[Info-vax] Another "Rendez-vous autour de VMS" in France (report)

[Arne Vajhøj]

On 12/3/2022 10:04 AM, Jan-Erik Söderholm wrote:
> Den 2022-12-03 kl. 15:38, skrev Arne Vajhøj:
>> VSI offers:
>>
>> ActiveMQ server + JVM client (JMS) - 
>> https://vmssoftware.com/products/activemq/
>>
>> Mosquito (MQTT) server - https://vmssoftware.com/products/mosquitto/
>>
>> RabbitMQ native client (librabbitmq) that I suspect will work with any 
>> server talking AMQP - https://vmssoftware.com/products/librabbitmq/
>>
>> Client for MQTT protocol - https://vmssoftware.com/products/paho-c/
>>
>> Outside of that:
>>
>> JFP VMS Python (I have not checked VSI VMS Python) comes with
>> an AMQP module and it is possible to get the standard stomp
>> module working.
>>
>> RabbitMQ JVM client should work on VMS if the Java version is new enough.
>>
>> And for those wanting native access then there exist open source
>> C code for STOMP protocol (plus I have created VMS wrappers for
>> it - https://www.vajhoej.dk/arne/opensource/vms/ grab the vmspstomp
>> library).
>>
>> So VMS does have something in this area.
> 
> Which of these (if any) has a VMS only complete solution?
> That is, that doesn't need some "external" Linux (or other)
> based server component?

Client is not a problem. Almost any programming language for
application any server will do today due to the standard
protocols. In https://www.vajhoej.dk/arne/articles/vmsipc.html#mq
I got Java, Jython, C, Python, Fortran, Pascal, Cobol and
Basic talking to ActiveMQ.

Server is the issue.

As far as I know then RabbitMQ server does not run on VMS. Erlang
is available for VMS, but not RabbitMQ (RabbitMQ is written
in Erlang).

VSI has ActiveMQ server for VMS I64, but not for VMS Alpha
(I assume the reason is that VMS I64 got Java 8 while VMS Alpha
only got Java 5).

VSI has the Mosqito server for both VMS I64 and VMS Alpha.
But MQTT is really intended for thingies-server communication
not for server-server communication, so I don't know how
well it will fit your use case.

 > If I just want to have a message based solution for communication
 > between different native VMS applications, I do not want to be
 > dependent on some other system/environment.

If the load is not big enough to require a separate server
then that makes sense.

 > Yes, mail boxes works quite nice, but there are some issues with
 > having multiple readers on a mailbox. And you can only "buffer" as
 > much as our mailbox buffer has room for.

Message queues are a huge improvement compared to mailboxes.

Arne