statistics: right deal with error for reading stats from storage (#58048)

pkg/statistics/handle/handletest/BUILD.bazel

@@ -9,7 +9,7 @@ go_test(
     ],
     flaky = True,
     race = "on",
-    shard_count = 36,
+    shard_count = 37,
     deps = [
         "//pkg/config",
         "//pkg/domain",

pkg/statistics/handle/handletest/handle_test.go

@@ -1667,3 +1667,31 @@ func TestSkipMissingPartitionStats(t *testing.T) {
 		require.True(t, idx.IsStatsInitialized())
 	}
 }
+
+func TestStatsCacheUpdateTimeout(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("set @@tidb_partition_prune_mode = 'dynamic'")
+	tk.MustExec("set @@tidb_skip_missing_partition_stats = 1")
+	tk.MustExec("create table t (a int, b int, c int, index idx_b(b)) partition by range (a) (partition p0 values less than (100), partition p1 values less than (200), partition p2 values less than (300))")
+	tk.MustExec("insert into t values (1,1,1), (2,2,2), (101,101,101), (102,102,102), (201,201,201), (202,202,202)")
+	analyzehelper.TriggerPredicateColumnsCollection(t, tk, store, "t", "a", "b", "c")
+	h := dom.StatsHandle()
+	require.NoError(t, h.DumpStatsDeltaToKV(true))
+	tk.MustExec("analyze table t partition p0, p1")
+	tbl, err := dom.InfoSchema().TableByName(context.Background(), model.NewCIStr("test"), model.NewCIStr("t"))
+	require.NoError(t, err)
+	tblInfo := tbl.Meta()
+	globalStats := h.GetTableStats(tblInfo)
+	require.Equal(t, 6, int(globalStats.RealtimeCount))
+	require.Equal(t, 2, int(globalStats.ModifyCount))
+	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/pkg/statistics/handle/util/ExecRowsTimeout", "return()"))
+	defer func() {
+		require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/pkg/statistics/handle/util/ExecRowsTimeout"))
+	}()
+	require.Error(t, h.Update(context.Background(), dom.InfoSchema()))
+	globalStats2 := h.GetTableStats(tblInfo)
+	require.Equal(t, 6, int(globalStats2.RealtimeCount))
+	require.Equal(t, 2, int(globalStats2.ModifyCount))
+}

pkg/statistics/handle/storage/read.go

@@ -475,8 +475,11 @@ func TableStatsFromStorage(sctx sessionctx.Context, snapshot uint64, tableInfo *
 	table.RealtimeCount = realtimeCount
 
 	rows, _, err := util.ExecRows(sctx, "select table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, flag, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %?", tableID)
+	if err != nil {
+		return nil, err
+	}
 	// Check deleted table.
-	if err != nil || len(rows) == 0 {
+	if len(rows) == 0 {
 		return nil, nil
 	}
 	for _, row := range rows {

pkg/statistics/handle/util/BUILD.bazel

@@ -26,6 +26,7 @@ go_library(
         "//pkg/util/sqlexec/mock",
         "@com_github_ngaut_pools//:pools",
         "@com_github_pingcap_errors//:errors",
+        "@com_github_pingcap_failpoint//:failpoint",
         "@com_github_pingcap_tipb//go-tipb",
         "@com_github_tiancaiamao_gp//:gp",
         "@com_github_tikv_client_go_v2//oracle",

pkg/statistics/handle/util/util.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/ngaut/pools"
 	"github.com/pingcap/errors"
+	"github.com/pingcap/failpoint"
 	"github.com/pingcap/tidb/pkg/kv"
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/terror"
@@ -221,6 +222,9 @@ func Exec(sctx sessionctx.Context, sql string, args ...interface{}) (sqlexec.Rec
 
 // ExecRows is a helper function to execute sql and return rows and fields.
 func ExecRows(sctx sessionctx.Context, sql string, args ...interface{}) (rows []chunk.Row, fields []*ast.ResultField, err error) {
+	failpoint.Inject("ExecRowsTimeout", func() {
+		failpoint.Return(nil, nil, errors.New("inject timeout error"))
+	})
 	if intest.InTest {
 		if v := sctx.Value(mock.RestrictedSQLExecutorKey{}); v != nil {
 			return v.(*mock.MockRestrictedSQLExecutor).ExecRestrictedSQL(StatsCtx,