commit | ca9c7c980980d3d9070aa7a09200c7cc7c4975a5 | [log] [tgz] |
---|---|---|
author | edwardcapriolo <edlinuxguru@gmail.com> | Fri Jan 01 19:23:48 2016 -0430 |
committer | edwardcapriolo <edlinuxguru@gmail.com> | Fri Jan 01 19:23:48 2016 -0430 |
tree | 9a060a227d4ead3487bd0ae8df7c16079c5a11a1 | |
parent | b18821d41e147589bf70a594bc6937666b65c406 [diff] | |
parent | f263fd41aefef73e3120db97765c91fbde9ae3b3 [diff] |
Merge pull request #11 from edwardcapriolo/logger-to-debug Logger to debug
Gossip protocol is a method for a group of nodes to discover and check the liveliness of a cluster. More information can be found at http://en.wikipedia.org/wiki/Gossip_protocol.
The original implementation was forked from https://code.google.com/p/java-gossip/. Several bug fixes and changes have already been added.
To gossip you need one or more seed nodes. Seed is just a list of places to initially connect to.
GossipSettings settings = new GossipSettings(); int seedNodes = 3; List<GossipMember> startupMembers = new ArrayList<>(); for (int i = 1; i < seedNodes+1; ++i) { startupMembers.add(new RemoteGossipMember("127.0.0." + i, 2000, i + "")); }
Here we start five gossip processes and check that they discover each other. (Normally these are on different hosts but here we give each process a distinct local ip.
List<GossipService> clients = new ArrayList<>(); int clusterMembers = 5; for (int i = 1; i < clusterMembers+1; ++i) { GossipService gossipService = new GossipService("127.0.0." + i, 2000, i + "", LogLevel.DEBUG, startupMembers, settings, null); clients.add(gossipService); gossipService.start(); }
Later we can check that the nodes discover each other
Thread.sleep(10000); for (int i = 0; i < clusterMembers; ++i) { Assert.assertEquals(4, clients.get(i).get_gossipManager().getMemberList().size()); }
The status can be polled using the getters that return immutable lists.
List<LocalGossipMember> getMemberList() public List<LocalGossipMember> getDeadList()
Users can also attach an event listener:
GossipService gossipService = new GossipService("127.0.0." + i, 2000, i + "", LogLevel.DEBUG, startupMembers, settings, new GossipListener(){ @Override public void gossipEvent(GossipMember member, GossipState state) { System.out.println(member+" "+ state); } });
You can get this software from maven central.
<dependency> <groupId>io.teknek</groupId> <artifactId>gossip</artifactId> <version>${pick_the_latest_version}</version> </dependency>