IBM Websphere MQ Channels-Changing queue manager configuration information - Middleware News

Use the Channels queue manager properties page from the WebSphere® MQ Explorer, or the CHANNELSstanza in the qm.ini file, to specify information about channels.

MaxChannels=100|number

The maximum number of channels allowed. The default is 100.

MaxActiveChannels=MaxChannels_value

The maximum number of channels allowed to be active at any time. The default is the value specified on the MaxChannels attribute.

MaxInitiators=3|number

The maximum number of initiators. The default and maximum value is 3. Any value greater than 3 will be taken as 3.

MQIBindType=FASTPATH|SHARED

The binding for applications:

FASTPATH

Channels connect using MQCONNX FASTPATH; there is no agent process.

SHARED

Channels connect using SHARED.

PipeLineLength=1|number

The maximum number of concurrent threads a channel will use. The default is 1. Any value greater than 1 is treated as 2.

When you use pipelining, configure the queue managers at both ends of the channel to have aPipeLineLength greater than 1.

Note: Pipelining is only effective for TCP/IP channels.

AdoptNewMCA=NO|SVR|SDR|RCVR|CLUSRCVR|ALL|FASTPATH

If WebSphere MQ receives a request to start a channel, but finds that an amqcrsta process already exists for the same channel, the existing process must be stopped before the new one can start. TheAdoptNewMCA attribute allows you to control the end of an existing process and the startup of a new one for a specified channel type.

If you specify the AdoptNewMCA attribute for a given channel type, but the new channel fails to start because the channel is already running:

1. The new channel tries to stop the previous one by requesting it to end.
2. If the previous channel server does not respond to this request by the time the AdoptNewMCATimeout wait interval expires, the process (or the thread) for the previous channel server is ended.
3. If the previous channel server has not ended after step 2, and after the AdoptNewMCATimeout wait interval expires for a second time, WebSphere MQ ends the channel with a CHANNEL IN USEerror.

Note: AdoptNewMCA is not supported on requester channels.

Specify one or more values, separated by commas or blanks, from the following list:

NO

The AdoptNewMCA feature is not required. This is the default.

SVR

Adopt server channels.

SDR

Adopt sender channels.

RCVR

Adopt receiver channels.

CLUSRCVR

Adopt cluster receiver channels.

ALL

Adopt all channel types except FASTPATH channels.

FASTPATH

Adopt the channel if it is a FASTPATH channel. This happens only if the appropriate channel type is also specified, for example, AdoptNewMCA=RCVR,SVR,FASTPATH.

Attention!: The AdoptNewMCA attribute might behave in an unpredictable fashion with FASTPATH channels. Exercise great caution when enabling the AdoptNewMCA attribute for FASTPATH channels.

AdoptNewMCATimeout=60|1 – 3600

The amount of time, in seconds, that the new process waits for the old process to end. Specify a value in the range 1 – 3600. The default value is 60.

AdoptNewMCACheck=QM|ADDRESS|NAME|ALL

The type of checking required when enabling the AdoptNewMCA attribute. If possible, perform all three of the following checks to protect your channels from being shut down, inadvertently or maliciously. At the very least, check that the channel names match.

Specify one or more values, separated by commas or blanks, to tell the listener process to:

QM

Check that the queue manager names match.

ADDRESS

Check the communications address. For example, the TCP/IP address.

NAME

Check that the channel names match.

ALL

Check for matching queue manager names, the communications address, and for matching channel names.

AdoptNewMCACheck=NAME,ADDRESS is the default for FAP1, FAP2, and FAP3, whileAdoptNewMCACheck=NAME,ADDRESS,QM is the default for FAP4 and later.