bitflicker64 commented on code in PR #3331: URL: https://github.com/apache/hugegraph/pull/3331#discussion_r4264088704
########## hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/LoadingMode.java: ########## @@ -0,0 +1,113 @@ +/* + * 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.hugegraph; + +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; +import java.util.UUID; + +import org.apache.hugegraph.type.define.GraphMode; +import org.apache.hugegraph.util.E; + +import com.google.common.collect.ImmutableMap; + +/** Same graph-instance ownership; this state is neither persisted nor distributed. */ +public final class LoadingMode { + + private static final int MAX_RELEASED = 1024; + + private final String instance = UUID.randomUUID().toString(); + private final Map<String, String> active = new HashMap<>(); + private final Map<String, String> released = new HashMap<>(); + private long epoch; + private volatile GraphMode mode = GraphMode.NONE; + + public GraphMode mode() { + return this.mode; + } + + public synchronized void mode(GraphMode mode) { + Objects.requireNonNull(mode, "mode"); + E.checkState(this.active.isEmpty(), "Loading owners are active; release them before setting graph mode"); + this.mode = mode; + } + + public synchronized Map<String, Object> capability() { + return ImmutableMap.of("protocol", 1, "instance", this.instance, "epoch", this.epoch); + } + + public synchronized Map<String, Object> update(String action, String instance, long epoch, + String token, String principal) { + E.checkArgument("acquire".equals(action) || "release".equals(action), + "Loading owner action must be acquire or release"); + E.checkArgument(this.instance.equals(instance), "Loading owner belongs to another graph instance"); + E.checkArgument(epoch >= 0 && epoch <= this.epoch, "Invalid loading owner epoch"); + E.checkArgument(token != null && token.length() == 36 && UUID.fromString(token).toString().equals(token), + "Loading owner token must be a canonical UUID"); + Objects.requireNonNull(principal, "principal"); + String key = epoch + "/" + token; + String owner = this.active.get(key); + if (owner != null) { + E.checkState(owner.equals(principal), "Loading owner belongs to another authenticated principal"); + if ("acquire".equals(action)) { + return this.receipt(epoch, token, "active"); + } + // Exhaustion must fail before changing an active registration. + E.checkState(epoch != this.epoch || this.released.size() < MAX_RELEASED || + this.epoch < Long.MAX_VALUE, "Loading owner epoch exhausted"); + this.active.remove(key); + if (this.active.isEmpty()) { + this.mode = GraphMode.NONE; + } + } else if ("acquire".equals(action)) { + if (epoch < this.epoch || this.released.containsKey(key)) { Review Comment: Important: after an epoch rotation, a Loader cannot tell a retired handle from a cancelled one, so it aborts an import it could have started. The 1025th distinct release in an epoch, including an unknown release with a fresh token, runs `this.epoch++` (line 98). If that lands between a Loader's `GET .../mode/owners` and its `PUT acquire`, this line returns `released` for a token it never saw. Probe on this head: B reads `{epoch=0}`, a rotation follows, and B's acquire gets `state=released, mode=NONE`. In #815, `LoadingModeOwner.verify` throws `InvalidResponseException` for that receipt, and `LoadContext` keeps the same owner, so a retry fails too. `LoadingModeTest.java:75` and the "permanently retires" sentence in `docs/server-runtime.md` treat this as intended, but they give the client no way to recover. Please return a distinct state (for example `stale`) for any older-epoch tuple that is not active, so the client can read the capability again and acquire with a new token. Update the assertion at `LoadingModeTest.java:75` to match. -- 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]
