From dde2dc8f9c8da32da2c7601f26964650007d5a65 Mon Sep 17 00:00:00 2001
From: Brian Reavis <brian@thirdroute.com>
Date: Thu, 15 Oct 2015 09:36:41 -0600
Subject: [PATCH] Fixed edge case when health check comes in post-close()

---
 lib/TileServer.js | 58 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/lib/TileServer.js b/lib/TileServer.js
index 13d9a0b..329d5ee 100755
--- a/lib/TileServer.js
+++ b/lib/TileServer.js
@@ -473,6 +473,10 @@ TileServer.prototype.bindBalancer = function() {
  * @return {void}
  */
 TileServer.prototype.handleBalancerPing = function() {
+	// in very rare cases a valid balancer health check might come
+	// in after the server has exited the pool via strata.close()
+	if (!this.balancer) return;
+
 	var self = this;
 	clearTimeout(this.balancer_timeout);
 	this.balancer_timeout = setTimeout(function() {
@@ -517,6 +521,38 @@ TileServer.prototype.listen = function(port) {
 	return server;
 };
 
+/**
+ * Exits the load balancing pool. See https://github.com/naturalatlas/tilestrata-balancer
+ *
+ * @param {function} [callback]
+ * @return {void}
+ */
+TileServer.prototype.closeBalancer = function(callback) {
+	callback = callback || function() {};
+
+	if (!this.balancer) return callback();
+	clearTimeout(this.balancer_timeout);
+	this.balancer.destroy();
+	this.balancer = null;
+
+	log.info('balancer', 'Server close() called, removing self from balancer...');
+	request({
+		method: 'DELETE',
+		url: 'http://' + this.options.balancer.host + '/nodes/' + this.uuid
+	}, function(err, res, body) {
+		if (err) {
+			log.warn('balancer', 'Unregistration failed (' + err.message + ')');
+		} else {
+			if (res.statusCode === 200) {
+				log.info('balancer', 'Successfully removed from the balancer');
+			} else {
+				log.warn('balancer', 'Received HTTP ' + res.statusCode + ' ' + HTTPStatus[res.statusCode] + ' when removing node');
+			}
+		}
+		callback();
+	});
+};
+
 /**
  * Stops listening and disconnects from the balancer (if needed)
  *
@@ -533,27 +569,7 @@ TileServer.prototype.close = function(callback) {
 
 	async.series([
 		function closeBalancer(callback) {
-			if (!self.balancer) return callback();
-			clearTimeout(self.balancer_timeout);
-			self.balancer.destroy();
-			self.balancer = null;
-
-			log.info('balancer', 'Server close() called, removing self from balancer...');
-			request({
-				method: 'DELETE',
-				url: 'http://' + self.options.balancer.host + '/nodes/' + self.uuid
-			}, function(err, res, body) {
-				if (err) {
-					log.warn('balancer', 'Unregistration failed (' + err.message + ')');
-				} else {
-					if (res.statusCode === 200) {
-						log.info('balancer', 'Successfully removed from the balancer');
-					} else {
-						log.warn('balancer', 'Received HTTP ' + res.statusCode + ' ' + HTTPStatus[res.statusCode] + ' when removing node');
-					}
-				}
-				callback();
-			});
+			self.closeBalancer(callback);
 		},
 		function closePort(callback) {
 			if (!self.http_server) return callback();