chore: add more logging in sync stream (#929)

Signed-off-by: Todd Baert <[email protected]>

providers/flagd/src/main/java/dev/openfeature/contrib/providers/flagd/resolver/process/storage/connector/grpc/GrpcStreamConnector.java

@@ -20,11 +20,12 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
- * Implements the {@link Connector} contract and emit flags obtained from flagd sync gRPC contract.
+ * Implements the {@link Connector} contract and emit flags obtained from flagd
+ * sync gRPC contract.
  */
 @Slf4j
-@SuppressFBWarnings(value = {"PREDICTABLE_RANDOM", "EI_EXPOSE_REP"},
-        justification = "Random is used to generate a variation & flag configurations require exposing")
+@SuppressFBWarnings(value = { "PREDICTABLE_RANDOM",
+    "EI_EXPOSE_REP" }, justification = "Random is used to generate a variation & flag configurations require exposing")
 public class GrpcStreamConnector implements Connector {
     private static final Random RANDOM = new Random();
 
@@ -111,40 +112,47 @@ public void shutdown() throws InterruptedException {
      * Contains blocking calls, to be used concurrently.
      */
     static void observeEventStream(final BlockingQueue<StreamPayload> writeTo,
-                                   final AtomicBoolean shutdown,
-                                   final FlagSyncServiceStub serviceStub,
-                                   final SyncFlagsRequest request)
+            final AtomicBoolean shutdown,
+            final FlagSyncServiceStub serviceStub,
+            final SyncFlagsRequest request)
             throws InterruptedException {
 
         final BlockingQueue<GrpcResponseModel> streamReceiver = new LinkedBlockingQueue<>(QUEUE_SIZE);
         int retryDelay = INIT_BACK_OFF;
 
+        log.info("Initializing sync stream observer");
+
         while (!shutdown.get()) {
+            log.debug("Initializing sync stream request");
             serviceStub.syncFlags(request, new GrpcStreamHandler(streamReceiver));
 
             while (!shutdown.get()) {
                 final GrpcResponseModel response = streamReceiver.take();
 
                 if (response.isComplete()) {
-                    // The stream is complete. This is not considered as an error
+                    log.info("Sync stream completed");
+                    // The stream is complete, this isn't really an error but we should try to
+                    // reconnect
                     break;
                 }
 
                 if (response.getError() != null) {
-                    log.warn(String.format("Error from grpc connection, retrying in %dms", retryDelay),
+                    log.error(String.format("Error from grpc connection, retrying in %dms", retryDelay),
                             response.getError());
 
                     if (!writeTo.offer(
                             new StreamPayload(StreamPayloadType.ERROR, "Error from stream connection, retrying"))) {
-                        log.warn("Failed to convey ERROR satus, queue is full");
+                        log.error("Failed to convey ERROR status, queue is full");
                     }
                     break;
                 }
 
                 final SyncFlagsResponse flagsResponse = response.getSyncFlagsResponse();
+                String data = flagsResponse.getFlagConfiguration();
+                log.debug("Got stream response: " + data);
                 if (!writeTo.offer(
-                        new StreamPayload(StreamPayloadType.DATA, flagsResponse.getFlagConfiguration()))) {
-                    log.warn("Stream writing failed");
+                        new StreamPayload(StreamPayloadType.DATA, data))) {
+                    log.error("Stream writing failed");
                 }
 
                 // reset retry delay if we succeeded in a retry attempt
@@ -158,6 +166,7 @@ static void observeEventStream(final BlockingQueue<StreamPayload> writeTo,
             }
 
             // busy wait till next attempt
+            log.warn(String.format("Stream failed, retrying in %dms", retryDelay));
             Thread.sleep(retryDelay + RANDOM.nextInt(INIT_BACK_OFF));
 
             if (retryDelay < MAX_BACK_OFF) {