How to use SSL on distributed vert.x EventBus?

Question

However, I can not make it work for me:

Setup:

two Verticles (Ping/Pong) from the EventBus SSL Example (https://github.com/vert-x3/vertx-examples/tree/master/core-examples/src/main/java/io/vertx/example/core/eventbus/ssl) with Hazelcust Cluster Manager (http://vertx.io/docs/vertx-hazelcast/java/)

Working:

deployment on one machine, no clustering, SSL enabled
deployment on two machines, Hazelcast clustering, SSL disabled

Failing:

deployment on two machines, Hazelcast clustering, SSL enabled (sending/receiving messages from remote verticles fails silently)

Log messages:

when trying to publish/send: "DEBUG: Cluster connection closed: localhost:44035 holder io.vertx.core.eventbus.impl.clustered.ConnectionHolder@b80002b"

I tried using different keys/certificates, keystore + trusted keystores, enabling/disabling client auth requirement. Nothing worked so far.

Questions:

How do I get more log messages from Netty/EventBus-Impl/Hazelcast?
Any idea what could be the issue with clustering + SSL?

Vassilis Bekiaris Vassilis Bekiaris · Accepted Answer · 2016-11-03T16:13:41

I tried executing the SSL eventbus example on two machines and in my case it failed due to Hazelcast not being able to establish a cluster at startup (so each hazelcast instance was a single-node cluster of its own). Once I fixed that, the example worked flawlessly. Vertx-hazelcast documentation has a related section on troubleshooting clustering.

The reason Hazelcast was not able to form a cluster in my case was that the default Hazelcast configuration (in $VERTX_HOME/conf/default-cluster.xml) configures Hazelcast for multicast discovery; this is by default disabled on OSX (also it's not unusual for home routers to disable multicast traffic). I copied $VERTX_HOME/conf/default-cluster.xml to my working directory, then changed the <multicast> and <tcp-ip> sections of the configuration as follows:

  <multicast enabled="false"> <!-- was originally true -->
    <multicast-group>224.2.2.3</multicast-group>
    <multicast-port>54327</multicast-port>
  </multicast>
  <tcp-ip enabled="true"> <!-- this one was false -->
    <!-- list your cluster machines IPs including the current one in member elements -->
    <member>192.168.2.1</member>
    <member>192.168.2.2</member>
  </tcp-ip>

Copy the cluster.xml on both machines, then start vertx from the directory where you placed cluster.xml in order for vertx to pick it up (I did that in the javascript example sources directory so I executed vertx run receiver.js -cluster / vertx run sender.js -cluster on each machine) and it worked.

Vertx-hazelcast module documentation also provides instructions for configuring logging, configuring vertx with the location of your hazelcast XML configuration and choosing the cluster host address to bind to (useful in case you have multiple network interfaces).

How to use SSL on distributed vert.x EventBus?

1 Answers