Add pendingResponse to ServerMetrics

core/src/main/java/com/linecorp/armeria/server/GracefulShutdownSupport.java

@@ -19,7 +19,6 @@
 import java.time.Duration;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ThreadPoolExecutor;
-import java.util.concurrent.atomic.LongAdder;
 
 import com.google.common.base.Ticker;
 
@@ -29,39 +28,48 @@
  */
 abstract class GracefulShutdownSupport {
 
- static GracefulShutdownSupport create(Duration quietPeriod, Executor blockingTaskExecutor) {
- return create(quietPeriod, blockingTaskExecutor, Ticker.systemTicker());
+ private final ServerMetrics serverMetrics;
+
+ static GracefulShutdownSupport create(Duration quietPeriod, Executor blockingTaskExecutor,
+ ServerMetrics serverMetrics) {
+ return create(quietPeriod, blockingTaskExecutor, Ticker.systemTicker(), serverMetrics);
  }
 
- static GracefulShutdownSupport create(Duration quietPeriod, Executor blockingTaskExecutor, Ticker ticker) {
- return new DefaultGracefulShutdownSupport(quietPeriod, blockingTaskExecutor, ticker);
+ static GracefulShutdownSupport create(Duration quietPeriod, Executor blockingTaskExecutor, Ticker ticker,
+ ServerMetrics serverMetrics) {
+ return new DefaultGracefulShutdownSupport(quietPeriod, blockingTaskExecutor, ticker, serverMetrics);
  }
 
- static GracefulShutdownSupport createDisabled() {
- return new DisabledGracefulShutdownSupport();
+ static GracefulShutdownSupport createDisabled(ServerMetrics serverMetrics) {
+ return new DisabledGracefulShutdownSupport(serverMetrics);
  }
 
- private final LongAdder pendingResponses = new LongAdder();
+ /**
+ * Creates a new instance.
+ */
+ private GracefulShutdownSupport(ServerMetrics serverMetrics) {
+ this.serverMetrics = serverMetrics;
+ }
 
  /**
  * Increases the number of pending responses.
  */
  final void inc() {
- pendingResponses.increment();
+ serverMetrics.increasePendingResponse();
  }
 
  /**
  * Decreases the number of pending responses.
  */
  void dec() {
- pendingResponses.decrement();
+ serverMetrics.decreasePendingResponse();
  }
 
  /**
  * Returns the number of pending responses.
  */
  final long pendingResponses() {
- return pendingResponses.sum();
+ return serverMetrics.pendingResponses();
  }
 
  /**
@@ -78,6 +86,14 @@ private static final class DisabledGracefulShutdownSupport extends GracefulShutd
 
  private volatile boolean shuttingDown;
 
+ /**
+ * Creates a new instance.
+ *
+ */
+ private DisabledGracefulShutdownSupport(ServerMetrics serverMetrics) {
+ super(serverMetrics);
+ }
+
  @Override
  boolean isShuttingDown() {
  return shuttingDown;
@@ -102,7 +118,9 @@ private static final class DefaultGracefulShutdownSupport extends GracefulShutdo
  private long lastResTimeNanos;
  private volatile long shutdownStartTimeNanos;
 
- DefaultGracefulShutdownSupport(Duration quietPeriod, Executor blockingTaskExecutor, Ticker ticker) {
+ private DefaultGracefulShutdownSupport(Duration quietPeriod, Executor blockingTaskExecutor, Ticker ticker,
+ ServerMetrics serverMetrics) {
+ super(serverMetrics);
  quietPeriodNanos = quietPeriod.toNanos();
  this.blockingTaskExecutor = blockingTaskExecutor;
  this.ticker = ticker;

core/src/main/java/com/linecorp/armeria/server/Server.java

@@ -502,11 +502,11 @@ private final class ServerStartStopSupport extends StartStopSupport<Void, Void,
  @Override
  protected CompletionStage<Void> doStart(@Nullable Void arg) {
  if (config().gracefulShutdownQuietPeriod().isZero()) {
- gracefulShutdownSupport = GracefulShutdownSupport.createDisabled();
+ gracefulShutdownSupport = GracefulShutdownSupport.createDisabled(config.serverMetrics());
  } else {
  gracefulShutdownSupport =
  GracefulShutdownSupport.create(config().gracefulShutdownQuietPeriod(),
- config().blockingTaskExecutor());
+ config().blockingTaskExecutor(), config.serverMetrics());
  }
 
  // Initialize the server sockets asynchronously.
@@ -585,8 +585,6 @@ private void setupServerMetrics() {
  final GracefulShutdownSupport gracefulShutdownSupport = this.gracefulShutdownSupport;
  assert gracefulShutdownSupport != null;
 
- meterRegistry.gauge("armeria.server.pending.responses", gracefulShutdownSupport,
- GracefulShutdownSupport::pendingResponses);
  config.serverMetrics().bindTo(meterRegistry);
  }
 

core/src/main/java/com/linecorp/armeria/server/ServerMetrics.java

@@ -39,6 +39,7 @@ public final class ServerMetrics implements MeterBinder {
  private final LongAdder activeHttp1WebSocketRequests = new LongAdder();
  private final LongAdder activeHttp1Requests = new LongAdder();
  private final LongAdder activeHttp2Requests = new LongAdder();
+ private final LongAdder pendingResponse = new LongAdder();
 
  /**
  * AtomicInteger is used to read the number of active connections frequently.
@@ -98,6 +99,13 @@ public long activeHttp2Requests() {
  return activeHttp2Requests.longValue();
  }
 
+ /**
+ * Returns the number of pending responses.
+ */
+ public long pendingResponses() {
+ return pendingResponse.longValue();
+ }
+
  /**
  * Returns the number of open connections.
  */
@@ -153,6 +161,14 @@ void decreaseActiveConnections() {
  activeConnections.decrementAndGet();
  }
 
+ void increasePendingResponse() {
+ pendingResponse.increment();
+ }
+
+ void decreasePendingResponse() {
+ pendingResponse.decrement();
+ }
+
  @Override
  public void bindTo(MeterRegistry meterRegistry) {
  meterRegistry.gauge("armeria.server.connections", activeConnections);
@@ -174,6 +190,10 @@ public void bindTo(MeterRegistry meterRegistry) {
  meterRegistry.gauge(allRequestsMeterName,
  ImmutableList.of(Tag.of("protocol", "http1.websocket"), Tag.of("state", "active")),
  activeHttp1WebSocketRequests);
+ // pending responses
+ meterRegistry.gauge(allRequestsMeterName,
+ ImmutableList.of(Tag.of("protocol", "all"), Tag.of("state", "active")),
+ pendingResponse);
  }
 
  @Override
@@ -185,6 +205,7 @@ public String toString() {
  .add("pendingHttp2Requests", pendingHttp2Requests)
  .add("activeHttp2Requests", activeHttp2Requests)
  .add("activeConnections", activeConnections)
+ .add("pendingResponse", pendingResponse)
  .toString();
  }
 }

core/src/test/java/com/linecorp/armeria/server/GracefulShutdownSupportTest.java

@@ -45,6 +45,8 @@ class GracefulShutdownSupportTest {
  @Mock
  private Ticker ticker;
 
+ private ServerMetrics serverMetrics;
+
  private GracefulShutdownSupport support;
  private ThreadPoolExecutor executor;
 
@@ -54,7 +56,9 @@ void setUp() {
  0, 1, 1, TimeUnit.SECONDS, new LinkedTransferQueue<>(),
  ThreadFactories.newThreadFactory("graceful-shutdown-test", true));
 
- support = GracefulShutdownSupport.create(Duration.ofNanos(QUIET_PERIOD_NANOS), executor, ticker);
+ serverMetrics = new ServerMetrics();
+ support = GracefulShutdownSupport.create(Duration.ofNanos(QUIET_PERIOD_NANOS), executor, ticker,
+ serverMetrics);
  }
 
  @AfterEach
@@ -64,7 +68,7 @@ void tearDown() {
 
  @Test
  void testDisabled() {
- final GracefulShutdownSupport support = GracefulShutdownSupport.createDisabled();
+ final GracefulShutdownSupport support = GracefulShutdownSupport.createDisabled(serverMetrics);
  assertThat(support.isShuttingDown()).isFalse();
  assertThat(support.completedQuietPeriod()).isTrue();
  assertThat(support.isShuttingDown()).isTrue();