Skip to content

Commit

Permalink
Add failing tests
Browse files Browse the repository at this point in the history
  • Loading branch information
@shaan1337
shaan1337 committed Apr 17, 2023
1 parent a6f481c commit 6ca83d0
Show file tree
Hide file tree
Showing 3 changed files with 319 additions and 0 deletions.
279 changes: 279 additions & 0 deletions src/EventStore.Core.XUnit.Tests/Scavenge/EmptyScavengedChunksTests.cs
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,279 @@
using System;
using System.Threading.Tasks;
using EventStore.Core.Data;
using EventStore.Core.Tests;
using EventStore.Core.Tests.TransactionLog.Scavenging.Helpers;
using EventStore.Core.TransactionLog.Scavenging;
using EventStore.Core.XUnit.Tests.Scavenge.Sqlite;
using Xunit;
using static EventStore.Core.XUnit.Tests.Scavenge.StreamMetadatas;

namespace EventStore.Core.XUnit.Tests.Scavenge;

// the old scavenger can leave behind empty, scavenged chunks when
// all events from a chunk are deleted. if the scavenger is interrupted
// before the index scavenge phase, entries pointing to these
// empty chunks may be present in the index.
//
// note: it may also happen that the merge phase has completed and the empty chunks
// have been merged but these will be similar to the before-merge case as the
// new scavenger works on logical chunk numbers.

public class EmptyScavengedChunksTests : SqliteDbPerTest<MaxAgeTests> {
// let's assume we have an index entry X pointing to an empty, scavenged chunk.
// call the stream for that index entry: S.
//
// there are the following cases:
//
// Case A. no scavenge data (metadata, tombstone) for S exists in the log:
// as usual:
// - no events of S will be deleted
// - X will stay in the index
//
// Case B. scavenge data (metadata, tombstone) for S exists in the log:
// - as usual, scavenge data will be accumulated and discard points calculated
// - X must or must not be deleted from the index, depending on the cases below:
//
// B.1: X is the first index entry for the stream
// delete X since all events prior to X are deleted and X doesn't exist in the log
//
// B.2: X is not the first index entry for the stream and the previous index entry is not another X
//
// B.2.1: based on scavenge data, the index entry prior to X will be discarded for sure (i.e not 'maybe' discardable)
// delete X since all events prior to X will be deleted and X doesn't exist in the log
//
// B.2.2: based on scavenge data, the index entry prior to X is 'maybe' discardable or will be kept for sure
// keep X since not all events prior to X may be deleted from the log
//
// B.3: X is not the first index entry for the stream and the previous index entry is another X: X'
//
// B.3.1: X' has/will be discarded from the index (due to rules B.1 or B.2.1)
// delete X since all events prior to X are/will be deleted and X doesn't exist in the log
//
// B.3.2: X' will not be discarded from the index (due to rule B.2.2)
// keep X since not all events prior to X may be deleted from the log
//
// assumptions:
// i) 'discardable for sure' events cannot be after 'maybe' discardable events or after 'kept for sure' events
// ii) 'maybe' discardable events cannot be after 'kept for sure' events

[Fact]
public async Task case_a() {
var t = 0;
await new Scenario<LogFormat.V2, string>()
.WithDbPath(Fixture.Directory)
.WithDb(x => x
.Chunk(
Rec.Write(t++, "ab-1"),
Rec.Write(t++, "ab-1"))
.Chunk(ScavengePointRec(t++)))
.EmptyChunk(0)
.WithState(x => x.WithConnectionPool(Fixture.DbConnectionPool))
.RunAsync(
x => new[] {
x.Recs[0].KeepNone(), // emptied prior to scavenge
x.Recs[1].KeepAll()
},
x => new[] {
x.Recs[0].KeepAll(),
x.Recs[1].KeepAll()
}
);
}

