adoroszlai commented on code in PR #10486: URL: https://github.com/apache/ozone/pull/10486#discussion_r3408509958
########## hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/utils/ConnectionFailureUtils.java: ########## @@ -0,0 +1,101 @@ +/* + * 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.hadoop.hdds.utils; + +import java.io.EOFException; +import java.net.ConnectException; +import java.net.NoRouteToHostException; +import java.net.SocketException; +import java.net.SocketTimeoutException; +import java.net.UnknownHostException; + +/** + * Shared classifier for exceptions where the cached peer IP is no longer + * reachable and DNS re-resolution is the only plausible recovery path. + * <p> + * Used by both {@code SCMFailoverProxyProviderBase} and + * {@code OMFailoverProxyProviderBase} to gate the DNS-refresh-on-failure + * code path so that application-level errors (NotLeader, AccessControl, + * OMException, RetryAction) do not trigger spurious DNS lookups. + * <p> + * The classifier must match the failure shapes seen in production + * Kubernetes deployments where the peer pod has been rescheduled to a + * new IP under a stable hostname: + * <ul> + * <li>{@link ConnectException} -- the TCP SYN was refused. Seen on + * OpenStack / fast-RST environments. </li> + * <li>{@link SocketTimeoutException} (and its IPC subclass + * {@code ConnectTimeoutException}) -- the SYN was dropped silently. + * This is the dominant failure shape on AWS EC2 / EKS where the + * network silently drops packets to a defunct pod IP. The PR that + * introduced this helper (HDDS-15514) is sold on this case; it + * must be in the filter. </li> + * <li>{@link NoRouteToHostException} -- routing table no longer + * reaches the cached IP. </li> + * <li>{@link UnknownHostException} -- the hostname itself failed to + * resolve at the time the IPC layer reconstructed the address. </li> + * <li>{@link EOFException} -- a load balancer or iptables RST closed + * the half-open connection cleanly. Common in Kubernetes when an + * IP is reassigned to an unrelated pod that rejects the RPC + * handshake. </li> + * <li>{@link SocketException} (e.g. "Connection reset") -- the peer + * sent RST mid-stream. </li> + * </ul> + * The walk is bounded to {@value #MAX_CAUSE_DEPTH} levels to defend + * against cause chains that have been constructed (in violation of + * {@code Throwable.initCause}'s contract) into a cycle of length > 1. Review Comment: ``` hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/utils/ConnectionFailureUtils.java:61: warning - invalid usage of tag > ``` ```suggestion * {@code Throwable.initCause}'s contract) into a cycle of length > 1. ``` -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
