Add UNDER_MAINTENANCE

core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckService.java

@@ -134,6 +134,7 @@ public static HealthCheckServiceBuilder builder() {
  private final AggregatedHttpResponse healthyResponse;
  private final AggregatedHttpResponse degradedResponse;
  private final AggregatedHttpResponse unhealthyResponse;
+ private final AggregatedHttpResponse underMaintenanceResponse;
  private final AggregatedHttpResponse stoppingResponse;
  private final ResponseHeaders ping;
  private final ResponseHeaders notModifiedHeaders;
@@ -155,11 +156,11 @@ public static HealthCheckServiceBuilder builder() {
  private Server server;
  private boolean serverStopping;
 
- HealthCheckService(Set<HealthChecker> healthCheckers,
- AggregatedHttpResponse healthyResponse, AggregatedHttpResponse degradedResponse,
- AggregatedHttpResponse unhealthyResponse,
- long maxLongPollingTimeoutMillis, double longPollingTimeoutJitterRate,
- long pingIntervalMillis, @Nullable HealthCheckUpdateHandler updateHandler,
+ HealthCheckService(Set<HealthChecker> healthCheckers, AggregatedHttpResponse healthyResponse,
+ AggregatedHttpResponse degradedResponse, AggregatedHttpResponse unhealthyResponse,
+ AggregatedHttpResponse underMaintenanceResponse, long maxLongPollingTimeoutMillis,
+ double longPollingTimeoutJitterRate, long pingIntervalMillis,
+ @Nullable HealthCheckUpdateHandler updateHandler,
  List<HealthCheckUpdateListener> updateListeners, boolean startHealthy,
  Set<TransientServiceOption> transientServiceOptions) {
  serverHealth = new SettableHealthChecker(HealthStatus.UNHEALTHY);
@@ -200,6 +201,7 @@ public static HealthCheckServiceBuilder builder() {
  this.healthyResponse = setCommonHeaders(healthyResponse);
  this.degradedResponse = setCommonHeaders(degradedResponse);
  this.unhealthyResponse = setCommonHeaders(unhealthyResponse);
+ this.underMaintenanceResponse = setCommonHeaders(underMaintenanceResponse);
  stoppingResponse = clearCommonHeaders(unhealthyResponse);
  notModifiedHeaders = ResponseHeaders.builder()
  .add(this.unhealthyResponse.headers())
@@ -301,7 +303,7 @@ public void serverStarted(Server server) {
  @Override
  public void serverStopping(Server server) {
  serverStopping = true;
- serverHealth.setHealthStatus(HealthStatus.UNHEALTHY);
+ serverHealth.setHealthStatus(HealthStatus.UNDER_MAINTENANCE);
  }
 
  @Override
@@ -333,6 +335,9 @@ public HttpResponse serve(ServiceRequestContext ctx, HttpRequest req) throws Exc
  useLongPolling = healthStatus == HealthStatus.DEGRADED;
  } else if ("\"unhealthy\"".equals(expectedState) || "w/\"unhealthy\"".equals(expectedState)) {
  useLongPolling = healthStatus == HealthStatus.UNHEALTHY;
+ } else if ("\"under_maintenance\"".equals(expectedState) ||
+ "w/\"under_maintenance\"".equals(expectedState)) {
+ useLongPolling = healthStatus == HealthStatus.UNDER_MAINTENANCE;
  } else {
  useLongPolling = false;
  }
@@ -528,11 +533,14 @@ private AggregatedHttpResponse getResponse(HealthStatus healthStatus) {
  return stoppingResponse;
  }
 
- if (healthStatus == HealthStatus.DEGRADED) {
- return degradedResponse;
+ switch (healthStatus) {
+ case DEGRADED:
+ return degradedResponse;
+ case UNDER_MAINTENANCE:
+ return underMaintenanceResponse;
+ default:
+ return unhealthyResponse;
  }
-
- return unhealthyResponse;
  }
 
  private void onHealthCheckerUpdate(HealthChecker unused) {

core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckServiceBuilder.java

@@ -51,14 +51,18 @@ public final class HealthCheckServiceBuilder implements TransientServiceBuilder
  MediaType.JSON_UTF_8,
  "{\"healthy\":true}");
 
- private AggregatedHttpResponse degradedResponse = AggregatedHttpResponse.of(HttpStatus.OK,
- MediaType.JSON_UTF_8,
- "{\"healthy\":true, " +
- "\"degraded\":true}");
+ private AggregatedHttpResponse degradedResponse =
+ AggregatedHttpResponse.of(HttpStatus.OK, MediaType.JSON_UTF_8,
+ "{\"healthy\":true,\"status\":\"DEGRADED\"}");
 
  private AggregatedHttpResponse unhealthyResponse = AggregatedHttpResponse.of(HttpStatus.SERVICE_UNAVAILABLE,
  MediaType.JSON_UTF_8,
  "{\"healthy\":false}");
+
+ private AggregatedHttpResponse underMaintenanceResponse =
+ AggregatedHttpResponse.of(HttpStatus.SERVICE_UNAVAILABLE, MediaType.JSON_UTF_8,
+ "{\"healthy\":false,\"status\":\"UNDER_MAINTENANCE\"}");
+
  private long maxLongPollingTimeoutMillis = TimeUnit.SECONDS.toMillis(DEFAULT_LONG_POLLING_TIMEOUT_SECONDS);
  private double longPollingTimeoutJitterRate = DEFAULT_LONG_POLLING_TIMEOUT_JITTER_RATE;
  private long pingIntervalMillis = TimeUnit.SECONDS.toMillis(DEFAULT_PING_INTERVAL_SECONDS);
@@ -119,7 +123,7 @@ public HealthCheckServiceBuilder healthyResponse(AggregatedHttpResponse healthyR
  * HTTP/1.1 200 OK
  * Content-Type: application/json; charset=utf-8
  *
- * { "healthy": true, "degraded": true }
+ * { "healthy": true, "status": "DEGRADED" }
  * }</pre>
  *
  * @return {@code this}
@@ -149,6 +153,25 @@ public HealthCheckServiceBuilder unhealthyResponse(AggregatedHttpResponse unheal
  return this;
  }
 
