spanconfig: enable range coalescing by default

docs/generated/settings/settings-for-tenants.txt

@@ -294,4 +294,4 @@ trace.opentelemetry.collector	string		address of an OpenTelemetry trace collecto
 trace.snapshot.rate	duration	0s	if non-zero, interval at which background trace snapshots are captured	tenant-rw
 trace.span_registry.enabled	boolean	true	if set, ongoing traces can be seen at https://<ui>/#/debug/tracez	tenant-rw
 trace.zipkin.collector	string		the address of a Zipkin instance to receive traces, as <host>:<port>. If no port is specified, 9411 will be used.	tenant-rw
-version	version	1000023.1-6	set the active cluster version in the format '<major>.<minor>'	tenant-rw
+version	version	1000023.1-8	set the active cluster version in the format '<major>.<minor>'	tenant-rw

docs/generated/settings/settings.html

@@ -119,6 +119,8 @@
 <tr><td><div id="setting-server-web-session-purge-ttl" class="anchored"><code>server.web_session.purge.ttl</code></div></td><td>duration</td><td><code>1h0m0s</code></td><td>if nonzero, entries in system.web_sessions older than this duration are periodically purged</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-web-session-timeout" class="anchored"><code>server.web_session_timeout</code></div></td><td>duration</td><td><code>168h0m0s</code></td><td>the duration that a newly created web session will be valid</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-spanconfig-bounds-enabled" class="anchored"><code>spanconfig.bounds.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>dictates whether span config bounds are consulted when serving span configs for secondary tenants</td><td>Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-spanconfig-storage-coalesce-adjacent-enabled" class="anchored"><code>spanconfig.storage_coalesce_adjacent.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>collapse adjacent ranges with the same span configs, for the ranges specific to the system tenant</td><td>Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-spanconfig-tenant-coalesce-adjacent-enabled" class="anchored"><code>spanconfig.tenant_coalesce_adjacent.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>collapse adjacent ranges with the same span configs across all secondary tenant keyspaces</td><td>Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-sql-auth-change-own-password-enabled" class="anchored"><code>sql.auth.change_own_password.enabled</code></div></td><td>boolean</td><td><code>false</code></td><td>controls whether a user is allowed to change their own password, even if they have no other privileges</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-sql-auth-resolve-membership-single-scan-enabled" class="anchored"><code>sql.auth.resolve_membership_single_scan.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>determines whether to populate the role membership cache with a single scan</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-sql-closed-session-cache-capacity" class="anchored"><code>sql.closed_session_cache.capacity</code></div></td><td>integer</td><td><code>1000</code></td><td>the maximum number of sessions in the cache</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
@@ -246,6 +248,6 @@
 <tr><td><div id="setting-trace-snapshot-rate" class="anchored"><code>trace.snapshot.rate</code></div></td><td>duration</td><td><code>0s</code></td><td>if non-zero, interval at which background trace snapshots are captured</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-trace-span-registry-enabled" class="anchored"><code>trace.span_registry.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>if set, ongoing traces can be seen at https://&lt;ui&gt;/#/debug/tracez</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-trace-zipkin-collector" class="anchored"><code>trace.zipkin.collector</code></div></td><td>string</td><td><code></code></td><td>the address of a Zipkin instance to receive traces, as &lt;host&gt;:&lt;port&gt;. If no port is specified, 9411 will be used.</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
-<tr><td><div id="setting-version" class="anchored"><code>version</code></div></td><td>version</td><td><code>1000023.1-6</code></td><td>set the active cluster version in the format &#39;&lt;major&gt;.&lt;minor&gt;&#39;</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-version" class="anchored"><code>version</code></div></td><td>version</td><td><code>1000023.1-8</code></td><td>set the active cluster version in the format &#39;&lt;major&gt;.&lt;minor&gt;&#39;</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 </tbody>
 </table>

pkg/clusterversion/cockroach_versions.go

@@ -534,6 +534,10 @@ const (
 	// indexes are enabled.
 	V23_2_PartiallyVisibleIndexes
 
+	// V23_2_EnableRangeCoalescingForSystemTenant enables range coalescing for
+	// the system tenant.
+	V23_2_EnableRangeCoalescingForSystemTenant
+
 	// *************************************************
 	// Step (1) Add new versions here.
 	// Do not add new versions to a patch release.
@@ -927,6 +931,10 @@ var rawVersionsSingleton = keyedVersions{
 		Key:     V23_2_PartiallyVisibleIndexes,
 		Version: roachpb.Version{Major: 23, Minor: 1, Internal: 6},
 	},
+	{
+		Key:     V23_2_EnableRangeCoalescingForSystemTenant,
+		Version: roachpb.Version{Major: 23, Minor: 1, Internal: 8},
+	},
 
