forked from mallocator/Elasticsearch-Exporter
-
Notifications
You must be signed in to change notification settings - Fork 0
/
cluster.js
214 lines (195 loc) · 6.25 KB
/
cluster.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
var cp = require('child_process');
var util = require('util');
var drivers = require('./drivers.js');
/**
* A helper class that wraps all communication with worker processes that do the actual import/export
* @param env
* @param numWorkers
* @constructor
*/
var Cluster = function(env, numWorkers) {
var that = this;
this.workers = {};
this.workListeners = [];
this.errorListeners = [];
this.endListeners = [];
this.processed = 0;
this.total = env.statistics.source.docs.total;
this.messageReceiver = function(m) {
var allDone = false;
switch (m.type) {
case 'Error':
that.errorListeners.forEach(function (listener) {
listener(m.message);
});
break;
case 'Done':
that.workers[m.id].state = 'ready';
that.processed += m.processed;
that.workListeners.forEach(function (listener) {
listener(m.processed);
});
for (var id in that.workers) {
allDone = allDone || that.workers[id].state == 'ready' || that.workers[id].state == 'end';
}
if (m.memUsage.heapUsed > env.statistics.memory.peak) {
exports.env.statistics.memory.peak = m.memUsage.heapUsed;
exports.env.statistics.memory.ratio = m.memUsage.ratio;
}
break;
case 'End':
that.workers[m.id].state = 'end';
break;
}
if (allDone && that.processed == that.total) {
that.endListeners.forEach(function (listener) {
listener();
});
for (var doneId in that.workers) {
that.send.done(doneId);
}
}
};
this.send = {
initialize: function (id, env) {
that.workers[id].process.send({
type: 'Initialize',
id: id,
env: env
});
that.workers[id].state = 'ready';
},
message: function (id, from, size) {
that.workers[id].process.send({
type: 'Work',
from: from,
size: size
});
that.workers[id].state = 'working';
},
done: function(id) {
that.workers[id].process.send({
type: 'Done'
});
}
};
for (var i = 0; i < numWorkers; i++) {
var worker = cp.fork(exports.workerPath, ["--nouse-idle-notification", "--expose-gc", "--always_compact"]);
worker.on('message', this.messageReceiver);
this.workers[i] = {
process: worker
};
this.send.initialize(i, env);
}
};
/**
* Sends a json object to an idle worker. If no worker is idle this will block until one becomes idle.
* @param message
* @param callback
*/
Cluster.prototype.work = function(from, size, callback) {
var allEnded = true;
for (var id in this.workers) {
var worker = this.workers[id];
if (worker.state == 'ready') {
this.send.message(id, from, size);
callback();
return;
}
if (worker.state != 'end') {
allEnded = false;
}
if (allEnded && this.processed != this.total) {
callback("The export has finished, but fewer documents than expected have beene exported.");
}
}
var that = this;
process.nextTick(function () {
that.work(from, size, callback);
});
};
/**
* Add a listener here to receive messages from _workers whenever they send a message.
* @param callback function(processedDocs) {}
*/
Cluster.prototype.onWorkDone = function (callback) {
this.workListeners.push(callback);
};
/**
* Add a listener here to receive messages from _workers whenever they throw an error.
* @param callback function(error) {}
*/
Cluster.prototype.onError = function (callback) {
this.errorListeners.push(callback);
};
/**
* When all _workers are in idle mode (and no more messages are queued up) this listener will be fired.
* @param callback
*/
Cluster.prototype.onEnd = function (callback) {
this.endListeners.push(callback);
};
/**
* An implementation of the cluster that is not a cluster, but instead calls the worker directly in the same process.
* @param env
* @constructor
*/
var NoCluster = function(env) {
Cluster.call(this, env, 0);
var that = this;
this.worker = require(exports.workerPath);
this.worker.env = env;
this.worker.id = 0;
var source = drivers.get(env.options.drivers.source).driver;
if (source.prepareTransfer) {
source.prepareTransfer(env, true);
}
var target = drivers.get(env.options.drivers.target).driver;
if (target.prepareTransfer) {
target.prepareTransfer(env, false);
}
this.worker.send.done = function (processed) {
that.processed += processed;
that.workListeners.forEach(function (listener) {
listener(processed);
});
if (that.processed == that.total) {
that.endListeners.forEach(function (listener) {
listener();
});
that.worker.end();
}
that.workDoneListener();
};
this.worker.send.error = function (exception) {
that.errorListeners.forEach(function (listener) {
listener(exception);
});
};
this.worker.state = 'ready';
};
util.inherits(NoCluster, Cluster);
/**
* Overrides the work function of the parent which would use process.send to communicate with the worker instead of
* calling him directly.
*
* @param from
* @param size
* @param callback
*/
NoCluster.prototype.work = function(from, size, callback) {
this.workDoneListener = callback;
this.worker.work(from, size);
};
exports.workerPath = './worker.js';
/**
* Create a new adapter for the data transfer which will be either a Clustered implementation (if numWorkers is
* greater 1) or a direct calling implementation that will be executed in the same process.
*
* @param env
* @param numWorkers
* @returns {Cluster}
*/
exports.run = function(env, numWorkers) {
return numWorkers < 2 ? new NoCluster(env) : new Cluster(env, numWorkers);
};