Merge pull request #73 from Azure/magordon/removeheartbeatchanges

Undo removal of worker heartbeat message

src/proto/FunctionRpc.proto

@@ -26,18 +26,21 @@ message StreamingMessage {
   oneof content {
 
     // Worker initiates stream
-    StartStream start_stream = 20;
+    StartStream start_stream = 20; 
 
     // Host sends capabilities/init data to worker
     WorkerInitRequest worker_init_request = 17;
     // Worker responds after initializing with its capabilities & status
     WorkerInitResponse worker_init_response = 16;
 
+    // Worker periodically sends empty heartbeat message to host
+    WorkerHeartbeat worker_heartbeat = 15;
+
     // Host sends terminate message to worker.
     // Worker terminates if it can, otherwise host terminates after a grace period
     WorkerTerminate worker_terminate = 14;
 
-    // Host periodically sends status request to the worker
+    // Add any worker relevant status to response
     WorkerStatusRequest worker_status_request = 12;
     WorkerStatusResponse worker_status_response = 13;
 
@@ -46,25 +49,25 @@ message StreamingMessage {
 
     // Worker requests a desired action (restart worker, reload function)
     WorkerActionResponse worker_action_response = 7;
-
+    
     // Host sends required metadata to worker to load function
     FunctionLoadRequest function_load_request = 8;
     // Worker responds after loading with the load result
     FunctionLoadResponse function_load_response = 9;
-
+    
     // Host requests a given invocation
     InvocationRequest invocation_request = 4;
 
     // Worker responds to a given invocation
     InvocationResponse invocation_response = 5;
 
-    // Host sends cancel message to attempt to cancel an invocation.
+    // Host sends cancel message to attempt to cancel an invocation. 
     // If an invocation is cancelled, host will receive an invocation response with status cancelled.
     InvocationCancel invocation_cancel = 21;
 
     // Worker logs a message back to the host
     RpcLog rpc_log = 2;
-
+    
     FunctionEnvironmentReloadRequest function_environment_reload_request = 25;
 
     FunctionEnvironmentReloadResponse function_environment_reload_response = 26;
@@ -88,15 +91,15 @@ message StreamingMessage {
 // Process.Start required info
 //   connection details
 //   protocol type
-//   protocol version
+//   protocol version 
 
 // Worker sends the host information identifying itself
 message StartStream {
   // id of the worker
   string worker_id = 2;
 }
 
-// Host requests the worker to initialize itself
+// Host requests the worker to initialize itself 
 message WorkerInitRequest {
   // version of the host sending init request
   string host_version = 1;
@@ -147,6 +150,11 @@ message StatusResult {
   repeated RpcLog logs = 3;
 }
 
+// TODO: investigate grpc heartbeat - don't limit to grpc implemention
+
+// Message is empty by design - Will add more fields in future if needed
+message WorkerHeartbeat {}
+
 // Warning before killing the process after grace_period
 // Worker self terminates ..no response on this
 message WorkerTerminate {
@@ -177,25 +185,24 @@ message FileChangeEventRequest {
 
 // Indicates whether worker reloaded successfully or needs a restart
 message WorkerActionResponse {
-  // indicates whether a restart is needed, or reload successfully
+  // indicates whether a restart is needed, or reload succesfully
   enum Action {
     Restart = 0;
     Reload = 1;
   }
-
+  
   // action for this response
   Action action = 1;
 
   // text reason for the response
   string reason = 2;
 }
 
-// Used by the host to determine worker health
-message WorkerStatusRequest {
+// NOT USED
+message WorkerStatusRequest{
 }
 
-// Worker responds with status message
-// TODO: Add any worker relevant status to response
+// NOT USED
 message WorkerStatusResponse {
 }
 
@@ -264,7 +271,7 @@ message RpcFunctionMetadata {
 
   // base directory for the Function
   string directory = 1;
-
+  
   // Script file specified
   string script_file = 2;
 
@@ -485,7 +492,7 @@ message BindingInfo {
   DataType data_type = 4;
 }
 
-// Used to send logs back to the Host
+// Used to send logs back to the Host 
 message RpcLog {
   // Matching ILogger semantics
   // https://github.com/aspnet/Logging/blob/9506ccc3f3491488fe88010ef8b9eb64594abf95/src/Microsoft.Extensions.Logging/Logger.cs
@@ -536,7 +543,7 @@ message RpcLog {
   map<string, TypedData> propertiesMap = 9;
 }
 
-// Encapsulates an Exception
+// Encapsulates an Exception 
 message RpcException {
   // Source of the exception
   string source = 3;
@@ -598,7 +605,7 @@ message RpcHttpCookie {
 // TODO - solidify this or remove it
 message RpcHttp {
   string method = 1;
-  string url = 2;
+  string url = 2; 
   map<string,string> headers = 3;
   TypedData body = 4;
   map<string,string> params = 10;