NATIVE_S3_PING

Discovery protocol using AWS S3 buckets as cluster information store. Based on the original code written by Tobias Sarnowski at Zalando [1,2], and ported to JGroups 4.x by Bela Ban in 2017.

To use it, include the following dependencies:

• module: org.jgroups.aws.s3 / artifactId: native-s3-ping / version: 1.0.0-SNAPSHOT (or higher)

Native means, it uses the AWS SDK [3] and does not implement the HTTP protocol on its own. The benefit is a more stable connection as well as usage of IAM server profiles and AWS standardized credential distribution.

Artifact

<dependency>
    <groupId>org.jgroups.aws.s3</groupId>
    <artifactId>native-s3-ping</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

Configuration

Like the original S3_PING, this library implement a JGroups discovery protocol which replaces protocols like MPING or TCPPING.

<org.jgroups.aws.s3.NATIVE_S3_PING
        region_name="us-east-1a"
        bucket_name="jgroups-s3-test" />

NATIVE_S3_PING automatically registers itself to JGroups with the magic number 789. You can overwrite this by setting the system property s3ping.magic_number to different number:

-Ds3ping.magic_number=123

Possible Configurations

• region_name: like "eu-west-1", "us-east-1", etc.
• bucket_name: the S3 bucket to store the files in
• bucket_prefix (optional): if you don't want the plugin to pollute your S3 bucket, you can configure a prefix like "jgroups/"
• endpoint (optional): you can override the S3 endpoint if you know what you are doing

Example Configuration

<!--
Based on tcp.xml but with new NATIVE_S3_PING.
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="urn:org:jgroups"
        xsi:schemaLocation="urn:org:jgroups http://www.jgroups.org/schema/jgroups.xsd">
    <TCP bind_port="7800"
         recv_buf_size="${tcp.recv_buf_size:5M}"
         send_buf_size="${tcp.send_buf_size:5M}"
         max_bundle_size="64K"
         thread_pool.enabled="true"
         thread_pool.min_threads="2"
         thread_pool.max_threads="8"
         thread_pool.keep_alive_time="5000"/>

    <org.jgroups.aws.s3.NATIVE_S3_PING
            region_name="eu-west-1"
            bucket_name="jgroups-s3-test"
            bucket_prefix="jgroups"/>

    <MERGE3 min_interval="10000"
            max_interval="30000"/>

    <FD_SOCK/>
    <FD_ALL timeout="30000" interval="5000"/>
    <VERIFY_SUSPECT timeout="1500"/>
    <pbcast.NAKACK2 use_mcast_xmit="false"
                    discard_delivered_msgs="true"/>

    <UNICAST3/>

    <pbcast.STABLE stability_delay="1000" desired_avg_gossip="50000"
                   max_bytes="4M"/>
    <pbcast.GMS print_local_addr="true" join_timeout="2000"
                view_bundling="true"/>
    <MFC max_credits="2M"
         min_threshold="0.4"/>
    <FRAG2 frag_size="60K"/>
</config>

[1] https://libraries.io/github/zalando/jgroups-native-s3-ping

[2] https://github.com/jwegne/jgroups-native-s3-ping

[3] http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingTheMPDotJavaAPI.html