Function TestAssignSequenceReleaseLoop

db/crud_test.go:1554–1596

TestAssignSequenceReleaseLoop repros conditions seen in CBG-3516 (where each sequence between nextSequence and docSequence has an unusedSeq doc)

(t *testing.T)

// TestAssignSequenceReleaseLoop repros conditions seen in CBG-3516 (where each sequence between nextSequence and docSequence has an unusedSeq doc)
func TestAssignSequenceReleaseLoop(t *testing.T) {
	if !base.TestUseXattrs() {
		t.Skip("This test only works with XATTRS enabled")
	}

	base.SetUpTestLogging(t, base.LevelDebug, base.KeyCache, base.KeyChanges, base.KeyCRUD, base.KeyDCP)

	// import disabled
	db, ctx := SetupTestDBWithOptions(t, DatabaseContextOptions{})
	defer db.Close(ctx)

	// positive sequence gap (other cluster's sequencing is higher)
	const otherClusterSequenceOffset = 10

	startReleasedSequenceCount := db.DbStats.Database().SequenceReleasedCount.Value()

	collection, ctx := GetSingleDatabaseCollectionWithUser(ctx, t, db)
	rev, doc, err := collection.Put(ctx, "doc1", Body{"foo": "bar"})
	require.NoError(t, err)
	t.Logf("doc sequence: %d", doc.Sequence)

	// but we can fiddle with the sequence in the metadata of the doc write to simulate a doc from a different cluster (with a higher sequence)
	var newSyncData map[string]interface{}
	sd, err := json.Marshal(doc.SyncData)
	require.NoError(t, err)
	err = json.Unmarshal(sd, &newSyncData)
	require.NoError(t, err)
	newSyncData["sequence"] = doc.SyncData.Sequence + otherClusterSequenceOffset
	_, err = collection.dataStore.UpdateXattrs(ctx, doc.ID, 0, doc.Cas, map[string][]byte{base.SyncXattrName: base.MustJSONMarshal(t, newSyncData)}, DefaultMutateInOpts())
	require.NoError(t, err)

	_, doc, err = collection.Put(ctx, "doc1", Body{"foo": "buzz", BodyRev: rev})
	require.NoError(t, err)
	require.Greaterf(t, doc.Sequence, uint64(otherClusterSequenceOffset), "Expected new doc sequence %d to be greater than other cluster's sequence %d", doc.Sequence, otherClusterSequenceOffset)

	// wait for the doc to be received
	err = db.changeCache.waitForSequence(ctx, doc.Sequence, time.Second*30)
	require.NoError(t, err)

	expectedReleasedSequenceCount := otherClusterSequenceOffset
	releasedSequenceCount := db.DbStats.Database().SequenceReleasedCount.Value() - startReleasedSequenceCount
	assert.Equal(t, int64(expectedReleasedSequenceCount), releasedSequenceCount)
}

// TestReleaseSequenceOnDocWrite:
//   - Define a leaky bucket callback for a conflicting write + define key to return a timeout error for