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maximum message length usage on local queue
- Thread starter sundrop
- Start date
Hi sundrop,
I just can speak of z/OS, where we recently had problems, as a queue, used by about 900 workstations per client channel, had been set to 4MB.
The CHIN-adress-space was filled up until its margin of 2 GB virtual storage, then it rejected all further connections.
HTH
I just can speak of z/OS, where we recently had problems, as a queue, used by about 900 workstations per client channel, had been set to 4MB.
The CHIN-adress-space was filled up until its margin of 2 GB virtual storage, then it rejected all further connections.
HTH
I do not believe that the Max Msg Length attribute of a queue has any bearing on the amount of space taken up, with the obvious exception being that bigger messages take up more disk space.
If you absolutely need to ensure that disk space is not filled you would need to balance the max msg length and max depth parameters accordingly.
Remember that prior to MQ 5.3 each queue has a maximum size of 2GB anyway.
That z/OS problem sounds odd - were all 900 workstations putting to the same queue? I would expect your page set to fill - not virtual storage.
Cheers,
Paul
If you absolutely need to ensure that disk space is not filled you would need to balance the max msg length and max depth parameters accordingly.
Remember that prior to MQ 5.3 each queue has a maximum size of 2GB anyway.
That z/OS problem sounds odd - were all 900 workstations putting to the same queue? I would expect your page set to fill - not virtual storage.
Cheers,
Paul
Paul,
I was not speaking of disk storage but of main storage.
The CHIN reserves a buffer in the range of the biggest messagelength used by the connection.
Therefore it results the same, if all users open the same queue or maybe everyone has ist own dynamic queue.
Regards,
Norbert
I was not speaking of disk storage but of main storage.
The CHIN reserves a buffer in the range of the biggest messagelength used by the connection.
Therefore it results the same, if all users open the same queue or maybe everyone has ist own dynamic queue.
Regards,
Norbert
Norbert,
Ok - I see what you mean. But how does it know what the messagelength is, in order to allocate a buffer of this size? I presume you are talking about client connections to the CHIN. Are you saying that each MQOPEN for Input results in the CHIN allocating a buffer equal to the max msg length of the queue?
I have never used clients on the mainframe but this design seems extremely limited - you would only need a few connections, with each opening several queues for input to blow out you CHIN virtual storage! And without the ability to run multiple CHINs, your only alternative is to run multiple QMgrs!!
Can this be correct?
Ok - I see what you mean. But how does it know what the messagelength is, in order to allocate a buffer of this size? I presume you are talking about client connections to the CHIN. Are you saying that each MQOPEN for Input results in the CHIN allocating a buffer equal to the max msg length of the queue?
I have never used clients on the mainframe but this design seems extremely limited - you would only need a few connections, with each opening several queues for input to blow out you CHIN virtual storage! And without the ability to run multiple CHINs, your only alternative is to run multiple QMgrs!!
Can this be correct?
Hi Paul,
you're right, this is the upper limit - 2 GB virtual storage.
The MSTR adress space tells the CHIN the maxmsglen when a queue is opened, and the CHIN increases the connection buffer, if it's too low for a new open (we still talk about one connection - one buffer) .
Regards,
Norbert
you're right, this is the upper limit - 2 GB virtual storage.
The MSTR adress space tells the CHIN the maxmsglen when a queue is opened, and the CHIN increases the connection buffer, if it's too low for a new open (we still talk about one connection - one buffer) .
Regards,
Norbert
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