 	// *************************************************
 	// Step (2): Add new versions here.

pkg/server/admin_test.go

@@ -2206,6 +2206,10 @@ func TestAdminAPIDataDistribution(t *testing.T) {
 	firstServer := testCluster.Server(0)
 	sqlDB := sqlutils.MakeSQLRunner(testCluster.ServerConn(0))
 
+	// TODO(irfansharif): The data-distribution page and underyling APIs don't
+	// know how to deal with coalesced ranges. See #97942.
+	sqlDB.Exec(t, `SET CLUSTER SETTING spanconfig.storage_coalesce_adjacent.enabled = false`)
+
 	// Create some tables.
 	sqlDB.Exec(t, `CREATE DATABASE roachblog`)
 	sqlDB.Exec(t, `CREATE TABLE roachblog.posts (id INT PRIMARY KEY, title text, body text)`)

pkg/spanconfig/spanconfigstore/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
     importpath = "github.com/cockroachdb/cockroach/pkg/spanconfig/spanconfigstore",
     visibility = ["//visibility:public"],
     deps = [
+        "//pkg/clusterversion",
         "//pkg/keys",
         "//pkg/multitenant/tenantcapabilities",
         "//pkg/roachpb",

pkg/spanconfig/spanconfigstore/span_store.go

@@ -14,6 +14,7 @@ import (
 	"context"
 	"sort"
 
+	"github.com/cockroachdb/cockroach/pkg/clusterversion"
 	"github.com/cockroachdb/cockroach/pkg/keys"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/settings"
@@ -24,25 +25,25 @@ import (
 	"github.com/cockroachdb/errors"
 )
 
-// tenantCoalesceAdjacentSetting is a hidden cluster setting that
+// tenantCoalesceAdjacentSetting is a public cluster setting that
 // controls whether we coalesce adjacent ranges across all secondary
 // tenant keyspaces if they have the same span config.
 var tenantCoalesceAdjacentSetting = settings.RegisterBoolSetting(
 	settings.SystemOnly,
 	"spanconfig.tenant_coalesce_adjacent.enabled",
 	`collapse adjacent ranges with the same span configs across all secondary tenant keyspaces`,
 	true,
-)
+).WithPublic()
 
-// StorageCoalesceAdjacentSetting is a hidden cluster setting that
-// controls whether we coalesce adjacent ranges outside of the
-// secondary tenant keyspaces if they have the same span config.
+// StorageCoalesceAdjacentSetting is a public cluster setting that controls
+// whether we coalesce adjacent ranges outside of the secondary tenant keyspaces
+// if they have the same span config.
 var StorageCoalesceAdjacentSetting = settings.RegisterBoolSetting(
 	settings.SystemOnly,
 	"spanconfig.storage_coalesce_adjacent.enabled",
-	`collapse adjacent ranges with the same span configs for the ranges specific to the system tenant`,
-	false,
-)
+	`collapse adjacent ranges with the same span configs, for the ranges specific to the system tenant`,
+	true,
+).WithPublic()
 
 // spanConfigStore is an in-memory data structure to store and retrieve
 // SpanConfigs associated with a single span. Internally it makes use of a
@@ -104,7 +105,9 @@ func (s *spanConfigStore) forEachOverlapping(
 
 // computeSplitKey returns the first key we should split on because of the
 // presence a span config given a start and end key pair.
-func (s *spanConfigStore) computeSplitKey(start, end roachpb.RKey) (roachpb.RKey, error) {
+func (s *spanConfigStore) computeSplitKey(
+	ctx context.Context, start, end roachpb.RKey,
+) (roachpb.RKey, error) {
 	sp := roachpb.Span{Key: start.AsRawKey(), EndKey: end.AsRawKey()}
 
 	// Generally split keys are going to be the start keys of span config entries.
@@ -152,7 +155,8 @@ func (s *spanConfigStore) computeSplitKey(start, end roachpb.RKey) (roachpb.RKey
 			// ranges.
 			systemTableUpperBound := keys.SystemSQLCodec.TablePrefix(keys.MaxReservedDescID + 1)
 			if roachpb.Key(rem).Compare(systemTableUpperBound) < 0 ||
-				!StorageCoalesceAdjacentSetting.Get(&s.settings.SV) {
+				!(StorageCoalesceAdjacentSetting.Get(&s.settings.SV) &&
+					s.settings.Version.IsActive(ctx, clusterversion.V23_2_EnableRangeCoalescingForSystemTenant)) {
 				return roachpb.RKey(match.span.Key), nil
 			}
 		} else {

