Artemis - Inhibit initial message distribution

[AntonR <an...@volvo.com>]

Hi,

I have set up a symmetrical Artemis cluster, running with lots of different
clients and addresses. I want the clients to be able to connect to any of
the brokers and receive messages sent to any other broker in the cluster. As
such, it is is configured with message-load-balancing "ON_DEMAND" and
redistribution-delay set to a positive integer.

This works really well, but I have a problem with some of the clients that
are running high message loads... To enable high throughput with them, they
connect both consumers and producers to all cluster members for increased
parallel throughput. This causes excessive forwards, as the "Initial
distribution" of ON_DEMAND distributes all incoming messages to all brokers,
since they all have active consumers on them.

I want to be able to run the cluster with redistribution enabled, to cover
the small clients scattered across the cluster, and no "Initial
distribution" to inhibit excessive forwarding of the messages for the high
volume clients.

Is there a way to set this up?

The  documentation
<https://activemq.apache.org/components/artemis/documentation/2.10.0/clusters.html>  
for "message-load-balancing" states the following: 

"Keep in mind that this message forwarding/balancing is what we call
"initial distribution." It is different than redistribution which is
discussed below."

And further down under "Message Redistribution" it says: 
"With message redistribution Apache ActiveMQ Artemis can be configured to
automatically redistribute messages from queues which have no consumers back
to other nodes in the cluster which do have matching consumers. To enable
this functionality message-load-balancing must be ON_DEMAND"

Can this be added as a feature flag instead, so I can have
"message-load-balancing" "OFF" and still redistribute messages if consumers
are missing on the local broker?

Br,
Anton



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Re: Artemis - Inhibit initial message distribution

[AntonR <an...@volvo.com>]

Hi,

That's great news! Though unfortunately I am not very good at coding and I
am not familiar with your development process. I can certainly look into a
quick fix for trying the changes out locally, but I can not provide you with
a PR right now.

I will look into learning your processes for future fixes though. If there
is there any other information you need from me to be able to try out a fix
for this i'd be happy to help the best I can.

Br,
Anton



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Re: Artemis - Inhibit initial message distribution

[Justin Bertram <jb...@apache.org>]

As noted in the docs currently redistribution requires ON_DEMAND. There is
already a JIRA [1] to change this.

All things being equal, this would be really easy to implement with just a
few changes to
org.apache.activemq.artemis.core.postoffice.impl.BindingsImpl. However, it
would be inadvisable to change the semantics for existing users so I think
there would need to be a couple new message-load-balancing types (e.g.
STRICT_WITH_REDISTRIBUTION and OFF_WITH_REDISTRIBUTION). Semantics for the
existing types would stay the same.

Would you consider sending a PR? If not, I could probably find some time to
put one together.


Justin

[1] https://issues.apache.org/jira/browse/ARTEMIS-1925

On Wed, Nov 6, 2019 at 8:59 AM AntonR <an...@volvo.com> wrote:

> Hi,
>
> I have set up a symmetrical Artemis cluster, running with lots of different
> clients and addresses. I want the clients to be able to connect to any of
> the brokers and receive messages sent to any other broker in the cluster.
> As
> such, it is is configured with message-load-balancing "ON_DEMAND" and
> redistribution-delay set to a positive integer.
>
> This works really well, but I have a problem with some of the clients that
> are running high message loads... To enable high throughput with them, they
> connect both consumers and producers to all cluster members for increased
> parallel throughput. This causes excessive forwards, as the "Initial
> distribution" of ON_DEMAND distributes all incoming messages to all
> brokers,
> since they all have active consumers on them.
>
> I want to be able to run the cluster with redistribution enabled, to cover
> the small clients scattered across the cluster, and no "Initial
> distribution" to inhibit excessive forwarding of the messages for the high
> volume clients.
>
> Is there a way to set this up?
>
> The  documentation
> <
> https://activemq.apache.org/components/artemis/documentation/2.10.0/clusters.html>
>
> for "message-load-balancing" states the following:
>
> "Keep in mind that this message forwarding/balancing is what we call
> "initial distribution." It is different than redistribution which is
> discussed below."
>
> And further down under "Message Redistribution" it says:
> "With message redistribution Apache ActiveMQ Artemis can be configured to
> automatically redistribute messages from queues which have no consumers
> back
> to other nodes in the cluster which do have matching consumers. To enable
> this functionality message-load-balancing must be ON_DEMAND"
>
> Can this be added as a feature flag instead, so I can have
> "message-load-balancing" "OFF" and still redistribute messages if consumers
> are missing on the local broker?
>
> Br,
> Anton
>
>
>
> --
> Sent from:
> http://activemq.2283324.n4.nabble.com/ActiveMQ-User-f2341805.html
>