nicusX commented on code in PR #1: URL: https://github.com/apache/flink-connector-prometheus/pull/1#discussion_r1597510275
########## prometheus-connector/src/main/java/org/apache/flink/connector/prometheus/sink/http/RemoteWriteRetryStrategy.java: ########## @@ -0,0 +1,106 @@ +/* + * 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.flink.connector.prometheus.sink.http; + +import org.apache.flink.connector.prometheus.sink.SinkMetrics; + +import org.apache.hc.client5.http.HttpRequestRetryStrategy; +import org.apache.hc.core5.http.HttpRequest; +import org.apache.hc.core5.http.HttpResponse; +import org.apache.hc.core5.http.protocol.HttpContext; +import org.apache.hc.core5.util.TimeValue; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.net.ssl.SSLException; + +import java.io.IOException; +import java.io.InterruptedIOException; +import java.net.ConnectException; +import java.net.NoRouteToHostException; +import java.net.UnknownHostException; +import java.util.List; + +/** Retry strategy for the http client. */ +public class RemoteWriteRetryStrategy implements HttpRequestRetryStrategy { + private static final Logger LOG = LoggerFactory.getLogger(RemoteWriteRetryStrategy.class); + + private static final List<Class<? extends IOException>> NON_RETRIABLE_EXCEPTIONS = + List.of( + InterruptedIOException.class, + UnknownHostException.class, + ConnectException.class, + NoRouteToHostException.class, + SSLException.class); + + private final long initialRetryDelayMs; + private final long maxRetryDelayMs; + private final int maxRetryCount; + + private final SinkMetrics counters; + + public RemoteWriteRetryStrategy(RetryConfiguration retryConfiguration, SinkMetrics counters) { + this.initialRetryDelayMs = retryConfiguration.getInitialRetryDelayMS(); + this.maxRetryDelayMs = retryConfiguration.getMaxRetryDelayMS(); + this.maxRetryCount = retryConfiguration.getMaxRetryCount(); + this.counters = counters; + } + + @Override + public boolean retryRequest( + HttpRequest httpRequest, IOException e, int execCount, HttpContext httpContext) { + // Retry on any IOException except those considered non-retriable + var retry = + (execCount <= maxRetryCount) && !(NON_RETRIABLE_EXCEPTIONS.contains(e.getClass())); + LOG.debug( + "{} retry on {}, at execution {}", + (retry) ? "DO" : "DO NOT", + e.getClass(), + execCount); + countRetry(retry); + return retry; + } + + @Override + public boolean retryRequest(HttpResponse httpResponse, int execCount, HttpContext httpContext) { + var retry = + (execCount <= maxRetryCount) + && RemoteWriteResponseClassifier.isRetriableErrorResponse(httpResponse); + LOG.debug( + "{} retry on response {} {}, at execution {}", + (retry) ? "DO" : "DO NOT", + httpResponse.getCode(), + httpResponse.getReasonPhrase(), + execCount); + countRetry(retry); + return retry; + } + + @Override + public TimeValue getRetryInterval( + HttpResponse httpResponse, int execCount, HttpContext httpContext) { + long calculatedDelay = initialRetryDelayMs << (execCount - 1); Review Comment: I don't see much value in making the backoff strategy more sophisticated. Prometheus Remote-write specs just say it "MUST use a backoff algorithm to prevent overwhelming the server". Tweaking the `initialRetryIntervalMs` and `maxRetryDelayMs` will be enough to make the strategy more or less aggressive. Also, I don't see much value in adding a jitter. There is one writer thread per subtask, and and it's very unlikely they will be synchronized when writing to the endpoint. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
