Simple HTTP (REST) Based Discovery for Hazelcast

Provides a HTTP REST endpoint based discovery strategy for Hazlecast 3.6+ enabled applications.

• Requirements
• Install
• REST Service Details
• Usage

Requirements

• Java 6+
• Hazelcast 3.6+
• A REST endpoint to return member list (see details in REST Service Details section)

Install

You can use JitPack to add the library to your project.

REST Service Details

This discovery plugin expect user to expose a REST service to return members.

Expected REST output is List<Map<Sting, String>.

In the map, user must return a private-address property. If public-address is used, it can be defined as well.

Expected address format: ip/host-name[:port]

Valid address examples: 127.0.0.1, my-member-node:5701

Example output (JSON Formatted):

[
    {
        "private-address": "10.0.0.1:5703"
    },
    {
        "private-address": "10.0.0.2"
    }
]

Usage

• Add this project as a dependency to your project.
• Disable join over multicast TCP/IP and AWS by setting the enabled attribute of the related tags to false.
• Enable Discovery SPI by adding hazelcast.discovery.enabled property to your config.

Following are example declarative and programmatic configuration snippets:

 <hazelcast>
   ...
  <properties>
     <property name="hazelcast.discovery.enabled">true</property>
  </properties>
  <network>
    ...
    <join>
        <tcp-ip enabled="false"></tcp-ip>
        <multicast enabled="false"/>
        <aws enabled="false" />
        <discovery-strategies>
            <!-- class equals to the DiscoveryStrategy not the factory! -->
            <discovery-strategy enabled="true" class="com.oner.discovery.rest.SimpleRestDiscoveryStrategy">
                <properties>
                   <property name="endpoint-url">http://localhost:8080/my-discovery-service</property>
                   <property name="request-params">my-request-params</property>
                   <property name="private-address-property">private-address</property>
                   <property name="public-address-property">public-address</property>
                   <property name="conn-timeout">10000</property>
                   <property name="read-timeout">10000</property>
                   <property name="member-port">5701</property>
                </properties>
            </discovery-strategy>
        </discovery-strategies>
    </join>
  </network>
 </hazelcast>

Here are the definitions of the properties

• endpoint-url: REST service url.
• request-params: Request parameters, if any. Format: param1=val1&param2=val2. It is optional. When using multiple parameters, & need to be escaped as &.
• private-address-property: Name of the private address property. Default value private-address. It is optional.
• public-address-property: Name of the public address property. Default value public-address. It is optional.
• conn-timeout: Connection timeout to REST service, in milis. Default value 10000. It is optional.
• read-timeout: Read timeout to REST service, in milis. Default value 10000. It is optional.
• member-port: If address doesn't contain port information or if you've members on different ports than 5701. It is optional.