eventpb: make the Timestamp field an int64

While exploring how to use the data in practice, I noticed that the
timestamp was encoded as a string in the JSON output, and that was
making the events hard to parse and to use. There are many
more functions that can operate on a number.

Moreover, the integer representation is just more compact.

Release note (api change):  The 'Timestamp' field of structured
notable events is now numeric, and encodes a number of nanoseconds
since the unix epoch. (Note that this API has not yet been published
in a released version of CockroachDB. The release note exists only to
track the list of relevant items for the doc project.)

pkg/server/node.go

@@ -797,7 +797,7 @@ func (n *Node) recordJoinEvent(ctx context.Context) {
 		nodeDetails = &ev.CommonNodeEventDetails
 		nodeDetails.LastUp = n.startedAt
 	}
-	event.CommonDetails().Timestamp = timeutil.Now()
+	event.CommonDetails().Timestamp = timeutil.Now().UnixNano()
 	nodeDetails.StartedAt = n.startedAt
 	nodeDetails.NodeID = int32(n.Descriptor.NodeID)
 

pkg/server/server.go

@@ -2032,7 +2032,7 @@ func (s *Server) Decommission(
 	} else {
 		panic("unexpected target membership status")
 	}
-	event.CommonDetails().Timestamp = timeutil.Now()
+	event.CommonDetails().Timestamp = timeutil.Now().UnixNano()
 	nodeDetails.RequestingNodeID = int32(s.NodeID())
 
 	for _, nodeID := range nodeIDs {

pkg/sql/event_log.go

@@ -13,7 +13,6 @@ package sql
 import (
 	"context"
 	"encoding/json"
-	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/base"
 	"github.com/cockroachdb/cockroach/pkg/kv"
@@ -23,6 +22,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/log/eventpb"
+	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
 	"github.com/cockroachdb/errors"
 )
 
@@ -49,7 +49,7 @@ func logEventInternalForSchemaChanges(
 	mutationID descpb.MutationID,
 	event eventpb.EventPayload,
 ) error {
-	event.CommonDetails().Timestamp = txn.ReadTimestamp().GoTime()
+	event.CommonDetails().Timestamp = txn.ReadTimestamp().WallTime
 	scCommon, ok := event.(eventpb.EventWithCommonSchemaChangePayload)
 	if !ok {
 		return errors.AssertionFailedf("unknown event type: %T", event)
@@ -84,7 +84,7 @@ func logEventInternalForSQLStatements(
 	event eventpb.EventPayload,
 ) error {
 	// Inject the common fields into the payload provided by the caller.
-	event.CommonDetails().Timestamp = txn.ReadTimestamp().GoTime()
+	event.CommonDetails().Timestamp = txn.ReadTimestamp().WallTime
 	sqlCommon, ok := event.(eventpb.EventWithCommonSQLPayload)
 	if !ok {
 		return errors.AssertionFailedf("unknown event type: %T", event)
@@ -135,8 +135,7 @@ func InsertEventRecord(
 	info.CommonDetails().EventType = eventType
 
 	// The caller is responsible for the timestamp field.
-	var zeroTime time.Time
-	if info.CommonDetails().Timestamp == zeroTime {
+	if info.CommonDetails().Timestamp == 0 {
 		return errors.AssertionFailedf("programming error: timestamp field in event not populated: %T", info)
 	}
 
@@ -160,7 +159,7 @@ VALUES(
 )
 `
 	args := []interface{}{
-		info.CommonDetails().Timestamp,
+		timeutil.Unix(0, info.CommonDetails().Timestamp),
 		eventType,
 		targetID,
 		reportingID,

pkg/util/log/event_log.go

@@ -13,7 +13,6 @@ package log
 import (
 	"context"
 	"encoding/json"
-	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/util/log/eventpb"
 	"github.com/cockroachdb/cockroach/pkg/util/log/severity"
@@ -24,9 +23,8 @@ import (
 func StructuredEvent(ctx context.Context, event eventpb.EventPayload) {
 	// Populate the missing common fields.
 	common := event.CommonDetails()
-	var zeroTime time.Time
-	if common.Timestamp == zeroTime {
-		common.Timestamp = timeutil.Now()
+	if common.Timestamp == 0 {
+		common.Timestamp = timeutil.Now().UnixNano()
 	}
 	if len(common.EventType) == 0 {
 		common.EventType = eventpb.GetEventTypeName(event)

pkg/util/log/eventpb/BUILD.bazel

@@ -19,6 +19,5 @@ go_library(
     deps = [
         "//pkg/util/log/logpb",
         "//vendor/github.com/gogo/protobuf/proto",
-        "//vendor/github.com/gogo/protobuf/types",
     ],
 )

pkg/util/log/eventpb/events.proto

@@ -24,8 +24,9 @@ import "google/protobuf/timestamp.proto";
 
 // CommonEventDetails contains the fields common to all events.
 message CommonEventDetails {
-  // The timestamp of the event.
-  google.protobuf.Timestamp timestamp = 1 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true, (gogoproto.jsontag) = ",omitempty"];
+  // The timestamp of the event. Expressed as nanoseconds since
+  // the Unix epoch.
+  int64 timestamp = 1 [(gogoproto.jsontag) = ",omitempty"];
   // The type of the event.
   string event_type = 2 [(gogoproto.jsontag) = ",omitempty"];
 }