHLDISP(SHARED)).
The channel is eligible to be trigger started when it goes into the inactive state. Shared channels that are trigger started always have a shared disposition (CHLDISP(SHARED)).
The channel is eligible to be started with CHLDISP(FIXSHARED), on any channel initiator, when it goes into the inactive state. You can also start it by specifying disposition = A (CHLDISP(SHARED)).
The channel is not recovered by any other active channel initiator in the queue-sharing group when the channel initiator on which it was started is stopped with SHARED(RESTART), or when the channel initiator terminates abnormally. The channel is recovered only when the channel initiator on which it was started is next restarted. This stops failed channel-recovery attempts being passed to other channel initiators in the queue-sharing group, which would add to their workload.

Testing a channel

To test a channel using the MQSC commands, use PING CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	5 (Perform^(TM))
Object type	SENDER, SERVER, or CHANNEL
Name	CHANNEL.TO.USE
Disposition	The disposition of the channel object.

The Perform a Channel Function panel is displayed. The text following the panel explains how to use the panel.:

Figure 42. Testing a channel

+--------------------------------------------------------------------------------+
|                           Perform a Channel Function                           |
|                                                                                |
| Select function type, complete fields, then press Enter.                       |
|                                                                                |
|                                                                                |
| Function type . . . . . . . . _     1. Reset   3. Resolve with commit          |
|                                     2. Ping    4. Resolve with backout         |
|                                                                                |
| Channel name  . . . . . . . : CHANNEL.TO.USE                                   |
| Channel type  . . . . . . . : SENDER                                           |
| Description . . . . . . . . : Description of CHANNEL.TO.USE                    |
|                                                                                |
|                                                                                |
| Disposition . . . . . . . . . P     P=Private on MQ25                          |
|                                     S=Shared on MQ25                           |
|                                     A=Shared on any queue manager              |
|                                                                                |
| Sequence number for reset . . 1          1 - 999999999                         |
| Data length for ping  . . . . 16     16 - 32768                                |
|                                                                                |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F9=Swap     F10=Messages F12=Cancel    |
|                                                                                |
+--------------------------------------------------------------------------------+

Select function type 2 (ping).

Select the disposition of the channel for which the test is to be done and on which queue manager it is to be tested.

The data length is initially set to 16. Change it if you want and press Enter.

Resetting message sequence numbers for a channel

To reset channel sequence numbers using the MQSC commands, use RESET CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	5 (Perform)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.USE
Disposition	The disposition of the channel object.

The Perform a Channel Function panel is displayed (see Figure 42 ).

Select Function type 1 (reset).

Select the disposition of the channel for which the reset is to be done and on which queue manager it is to be done.

The sequence number field is initially set to one. Change this if you want, and press Enter.

Resolving in-doubt messages on a channel

To resolve in-doubt messages on a channel using the MQSC commands, use RESOLVE CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	5 (Perform)
Object type	SENDER, SERVER, or CHANNEL
Name	CHANNEL.TO.USE
Disposition	The disposition of the object.

The Perform a Channel Function panel is displayed (see Figure 42 ).

Select Function type 3 or 4 (resolve with commit or backout). (See In-doubt channels for more information.)

Select the disposition of the channel for which resolution is to be done and which queue manager it is to be done on. Press Enter.

Stopping a channel

To stop a channel using the MQSC commands, use STOP CHANNEL.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	7 (Stop)
Object type	channel type (for example SENDER) or CHANNEL
Name	CHANNEL.TO.USE
Disposition	The disposition of the object.

The Stop a Channel panel is displayed. The text following the panel explains how to use the panel.:

Figure 43. Stopping a channel

+--------------------------------------------------------------------------------+
|                                 Stop a Channel                                 |
|                                                                                |
| Complete fields, then press Enter to stop channel.                             |
|                                                                                |
|                                                                                |
| Channel name  . . . . . . . : CHANNEL.TO.USE                                   |
| Channel type  . . . . . . . : SENDER                                           |
| Description . . . . . . . . : Description of CHANNEL.TO.USE                    |
|                                                                                |
|                                                                                |
| Disposition . . . . . . . . . P     P=Private on MQ25                          |
|                                     A=Shared on any queue manager              |
|                                                                                |
| Stop mode . . . . . . . . . . 1     1. Quiesce   2. Force                      |
| Stop status . . . . . . . . . 1     1. Stopped   2. Inactive                   |
|                                                                                |
| Queue manager . . . . . . . . ________________________________________________ |
| Connection name . . . . . . . ________________________________________________ |
|                                                                                |
|                                                                                |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F9=Swap     F10=Messages F12=Cancel    |
|                                                                                |
+--------------------------------------------------------------------------------+

Select the disposition of the channel for which the stop is to be done and on which queue manager it is to be stopped.

Choose the stop mode that you require:

Quiesce: The channel will stop when the current message is completed and the batch will then be ended, even if the batch size value has not been reached and there are messages already waiting on the transmission queue. No new batches will be started. This is the default.
Force: The channel stops immediately. If a batch of messages is in progress, an 'in-doubt' situation may result.

Choose the queue manager and connection name for the channel you want to stop.

Choose the status that you require:

Stopped: The channel will not be restarted automatically, and must be restarted manually. This is the default value if no queue manager or connection name is specified. If a name is specified, it is not allowed.
Inactive: The channel will be restarted automatically when required. This is the default value if a queue manager or connection name is specified.

Press Enter to stop the channel.

Usage notes

This section gives some usage notes about stopping a channel:

If a shared channel is in a retry state and the channel initiator on which it was started is not running, a STOP request for the channel is issued on the queue manager where the command was entered.

See Stopping and quiescing channels for more information. For information about restarting stopped channels, see Restarting stopped channels.