[Fact]
public async Task case_b() {
var t = 0;
await new Scenario<LogFormat.V2, string>()
.WithDbPath(Fixture.Directory)
.WithDb(x => x
.Chunk(
Rec.Write(t++, "ab-1"), // B.1: delete
Rec.Write(t++, "ab-1")) // B.3.1: delete
.Chunk(
Rec.Write(t++, "ab-1"), // delete (before truncate before)
Rec.Write(t++, "ab-1")) // delete (before truncate before)
.Chunk(
Rec.Write(t++, "ab-1"), // B.2.1: delete
Rec.Write(t++, "ab-1")) // B.3.1: delete <-- discard point must move here at event 5
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Cutoff - TimeSpan.FromSeconds(1)), // maybe deleted
Rec.Write(t++, "ab-1", timestamp: Cutoff), // maybe deleted
Rec.Write(t++, "ab-1", timestamp: Cutoff + TimeSpan.FromSeconds(1))) // maybe deleted <-- maybe discard point must move here at event 8
.Chunk(
Rec.Write(t++, "ab-1"), // B.2.2: keep
Rec.Write(t++, "ab-1")) // B.3.2: keep
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Active), // keep (not expired)
Rec.Write(t++, "ab-1", timestamp: Active), // keep (not expired)
Rec.Write(t++, "ab-1", timestamp: Active)) // keep (not expired)
.Chunk(
Rec.Write(t++, "ab-1"), // B.2.2: keep
Rec.Write(t++, "ab-1")) // B.3.2: keep
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Active), // added just to create a valid last event
Rec.Write(t++, "$$ab-1", "$metadata", metadata: new StreamMetadata(
maxAge: MaxAgeTimeSpan,
truncateBefore: 4
)))
.Chunk(ScavengePointRec(t++)))
.EmptyChunk(0)
.EmptyChunk(2)
.EmptyChunk(4)
.EmptyChunk(6)
.WithState(x => x.WithConnectionPool(Fixture.DbConnectionPool))
.AssertState(x => {
if (!x.TryGetOriginalStreamData("ab-1", out var data))
Assert.Fail("Failed to get original stream data");
Assert.Equal(DiscardPoint.DiscardIncluding(5), data.DiscardPoint);
Assert.Equal(DiscardPoint.DiscardIncluding(8), data.MaybeDiscardPoint);
})
.RunAsync(
x => new[] {
x.Recs[0].KeepNone(), // emptied prior to scavenge
x.Recs[1].KeepNone(),
x.Recs[2].KeepNone(), // emptied prior to scavenge
x.Recs[3].KeepIndexes(1, 2),
x.Recs[4].KeepNone(), // emptied prior to scavenge
x.Recs[5].KeepAll(),
x.Recs[6].KeepNone(), // emptied prior to scavenge
x.Recs[7].KeepAll(),
x.Recs[8].KeepAll()
},
x => new[] {
x.Recs[0].KeepNone(),
x.Recs[1].KeepNone(),
x.Recs[2].KeepNone(),
x.Recs[3].KeepAll(), // all kept since 'maybe' discardable
x.Recs[4].KeepAll(),
x.Recs[5].KeepAll(),
x.Recs[6].KeepAll(),
x.Recs[7].KeepAll(),
x.Recs[8].KeepAll()
}
);
}

[Fact]
public async Task case_b_with_no_events_in_the_log() {
var t = 0;
await new Scenario<LogFormat.V2, string>()
.WithDbPath(Fixture.Directory)
.WithDb(x => x
.Chunk(
Rec.Write(t++, "ab-1"), // B.1: delete
Rec.Write(t++, "ab-1"), // B.3.1: delete <-- discard point must move here
Rec.Write(t++, "ab-1")) // B.3.1: normally deleted but kept due to overriding rule to keep last index entry
.Chunk(
Rec.Write(t++, "$$ab-1", "$metadata", metadata: MaxAgeMetadata))
.Chunk(ScavengePointRec(t++)))
.EmptyChunk(0)
.WithState(x => x.WithConnectionPool(Fixture.DbConnectionPool))
.AssertState(x => {
if (!x.TryGetOriginalStreamData("ab-1", out var data))
Assert.Fail("Failed to get original stream data");
Assert.Equal(DiscardPoint.DiscardIncluding(1), data.DiscardPoint);
})
.RunAsync(
x => new[] {
x.Recs[0].KeepNone(), // emptied prior to scavenge
x.Recs[1].KeepAll(),
x.Recs[2].KeepAll()
},
x => new[] {
x.Recs[0].KeepIndexes(2),
x.Recs[1].KeepAll(),
x.Recs[2].KeepAll()
}
);
}

