kvserver/rangefeed: enable bulk delivery by default

dt · dt · commit 4c933b830ec7 · 2025-07-24T17:14:46.000Z
This enables bulk delivery during catch up scans by default, so long as
it is also requested by the client, with a ~2MB size target.

Release note (performance improvement): the efficiency and throughput of
catch-up scans used by CDC and PCR is improved in cases where
substantial catch-up work is required.

Epic: none.
diff --git a/pkg/kv/kvserver/replica_rangefeed.go b/pkg/kv/kvserver/replica_rangefeed.go
@@ -225,7 +225,7 @@ var rangeFeedBulkDeliverySize = settings.RegisterIntSetting(
 	settings.SystemOnly,
 	"kv.rangefeed.bulk_delivery.size",
 	"approx size up to which rangefeeds may buffer events to be delivered in bulk during scans (0=disabled)",
-	int64(metamorphic.ConstantWithTestRange("rangefeed-bulk_delivery", 0, 0, 4<<20)),
+	int64(metamorphic.ConstantWithTestRange("rangefeed-bulk_delivery", 2<<20, 0, 4<<20)),
 )
 
 // RangeFeed registers a rangefeed over the specified span. It sends updates to

Original file line number	Diff line number	Diff line change
`@@ -225,7 +225,7 @@ var rangeFeedBulkDeliverySize = settings.RegisterIntSetting(`
`225`	`225`	`settings.SystemOnly,`
`226`	`226`	`"kv.rangefeed.bulk_delivery.size",`
`227`	`227`	`"approx size up to which rangefeeds may buffer events to be delivered in bulk during scans (0=disabled)",`
`228`		`- int64(metamorphic.ConstantWithTestRange("rangefeed-bulk_delivery", 0, 0, 4<<20)),`
	`228`	`+ int64(metamorphic.ConstantWithTestRange("rangefeed-bulk_delivery", 2<<20, 0, 4<<20)),`
`229`	`229`	`)`
`230`	`230`
`231`	`231`	`// RangeFeed registers a rangefeed over the specified span. It sends updates to`