schema cache: fix wrong timestamp in schema cache (pingcap#46326)

close pingcap#46325
crazycs520 · Sep 1, 2023 · d86325d · d86325d
1 parent 298bb31
commit d86325d
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Showing 3 changed files with 20 additions and 0 deletions.
diff --git a/domain/domain.go b/domain/domain.go
@@ -186,6 +186,9 @@ func (do *Domain) loadInfoSchema(startTS uint64) (infoschema.InfoSchema, bool, i
 	}
 
 	if is := do.infoCache.GetByVersion(neededSchemaVersion); is != nil {
+		// try to insert here as well to correct the schemaTs if previous is wrong
+		// the insert method check if schemaTs is zero
+		do.infoCache.Insert(is, uint64(schemaTs))
 		return is, true, 0, nil, nil
 	}
 

diff --git a/infoschema/cache.go b/infoschema/cache.go
@@ -73,6 +73,11 @@ func (h *InfoCache) GetLatest() InfoSchema {
 	return nil
 }
 
+// Len returns the size of the cache
+func (h *InfoCache) Len() int {
+	return len(h.cache)
+}
+
 func (h *InfoCache) getSchemaByTimestampNoLock(ts uint64) (InfoSchema, bool) {
 	logutil.BgLogger().Debug("SCHEMA CACHE get schema", zap.Uint64("timestamp", ts))
 	// search one by one instead of binary search, because the timestamp of a schema could be 0

diff --git a/infoschema/cache_test.go b/infoschema/cache_test.go
@@ -137,12 +137,14 @@ func TestGetByTimestamp(t *testing.T) {
 	ic := infoschema.NewCache(16)
 	require.NotNil(t, ic)
 	require.Nil(t, ic.GetLatest())
+	require.Equal(t, 0, ic.Len())
 
 	is1 := infoschema.MockInfoSchemaWithSchemaVer(nil, 1)
 	ic.Insert(is1, 1)
 	require.Nil(t, ic.GetBySnapshotTS(0))
 	require.Equal(t, is1, ic.GetBySnapshotTS(1))
 	require.Equal(t, is1, ic.GetBySnapshotTS(2))
+	require.Equal(t, 1, ic.Len())
 
 	is3 := infoschema.MockInfoSchemaWithSchemaVer(nil, 3)
 	ic.Insert(is3, 3)
@@ -152,6 +154,7 @@ func TestGetByTimestamp(t *testing.T) {
 	require.Nil(t, ic.GetBySnapshotTS(2))
 	require.Equal(t, is3, ic.GetBySnapshotTS(3))
 	require.Equal(t, is3, ic.GetBySnapshotTS(4))
+	require.Equal(t, 2, ic.Len())
 
 	is2 := infoschema.MockInfoSchemaWithSchemaVer(nil, 2)
 	// schema version 2 doesn't have timestamp set
@@ -164,4 +167,13 @@ func TestGetByTimestamp(t *testing.T) {
 	require.Nil(t, ic.GetBySnapshotTS(2))
 	require.Equal(t, is3, ic.GetBySnapshotTS(3))
 	require.Equal(t, is3, ic.GetBySnapshotTS(4))
+	require.Equal(t, 3, ic.Len())
+
+	// insert is2 again with correct timestamp, to correct previous wrong timestamp
+	ic.Insert(is2, 2)
+	require.Equal(t, is3, ic.GetLatest())
+	require.Equal(t, is1, ic.GetBySnapshotTS(1))
+	require.Equal(t, is2, ic.GetBySnapshotTS(2))
+	require.Equal(t, is3, ic.GetBySnapshotTS(3))
+	require.Equal(t, 3, ic.Len())
 }