ft: ZENKO-2968 enable sharding on bucket creation

lib/storage/metadata/MetadataWrapper.js

@@ -85,6 +85,7 @@ class MetadataWrapper {
                 replicaSetHosts: params.mongodb.replicaSetHosts,
                 writeConcern: params.mongodb.writeConcern,
                 replicaSet: params.mongodb.replicaSet,
+                enableSharding: params.mongodb.enableSharding,
                 readPreference: params.mongodb.readPreference,
                 database: params.mongodb.database,
                 replicationGroupId: params.replicationGroupId,

lib/storage/metadata/mongoclient/LogConsumer.js

@@ -17,10 +17,13 @@ class LogConsumer {
      * @param {string} logger - logger
      */
     constructor(mongoConfig, logger) {
-        const { authCredentials, replicaSetHosts, replicaSet, database } = mongoConfig;
+        const { authCredentials, replicaSetHosts, replicaSet, database,
+                enableSharding } = mongoConfig;
         const cred = MongoUtils.credPrefix(authCredentials);
         this._mongoUrl = `mongodb://${cred}${replicaSetHosts}/`;
         this._replicaSet = replicaSet;
+        this._enableSharding =
+            enableSharding !== undefined ? enableSharding : false;
         this._logger = logger;
         this._oplogNsRegExp = new RegExp(`^${database}\\.`);
         // oplog collection
@@ -36,10 +39,15 @@ class LogConsumer {
      * @return {undefined}
     */
     connectMongo(done) {
-        MongoClient.connect(this._mongoUrl, {
+        const options = {
-            replicaSet: this._replicaSet,
             useNewUrlParser: true,
-        },
+        };
+        if (!this._enableSharding) {
+            // XXX real fix is with change streams
+            options.replicaSet = this._replicaSet;
+        }
+        MongoClient.connect(this._mongoUrl,
+                            options,
         (err, client) => {
             if (err) {
                 this._logger.error('Unable to connect to MongoDB',

lib/storage/metadata/mongoclient/MongoClientInterface.js

@@ -91,11 +91,15 @@ function generatePHDVersion(versionId) {
 class MongoClientInterface {
     constructor(params) {
         const { replicaSetHosts, writeConcern, replicaSet, readPreference, path,
-            database, logger, replicationGroupId, authCredentials,
+                database, enableSharding, logger,
+                replicationGroupId, authCredentials,
             isLocationTransient } = params;
         const cred = MongoUtils.credPrefix(authCredentials);
+        this._enableSharding =
+            enableSharding !== undefined ? enableSharding : false;
         this.mongoUrl = `mongodb://${cred}${replicaSetHosts}/` +
-            `?w=${writeConcern}&replicaSet=${replicaSet}` +
+            `?w=${writeConcern}` +
+            `${!this._enableSharding && !!replicaSet ? `&replicaSet=${replicaSet}` : ''}` +
             `&readPreference=${readPreference}`;
         this.logger = logger;
         this.client = null;
@@ -142,6 +146,7 @@ class MongoClientInterface {
             this.db = client.db(this.database, {
                 ignoreUndefined: true,
             });
+            this.adminDb = client.db('admin');
             return this.usersBucketHack(cb);
         });
     }
@@ -219,6 +224,21 @@ class MongoClientInterface {
                         { error: err.message });
                         return cb(errors.InternalError);
                     }
+                    if (this._enableSharding) {
+                        const cmd = {
+                            shardCollection: `${this.database}.${bucketName}`,
+                            key: { _id: 1 },
+                        };
+                        return this.adminDb.command(cmd, {}, err => {
+                            if (err) {
+                                log.error(
+                                    'createBucket: enabling sharding',
+                                    { error: err.message });
+                                return cb(errors.InternalError);
+                            }
+                            return cb();
+                        });
+                    }
                     return cb();
                 });
             }