+ /**
+ * Sets the {@link AggregatedHttpResponse} to send when the {@link Service} is under maintenance. The
+ * following response is sent by default:
+ *
+ * <pre>{@code
+ * HTTP/1.1 503 Service Unavailable
+ * Content-Type: application/json; charset=utf-8
+ *
+ * { "healthy": false, "status": "UNDER_MAINTENANCE" }
+ * }</pre>
+ *
+ * @return {@code this}
+ */
+ public HealthCheckServiceBuilder underMaintenanceResponse(AggregatedHttpResponse underMaintenanceResponse) {
+ requireNonNull(underMaintenanceResponse, "underMaintenanceResponse");
+ this.underMaintenanceResponse = copyResponse(underMaintenanceResponse);
+ return this;
+ }
+
  /**
  * Make a copy just in case the content is modified by the caller or is backed by ByteBuf.
  */
@@ -330,8 +353,8 @@ public HealthCheckServiceBuilder transientServiceOptions(
  public HealthCheckService build() {
  checkState(startHealthy || updateHandler != null,
  "Healthiness must be updatable by server listener or update handler.");
- return new HealthCheckService(healthCheckers.build(),
- healthyResponse, degradedResponse, unhealthyResponse,
+ return new HealthCheckService(healthCheckers.build(), healthyResponse, degradedResponse,
+ unhealthyResponse, underMaintenanceResponse,
  maxLongPollingTimeoutMillis, longPollingTimeoutJitterRate,
  pingIntervalMillis, updateHandler, updateListenersBuilder.build(),
  startHealthy, transientServiceOptionsBuilder.build());

core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthStatus.java

@@ -22,9 +22,10 @@
  * The health status of a {@link Server}.
  */
 public enum HealthStatus {
- HEALTHY(2, true),
- DEGRADED(1, true),
- UNHEALTHY(0, false);
+ HEALTHY(3, true),
+ DEGRADED(2, true),
+ UNHEALTHY(1, false),
+ UNDER_MAINTENANCE(0, false);
 
  private final int priority;
  private final boolean isAvailable;

core/src/test/java/com/linecorp/armeria/server/healthcheck/HealthCheckServiceTest.java

@@ -41,6 +41,8 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.slf4j.Logger;
 
 import com.google.common.collect.ImmutableList;
@@ -503,29 +505,34 @@ void checkDegradedStatus() {
  ResponseHeaders.of(HttpStatus.OK,
  HttpHeaderNames.CONTENT_TYPE, MediaType.JSON_UTF_8,
  "armeria-lphc", "60, 5"),
- HttpData.ofUtf8("{\"healthy\":true, \"degraded\":true}")));
+ HttpData.ofUtf8("{\"healthy\":true,\"status\":\"DEGRADED\"}")));
  }
 
- @Test
- void notifyDegradedStatus() throws Exception {
+ @ParameterizedTest
+ @ValueSource(strings = { "DEGRADED", "UNHEALTHY", "UNDER_MAINTENANCE" })
+ void notifyHealthStatus(String healthStatus) throws Exception {
  final CompletableFuture<AggregatedHttpResponse> f =
  sendLongPollingGet("healthy", "/hc");
-
- // Should not wake up until the server becomes degraded.
  assertThatThrownBy(() -> f.get(1, TimeUnit.SECONDS))
  .isInstanceOf(TimeoutException.class);
 
- // Make the server degraded
- checker.setHealthStatus(HealthStatus.DEGRADED);
- assertThat(f.get()).isEqualTo(AggregatedHttpResponse.of(
- ImmutableList.of(ResponseHeaders.builder(HttpStatus.PROCESSING)
- .set("armeria-lphc", "60, 5")
- .build()),
- ResponseHeaders.of(HttpStatus.OK,
- HttpHeaderNames.CONTENT_TYPE, MediaType.JSON_UTF_8,
- "armeria-lphc", "60, 5"),
- HttpData.ofUtf8("{\"healthy\":true, \"degraded\":true}"),
- HttpHeaders.of()));
+ switch (healthStatus) {
+ case "DEGRADED":
+ checker.setHealthStatus(HealthStatus.DEGRADED);
+ assertThat(f.get().contentUtf8())
+ .isEqualTo("{\"healthy\":true,\"status\":\"DEGRADED\"}");
+ break;
+ case "UNHEALTHY":
+ checker.setHealthStatus(HealthStatus.UNHEALTHY);
+ assertThat(f.get().contentUtf8())
+ .isEqualTo( "{\"healthy\":false}");
+ break;
+ case "UNDER_MAINTENANCE":
+ checker.setHealthStatus(HealthStatus.UNDER_MAINTENANCE);
+ assertThat(f.get().contentUtf8())
+ .isEqualTo("{\"healthy\":false,\"status\":\"UNDER_MAINTENANCE\"}");
+ break;
+ }
  }
 
  private static void verifyDebugEnabled(Logger logger) {