allow admins to inspect index/metadata caches

lib/commands/admin-rpc.js

@@ -19,6 +19,26 @@ var getFileDescriptorLimit = function (env, server, cb) {
     Ulimit(cb);
 };
 
+var getCacheStats = function (env, server, cb) {
+    var metaCount = 0;
+    var channelCount = 0;
+
+    var meta = env.metadata_cache;
+    for (var x in meta) {
+        if (meta.hasOwnProperty(x)) { metaCount++; }
+    }
+
+    var channels = env.channel_cache;
+    for (var y in channels) {
+        if (channels.hasOwnProperty(y)) { channelCount++; }
+    }
+
+    cb(void 0, {
+        metadata: metaCount,
+        channel: channelCount,
+    });
+};
+
 var getActiveSessions = function (Env, Server, cb) {
     var stats = Server.getSessionStats();
     cb(void 0, [
@@ -137,6 +157,7 @@ var commands = {
     GET_FILE_DESCRIPTOR_COUNT: getFileDescriptorCount,
     GET_FILE_DESCRIPTOR_LIMIT: getFileDescriptorLimit,
     SET_DEFAULT_STORAGE_LIMIT: setDefaultStorageLimit,
+    GET_CACHE_STATS: getCacheStats,
 };
 
 Admin.command = function (Env, safeKey, data, _cb, Server) {