Add some comments to module proxy, No code change

proxy/src/main/java/org/apache/rocketmq/proxy/ProxyStartup.java

@@ -55,6 +55,14 @@
 
 public class ProxyStartup {
     private static final Logger log = LoggerFactory.getLogger(LoggerName.PROXY_LOGGER_NAME);
+    /**
+     * proxy components container, manager components with method start/shutdown/...
+     * - gRPC thread pool executor
+     * - message processor (wrap broker controller)
+     * - grpc server
+     * - remoting protocol server
+     * - ...
+     */
     private static final ProxyStartAndShutdown PROXY_START_AND_SHUTDOWN = new ProxyStartAndShutdown();
 
     private static class ProxyStartAndShutdown extends AbstractStartAndShutdown {
@@ -73,8 +81,10 @@ public static void main(String[] args) {
             // init thread pool monitor for proxy.
             initThreadPoolMonitor();
 
+            // init business thread pool for grpc server
             ThreadPoolExecutor executor = createServerExecutor();
 
+            // create message processor, wrap broker controller in local mode
             MessagingProcessor messagingProcessor = createMessagingProcessor();
 
             // tls cert update

proxy/src/main/java/org/apache/rocketmq/proxy/config/ProxyConfig.java

@@ -243,17 +243,46 @@ public class ProxyConfig implements ConfigFile {
     private String remotingAccessAddr = "";
     private int remotingListenPort = 8080;
 
-    // related to proxy's send strategy in cluster mode.
+    // related to proxy's sending strategy in cluster mode.
     private boolean sendLatencyEnable = false;
     private boolean startDetectorEnable = false;
     private int detectTimeout = 200;
     private int detectInterval = 2 * 1000;
 
     private int remotingHeartbeatThreadPoolNums = 2 * PROCESSOR_NUMBER;
     private int remotingTopicRouteThreadPoolNums = 2 * PROCESSOR_NUMBER;
+    /**
+     * thread pool number for
+     * 1. send message(and send message v2)
+     * 2. send batch message
+     * 3. consume send message back
+     * 4. end transaction
+     * 5. recall message
+     */
     private int remotingSendMessageThreadPoolNums = 4 * PROCESSOR_NUMBER;
+    /**
+     * thread pool number for
+     * 1. pull message
+     * 2. lite pull message
+     * 3. pop message
+     */
     private int remotingPullMessageThreadPoolNums = 4 * PROCESSOR_NUMBER;
+    /**
+     * thread pool number for
+     * 1. update consumer offset
+     * 2. ack message
+     * 3. change message invisible time
+     * 4. get consumer connection list
+     */
     private int remotingUpdateOffsetThreadPoolNums = 4 * PROCESSOR_NUMBER;
+    /**
+     * thread pool number for
+     * 1. unregister client
+     * 2. check client config
+     * 3. get consumer list by group
+     * 4. get min/max offset, query consume offset, search offset by timestamp
+     * 5. lock/unlock batch mq
+     */
     private int remotingDefaultThreadPoolNums = 4 * PROCESSOR_NUMBER;
 
     private int remotingHeartbeatThreadPoolQueueCapacity = 50000;

proxy/src/main/java/org/apache/rocketmq/proxy/grpc/v2/GrpcMessagingApplication.java

@@ -71,6 +71,15 @@
 import org.apache.rocketmq.proxy.grpc.v2.common.ResponseWriter;
 import org.apache.rocketmq.proxy.processor.MessagingProcessor;
 
+/**
+ * RocketMQ gRPC protocol implementation
+ *
+ * <ul>
+ *   <li>implements gRPC protocol</li>
+ *   <li>execute request in independent thread pool</li>
+ *   <li>execute pipeline, ...</li>
+ * </ul>
+ */
 public class GrpcMessagingApplication extends MessagingServiceGrpc.MessagingServiceImplBase implements StartAndShutdown {
     private final static Logger log = LoggerFactory.getLogger(LoggerName.PROXY_LOGGER_NAME);
 
@@ -167,6 +176,16 @@ protected Status convertExceptionToStatus(Throwable t) {
         return ResponseBuilder.getInstance().buildStatus(t);
     }
 
+    /**
+     * submit grpc task to related thread pool.
+     *
+     * @param executor thread pool
+     * @param context context
+     * @param request grpc request
+     * @param runnable process task
+     * @param responseObserver grpc response observer
+     * @param statusResponseCreator error response creator
+     */
     protected <V, T> void addExecutor(ExecutorService executor, ProxyContext context, V request, Runnable runnable,
         StreamObserver<T> responseObserver, Function<Status, T> statusResponseCreator) {
         if (request instanceof GeneratedMessageV3) {
@@ -200,6 +219,12 @@ protected void validateContext(ProxyContext context) {
         }
     }
 
+    /**
+     * route query api, producer/consumer will call this api while starting.
+     *
+     * @param request request
+     * @param responseObserver gRPC response observer
+     */
     @Override
     public void queryRoute(QueryRouteRequest request, StreamObserver<QueryRouteResponse> responseObserver) {
         Function<Status, QueryRouteResponse> statusResponseCreator = status -> QueryRouteResponse.newBuilder().setStatus(status).build();
@@ -217,6 +242,12 @@ public void queryRoute(QueryRouteRequest request, StreamObserver<QueryRouteRespo
         }
     }
 
+    /**
+     * heartbeat api, register producer/consumer
+     *
+     * @param request request
+     * @param responseObserver responseObserver
+     */
     @Override
     public void heartbeat(HeartbeatRequest request, StreamObserver<HeartbeatResponse> responseObserver) {
         Function<Status, HeartbeatResponse> statusResponseCreator = status -> HeartbeatResponse.newBuilder().setStatus(status).build();
@@ -251,6 +282,12 @@ public void sendMessage(SendMessageRequest request, StreamObserver<SendMessageRe
         }
     }
 
+    /**
+     * assignment query api, consumer will call this api while starting.
+     *
+     * @param request request
+     * @param responseObserver gRPC response observer
+     */
     @Override
     public void queryAssignment(QueryAssignmentRequest request,
         StreamObserver<QueryAssignmentResponse> responseObserver) {
@@ -399,6 +436,15 @@ public void recallMessage(RecallMessageRequest request, StreamObserver<RecallMes
         }
     }
 
+    /**
+     * telemetry API
+     *
+     * <ul>
+     *   <li>register producer/consumer</li>
+     *   <li>process trace</li>
+     *   <li>verify message result</li>
+     * </ul>
+     */
     @Override
     public StreamObserver<TelemetryCommand> telemetry(StreamObserver<TelemetryCommand> responseObserver) {
         Function<Status, TelemetryCommand> statusResponseCreator = status -> TelemetryCommand.newBuilder().setStatus(status).build();