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Posted to commits@ratis.apache.org by ru...@apache.org on 2020/11/04 05:28:01 UTC
[incubator-ratis] branch master updated: RATIS-1120. Terminate
election in advance if majority peers reject (#241)
This is an automated email from the ASF dual-hosted git repository.
runzhiwang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-ratis.git
The following commit(s) were added to refs/heads/master by this push:
new 9f5fd11 RATIS-1120. Terminate election in advance if majority peers reject (#241)
9f5fd11 is described below
commit 9f5fd11aa6ed33a7f439e92a21fc0a78b4254b23
Author: dengziming <de...@gmail.com>
AuthorDate: Wed Nov 4 13:27:52 2020 +0800
RATIS-1120. Terminate election in advance if majority peers reject (#241)
Co-authored-by: dengziming <de...@growingio.com>
---
.../apache/ratis/server/impl/LeaderElection.java | 6 ++
.../ratis/server/impl/PeerConfiguration.java | 10 ++++
.../ratis/server/impl/RaftConfiguration.java | 6 ++
.../ratis/server/impl/PeerConfigurationTest.java | 68 ++++++++++++++++++++++
4 files changed, 90 insertions(+)
diff --git a/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java b/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
index 4796a75..5c023c6 100644
--- a/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
+++ b/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
@@ -289,6 +289,7 @@ class LeaderElection implements Runnable {
final List<Exception> exceptions = new ArrayList<>();
int waitForNum = submitted;
Collection<RaftPeerId> votedPeers = new ArrayList<>();
+ Collection<RaftPeerId> rejectedPeers = new ArrayList<>();
Set<RaftPeerId> higherPriorityPeers = getHigherPriorityPeers(conf);
while (waitForNum > 0 && shouldRun(electionTerm)) {
@@ -344,6 +345,11 @@ class LeaderElection implements Runnable {
if (higherPriorityPeers.size() == 0 && conf.hasMajority(votedPeers, server.getId())) {
return logAndReturn(Result.PASSED, responses, exceptions, -1);
}
+ } else {
+ rejectedPeers.add(replierId);
+ if (conf.majorityRejectVotes(rejectedPeers)) {
+ return logAndReturn(Result.REJECTED, responses, exceptions, -1);
+ }
}
} catch(ExecutionException e) {
LogUtils.infoOrTrace(LOG, () -> this + " got exception when requesting votes", e);
diff --git a/ratis-server/src/main/java/org/apache/ratis/server/impl/PeerConfiguration.java b/ratis-server/src/main/java/org/apache/ratis/server/impl/PeerConfiguration.java
index 7215665..60cd33d 100644
--- a/ratis-server/src/main/java/org/apache/ratis/server/impl/PeerConfiguration.java
+++ b/ratis-server/src/main/java/org/apache/ratis/server/impl/PeerConfiguration.java
@@ -94,6 +94,16 @@ class PeerConfiguration {
return num > size() / 2;
}
+ boolean majorityRejectVotes(Collection<RaftPeerId> rejected) {
+ int num = size();
+ for (RaftPeerId other : rejected) {
+ if (contains(other)) {
+ num --;
+ }
+ }
+ return num <= size() / 2;
+ }
+
@Override
public boolean equals(Object obj) {
if (this == obj) {
diff --git a/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftConfiguration.java b/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftConfiguration.java
index a56bd5a..44080da 100644
--- a/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftConfiguration.java
+++ b/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftConfiguration.java
@@ -206,6 +206,12 @@ public final class RaftConfiguration {
(oldConf == null || oldConf.hasMajority(others, selfId));
}
+ /** @return true if the rejects are in the majority(maybe half is enough in some cases). */
+ boolean majorityRejectVotes(Collection<RaftPeerId> rejects) {
+ return conf.majorityRejectVotes(rejects) ||
+ (oldConf != null && oldConf.majorityRejectVotes(rejects));
+ }
+
@Override
public String toString() {
return logEntryIndex + ": " + conf + ", old=" + oldConf;
diff --git a/ratis-server/src/test/java/org/apache/ratis/server/impl/PeerConfigurationTest.java b/ratis-server/src/test/java/org/apache/ratis/server/impl/PeerConfigurationTest.java
new file mode 100644
index 0000000..e40ad71
--- /dev/null
+++ b/ratis-server/src/test/java/org/apache/ratis/server/impl/PeerConfigurationTest.java
@@ -0,0 +1,68 @@
+/*
+ * 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.ratis.server.impl;
+
+import org.apache.ratis.protocol.RaftPeer;
+import org.apache.ratis.protocol.RaftPeerId;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class PeerConfigurationTest {
+
+ @Test
+ public void testOddNodesQuorum() {
+ String localId = "0";
+ String node1 = "1";
+ String node2 = "2";
+ PeerConfiguration conf = new PeerConfiguration(raftPeers(localId, node1, node2));
+ // in odd quorum, half + self is majority
+ assertTrue(conf.hasMajority(raftPeerIds(node1), RaftPeerId.valueOf(localId)));
+ // in odd quorum, majority is impossible after half rejected
+ assertFalse(conf.majorityRejectVotes(raftPeerIds(node1)));
+ }
+
+ @Test
+ public void testEvenNodeQuorum() {
+ String localId = "0";
+ String node1 = "1";
+ String node2 = "2";
+ String node3 = "3";
+ PeerConfiguration conf = new PeerConfiguration(raftPeers(localId, node1, node2, node3));
+ // in even quorum, half + self is majority
+ assertFalse(conf.hasMajority(raftPeerIds(node1), RaftPeerId.valueOf(localId)));
+ assertTrue(conf.hasMajority(raftPeerIds(node1, node2), RaftPeerId.valueOf(localId)));
+ // in even quorum, majority is impossible after half rejected
+ assertFalse(conf.majorityRejectVotes(raftPeerIds(node1)));
+ assertTrue(conf.majorityRejectVotes(raftPeerIds(node1, node2)));
+ }
+
+ private Collection<RaftPeer> raftPeers(String... voters) {
+ return Arrays.stream(voters).map(voter -> new RaftPeer(RaftPeerId.valueOf(voter))).collect(Collectors.toSet());
+ }
+
+ private Collection<RaftPeerId> raftPeerIds(String... voters) {
+ return Arrays.stream(voters).map(RaftPeerId::valueOf).collect(Collectors.toSet());
+ }
+
+}