RATIS-2185. Improve gRPC log messages debugability.

ratis-common/src/main/java/org/apache/ratis/util/LogUtils.java

@@ -118,7 +118,13 @@ static void warn(Logger log, Supplier<String> message, Throwable t, Class<?>...
     if (log.isWarnEnabled()) {
       if (ReflectionUtils.isInstance(t, exceptionClasses)) {
         // do not print stack trace for known exceptions.
-        log.warn(message.get() + ": " + t);
+        final StringBuilder b = new StringBuilder()
+            .append(message.get())
+            .append(": ").append(t);
+        for(Throwable cause = t.getCause(); cause != null; cause = cause.getCause()) {
+          b.append("\n  Caused by: ").append(cause);
+        }
+        log.warn(b.toString());
       } else {
         log.warn(message.get(), t);
       }

ratis-grpc/src/main/java/org/apache/ratis/grpc/GrpcUtil.java

@@ -161,13 +161,6 @@ static IOException unwrapIOException(Throwable t) {
     return e;
   }
 
-  static <REPLY, REPLY_PROTO> void asyncCall(
-      StreamObserver<REPLY_PROTO> responseObserver,
-      CheckedSupplier<CompletableFuture<REPLY>, IOException> supplier,
-      Function<REPLY, REPLY_PROTO> toProto) {
-    asyncCall(responseObserver, supplier, toProto, throwable -> {});
-  }
-
   static <REPLY, REPLY_PROTO> void asyncCall(
           StreamObserver<REPLY_PROTO> responseObserver,
           CheckedSupplier<CompletableFuture<REPLY>, IOException> supplier,

ratis-grpc/src/main/java/org/apache/ratis/grpc/server/GrpcAdminProtocolService.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -32,8 +32,12 @@
 import org.apache.ratis.proto.RaftProtos.RaftClientReplyProto;
 import org.apache.ratis.proto.RaftProtos.GroupManagementRequestProto;
 import org.apache.ratis.proto.grpc.AdminProtocolServiceGrpc.AdminProtocolServiceImplBase;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class GrpcAdminProtocolService extends AdminProtocolServiceImplBase {
+  static final Logger LOG = LoggerFactory.getLogger(GrpcAdminProtocolService.class);
+
   private final AdminAsynchronousProtocol protocol;
 
   public GrpcAdminProtocolService(AdminAsynchronousProtocol protocol) {
@@ -45,53 +49,60 @@ public void groupManagement(GroupManagementRequestProto proto,
         StreamObserver<RaftClientReplyProto> responseObserver) {
     final GroupManagementRequest request = ClientProtoUtils.toGroupManagementRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.groupManagementAsync(request),
-        ClientProtoUtils::toRaftClientReplyProto);
+        ClientProtoUtils::toRaftClientReplyProto,
+        t -> LOG.warn("Failed groupManagement: {}, {}", proto.getOpCase(), request, t));
   }
 
   @Override
   public void groupList(GroupListRequestProto proto,
         StreamObserver<GroupListReplyProto> responseObserver) {
     final GroupListRequest request = ClientProtoUtils.toGroupListRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.getGroupListAsync(request),
-        ClientProtoUtils::toGroupListReplyProto);
+        ClientProtoUtils::toGroupListReplyProto,
+        t -> LOG.warn("Failed to groupList: {}", request, t));
   }
 
   @Override
   public void groupInfo(GroupInfoRequestProto proto, StreamObserver<GroupInfoReplyProto> responseObserver) {
     final GroupInfoRequest request = ClientProtoUtils.toGroupInfoRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.getGroupInfoAsync(request),
-        ClientProtoUtils::toGroupInfoReplyProto);
+        ClientProtoUtils::toGroupInfoReplyProto,
+        t -> LOG.warn("Failed to groupInfo: {}", request, t));
   }
 
   @Override
   public void setConfiguration(SetConfigurationRequestProto proto,
       StreamObserver<RaftClientReplyProto> responseObserver) {
     final SetConfigurationRequest request = ClientProtoUtils.toSetConfigurationRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.setConfigurationAsync(request),
-        ClientProtoUtils::toRaftClientReplyProto);
+        ClientProtoUtils::toRaftClientReplyProto,
+        t -> LOG.warn("Failed to setConfiguration: {}", request, t));
   }
 
   @Override
   public void transferLeadership(TransferLeadershipRequestProto proto,
       StreamObserver<RaftClientReplyProto> responseObserver) {
     final TransferLeadershipRequest request = ClientProtoUtils.toTransferLeadershipRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.transferLeadershipAsync(request),
-        ClientProtoUtils::toRaftClientReplyProto);
+        ClientProtoUtils::toRaftClientReplyProto,
+        t -> LOG.warn("Failed to transferLeadership: {}", request, t));
   }
 
   @Override
   public void snapshotManagement(SnapshotManagementRequestProto proto,
       StreamObserver<RaftClientReplyProto> responseObserver) {
     final SnapshotManagementRequest request = ClientProtoUtils.toSnapshotManagementRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.snapshotManagementAsync(request),
-        ClientProtoUtils::toRaftClientReplyProto);
+        ClientProtoUtils::toRaftClientReplyProto,
+    t -> LOG.warn("Failed snapshotManagement: {}, {}", proto.getOpCase(), request, t));
   }
 
   @Override
   public void leaderElectionManagement(LeaderElectionManagementRequestProto proto,
       StreamObserver<RaftClientReplyProto> responseObserver) {
     final LeaderElectionManagementRequest request = ClientProtoUtils.toLeaderElectionManagementRequest(proto);
     GrpcUtil.asyncCall(responseObserver, () -> protocol.leaderElectionManagementAsync(request),
-        ClientProtoUtils::toRaftClientReplyProto);
+        ClientProtoUtils::toRaftClientReplyProto,
+        t -> LOG.warn("Failed leaderElectionManagement: {}, {}", proto.getOpCase(), request, t));
   }
 }