Displaying channel status

To display the status of a channel or a set of channels using the MQSC commands, use DISPLAY CHSTATUS.

Note:: Displaying channel status information may take some time if you have lots of channels.

Using the operations and control panels on the List Channel panel (see Figure 38), a summary of the channel status is shown for each channel as follows:

INACTIVE	No connections are active
`status`	One connection is active
`nnn` `status`	More than one connection is current and all current connections have the same status
`nnn` CURRENT	More than one connection is current and the current connections do not all have the same status
Blank	WebSphere MQ is unable to determine how many connections are active (for example, because the channel initiator is not running)
	Note: For channel objects with the disposition GROUP, no status is displayed.

where nnn is the number of active connections, and status is one of the following:

INIT	INITIALIZING
BIND	BINDING
START	STARTING
RUN	RUNNING
STOP	STOPPING or STOPPED
RETRY	RETRYING
REQST	REQUESTING

To display more information about the channel status, press the Status key (F11) on the List Channel or the Display, or Alter channel panels to display the List Channels - Current Status panel (see Figure 44).

Figure 44. Listing channel connections

+--------------------------------------------------------------------------------+
|                         List Channels - Current Status - MQ25           Row 1 o|
|                                                                                |
| Use '/' to select one or more connections, then press Enter to display current |
| connection status.                                                             |
|                                                                                |
|    Channel name         Connection name                                  State |
|      Start time           Messages  Last message time   Type      Disposition  |
| <> *                                                    CHANNEL   ALL     MQ25 |
| _  RMA0.CIRCUIT.ACL.F   RMA1                                             STOP  |
| _    2000-03-21 10.22.36  557735    2000-03-24 09.51.11 SENDER    PRIVATE MQ25 |
| _  RMA0.CIRCUIT.ACL.N   RMA1                                                   |
| _    2000-03-21 10.23.09  378675    2000-03-24 09.51.10 SENDER    PRIVATE MQ25 |
| _  RMA0.CIRCUIT.CL.F    RMA2                                                   |
| _    2000-03-24 01.12.51  45544     2000-03-24 09.51.08 SENDER    PRIVATE MQ25 |
| _  RMA0.CIRCUIT.CL.N    RMA2                                                   |
| _    2000-03-24 01.13.55  45560     2000-03-24 09.51.11 SENDER    PRIVATE MQ25 |
| _  RMA1.CIRCUIT.CL.F    RMA1                                                   |
| _    2000-03-21 10.24.12  360757    2000-03-24 09.51.11 RECEIVER  PRIVATE MQ25 |
| _  RMA1.CIRCUIT.CL.N    RMA1                                                   |
| _    2000-03-21 10.23.40  302870    2000-03-24 09.51.09 RECEIVER  PRIVATE MQ25 |
|                      ******** End of list ********                             |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F5=Refresh   F7=Bkwd      F8=Fwd       |
|  F9=Swap     F10=Messages F11=Saved    F12=Cancel                              |
|                                                                                |
+--------------------------------------------------------------------------------+

The values for status are as follows:

INIT	INITIALIZING
BIND	BINDING
START	STARTING
RUN	RUNNING
STOP	STOPPING or STOPPED
RETRY	RETRYING
REQST	REQUESTING
DOUBT	STOPPED and INDOUBT(YES)

See Channel states for more information about these.

You can press F11 to see a similar list of channel connections with saved status; press F11 to get back to the current list. Note that the saved status does not apply until at least one batch of messages has been transmitted on the channel.

Use a slash (/) to select a connection and press Enter. The Display Channel Connection Current Status panels are displayed.

Displaying cluster channels

To display all the cluster channels that have been defined (explicitly or using auto-definition), use the MQSC command, DISPLAY CLUSQMGR.

Using the operations and control panels, starting from the initial panel, complete these fields and press Enter:

Field	Value
Action	1 (Display)
Object type	CLUSCHL
Name	*

You are presented with a panel like figure Figure 45, in which the information for each cluster channel occupies three lines, and includes its channel, cluster, and queue manager names. For cluster-sender channels, the overall state is shown.

Figure 45. Listing cluster channels

+--------------------------------------------------------------------------------+
|                      List Cluster-queue-manager Channels - MQ25        Row 1 of|
|                                                                                |
| Type action codes. Then press Enter.                                           |
|  1=Display   5=Perform   6=Start   7=Stop                                      |
|                                                                                |
|    Channel name         Connection name                                  State |
|      Type         Cluster name                                      Suspended  |
|        Cluster queue manager name                       Disposition            |
| <> *                                                    -     MQ25             |
| _  TO.MQ90.T            HURSLEY.MACH90.COM(1590)                               |
| _    CLUSRCVR     VJH01T                                            N          |
| _      MQ90                                             -     MQ25             |
| _  TO.MQ95.T            HURSLEY.MACH95.COM(1595)                         RUN   |
| _    CLUSSDRA     VJH01T                                            N          |
| _      MQ95                                             -     MQ25             |
| _  TO.MQ96.T            HURSLEY.MACH96.COM(1596)                         RUN   |
| _    CLUSSDRB     VJH01T                                            N          |
| _      MQ96                                             -     MQ25             |
|                      ******** End of list ********                             |
|                                                                                |
|                                                                                |
| Command ===> ________________________________________________________________  |
|  F1=Help      F2=Split     F3=Exit      F5=Refresh   F7=Bkwd      F8=Fwd       |
|  F9=Swap     F10=Messages F11=Status   F12=Cancel                              |
|                                                                                |
+--------------------------------------------------------------------------------+

To display full information about one or more channels, type Action code 1 against their names and press Enter. Use Action codes 5, 6, or 7 to perform functions (such as ping, resolve, and reset), and start or stop a cluster channel.

To display more information about the channel status, press the Status key (F11).