| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.servicecomb.loadbalance; |
| |
| import java.time.Clock; |
| import java.util.concurrent.atomic.AtomicLong; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import org.apache.servicecomb.core.Invocation; |
| import org.apache.servicecomb.foundation.common.utils.TimeUtils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Special stats that com.netflix.loadbalancer.ServerStats not provided. |
| * |
| * In concurrent scenarios, we can't count statistics accurately, but it's fine. |
| */ |
| public class ServiceCombServerStats { |
| private static final long TIME_WINDOW_IN_MILLISECONDS = 60000; |
| |
| private static final Logger LOGGER = LoggerFactory.getLogger(ServiceCombServerStats.class); |
| |
| private final Object lock = new Object(); |
| |
| /** |
| * There is not more than 1 server allowed to stay in TRYING status concurrently. |
| * This flag is designed to ensure such mechanism. And it makes the ServiceCombServerStats stateful. |
| * Therefore, the flag should be reset correctly after the trying server gets handled. |
| */ |
| static AtomicReference<TryingIsolatedServerMarker> globalAllowIsolatedServerTryingFlag = new AtomicReference<>(); |
| |
| Clock clock; |
| |
| private long lastWindow; |
| |
| private AtomicLong continuousFailureCount; |
| |
| private long lastVisitTime; |
| |
| private long lastActiveTime; |
| |
| private long isolatedTime; |
| |
| private AtomicLong totalRequests; |
| |
| private AtomicLong successRequests; |
| |
| private AtomicLong failedRequests; |
| |
| private boolean isolated = false; |
| |
| private final String microserviceName; |
| |
| public ServiceCombServerStats(String microserviceName) { |
| this(microserviceName, TimeUtils.getSystemDefaultZoneClock()); |
| } |
| |
| public ServiceCombServerStats(String microserviceName, Clock clock) { |
| this.clock = clock; |
| this.microserviceName = microserviceName; |
| init(); |
| } |
| |
| private void init() { |
| lastWindow = clock.millis(); |
| continuousFailureCount = new AtomicLong(0); |
| lastVisitTime = clock.millis(); |
| lastActiveTime = clock.millis(); |
| totalRequests = new AtomicLong(0L); |
| successRequests = new AtomicLong(0L); |
| failedRequests = new AtomicLong(0L); |
| } |
| |
| public static boolean isolatedServerCanTry() { |
| TryingIsolatedServerMarker marker = globalAllowIsolatedServerTryingFlag.get(); |
| if (marker == null) { |
| return true; |
| } |
| return marker.isOutdated(); |
| } |
| |
| /** |
| * Applying for a trying chance for the isolated server. There is only 1 trying chance globally concurrently. |
| * |
| * @return true if the chance is applied successfully, otherwise false |
| */ |
| public static boolean applyForTryingChance(Invocation invocation) { |
| TryingIsolatedServerMarker marker = globalAllowIsolatedServerTryingFlag.get(); |
| if (marker == null) { |
| return globalAllowIsolatedServerTryingFlag.compareAndSet(null, new TryingIsolatedServerMarker(invocation)); |
| } |
| if (marker.isOutdated()) { |
| return globalAllowIsolatedServerTryingFlag.compareAndSet(marker, new TryingIsolatedServerMarker(invocation)); |
| } |
| return false; |
| } |
| |
| public static void checkAndReleaseTryingChance(Invocation invocation) { |
| TryingIsolatedServerMarker marker = globalAllowIsolatedServerTryingFlag.get(); |
| if (marker == null || marker.getInvocation() != invocation) { |
| return; |
| } |
| globalAllowIsolatedServerTryingFlag.compareAndSet(marker, null); |
| } |
| |
| public void markIsolated(boolean isolated) { |
| this.isolated = isolated; |
| this.isolatedTime = System.currentTimeMillis(); |
| } |
| |
| public void markSuccess() { |
| long time = clock.millis(); |
| ensureWindow(time); |
| |
| if (isolated) { |
| if (Configuration.INSTANCE.isRecoverImmediatelyWhenSuccess(microserviceName) |
| && time - this.isolatedTime > Configuration.INSTANCE |
| .getMinIsolationTime(microserviceName)) { |
| resetStats(); |
| LOGGER.info("trying server invocation success, and reset stats."); |
| } else { |
| LOGGER.info("trying server invocation success!"); |
| } |
| } |
| |
| totalRequests.incrementAndGet(); |
| successRequests.incrementAndGet(); |
| continuousFailureCount.set(0); |
| lastVisitTime = time; |
| lastActiveTime = time; |
| } |
| |
| public void markFailure() { |
| long time = clock.millis(); |
| ensureWindow(time); |
| lastVisitTime = time; |
| |
| // when isolated, do not update any failure statistics, or we can not recover from failure very quickly |
| if (!isolated) { |
| totalRequests.incrementAndGet(); |
| failedRequests.incrementAndGet(); |
| continuousFailureCount.incrementAndGet(); |
| } |
| } |
| |
| private void ensureWindow(long time) { |
| if (time - lastWindow > TIME_WINDOW_IN_MILLISECONDS) { |
| synchronized (lock) { |
| if (time - lastWindow > TIME_WINDOW_IN_MILLISECONDS) { |
| if (!isolated) { |
| resetStats(); |
| } |
| lastWindow = time; |
| } |
| } |
| } |
| } |
| |
| private void resetStats() { |
| continuousFailureCount.set(0); |
| totalRequests.set(0); |
| successRequests.set(0); |
| failedRequests.set(0); |
| } |
| |
| public long getLastVisitTime() { |
| return lastVisitTime; |
| } |
| |
| public long getIsolatedTime() { |
| return isolatedTime; |
| } |
| |
| public long getLastActiveTime() { |
| return lastActiveTime; |
| } |
| |
| public long getContinuousFailureCount() { |
| return continuousFailureCount.get(); |
| } |
| |
| public long getTotalRequests() { |
| return totalRequests.get(); |
| } |
| |
| public long getSuccessRequests() { |
| return successRequests.get(); |
| } |
| |
| public long getFailedRequests() { |
| return failedRequests.get(); |
| } |
| |
| public int getSuccessRate() { |
| return calcRequestRate(successRequests); |
| } |
| |
| public int getFailedRate() { |
| return calcRequestRate(failedRequests); |
| } |
| |
| private int calcRequestRate(AtomicLong requestCnt) { |
| long totalReqs = totalRequests.get(); |
| if (totalReqs == 0L) { |
| return 0; |
| } |
| return (int) (requestCnt.get() * 100 / totalReqs); |
| } |
| |
| public boolean isIsolated() { |
| return isolated; |
| } |
| } |