[Fact]
public async Task case_b_with_only_tb_metadata() {
var t = 0;
await new Scenario<LogFormat.V2, string>()
.WithDbPath(Fixture.Directory)
.WithDb(x => x
.Chunk(
Rec.Write(t++, "ab-1"), // delete (before truncate before)
Rec.Write(t++, "ab-1")) // delete (before truncate before)
.Chunk(
Rec.Write(t++, "ab-1"), // B.2.1: deleted, although it's after the truncate before
Rec.Write(t++, "ab-1")) // B.3.1: deleted, although it's after the truncate before <-- discard point must move here at event 3
.Chunk(
Rec.Write(t++, "ab-1"), // keep (after truncate before)
Rec.Write(t++, "ab-1"), // keep (after truncate before)
Rec.Write(t++, "ab-1")) // keep (after truncate before)
.Chunk(
Rec.Write(t++, "$$ab-1", "$metadata", metadata: TruncateBefore2))
.Chunk(ScavengePointRec(t++)))
.EmptyChunk(1)
.WithState(x => x.WithConnectionPool(Fixture.DbConnectionPool))
.AssertState(x => {
Assert.False(x.TryGetOriginalStreamData("ab-1", out _)); // calculation status is 'spent'
})
.RunAsync(
x => new[] {
x.Recs[0].KeepNone(),
x.Recs[1].KeepNone(), // emptied prior to scavenge
x.Recs[2].KeepAll(),
x.Recs[3].KeepAll(),
x.Recs[4].KeepAll()
},
x => new[] {
x.Recs[0].KeepNone(),
x.Recs[1].KeepNone(), // all index entries deleted
x.Recs[2].KeepAll(),
x.Recs[3].KeepAll(),
x.Recs[4].KeepAll()
}
);
}

[Fact]
public async Task case_b_with_only_maxage_metadata() {
var t = 0;
await new Scenario<LogFormat.V2, string>()
.WithDbPath(Fixture.Directory)
.WithDb(x => x
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Expired), // delete (expired)
Rec.Write(t++, "ab-1", timestamp: Expired)) // delete (before truncate before)
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Active), // B.2.1: deleted, although original event wasn't expired
Rec.Write(t++, "ab-1", timestamp: Active)) // B.3.1: deleted, although original event wasn't expired <-- discard point must move here at event 3
.Chunk(
Rec.Write(t++, "ab-1", timestamp: Active), // keep (not expired)
Rec.Write(t++, "ab-1", timestamp: Active), // keep (not expired)
Rec.Write(t++, "ab-1", timestamp: Active)) // keep (not expired)
.Chunk(
Rec.Write(t++, "$$ab-1", "$metadata", metadata: MaxAgeMetadata))
.Chunk(ScavengePointRec(t++)))
.EmptyChunk(1)
.WithState(x => x.WithConnectionPool(Fixture.DbConnectionPool))
.AssertState(x => {
if (!x.TryGetOriginalStreamData("ab-1", out var data))
Assert.Fail("Failed to get original stream data");
Assert.Equal(DiscardPoint.DiscardIncluding(3), data.DiscardPoint);
})
.RunAsync(
x => new[] {
x.Recs[0].KeepNone(),
x.Recs[1].KeepNone(), // emptied prior to scavenge
x.Recs[2].KeepAll(),
x.Recs[3].KeepAll(),
x.Recs[4].KeepAll()
},
x => new[] {
x.Recs[0].KeepNone(),
x.Recs[1].KeepNone(), // all index entries deleted
x.Recs[2].KeepAll(),
x.Recs[3].KeepAll(),
x.Recs[4].KeepAll()
}
);
}
}
39 changes: 39 additions & 0 deletions src/EventStore.Core.XUnit.Tests/Scavenge/Infrastructure/Scenario.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
using EventStore.Core.Tests.TransactionLog.Scavenging.Helpers;
using EventStore.Core.TransactionLog;
using EventStore.Core.TransactionLog.Chunks;
using EventStore.Core.TransactionLog.Chunks.TFChunk;
using EventStore.Core.TransactionLog.LogRecords;
using EventStore.Core.TransactionLog.Scavenging;
using EventStore.Core.Util;
Expand Down Expand Up @@ -54,6 +55,7 @@ public class Scenario<TLogFormat, TStreamId> : Scenario {
private Type _cancelWhenCheckpointingType;
private (string Message, int Line)[] _expectedTrace;
private bool _unsafeIgnoreHardDeletes;
private readonly HashSet<int> _chunkNumsToEmpty = new();

