[GitHub] [kafka] jsancio commented on a change in pull request #10309: KAFKA-12181; Loosen raft fetch offset validation of remote replicas
jsancio commented on a change in pull request #10309: URL: https://github.com/apache/kafka/pull/10309#discussion_r593492361 ## File path: raft/src/main/java/org/apache/kafka/raft/LeaderState.java ## @@ -247,7 +267,7 @@ private boolean isVoter(int remoteNodeId) { return voterReplicaStates.containsKey(remoteNodeId); } -private static class ReplicaState implements Comparable { +private static abstract class ReplicaState implements Comparable { Review comment: Do we really need to distinguish between `VoterState` and `ObserverState`? For example, the only different is `hasAcknowledgedLeader`. I would argue that we could just move this field to `ReplicateState` and say that observers will have this value always false or the value is ignored. I am leaning towards just updating the value irrespective of if it is a voter or observer. This is probably useful to have it when we implement quorum reassignment. We can document whatever semantic you decide as a comment for this type. ## File path: raft/src/test/java/org/apache/kafka/raft/LeaderStateTest.java ## @@ -140,6 +160,22 @@ public void testUpdateHighWatermarkQuorumSizeThree() { assertEquals(Optional.of(new LogOffsetMetadata(20L)), state.highWatermark()); } +@Test +public void testNonMonotonicHighWatermarkUpdate() { +MockTime time = new MockTime(); +int node1 = 1; +LeaderState state = newLeaderState(mkSet(localId, node1), 0L); +state.updateLocalState(time.milliseconds(), new LogOffsetMetadata(10L)); +state.updateReplicaState(node1, time.milliseconds(), new LogOffsetMetadata(10L)); +assertEquals(Optional.of(new LogOffsetMetadata(10L)), state.highWatermark()); + +// Follower crashes and disk is lost. It fetches an earlier offset to rebuild state. +state.updateReplicaState(node1, time.milliseconds(), new LogOffsetMetadata(5L)); Review comment: Let's check that this calls returns `false`. Let's also add a test that calls `getVoterEndOffsets` and checks the returned map is correct. 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
[GitHub] [kafka] jsancio commented on a change in pull request #10309: KAFKA-12181; Loosen raft fetch offset validation of remote replicas
jsancio commented on a change in pull request #10309: URL: https://github.com/apache/kafka/pull/10309#discussion_r594031740 ## File path: raft/src/test/java/org/apache/kafka/raft/RaftEventSimulationTest.java ## @@ -401,6 +401,51 @@ private void checkBackToBackLeaderFailures(QuorumConfig config) { } } +@Test +public void checkSingleNodeCommittedDataLossQuorumSizeThree() { +checkSingleNodeCommittedDataLoss(new QuorumConfig(3, 0)); +} + +private void checkSingleNodeCommittedDataLoss(QuorumConfig config) { +assertTrue(config.numVoters > 2, +"This test requires the cluster to be able to recover from one failed node"); + +for (int seed = 0; seed < 100; seed++) { +// We run this test without the `MonotonicEpoch` and `MajorityReachedHighWatermark` +// invariants since the loss of committed data on one node can violate them. + +Cluster cluster = new Cluster(config, seed); +EventScheduler scheduler = new EventScheduler(cluster.random, cluster.time); +scheduler.addInvariant(new MonotonicHighWatermark(cluster)); +scheduler.addInvariant(new SingleLeader(cluster)); +scheduler.addValidation(new ConsistentCommittedData(cluster)); + +MessageRouter router = new MessageRouter(cluster); + +cluster.startAll(); +schedulePolling(scheduler, cluster, 3, 5); +scheduler.schedule(router::deliverAll, 0, 2, 5); +scheduler.schedule(new SequentialAppendAction(cluster), 0, 2, 3); +scheduler.runUntil(() -> cluster.anyReachedHighWatermark(10)); + +RaftNode node = cluster.randomRunning().orElseThrow(() -> +new AssertionError("Failed to find running node") +); + +// Kill a random node and drop all of its persistent state. The Raft +// protocol guarantees should still ensure we lose no committed data +// as long as a new leader is elected before the failed node is restarted. +cluster.kill(node.nodeId); +cluster.deletePersistentState(node.nodeId); +scheduler.runUntil(() -> !cluster.hasLeader(node.nodeId) && cluster.hasConsistentLeader()); Review comment: Hmm. I was looking at the implementation for `hasConsistentLeader`. It checks that all of the `LeaderState` match. Which means that all of the replicas need to vote for the same leader. This is not strictly required for having a consistent leader. Maybe this works in this test because the number of voters is 3 and one of the nodes was killed. ## File path: raft/src/test/java/org/apache/kafka/raft/RaftEventSimulationTest.java ## @@ -401,6 +401,51 @@ private void checkBackToBackLeaderFailures(QuorumConfig config) { } } +@Test +public void checkSingleNodeCommittedDataLossQuorumSizeThree() { +checkSingleNodeCommittedDataLoss(new QuorumConfig(3, 0)); +} + +private void checkSingleNodeCommittedDataLoss(QuorumConfig config) { +assertTrue(config.numVoters > 2, +"This test requires the cluster to be able to recover from one failed node"); + +for (int seed = 0; seed < 100; seed++) { +// We run this test without the `MonotonicEpoch` and `MajorityReachedHighWatermark` +// invariants since the loss of committed data on one node can violate them. + +Cluster cluster = new Cluster(config, seed); +EventScheduler scheduler = new EventScheduler(cluster.random, cluster.time); +scheduler.addInvariant(new MonotonicHighWatermark(cluster)); +scheduler.addInvariant(new SingleLeader(cluster)); +scheduler.addValidation(new ConsistentCommittedData(cluster)); + +MessageRouter router = new MessageRouter(cluster); + +cluster.startAll(); +schedulePolling(scheduler, cluster, 3, 5); +scheduler.schedule(router::deliverAll, 0, 2, 5); +scheduler.schedule(new SequentialAppendAction(cluster), 0, 2, 3); +scheduler.runUntil(() -> cluster.anyReachedHighWatermark(10)); + +RaftNode node = cluster.randomRunning().orElseThrow(() -> +new AssertionError("Failed to find running node") +); + +// Kill a random node and drop all of its persistent state. The Raft +// protocol guarantees should still ensure we lose no committed data +// as long as a new leader is elected before the failed node is restarted. +cluster.kill(node.nodeId); +cluster.deletePersistentState(node.nodeId); Review comment: The implementation for `deletePersistentState` assumes that `kill` was or will be called for the change to take effect. Should we instead have tests call a method called `killAndDeletePersistentState`? -
[GitHub] [kafka] jsancio commented on a change in pull request #10309: KAFKA-12181; Loosen raft fetch offset validation of remote replicas
jsancio commented on a change in pull request #10309: URL: https://github.com/apache/kafka/pull/10309#discussion_r594638669 ## File path: raft/src/test/java/org/apache/kafka/raft/RaftEventSimulationTest.java ## @@ -401,6 +401,51 @@ private void checkBackToBackLeaderFailures(QuorumConfig config) { } } +@Test +public void checkSingleNodeCommittedDataLossQuorumSizeThree() { +checkSingleNodeCommittedDataLoss(new QuorumConfig(3, 0)); +} + +private void checkSingleNodeCommittedDataLoss(QuorumConfig config) { +assertTrue(config.numVoters > 2, +"This test requires the cluster to be able to recover from one failed node"); + +for (int seed = 0; seed < 100; seed++) { +// We run this test without the `MonotonicEpoch` and `MajorityReachedHighWatermark` +// invariants since the loss of committed data on one node can violate them. + +Cluster