CNS-180 use multiple connections to redis to avoid blocking

lib/api-server.js

@@ -37,8 +37,8 @@ var NS_TTL = consts.NS_TTL;
 function APIServer(opts) {
 	assert.object(opts, 'options');
 
-	assert.object(opts.client, 'options.client');
-	this.redis = opts.client;
+	assert.object(opts.redisPool, 'options.redisPool');
+	this.redisPool = opts.redisPool;
 
 	assert.object(opts.dnsServer, 'options.dnsServer');
 	this.dnsServer = opts.dnsServer;
@@ -122,7 +122,7 @@ function APIServer(opts) {
 		log: this.log,
 		config: this.config,
 		agent: agent,
-		client: this.redis,
+		redisPool: this.redisPool,
 		ufdsConnections: 1
 	};
 	popts.ufdsPool = createUfdsPool(popts);
@@ -213,7 +213,13 @@ function setupServer(addr) {
 
 	server.pre(function (req, res, next) {
 		req.log = slog.child({req: req, res: res});
-		next();
+		self.redisPool.claim(function (err, handle, redis) {
+			if (err)
+				throw (err);
+			req.redis = redis;
+			req.redisHandle = handle;
+			next();
+		});
 	});
 
 	server.use(restify.queryParser());
@@ -224,6 +230,13 @@ function setupServer(addr) {
 	server.on('after', restify.auditLogger({
 		log: slog
 	}));
+	server.on('after', function (req) {
+		if (req.redisHandle) {
+			req.redisHandle.release();
+			delete (req.redisHandle);
+			delete (req.redis);
+		}
+	});
 	server.on('uncaughtException', function (req, res, route, err) {
 		req.log.error(err);
 		res.send(err);
@@ -283,12 +296,11 @@ function ping_v1(req, res, next) {
 }
 
 function getVM_v1(req, res, next) {
-	var self = this;
 	var uuid = req.params.uuid;
 	var result = {};
 	result.uuid = uuid;
 
-	self.redis.hgetall('vm:' + uuid, function (err, val) {
+	req.redis.hgetall('vm:' + uuid, function (err, val) {
 		var e;
 		if (err) {
 			e = new Error('Error communicating with ' +
@@ -347,7 +359,7 @@ function getPeer_v1(req, res, next) {
 	});
 
 	function fetchSerials(_, cb) {
-		self.redis.hgetall('peer:' + addr, function (err, serials) {
+		req.redis.hgetall('peer:' + addr, function (err, serials) {
 			var rerr;
 			if (err) {
 				rerr = new Error('Error communicating with ' +
@@ -373,7 +385,7 @@ function getPeer_v1(req, res, next) {
 	}
 
 	function fetchVersion(_, cb) {
-		self.redis.get('peer:' + addr + ':version',
+		req.redis.get('peer:' + addr + ':version',
 		    function (err, ver) {
 			var rerr;
 			if (err) {
@@ -413,7 +425,7 @@ function getPeer_v1(req, res, next) {
 function delPeer_v1(req, res, next) {
 	var addr = normalizeIP(req.params.addr);
 
-	this.redis.del('peer:' + addr, 'peer:' + addr + ':version',
+	req.redis.del('peer:' + addr, 'peer:' + addr + ':version',
 	    function (err) {
 		if (err) {
 			next(err);
@@ -449,7 +461,7 @@ function getPeers_v1(req, res, next) {
 	});
 
 	function fetchSerials(_, cb) {
-		self.dnsServer.getPeerSerials(function (err, sres) {
+		self.dnsServer.getPeerSerials(req.redis, function (err, sres) {
 			if (err) {
 				cb(err);
 				return;
@@ -492,11 +504,10 @@ function getPeers_v1(req, res, next) {
 }
 
 function getZones_v1(req, res, next) {
-	var self = this;
 	var zoneNames = Object.keys(this.config.forward_zones);
 	var zones = [];
 
-	this.redis.keys('zone:*.arpa', function (err, keys) {
+	req.redis.keys('zone:*.arpa', function (err, keys) {
 		if (!err && keys !== null) {
 			for (var i = 0; i < keys.length; ++i) {
 				var k = keys[i].split(':')[1];
@@ -517,7 +528,7 @@ function getZones_v1(req, res, next) {
 		});
 
 		function addZone(z, cb) {
-			self.redis.get('zone:' + z + ':latest',
+			req.redis.get('zone:' + z + ':latest',
 			    function (err2, val) {
 				if (err2) {
 					var e = new Error('Redis error: ' +