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19: Implement cluster discovery using dns

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This commit is contained in:
Nicolas Dextraze
2017-01-29 10:57:59 -08:00
parent 0463d85cfe
commit 1558918692
3 changed files with 91 additions and 47 deletions
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97
src/core/clusterDnsEndPointDiscoverer.js
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@ -1,5 +1,6 @@
var http = require('http');
var util = require('util');
var dns = require('dns');
var GossipSeed = require('../gossipSeed');
function NodeEndPoints(tcpEndPoint, secureTcpEndPoint) {
@ -61,37 +62,37 @@ ClusterDnsEndPointDiscoverer.prototype.discover = function(failedTcpEndPoint) {
*/
ClusterDnsEndPointDiscoverer.prototype._discoverEndPoint = function (failedTcpEndPoint) {
try {
var gossipCandidates = this._oldGossip
? this._getGossipCandidatesFromOldGossip(this._oldGossip, failedTcpEndPoint)
var mainPromise = this._oldGossip
? Promise.resolve(this._getGossipCandidatesFromOldGossip(this._oldGossip, failedTcpEndPoint))
: this._getGossipCandidatesFromDns();
var self = this;
var promise = Promise.resolve();
var j = 0;
self._log.debug('Gossip candidates', gossipCandidates);
for (var i = 0; i < gossipCandidates.length; i++) {
promise = promise.then(function (endPoints) {
if (endPoints) return endPoints;
return self._tryGetGossipFrom(gossipCandidates[j++])
.then(function (gossip) {
if (gossip === null || gossip.members === null || gossip.members.length === 0)
return;
var bestNode = self._tryDetermineBestNode(gossip.members);
if (bestNode !== null) {
self._oldGossip = gossip.members;
return bestNode;
}
});
});
}
return promise;
return mainPromise.then(function (gossipCandidates) {
var loopPromise = Promise.resolve();
for (var i = 0; i < gossipCandidates.length; i++) {
loopPromise = loopPromise.then(function (endPoints) {
if (endPoints) return endPoints;
return self._tryGetGossipFrom(gossipCandidates[j++])
.then(function (gossip) {
if (!gossip || !gossip.members || gossip.members.length === 0)
return;
var bestNode = self._tryDetermineBestNode(gossip.members);
if (bestNode) {
self._oldGossip = gossip.members;
return bestNode;
}
});
});
}
return loopPromise;
});
} catch (e) {
return Promise.reject(e);
}
};
ClusterDnsEndPointDiscoverer.prototype._getGossipCandidatesFromOldGossip = function (oldGossip, failedTcpEndPoint) {
if (failedTcpEndPoint === null) return this._arrangeGossipCandidates(oldGossip);
if (!failedTcpEndPoint) return this._arrangeGossipCandidates(oldGossip);
var gossipCandidates = oldGossip.filter(function(x) {
return !(x.externalTcpPort === failedTcpEndPoint.port && x.externalTcpIp === failedTcpEndPoint.host);
});
@ -115,20 +116,33 @@ ClusterDnsEndPointDiscoverer.prototype._arrangeGossipCandidates = function (memb
};
ClusterDnsEndPointDiscoverer.prototype._getGossipCandidatesFromDns = function () {
var endpoints = [];
if(this._gossipSeeds !== null && this._gossipSeeds.length > 0)
{
endpoints = this._gossipSeeds;
}
else
{
//TODO: dns resolve
throw new Error('Not implemented.');
//endpoints = ResolveDns(_clusterDns).Select(x => new GossipSeed(new IPEndPoint(x, _managerExternalHttpPort))).ToArray();
}
this._randomShuffle(endpoints, 0, endpoints.length-1);
return endpoints;
var self = this;
return new Promise(function (resolve, reject) {
if (self._gossipSeeds && self._gossipSeeds.length > 0) {
var endpoints = self._gossipSeeds;
self._randomShuffle(endpoints, 0, endpoints.length - 1);
resolve(endpoints);
}
else {
const dnsOptions = {
family: 4,
hints: dns.ADDRCONFIG | dns.V4MAPPED,
all: true
};
dns.lookup(self._clusterDns, dnsOptions, function (err, addresses) {
if (err) {
return reject(err);
}
if (!addresses || addresses.length === 0) {
return reject(new Error('No result from dns lookup for ' + self._clusterDns));
}
var endpoints = addresses.map(function (x) {
return new GossipSeed({host: x.address, port: self._managerExternalHttpPort});
});
resolve(endpoints);
});
}
});
};
ClusterDnsEndPointDiscoverer.prototype._tryGetGossipFrom = function (endPoint) {
@ -143,9 +157,9 @@ ClusterDnsEndPointDiscoverer.prototype._tryGetGossipFrom = function (endPoint) {
this._log.info('Try get gossip from', endPoint);
var self = this;
return new Promise(function (resolve, reject) {
try {
http
.request(options, function (res) {
var timedout = false;
http.request(options, function (res) {
if (timedout) return;
var result = '';
if (res.statusCode !== 200) {
self._log.info('Trying to get gossip from', endPoint, 'failed with status code:', res.statusCode);
@ -166,16 +180,15 @@ ClusterDnsEndPointDiscoverer.prototype._tryGetGossipFrom = function (endPoint) {
})
.setTimeout(self._gossipTimeout, function () {
self._log.info('Trying to get gossip from', endPoint, 'timed out.');
timedout = true;
resolve();
})
.on('error', function (e) {
if (timedout) return;
self._log.info('Trying to get gossip from', endPoint, 'failed with error:', e);
resolve();
})
.end();
} catch(e) {
reject(e);
}
});
};