added error count of failed requests from query service to pinot (#138)

* added error count of failed request from query-service to pinot/other request handler

* added success metric for response returned in query-layer

* added success metric and applied the spotless github action fix

* addressing the PR comments 1

Author: Harnoor-se7en

query-service-impl/src/main/java/org/hypertrace/core/query/service/QueryServiceImpl.java

@@ -2,9 +2,11 @@
 
 import static org.hypertrace.core.query.service.RowChunkingOperator.chunkRows;
 
+import com.google.common.collect.ImmutableMap;
 import io.grpc.Status;
 import io.grpc.stub.ServerCallStreamObserver;
 import io.grpc.stub.StreamObserver;
+import io.micrometer.core.instrument.Counter;
 import io.reactivex.rxjava3.core.Maybe;
 import io.reactivex.rxjava3.core.Observable;
 import javax.inject.Inject;
@@ -16,14 +18,21 @@
 import org.hypertrace.core.query.service.api.QueryServiceGrpc;
 import org.hypertrace.core.query.service.api.ResultSetChunk;
 import org.hypertrace.core.query.service.validation.QueryValidator;
+import org.hypertrace.core.serviceframework.metrics.PlatformMetricsRegistry;
 
 @Singleton
 @Slf4j
 class QueryServiceImpl extends QueryServiceGrpc.QueryServiceImplBase {
+
   private final RequestHandlerSelector handlerSelector;
   private final QueryTransformationPipeline queryTransformationPipeline;
   private final QueryValidator queryValidator;
 
+  private Counter requestStatusErrorCounter;
+  private Counter requestStatusSuccessCounter;
+  private static final String SERVICE_REQUESTS_STATUS_COUNTER =
+      "hypertrace.query.service.requests.status";
+
   @Inject
   public QueryServiceImpl(
       RequestHandlerSelector handlerSelector,
@@ -32,6 +41,17 @@ public QueryServiceImpl(
     this.handlerSelector = handlerSelector;
     this.queryTransformationPipeline = queryTransformationPipeline;
     this.queryValidator = queryValidator;
+    initMetrics();
+  }
+
+  private void initMetrics() {
+    requestStatusErrorCounter =
+        PlatformMetricsRegistry.registerCounter(
+            SERVICE_REQUESTS_STATUS_COUNTER, ImmutableMap.of("error", "true"));
+
+    requestStatusSuccessCounter =
+        PlatformMetricsRegistry.registerCounter(
+            SERVICE_REQUESTS_STATUS_COUNTER, ImmutableMap.of("error", "false"));
   }
 
   @Override
@@ -45,7 +65,12 @@ public void execute(
                 () ->
                     this.transformAndExecute(
                         originalRequest, requestContext.getTenantId().orElseThrow())))
-        .doOnError(error -> log.error("Query failed: {}", originalRequest, error))
+        .doOnError(
+            error -> {
+              log.error("Query failed: {}", originalRequest, error);
+              requestStatusErrorCounter.increment();
+            })
+        .doOnComplete(() -> requestStatusSuccessCounter.increment())
         .subscribe(
             new ServerCallStreamRxObserver<>(
                 (ServerCallStreamObserver<ResultSetChunk>) callStreamObserver));