feat(command-monitoring): support enabling command monitoring

This allows passing a new option `enableCommandMonitoring` to
MongoClient, or any of the native topologies, which will be passed
to the core topology to enable monitoring in the connection pool.

NODE-1390

Author: mbroadst

lib/mongo_client.js

@@ -106,7 +106,8 @@ var validOptionNames = [
   'readPreferenceTags',
   'numberOfRetries',
   'auto_reconnect',
-  'minSize'
+  'minSize',
+  'enableCommandMonitoring'
 ];
 
 var ignoreOptionNames = ['native_parser'];
@@ -199,6 +200,7 @@ function validOptions(options) {
  * @param {array} [options.readPreferenceTags=null] Read preference tags
  * @param {number} [options.numberOfRetries=5] The number of retries for a tailable cursor
  * @param {boolean} [options.auto_reconnect=true] Enable auto reconnecting for single server instances
+ * @param {boolean} [options.enableCommandMonitoring=false] Enable command monitoring for this client
  * @param {MongoClient~connectCallback} [callback] The command result callback
  * @return {MongoClient} a MongoClient instance
  */

lib/topologies/mongos.js

@@ -58,7 +58,8 @@ var legalOptionNames = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
-  'promiseLibrary'
+  'promiseLibrary',
+  'enableCommandMonitoring'
 ];
 
 /**
@@ -149,7 +150,11 @@ class Mongos extends TopologyBase {
         cursorFactory: Cursor,
         reconnect: reconnect,
         emitError: typeof options.emitError === 'boolean' ? options.emitError : true,
-        size: typeof options.poolSize === 'number' ? options.poolSize : 5
+        size: typeof options.poolSize === 'number' ? options.poolSize : 5,
+        enableCommandMonitoring:
+          typeof options.enableCommandMonitoring === 'boolean'
+            ? options.enableCommandMonitoring
+            : false
       }
     );
 

lib/topologies/replset.js

@@ -66,7 +66,8 @@ var legalOptionNames = [
   'promoteBuffers',
   'maxStalenessSeconds',
   'promiseLibrary',
-  'minSize'
+  'minSize',
+  'enableCommandMonitoring'
 ];
 
 /**
@@ -156,7 +157,11 @@ class ReplSet extends TopologyBase {
         cursorFactory: Cursor,
         reconnect: false,
         emitError: typeof options.emitError === 'boolean' ? options.emitError : true,
-        size: typeof options.poolSize === 'number' ? options.poolSize : 5
+        size: typeof options.poolSize === 'number' ? options.poolSize : 5,
+        enableCommandMonitoring:
+          typeof options.enableCommandMonitoring === 'boolean'
+            ? options.enableCommandMonitoring
+            : false
       }
     );
 

lib/topologies/server.js

@@ -61,7 +61,8 @@ var legalOptionNames = [
   'promoteValues',
   'promoteBuffers',
   'compression',
-  'promiseLibrary'
+  'promiseLibrary',
+  'enableCommandMonitoring'
 ];
 
 /**
@@ -149,7 +150,11 @@ class Server extends TopologyBase {
         cursorFactory: Cursor,
         reconnect: reconnect,
         emitError: typeof options.emitError === 'boolean' ? options.emitError : true,
-        size: typeof options.poolSize === 'number' ? options.poolSize : 5
+        size: typeof options.poolSize === 'number' ? options.poolSize : 5,
+        enableCommandMonitoring:
+          typeof options.enableCommandMonitoring === 'boolean'
+            ? options.enableCommandMonitoring
+            : false
       }
     );