ask follower to follow

weed/pb/mq.proto

@@ -45,6 +45,11 @@ service SeaweedMessaging {
     }
     rpc SubscribeMessage (SubscribeMessageRequest) returns (stream SubscribeMessageResponse) {
     }
+    // The lead broker asks a follower broker to follow itself
+    rpc PublishFollowMe (PublishFollowMeRequest) returns (PublishFollowMeResponse) {
+    }
+    rpc FollowInMemoryMessages (FollowInMemoryMessagesRequest) returns (stream FollowInMemoryMessagesResponse) {
+    }
 }
 
 //////////////////////////////////////////////////
@@ -205,6 +210,14 @@ message PublishMessageResponse {
     string error = 2;
     bool should_close = 3;
 }
+message PublishFollowMeRequest {
+    Topic topic = 1;
+    Partition partition = 2;
+    string broker_self = 3;
+}
+message PublishFollowMeResponse {
+    string error = 1;
+}
 message SubscribeMessageRequest {
     message InitMessage {
         string consumer_group = 1;
@@ -233,6 +246,32 @@ message SubscribeMessageResponse {
         DataMessage data = 2;
     }
 }
+message FollowInMemoryMessagesRequest {
+    message InitMessage {
+        string consumer_group = 1;
+        string consumer_id = 2;
+        int32 follower_id = 3;
+        Topic topic = 4;
+        PartitionOffset partition_offset = 5;
+    }
+    message AckMessage {
+        int64 sequence = 1;
+    }
+    oneof message {
+        InitMessage init = 1;
+        AckMessage ack = 2;
+    }
+}
+message FollowInMemoryMessagesResponse {
+    message CtrlMessage {
+        int64 flushed_sequence = 1;
+        int32 follower_changed_to_id = 2;
+    }
+    oneof message {
+        CtrlMessage ctrl = 1;
+        DataMessage data = 2;
+    }
+}
 message ClosePublishersRequest {
     Topic topic = 1;
     int64 unix_time_ns = 2;