How does cluster node discovery work?

[dastultz]

Hello,

I'm giving Infinispan a try for the first time. I am running the replication example here: Replicated Cache Tutorial - Infinispan

I have cloned it from GitHub, compiled, and run it with Maven in 2 terminals concurrently. I believe what is supposed to happen is that the 2 instances discover each other. Each creates a random set of items on the cache and the prints everything in the cache. The idea is that the items created by one node are replicated to the other so both terminal windows will show items created by the other node. Is this correct?

I don't see anything in the console about discovery going on and each node prints the 20 items created locally rather than close to 40. Is there something else special I need to do to get the nodes to discover each other?

I'm running on Mac OSX, Java 1.8.0_181.

Thanks.

/Daryl

[nadirx]

IIRC there might be an issue with the default multicast routing on OSX ([JGRP-1808] Mac OS: no multicast route for 127.0.0.1 - JBoss Issue Tracker )

Discovery is performed by JGroups (our underlying communication library): Chapter 7. List of Protocols

Read our docs http://infinispan.org/docs/stable/user_guide/user_guide.html#clustered_configuration for more information.

[dastultz]

OK, thanks for that. I'm not swift enough with networking so I wasn't able to get the proposed solution to work.

/Daryl

[galder.zamarreno]

Did you try running with these system properties?

-Djava.net.preferIPv4Stack=true -Djgroups.bind_addr=127.0.0.1

[dastultz]

I had run the infinispan-simple-tutorials/replicated as-is so assumed it would do the right thing. I applied your suggestion to the code I copied into my project and it appears to have worked. Thanks!

/Daryl

[dastultz]

I marked Galder as correct, but I believe I owe credit to Tristan as well.

[galder.zamarreno]

The simple tutorial preferIPv4Stack enabled. What it didn't do is default to 127.0.0.1 for JGroups bind address, I guess that's what made it work?

The tutorial can be run in a single machine, or you can run it in multiple machines, hence lack of default value.

It would probably make sense to default to 127.0.0.1 bind_addr and add it to the pom. We can then explain that to run it in multiple machines the value needs adjusting.

[galder.zamarreno]

I've created [ISPN-9571] Clustered tutorials should bind to localhost by default so that maven options show how to set a bind address. By default this would be 127.0.0.1.