protected Tracer Tracer { get; set; }

Expand Down Expand Up @@ -179,6 +181,11 @@ public class Scenario<TLogFormat, TStreamId> : Scenario {
return this;
}

public Scenario<TLogFormat, TStreamId> EmptyChunk(int chunkNumber) {
_chunkNumsToEmpty.Add(chunkNumber);
return this;
}

public async Task<DbResult> RunAsync(
Func<DbResult, ILogRecord[][]> getExpectedKeptRecords = null,
Func<DbResult, ILogRecord[][]> getExpectedKeptIndexEntries = null) {
Expand Down Expand Up @@ -288,6 +295,8 @@ public class Scenario<TLogFormat, TStreamId> : Scenario {
}
}

EmptyChunks(dbResult.Db);

Scavenger<TStreamId> sut = null;
try {
var cancellationTokenSource = new CancellationTokenSource();
Expand Down Expand Up @@ -678,5 +687,35 @@ public class Scenario<TLogFormat, TStreamId> : Scenario {
});
}
}

private void EmptyChunks(TFChunkDb db) {
foreach (var chunkNum in _chunkNumsToEmpty) {
var chunk = db.Manager.GetChunk(chunkNum);
var header = chunk.ChunkHeader;

var newChunkHeader = new ChunkHeader(
version: header.Version,
chunkSize: header.ChunkSize,
chunkStartNumber: header.ChunkStartNumber,
chunkEndNumber: header.ChunkEndNumber,
isScavenged: true,
chunkId: Guid.NewGuid());

var newChunk = TFChunk.CreateWithHeader(
filename: $"{chunk.FileName}.tmp",
header: newChunkHeader,
fileSize: ChunkHeader.Size,
inMem: false,
unbuffered: false,
writethrough: false,
initialReaderCount: 1,
maxReaderCount: 1,
reduceFileCachePressure: false);

newChunk.CompleteScavenge(null);

db.Manager.SwitchChunk(newChunk, false, false);
}
}
}
}
1 change: 1 addition & 0 deletions src/EventStore.Core.XUnit.Tests/Scavenge/Infrastructure/StreamMetadatas.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@ public class StreamMetadatas {

public static DateTime EffectiveNow { get; } = new DateTime(2022, 1, 5, 00, 00, 00);
public static DateTime Expired { get; } = EffectiveNow - TimeSpan.FromDays(3);
public static DateTime Cutoff { get; } = EffectiveNow - MaxAgeTimeSpan;
public static DateTime Active { get; } = EffectiveNow - TimeSpan.FromDays(1);

public static Rec ScavengePointRec(int transaction, int threshold = 0, DateTime? timeStamp = null) => Rec.Write(
Expand Down

0 comments on commit 6ca83d0

Please sign in to comment.