JarCastingHazelcast Heroku Discovery 
This Hazelcast Discovery Plugin will lookup IP addresses of other members by resolving service names against the Heroku DNS Discovery in Heroku Private Spaces.
Usage
In Maven:
<dependency>
<groupId>com.github.jkutner</groupId>
<artifactId>hazelcast-heroku-discovery</artifactId>
<version>3.7.0</version>
</dependency>
In Gradle:
dependencies {
compile('com.github.jkutner:hazelcast-heroku-discovery:3.7.0')
}
A minimal hazelcast.xml looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<hazelcast xsi:schemaLocation="http://www.hazelcast.com/schema/config hazelcast-config-3.7.xsd"
xmlns="http://www.hazelcast.com/schema/config"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<properties>
<property name="hazelcast.discovery.enabled">true</property>
</properties>
<network>
<join>
<!-- deactivate normal discovery -->
<multicast enabled="false"/>
<tcp-ip enabled="false" />
<!-- activate the Heroku DNS Discovery -->
<discovery-strategies>
<discovery-strategy
enabled="true"
class="com.github.jkutner.hazelcast.HerokuDiscoveryStrategy">
</discovery-strategy>
</discovery-strategies>
</join>
</network>
</hazelcast>
Hazelcast Discovery SPI
Hazelcast, since 3.6, offers a, so called, Discovery SPI to integrate external discovery mechanisms into the system. For more information please rely on the official documentation, available here.
Configuration
No configuration is required by default. The plugin will detect the service name from the $HEROKU_DNS_FORMATION_NAME environment variable set by Heroku.
If you want to configure the hazelcast.merge.first.run.delay.seconds, set the following in your hazelcast.xml:
<discovery-strategy
enabled="true"
class="com.github.jkutner.hazelcast.HerokuDiscoveryStrategy">
<properties>
<property name="mergeDelay">30</property>
</properties>
</discovery-strategy>
If you want to configure the service names (i.e. the process types) that will be discovered, you can set a ; delimited list like this:
<discovery-strategy
enabled="true"
class="com.github.jkutner.hazelcast.HerokuDiscoveryStrategy">
<properties>
<property name="serviceNames">web;worker;job</property>
</properties>
</discovery-strategy>
License
MIT