closedts: delete old closedts mechanism

Closes cockroachdb#61989
Closes cockroachdb#60682
Closes cockroachdb#59448

docs/generated/redact_safe.md

@@ -4,7 +4,8 @@ File | Type
 --|--
 pkg/cli/exit/exit.go | `Code`
 pkg/jobs/jobspb/wrap.go | `Type`
-pkg/kv/kvserver/closedts/ctpb/entry.go | `LAI`
+pkg/kv/kvserver/closedts/ctpb/service.go | `LAI`
+pkg/kv/kvserver/closedts/ctpb/service.go | `SeqNum`
 pkg/kv/kvserver/concurrency/lock/locking.go | `WaitPolicy`
 pkg/kv/kvserver/raft.go | `SnapshotRequest_Type`
 pkg/roachpb/data.go | `LeaseSequence`

pkg/clusterversion/cockroach_versions.go

@@ -222,9 +222,6 @@ const (
 	// are propagated across RPC boundaries independently of their verbosity setting.
 	// This requires a version gate this violates implicit assumptions in v20.2.
 	TracingVerbosityIndependentSemantics
-	// ClosedTimestampsRaftTransport enables the Raft transport for closed
-	// timestamps and disables the previous per-node transport.
-	ClosedTimestampsRaftTransport
 	// PriorReadSummaries introduces support for the use of read summary objects
 	// to ship information about reads on a range through lease changes and
 	// range merges.
@@ -410,10 +407,6 @@ var versionsSingleton = keyedVersions{
 		Key:     TracingVerbosityIndependentSemantics,
 		Version: roachpb.Version{Major: 20, Minor: 2, Internal: 28},
 	},
-	{
-		Key:     ClosedTimestampsRaftTransport,
-		Version: roachpb.Version{Major: 20, Minor: 2, Internal: 36},
-	},
 	{
 		Key:     PriorReadSummaries,
 		Version: roachpb.Version{Major: 20, Minor: 2, Internal: 44},

pkg/kv/kvserver/BUILD.bazel

@@ -114,10 +114,8 @@ go_library(
         "//pkg/kv/kvserver/batcheval",
         "//pkg/kv/kvserver/batcheval/result",
         "//pkg/kv/kvserver/closedts",
-        "//pkg/kv/kvserver/closedts/container",
         "//pkg/kv/kvserver/closedts/ctpb",
         "//pkg/kv/kvserver/closedts/sidetransport",
-        "//pkg/kv/kvserver/closedts/storage",
         "//pkg/kv/kvserver/closedts/tracker",
         "//pkg/kv/kvserver/concurrency",
         "//pkg/kv/kvserver/constraint",
@@ -207,7 +205,6 @@ go_test(
         "batch_spanset_test.go",
         "below_raft_protos_test.go",
         "client_atomic_membership_change_test.go",
-        "client_closed_timestamp_test.go",
         "client_lease_test.go",
         "client_merge_test.go",
         "client_metrics_test.go",

pkg/kv/kvserver/batcheval/BUILD.bazel

@@ -57,8 +57,6 @@ go_library(
         "//pkg/keys",
         "//pkg/kv/kvserver/abortspan",
         "//pkg/kv/kvserver/batcheval/result",
-        "//pkg/kv/kvserver/closedts",
-        "//pkg/kv/kvserver/closedts/ctpb",
         "//pkg/kv/kvserver/concurrency",
         "//pkg/kv/kvserver/concurrency/lock",
         "//pkg/kv/kvserver/gc",

pkg/kv/kvserver/batcheval/cmd_query_resolved_timestamp.go

@@ -54,7 +54,7 @@ func QueryResolvedTimestamp(
 	// because QueryResolvedTimestamp requests are often run without acquiring
 	// latches (see roachpb.INCONSISTENT) and often also on follower replicas,
 	// so latches won't help them to synchronize with writes.
-	closedTS := cArgs.EvalCtx.GetClosedTimestampV2(ctx)
+	closedTS := cArgs.EvalCtx.GetClosedTimestamp(ctx)
 
 	// Compute the minimum timestamp of any intent in the request's key span,
 	// which may span the entire range, but does not need to.

pkg/kv/kvserver/batcheval/cmd_subsume.go

@@ -16,7 +16,6 @@ import (
 
 	"github.com/cockroachdb/cockroach/pkg/keys"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/batcheval/result"
-	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/closedts/ctpb"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/readsummary/rspb"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/spanset"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
@@ -125,50 +124,10 @@ func Subsume(
 		return result.Result{}, errors.Wrap(err, "watching for merge during subsume")
 	}
 
