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planner: Limit fine grained shuffle usage for mpp join operators to ensure shuffle keys are the same with actual join keys #59884

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merged 2 commits into from
Mar 5, 2025
Merged

planner: Limit fine grained shuffle usage for mpp join operators to ensure shuffle keys are the same with actual join keys #59884

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2d0beb3
Limit fine grained shuffle for mpp join operators
yibin87 Mar 4, 2025
8d20972
Fix compilation issue
yibin87 Mar 4, 2025
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2 changes: 1 addition & 1 deletion pkg/executor/test/tiflashtest/BUILD.bazel
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ go_test(
],
flaky = True,
race = "on",
shard_count = 47,
shard_count = 48,
deps = [
"//pkg/config",
"//pkg/domain",
Expand Down
56 changes: 56 additions & 0 deletions pkg/executor/test/tiflashtest/tiflash_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -2246,3 +2246,59 @@ func TestIssue59703(t *testing.T) {
require.Contains(t, err.Error(), "mock mpp error")
require.Equal(t, mppcoordmanager.InstanceMPPCoordinatorManager.GetCoordCount(), 0)
}

func TestIssue59877(t *testing.T) {
store := testkit.CreateMockStore(t, withMockTiFlash(1))
tk := testkit.NewTestKit(t, store)
tk.MustExec("use test")
tk.MustExec("drop table if exists t1, t2, t3")
tk.MustExec("create table t1(id bigint, v1 int)")
tk.MustExec("alter table t1 set tiflash replica 1")
tb := external.GetTableByName(t, tk, "test", "t1")
err := domain.GetDomain(tk.Session()).DDLExecutor().UpdateTableReplicaInfo(tk.Session(), tb.Meta().ID, true)
require.NoError(t, err)
tk.MustExec("create table t2(id bigint unsigned, v1 int)")
tk.MustExec("alter table t2 set tiflash replica 1")
tb = external.GetTableByName(t, tk, "test", "t2")
err = domain.GetDomain(tk.Session()).DDLExecutor().UpdateTableReplicaInfo(tk.Session(), tb.Meta().ID, true)
require.NoError(t, err)
tk.MustExec("create table t3(id bigint, v1 int)")
tk.MustExec("alter table t3 set tiflash replica 1")
tb = external.GetTableByName(t, tk, "test", "t3")
err = domain.GetDomain(tk.Session()).DDLExecutor().UpdateTableReplicaInfo(tk.Session(), tb.Meta().ID, true)
require.NoError(t, err)