pkg/spanconfig/spanconfigstore/span_store_test.go

@@ -234,6 +234,7 @@ func TestRandomized(t *testing.T) {
 		// span and asserts on all the properties above.
 		querySpan := getRandomSpan()
 		splitKeys := store.TestingSplitKeys(t,
+			ctx,
 			roachpb.RKey(querySpan.Key),
 			roachpb.RKey(querySpan.EndKey),
 		)

pkg/spanconfig/spanconfigstore/store.go

@@ -123,11 +123,13 @@ func (s *Store) NeedsSplit(ctx context.Context, start, end roachpb.RKey) (bool,
 }
 
 // ComputeSplitKey is part of the spanconfig.StoreReader interface.
-func (s *Store) ComputeSplitKey(_ context.Context, start, end roachpb.RKey) (roachpb.RKey, error) {
+func (s *Store) ComputeSplitKey(
+	ctx context.Context, start, end roachpb.RKey,
+) (roachpb.RKey, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	return s.mu.spanConfigStore.computeSplitKey(start, end)
+	return s.mu.spanConfigStore.computeSplitKey(ctx, start, end)
 }
 
 // GetSpanConfigForKey is part of the spanconfig.StoreReader interface.

pkg/spanconfig/spanconfigstore/store_test.go

@@ -37,20 +37,24 @@ func (s *Store) TestingApplyInternal(
 
 // TestingSplitKeys returns the computed list of range split points between
 // [start, end).
-func (s *Store) TestingSplitKeys(tb testing.TB, start, end roachpb.RKey) []roachpb.RKey {
+func (s *Store) TestingSplitKeys(
+	tb testing.TB, ctx context.Context, start, end roachpb.RKey,
+) []roachpb.RKey {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	return s.mu.spanConfigStore.TestingSplitKeys(tb, start, end)
+	return s.mu.spanConfigStore.TestingSplitKeys(tb, ctx, start, end)
 }
 
 // TestingSplitKeys returns the computed list of range split points between
 // [start, end).
-func (s *spanConfigStore) TestingSplitKeys(tb testing.TB, start, end roachpb.RKey) []roachpb.RKey {
+func (s *spanConfigStore) TestingSplitKeys(
+	tb testing.TB, ctx context.Context, start, end roachpb.RKey,
+) []roachpb.RKey {
 	var splitKeys []roachpb.RKey
 	computeStart := start
 	for {
-		splitKey, err := s.computeSplitKey(computeStart, end)
+		splitKey, err := s.computeSplitKey(ctx, computeStart, end)
 		require.NoError(tb, err)
 		if splitKey == nil {
 			break
@@ -184,7 +188,7 @@ func TestDataDriven(t *testing.T) {
 				span := spanconfigtestutils.ParseSpan(t, spanStr)
 
 				start, end := roachpb.RKey(span.Key), roachpb.RKey(span.EndKey)
-				splitKeys := store.TestingSplitKeys(t, start, end)
+				splitKeys := store.TestingSplitKeys(t, ctx, start, end)
 				var b strings.Builder
 				for _, splitKey := range splitKeys {
 					b.WriteString(fmt.Sprintf("key=%s\n", string(splitKey)))

pkg/spanconfig/testing_knobs.go

@@ -123,7 +123,7 @@ type TestingKnobs struct {
 	StoreDisableCoalesceAdjacent bool
 
 	// StoreIgnoreCoalesceAdjacentExceptions, if set, ignores the cluster settings
-	// spanconfig.{host,tenant}_coalesce_adjacent.enabled. It also allows
+	// spanconfig.{storage,tenant}_coalesce_adjacent.enabled. It also allows
 	// coalescing system database ranges for the host tenant.
 	StoreIgnoreCoalesceAdjacentExceptions bool
 

pkg/ui/workspaces/db-console/src/views/cluster/containers/dataDistribution/index.tsx

@@ -182,6 +182,15 @@ export class DataDistributionPage extends React.Component<
         <BackToAdvanceDebug history={this.props.history} />
         <section className="section">
           <h1 className="base-heading">Data Distribution</h1>
+          <p style={{ maxWidth: 300, paddingTop: 10 }}>
+            Note: the data distribution render does not work with coalesced
+            ranges. To disable coalesced ranges (would increase range count),
+            run the following SQL statement:
+          </p>
+          <pre>
+            SET CLUSTER SETTING spanconfig.storage_coalesce_adjacent.enabled =
+            false;
+          </pre>
         </section>
         <section className="section">
           <Loading