fix: fence command events by dispatch generation

internal/server/store/event.go

@@ -32,19 +32,20 @@ type FaultInjectorFunc func(name string) error
 func (function FaultInjectorFunc) Checkpoint(name string) error { return function(name) }
 
 type EventAppend struct {
-	IssueUUID        [16]byte
-	ClientID         string
-	EventSeq         uint64
-	ObservedUnixNano int64
-	ReceiptUnixNano  int64
-	EventType        uint16
-	Stream           uint16
-	Compression      uint16
-	RawLength        uint64
-	Payload          []byte
-	ImmutableSHA256  [32]byte
-	Output           bool
-	UseCloseout      bool
+	IssueUUID         [16]byte
+	ClientID          string
+	SessionGeneration uint64
+	EventSeq          uint64
+	ObservedUnixNano  int64
+	ReceiptUnixNano   int64
+	EventType         uint16
+	Stream            uint16
+	Compression       uint16
+	RawLength         uint64
+	Payload           []byte
+	ImmutableSHA256   [32]byte
+	Output            bool
+	UseCloseout       bool
 }
 
 type EventAppendResult struct {
@@ -91,6 +92,10 @@ JOIN storage_counters ON storage_counters.singleton = 1 WHERE commands.issue_uui
 		query += ` AND commands.client_id = ?`
 		arguments = append(arguments, event.ClientID)
 	}
+	if event.SessionGeneration != 0 {
+		query += ` AND commands.target_session_generation = ?`
+		arguments = append(arguments, event.SessionGeneration)
+	}
 	err = database.QueryRowContext(ctx, query, arguments...).Scan(
 		&lastSequence, &commandOutputCharged, &commandCharged, &closeoutRemaining, &clientID, &clientCharged, &serverCharged)
 	if errors.Is(err, sql.ErrNoRows) {