nominate master

README.md

@@ -1,5 +1,3 @@
-**using node ^6.0.0**
-
 [![npm](https://img.shields.io/npm/v/vertex.svg)](https://www.npmjs.com/package/vertex)
 [![Build Status](https://travis-ci.org/nomilous/vertex.svg?branch=master)](https://travis-ci.org/nomilous/vertex)
 [![Coverage Status](https://coveralls.io/repos/nomilous/vertex/badge.svg?branch=master&service=github)](https://coveralls.io/github/nomilous/vertex?branch=master)
@@ -73,6 +71,7 @@ Notably:
 ```javascript
 logLevel: (nfo) => {
   // called to assign level as each new logger in the tree initialises
+  // console.log(nfo);
   if (nfo.??) return 'trace';
   return 'warn';
 }
@@ -96,4 +95,57 @@ Host and port to listen.
 
 #### config.cluster
 
-...
+If the cluster section is specified the vertex will join a cluster of vertexes
+
+##### config.cluster.name
+
+Optional cluster name. If unspecified a random name will be generated. If specified it must much the name of the cluster being joined (to).
+
+##### config.cluster.seed
+
+Set true on the first node joining (seeding) the cluster.
+
+##### config.cluster.sync
+
+Upon joining the cluster the contents of the clusters key-storage is synchronised onto the new member.
+
+###### config.cluster.sync.limit
+
+Maximum key-store records per synchronisation data-frame.
+
+###### config.cluster.sync.timeout
+
+Timeout applied on send of each data-frame.
+
+##### config.cluster.join
+
+At least one host already present in the cluster should be specified. It is recommended that all cluster members use the same set of join hosts. At least one of the join hosts should be running at all times.
+
+Join hosts are attempted one at a time. Upon success the remaining hosts are not tried.
+
+###### config.cluster.join.timeout
+
+Timeout on each attempt to join.
+
+##### config.cluster.leave
+
+When one member detects the departure of another member it deletes the member from the members key-store. This action requires consensus among the cluster members independantly also detecting the departure. If consensus is not reached the member(s) making the false deletion is shut down since it is no longer fully connected to the cluster (has lost link to member that others have not lost link to)
+
+###### config.cluster.leave.consensus
+
+Proportion of cluster members required for consensus. 1.0 is all members. 0.5 is half of the members.
+
+###### config.cluster.leave.expire
+
+Allotted discovery/accumulation time for the consensus to be reached.
+
+##### config.cluster.nominate
+
+When the cluster master is shut down a new master is selected by the cluster. Since all members share the fill list of cluster members with a common sequence number the master is selected from that list (the next member in the sequence). All remaining members nominate the next member in the sequence as master. And again if that member also goes down while the nomination is still in progress (expire).
+
+###### config.cluster.nominate.expire
+
+The nomination expire time.
+
+
+

lib/Cluster.js

@@ -2,13 +2,15 @@ const deepcopy = require('deepcopy');
 const {VertexSocket} = require('vertex-transport');
 const {createWord} = require('vertex-names');
 const {format} = require('util');
+const {satisfies} = require('semver');
 
 const KeyStore = require('./KeyStore');
 const Member = require('./Member');
 const {isInt, isntSelf} = require('./utils');
 const {VertexError, VertexConfigError, VertexJoinError} = require('./errors');
 const {VertexSocketClosedError} = require('vertex-transport').errors;
 const constants = require('./constants');
+const version = require('../package.json').version;
 
 class Cluster {
 
@@ -475,6 +477,12 @@ class Cluster {
       ));
     }
 
+    if (!satisfies(version, data.version)) {
+      return reply('nak', new Error(
+        format('Version mismatch, server is \'%s\'', version)
+      ));
+    }
+
     reply('join1', this.getMaster().then(member => {
       return {
         cluster: this.name,
@@ -672,9 +680,15 @@ class Cluster {
 
 
   _join1Payload() {
+
+    var compat = version.split('.');
+    compat[1] = 'x';
+    compat[2] = 'x';
+
     return [
       this._payloadHeader(constants.CLUSTER_HANDLER_JOIN_1), {
-        name: this.name
+        name: this.name,
+        version: compat.join('.')
       }
     ]
   }

lib/errors/VertexError.js

@@ -2,7 +2,9 @@ module.exports = class VertexError extends Error {
 
   constructor(message) {
     super(message);
-    this.name = this.constructor.name;
+    Object.defineProperty(this, 'name', {
+      value: this.constructor.name
+    });
   }
 
 };

package.json

@@ -23,6 +23,7 @@
   "dependencies": {
     "deep-equal": "^1.0.1",
     "deepcopy": "^0.6.3",
+    "semver": "^5.3.0",
     "vertex-logger": "^2.3.2",
     "vertex-names": "^1.1.4",
     "vertex-transport": "^3.1.3"

test/func-Cluster.js

@@ -81,6 +81,8 @@ describe(filename, () => {
         .catch(done);
     });
 
+    it('fails to join if incompatible version');
+
     it('cannot join self', done => {
 
       Vertex.create({

test/func-KeyStore.js

@@ -709,7 +709,7 @@ describe(filename, function () {
 
   });
 
-  xcontext('load', function () {
+  context('load', function () {
 
     // TODO: try with/without deepcopy
 
@@ -723,7 +723,7 @@ describe(filename, function () {
       }
     };
 
-    [2, 4, 6, 8, 10, 12, 14, 16, 18, 20].forEach(clusterSize => {
+    [2, 4, 6, 8, 10, 12, 14, 16 /*, 18, 20 */].forEach(clusterSize => {
 
       context('in cluster of ' + clusterSize, () => {