Github user HeartSaVioR commented on a diff in the pull request:
https://github.com/apache/storm/pull/2433#discussion_r152702042
--- Diff:
storm-client/src/jvm/org/apache/storm/assignments/ILocalAssignmentsBackend.java
---
@@ -0,0 +1,103 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.storm.assignments;
+
+import org.apache.storm.generated.Assignment;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Interface for storing local assignments.
+ */
+public interface ILocalAssignmentsBackend {
+
+ /**
+ * initial function for creating backend.
+ * @param conf
+ */
+ void prepare(Map conf);
+
+ /**
+ * Keep a storm assignment to local state or update old assignment.
+ * @param stormID storm runtime id
+ * @param assignment assignment as thrift
+ */
+ void keepOrUpdateAssignment(String stormID, Assignment assignment);
+
+ /**
+ * Get assignment as byte[] for a storm
+ * @param stormID storm runtime id
+ * @return
+ */
+ Assignment getAssignment(String stormID);
+
+ void removeAssignment(String stormID);
+
+ /**
+ * List all the storm runtime ids of local assignments
+ * @return a list of storm ids
+ */
+ List<String> assignments();
+
+ /**
+ * Get all the local assignments of local state
+ * @return mapping of storm-id -> assignment
+ */
+ Map<String, Assignment> assignmentsInfo();
+
+ /**
+ * Sync remote assignments to local, if remote is null, we will sync
it from zk
+ * @param remote specific remote assignments, if is null, it will sync
from zookeeper[only used for nimbus]
+ */
+ void syncRemoteAssignments(Map<String, byte[]> remote);
+
+ /**
+ * Keep a mapping storm-name -> storm-id to local state
+ * @param stormName
+ * @param stormID storm runtime id
+ */
+ void keepStormId(String stormName, String stormID);
+
+ /**
+ * Get storm runtime id from local
+ * @param stormName name of a storm
+ * @return
+ */
+ String getStormId(String stormName);
+
+ /**
+ * sync remote storm ids to local, will just used for nimbus.
+ * @param remote
+ */
+ void syncRemoteIDS(Map<String, String> remote);
--- End diff --
`syncRemoteIDS` -> `syncRemoteIds` (due to checkstyle)
---
