release-20.1: stmtdiagnostics: break into chunks

pkg/sql/explain_bundle_test.go

@@ -16,6 +16,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"math/rand"
 	"regexp"
 	"sort"
 	"strings"
@@ -42,6 +43,13 @@ func TestExplainAnalyzeDebug(t *testing.T) {
 	base := "statement.txt trace.json trace.txt trace-jaeger.json env.sql"
 	plans := "schema.sql opt.txt opt-v.txt opt-vv.txt plan.txt"
 
+	// Set a small chunk size to test splitting into chunks. The bundle files are
+	// on the order of 10KB.
+	r.Exec(t, fmt.Sprintf(
+		"SET CLUSTER SETTING sql.stmt_diagnostics.bundle_chunk_size = '%d'",
+		5000+rand.Intn(10000),
+	))
+
 	t.Run("basic", func(t *testing.T) {
 		rows := r.QueryStr(t, "EXPLAIN ANALYZE (DEBUG) SELECT * FROM abc WHERE c=1")
 		checkBundle(

pkg/sql/stmtdiagnostics/statement_diagnostics.go

@@ -33,11 +33,23 @@ import (
 	"github.com/cockroachdb/errors"
 )
 
-var stmtDiagnosticsPollingInterval = settings.RegisterDurationSetting(
+var pollingInterval = settings.RegisterDurationSetting(
 	"sql.stmt_diagnostics.poll_interval",
 	"rate at which the stmtdiagnostics.Registry polls for requests, set to zero to disable",
 	10*time.Second)
 
+var bundleChunkSize = settings.RegisterValidatedByteSizeSetting(
+	"sql.stmt_diagnostics.bundle_chunk_size",
+	"chunk size for statement diagnostic bundles",
+	1024*1024,
+	func(val int64) error {
+		if val < 16 {
+			return errors.Errorf("chunk size must be at least 16 bytes")
+		}
+		return nil
+	},
+)
+
 // Registry maintains a view on the statement fingerprints
 // on which data is to be collected (i.e. system.statement_diagnostics_requests)
 // and provides utilities for checking a query against this list and satisfying
@@ -101,7 +113,7 @@ func (r *Registry) poll(ctx context.Context) {
 		deadline            time.Time
 		pollIntervalChanged = make(chan struct{}, 1)
 		maybeResetTimer     = func() {
-			if interval := stmtDiagnosticsPollingInterval.Get(&r.st.SV); interval <= 0 {
+			if interval := pollingInterval.Get(&r.st.SV); interval <= 0 {
 				// Setting the interval to a non-positive value stops the polling.
 				timer.Stop()
 			} else {
@@ -122,7 +134,7 @@ func (r *Registry) poll(ctx context.Context) {
 			lastPoll = timeutil.Now()
 		}
 	)
-	stmtDiagnosticsPollingInterval.SetOnChange(&r.st.SV, func() {
+	pollingInterval.SetOnChange(&r.st.SV, func() {
 		select {
 		case pollIntervalChanged <- struct{}{}:
 		default:
@@ -387,27 +399,30 @@ func (r *Registry) insertStatementDiagnostics(
 			errorVal = tree.NewDString(collectionErr.Error())
 		}
 
-		bundleChunksVal := tree.DNull
-		if len(bundle) != 0 {
-			// Insert the bundle into system.statement_bundle_chunks.
-			// TODO(radu): split in chunks.
+		bundleChunksVal := tree.NewDArray(types.Int)
+		for len(bundle) > 0 {
+			chunkSize := int(bundleChunkSize.Get(&r.st.SV))
+			chunk := bundle
+			if len(chunk) > chunkSize {
+				chunk = chunk[:chunkSize]
+			}
+			bundle = bundle[len(chunk):]
+
+			// Insert the chunk into system.statement_bundle_chunks.
 			row, err := r.ie.QueryRowEx(
 				ctx, "stmt-bundle-chunks-insert", txn,
 				sqlbase.InternalExecutorSessionDataOverride{User: security.RootUser},
 				"INSERT INTO system.statement_bundle_chunks(description, data) VALUES ($1, $2) RETURNING id",
 				"statement diagnostics bundle",
-				tree.NewDBytes(tree.DBytes(bundle)),
+				tree.NewDBytes(tree.DBytes(chunk)),
 			)
 			if err != nil {
 				return err
 			}
 			chunkID := row[0].(*tree.DInt)
-
-			array := tree.NewDArray(types.Int)
-			if err := array.Append(chunkID); err != nil {
+			if err := bundleChunksVal.Append(chunkID); err != nil {
 				return err
 			}
-			bundleChunksVal = array
 		}
 
 		collectionTime := timeutil.Now()