cluster = new Cluster(config, seed); +EventScheduler scheduler = new EventScheduler(cluster.random, cluster.time); +scheduler.addInvariant(new MonotonicHighWatermark(cluster)); +scheduler.addInvariant(new SingleLeader(cluster)); +scheduler.addValidation(new ConsistentCommittedData(cluster)); + +MessageRouter router = new MessageRouter(cluster); + +cluster.startAll(); +schedulePolling(scheduler, cluster, 3, 5); +scheduler.schedule(router::deliverAll, 0, 2, 5); +scheduler.schedule(new SequentialAppendAction(cluster), 0, 2, 3); +scheduler.runUntil(() -> cluster.anyReachedHighWatermark(10)); + +RaftNode node = cluster.randomRunning().orElseThrow(() -> +new AssertionError("Failed to find running node") +); + +// Kill a random node and drop all of its persistent state. The Raft +// protocol guarantees should still ensure we lose no committed data +// as long as a new leader is elected before the failed node is restarted. +cluster.kill(node.nodeId); +cluster.deletePersistentState(node.nodeId); +scheduler.runUntil(() -> !cluster.hasLeader(node.nodeId) && cluster.hasConsistentLeader()); Review comment: Yes. I meant to say `ElectionState` instead of `LeaderState`. `ElectionState` has a field called `votedIdOpt` for which `equals` checks for equality. This is not strictly required for having a "consistent" leader. I think for having a consistent leader for an epoch, only the `epoch` and `leaderIdOpt` need to match for all of the replicas. 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
[GitHub] [kafka] jsancio commented on a change in pull request #10309: KAFKA-12181; Loosen raft fetch offset validation of remote replicas
jsancio commented on a change in pull request #10309: URL: https://github.com/apache/kafka/pull/10309#discussion_r594787145 ## File path: raft/src/test/java/org/apache/kafka/raft/RaftEventSimulationTest.java ## @@ -401,6 +401,51 @@ private void checkBackToBackLeaderFailures(QuorumConfig config) { } } +@Test +public void checkSingleNodeCommittedDataLossQuorumSizeThree() { +checkSingleNodeCommittedDataLoss(new QuorumConfig(3, 0)); +} + +private void checkSingleNodeCommittedDataLoss(QuorumConfig config) { +assertTrue(config.numVoters > 2, +"This test requires the cluster to be able to recover from one failed node"); + +for (int seed = 0; seed < 100; seed++) { +// We run this test without the `MonotonicEpoch` and `MajorityReachedHighWatermark` +// invariants since the loss of committed data on one node can violate them. + +Cluster cluster = new Cluster(config, seed); +EventScheduler scheduler = new EventScheduler(cluster.random, cluster.time); +scheduler.addInvariant(new MonotonicHighWatermark(cluster)); +scheduler.addInvariant(new SingleLeader(cluster)); +scheduler.addValidation(new ConsistentCommittedData(cluster)); + +MessageRouter router = new MessageRouter(cluster); + +cluster.startAll(); +schedulePolling(scheduler, cluster, 3, 5); +scheduler.schedule(router::deliverAll, 0, 2, 5); +scheduler.schedule(new SequentialAppendAction(cluster), 0, 2, 3); +scheduler.runUntil(() -> cluster.anyReachedHighWatermark(10)); + +RaftNode node = cluster.randomRunning().orElseThrow(() -> +new AssertionError("Failed to find running node") +); + +// Kill a random node and drop all of its persistent state. The Raft +// protocol guarantees should still ensure we lose no committed data +// as long as a new leader is elected before the failed node is restarted. +cluster.kill(node.nodeId); +cluster.deletePersistentState(node.nodeId); +scheduler.runUntil(() -> !cluster.hasLeader(node.nodeId) && cluster.hasConsistentLeader()); Review comment: Got it. I missed that `votedIdOpt` is set to `empty` by the leader and the followers. 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org