fix(scheduler): the session cleanup generator is reset too often (#2220)

This causes the "fair" scheduler to run it too often in the detriment of other generators.
The intention was to run it every 2 hours but the measurement unit for 7200 was not specified.

Add more logs, including showing a generator name, in order to troubleshoot this kind of issues easier in the future.

Signed-off-by: Andrei Aaron <aaaron@luxoft.com>

pkg/api/cookiestore.go

@@ -30,7 +30,11 @@ type CookieStore struct {
 
 func (c *CookieStore) RunSessionCleaner(sch *scheduler.Scheduler) {
 	if c.needsCleanup {
-		sch.SubmitGenerator(&SessionCleanup{rootDir: c.rootDir}, cookiesMaxAge, scheduler.LowPriority)
+		sch.SubmitGenerator(
+			&SessionCleanup{rootDir: c.rootDir},
+			cookiesMaxAge*time.Second,
+			scheduler.LowPriority,
+		)
 	}
 }
 
@@ -122,6 +126,10 @@ type SessionCleanup struct {
 	done    bool
 }
 
+func (gen *SessionCleanup) Name() string {
+	return "SessionCleanupGenerator"
+}
+
 func (gen *SessionCleanup) Next() (scheduler.Task, error) {
 	sessions, err := getExpiredSessions(gen.rootDir)
 	if err != nil {