tk.MustExec("set @@session.tidb_isolation_read_engines=\"tiflash\"")
// unistore does not support later materialization
tk.MustExec("set tidb_opt_enable_late_materialization=0")
tk.MustExec("set @@session.tidb_allow_mpp=ON")
tk.MustExec("set @@session.tidb_enforce_mpp=ON")
tk.MustExec("set tidb_broadcast_join_threshold_size=0")
tk.MustExec("set tidb_broadcast_join_threshold_count=0")
tk.MustExec("set tiflash_fine_grained_shuffle_stream_count=8")
tk.MustExec("set tidb_enforce_mpp=1")
tk.MustQuery("explain format=\"brief\" select /*+ hash_join_build(t3) */ count(*) from t1 straight_join t2 on t1.id = t2.id straight_join t3 on t1.id = t3.id").Check(
testkit.Rows("HashAgg 1.00 root funcs:count(Column#18)->Column#10",
"└─TableReader 1.00 root MppVersion: 3, data:ExchangeSender",
" └─ExchangeSender 1.00 mpp[tiflash] ExchangeType: PassThrough",
" └─HashAgg 1.00 mpp[tiflash] funcs:count(1)->Column#18",
" └─Projection 15609.38 mpp[tiflash] test.t1.id, Column#14",
" └─HashJoin 15609.38 mpp[tiflash] inner join, equal:[eq(test.t1.id, test.t3.id)]",
" ├─ExchangeReceiver(Build) 9990.00 mpp[tiflash] ",
" │ └─ExchangeSender 9990.00 mpp[tiflash] ExchangeType: HashPartition, Compression: FAST, Hash Cols: [name: Column#17, collate: binary]",
" │ └─Projection 9990.00 mpp[tiflash] test.t3.id, cast(test.t3.id, decimal(20,0))->Column#17",
" │ └─Selection 9990.00 mpp[tiflash] not(isnull(test.t3.id))",
" │ └─TableFullScan 10000.00 mpp[tiflash] table:t3 keep order:false, stats:pseudo",
" └─Projection(Probe) 12487.50 mpp[tiflash] test.t1.id, Column#14",
" └─HashJoin 12487.50 mpp[tiflash] inner join, equal:[eq(test.t1.id, test.t2.id)]",
" ├─ExchangeReceiver(Build) 9990.00 mpp[tiflash] ",
" │ └─ExchangeSender 9990.00 mpp[tiflash] ExchangeType: HashPartition, Compression: FAST, Hash Cols: [name: Column#13, collate: binary]",
" │ └─Projection 9990.00 mpp[tiflash] test.t1.id, cast(test.t1.id, decimal(20,0))->Column#13",
" │ └─Selection 9990.00 mpp[tiflash] not(isnull(test.t1.id))",
" │ └─TableFullScan 10000.00 mpp[tiflash] table:t1 keep order:false, stats:pseudo",
" └─ExchangeReceiver(Probe) 9990.00 mpp[tiflash] ",
" └─ExchangeSender 9990.00 mpp[tiflash] ExchangeType: HashPartition, Compression: FAST, Hash Cols: [name: Column#14, collate: binary]",
" └─Projection 9990.00 mpp[tiflash] test.t2.id, cast(test.t2.id, decimal(20,0) UNSIGNED)->Column#14",
" └─Selection 9990.00 mpp[tiflash] not(isnull(test.t2.id))",
" └─TableFullScan 10000.00 mpp[tiflash] table:t2 keep order:false, stats:pseudo"))
}
20 changes: 16 additions & 4 deletions pkg/planner/core/optimizer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -668,7 +668,7 @@ const (
type fineGrainedShuffleHelper struct {
shuffleTarget shuffleTarget
plans []*physicalop.BasePhysicalPlan
joinKeysCount int
joinKeys []*expression.Column
}

type tiflashClusterInfoStatus uint8
Expand All @@ -687,7 +687,7 @@ type tiflashClusterInfo struct {
func (h *fineGrainedShuffleHelper) clear() {
h.shuffleTarget = unknown
h.plans = h.plans[:0]
h.joinKeysCount = 0
h.joinKeys = nil
}

func (h *fineGrainedShuffleHelper) updateTarget(t shuffleTarget, p *physicalop.BasePhysicalPlan) {
Expand Down Expand Up @@ -888,7 +888,7 @@ func setupFineGrainedShuffleInternal(ctx context.Context, sctx base.PlanContext,
if len(joinKeys) > 0 { // Not cross join
buildHelper := fineGrainedShuffleHelper{shuffleTarget: joinBuild, plans: []*physicalop.BasePhysicalPlan{}}
buildHelper.plans = append(buildHelper.plans, &x.BasePhysicalPlan)
buildHelper.joinKeysCount = len(joinKeys)
buildHelper.joinKeys = joinKeys
setupFineGrainedShuffleInternal(ctx, sctx, buildChild, &buildHelper, streamCountInfo, tiflashServerCountInfo)
} else {
buildHelper := fineGrainedShuffleHelper{shuffleTarget: unknown, plans: []*physicalop.BasePhysicalPlan{}}
Expand Down Expand Up @@ -918,7 +918,19 @@ func setupFineGrainedShuffleInternal(ctx context.Context, sctx base.PlanContext,
}
case joinBuild:
// Support hashJoin only when shuffle hash keys equals to join keys due to tiflash implementations
if len(x.HashCols) != helper.joinKeysCount {
if len(x.HashCols) != len(helper.joinKeys) {
break
}
// Check the shuffle key should be equal to joinKey, otherwise the shuffle hash code may not be equal to
// actual join hash code due to type cast
applyFlag := true
for i, joinKey := range helper.joinKeys {
if !x.HashCols[i].Col.EqualColumn(joinKey) {
applyFlag = false
break
}
}
if !applyFlag {
break
}
applyFlag, streamCount := checkFineGrainedShuffleForJoinAgg(ctx, sctx, streamCountInfo, tiflashServerCountInfo, exchangeColCount, 600) // 600: performance test result
Expand Down