[Info-vax] Large mailboxes

[Dave Froble]

On 11/27/2020 9:00 PM, Jan-Erik Söderholm wrote:
> Den 2020-11-27 kl. 23:41, skrev Arne Vajhøj:
>> On 11/26/2020 1:27 PM, Arne Vajhøj wrote:
>>> On 11/26/2020 11:30 AM, Marc Van Dyck wrote:
>>>> So my question is, why this limitation ? Is it just because when this
>>>> interface was written, noone imagined that there could ever be a
>>>> mailbox with more than 64k outstanding messages ? Or am I really going
>>>> to break something other than this counter if I try loading more
>>>> than 64k messages ?
>>>
>>> I don't know.
>>>
>>> But it seems likely that noone imagined it being a problem.
>>>
>>> It uses non-paged pool. How big was available non-paged pool on
>>> VAX systems?
>>>
>>> My guess is that available non-paged pool divided by a
>>> normal message size would fit into 16 bit.
>>
>> I could add that as a rule of thumb I would
>> only use VMS mailboxes (or Windows pipes or
>> *nix unix sockets) to buffer hundreds or a
>> few thousands of messages.
>>
>> If I needed hundreds of thousands or
>> millions I would look for a message queue
>> (and if I needed billions I would look at
>> Kafka).
>>
>> Arne
>>
>
> Isn't the normal way to use a VMS mailbox as an on-line interface
> between one (or more) senders and one recevier? That is, the
> mailbox as such is never intended to "store" anything apart from
> a very short time during the transmission.

That is how I use them.  Trust the mailbox to hold data, and what 
happens when there is a system crash?

> If the intention is to buffer 10000's or 100000's of messages,
> VMS mailboxes looks as the wrong tool from the toolbox...

For that type of volume, perhaps a database?

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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