-	// We prevent followers of the RHS from being able to serve follower reads on
-	// timestamps that fall in the timestamp window representing the range's
-	// subsumed state (i.e. between the subsumption time (FreezeStart) and the
-	// timestamp at which the merge transaction commits or aborts), by requiring
-	// follower replicas to catch up to an MLAI that succeeds the range's current
-	// LeaseAppliedIndex (note that we're tracking lai + 1 below instead of lai).
-	// In case the merge successfully commits, this MLAI will never be caught up
-	// to since the RHS will be destroyed. In case the merge aborts, this ensures
-	// that the followers can only activate the newer closed timestamps once they
-	// catch up to the LAI associated with the merge abort. We need to do this
-	// because the closed timestamps that are broadcast by RHS in this subsumed
-	// state are not going to be reflected in the timestamp cache of the LHS range
-	// after the merge, which can cause a serializability violation.
-	//
-	// Note that we are essentially lying to the closed timestamp tracker here in
-	// order to achieve the effect of unactionable closed timestamp updates until
-	// the merge concludes. Tracking lai + 1 here ensures that the follower
-	// replicas need to catch up to at least that index before they are able to
-	// activate _any of the closed timestamps from this point onwards_. In other
-	// words, we will never publish a closed timestamp update for this range below
-	// this lai, regardless of whether a different proposal untracks a lower lai
-	// at any point in the future.
-	//
-	// NB: The above statement relies on the invariant that the LAI that follows a
-	// Subsume request will be applied only after the merge aborts. More
-	// specifically, this means that no intervening request can bump the LAI of
-	// range while it is subsumed. This invariant is upheld because the only Raft
-	// proposals allowed after a range has been subsumed are lease requests, which
-	// do not bump the LAI. In case there is lease transfer on this range while it
-	// is subsumed, we ensure that the initial MLAI update broadcast by the new
-	// leaseholder respects the invariant in question, in much the same way we do
-	// here. Take a look at `EmitMLAI()` in replica_closedts.go for more details.
-	//
-	// TODO(nvanbenschoten): remove this in v21.2 when the rest of the v1 closed
-	// timestamp system disappears.
-	_, untrack := cArgs.EvalCtx.GetTracker().Track(ctx)
-	lease, _ := cArgs.EvalCtx.GetLease()
-	lai := cArgs.EvalCtx.GetLeaseAppliedIndex()
-	untrack(ctx, ctpb.Epoch(lease.Epoch), desc.RangeID, ctpb.LAI(lai+1))
-
 	// Now that the range is frozen, collect some information to ship to the LHS
 	// leaseholder through the merge trigger.
 	reply.MVCCStats = cArgs.EvalCtx.GetMVCCStats()
-	reply.LeaseAppliedIndex = lai
+	reply.LeaseAppliedIndex = cArgs.EvalCtx.GetLeaseAppliedIndex()
 	reply.FreezeStart = cArgs.EvalCtx.Clock().NowAsClockTimestamp()
 
 	// Collect a read summary from the RHS leaseholder to ship to the LHS
@@ -188,16 +147,7 @@ func Subsume(
 	// think about.
 	priorReadSum.Merge(rspb.FromTimestamp(reply.FreezeStart.ToTimestamp()))
 	reply.ReadSummary = &priorReadSum
-	// NOTE FOR v21.1: GetClosedTimestampV2 might return an empty timestamp if
-	// the Raft-based closed timestamp transport hasn't been enabled yet. That's
-	// OK because, if the new transport is not enabled, then ranges with leading
-	// closed timestamps can't exist yet, and so the closed timestamp must be
-	// below the FreezeStart. The FreezeStart is used by Store.MergeRange to
-	// bump the RHS' ts cache if LHS/RHS leases are not collocated. The case
-	// when the leases are collocated also works out because then the closed
-	// timestamp (according to the old mechanism) is the same for both ranges
-	// being merged.
-	reply.ClosedTimestamp = cArgs.EvalCtx.GetClosedTimestampV2(ctx)
+	reply.ClosedTimestamp = cArgs.EvalCtx.GetClosedTimestamp(ctx)
 
 	return result.Result{}, nil
 }

pkg/kv/kvserver/batcheval/eval_context.go

@@ -16,7 +16,6 @@ import (
 
 	"github.com/cockroachdb/cockroach/pkg/cloud"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/abortspan"
-	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/closedts"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/concurrency"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/kvserverbase"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/readsummary/rspb"
@@ -63,7 +62,6 @@ type EvalContext interface {
 	GetFirstIndex() (uint64, error)
 	GetTerm(uint64) (uint64, error)
 	GetLeaseAppliedIndex() uint64
-	GetTracker() closedts.TrackerI
 
 	Desc() *roachpb.RangeDescriptor
 	ContainsKey(key roachpb.Key) bool
@@ -109,11 +107,11 @@ type EvalContext interface {
 	// requests on the range.
 	GetCurrentReadSummary(ctx context.Context) rspb.ReadSummary
 
-	// GetClosedTimestampV2 returns the current closed timestamp on the range.
+	// GetClosedTimestamp returns the current closed timestamp on the range.
 	// It is expected that a caller will have performed some action (either
 	// calling RevokeLease or WatchForMerge) to freeze further progression of
 	// the closed timestamp before calling this method.
-	GetClosedTimestampV2(ctx context.Context) hlc.Timestamp
+	GetClosedTimestamp(ctx context.Context) hlc.Timestamp
 
 	GetExternalStorage(ctx context.Context, dest roachpb.ExternalStorage) (cloud.ExternalStorage, error)
 	GetExternalStorageFromURI(ctx context.Context, uri string, user security.SQLUsername) (cloud.ExternalStorage,
@@ -208,9 +206,6 @@ func (m *mockEvalCtxImpl) GetTerm(uint64) (uint64, error) {
 func (m *mockEvalCtxImpl) GetLeaseAppliedIndex() uint64 {
 	panic("unimplemented")
 }
-func (m *mockEvalCtxImpl) GetTracker() closedts.TrackerI {
-	panic("unimplemented")
-}
 func (m *mockEvalCtxImpl) Desc() *roachpb.RangeDescriptor {
 	return m.MockEvalCtx.Desc
 }
@@ -246,7 +241,7 @@ func (m *mockEvalCtxImpl) GetRangeInfo(ctx context.Context) roachpb.RangeInfo {
 func (m *mockEvalCtxImpl) GetCurrentReadSummary(ctx context.Context) rspb.ReadSummary {
 	return m.CurrentReadSummary
 }
-func (m *mockEvalCtxImpl) GetClosedTimestampV2(ctx context.Context) hlc.Timestamp {
+func (m *mockEvalCtxImpl) GetClosedTimestamp(ctx context.Context) hlc.Timestamp {
 	return m.ClosedTimestamp
 }
 func (m *mockEvalCtxImpl) GetExternalStorage(