perf: use `modified` instead of `creation` in scheduler (#18234) (#18240)

creation doesn't have index and does full table scan. On large site with
~3M activity logs it takes ~1.5 seconds just to begin scheduler.

[skip ci]

(cherry picked from commit 0642708f01)

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/tests/test_scheduler.py

@@ -7,7 +7,12 @@ import frappe
 from frappe.core.doctype.scheduled_job_type.scheduled_job_type import ScheduledJobType, sync_jobs
 from frappe.utils import add_days, get_datetime
 from frappe.utils.doctor import purge_pending_jobs
-from frappe.utils.scheduler import enqueue_events, is_dormant, schedule_jobs_based_on_activity
+from frappe.utils.scheduler import (
+	_get_last_modified_timestamp,
+	enqueue_events,
+	is_dormant,
+	schedule_jobs_based_on_activity,
+)
 
 
 def test_timeout_10():
@@ -56,7 +61,7 @@ class TestScheduler(TestCase):
 		self.assertFalse(is_dormant(check_time=frappe.db.get_last_created("Activity Log")))
 
 	def test_once_a_day_for_dormant(self):
-		frappe.db.clear_table("Scheduled Job Log")
+		frappe.db.truncate("Scheduled Job Log")
 		self.assertTrue(schedule_jobs_based_on_activity(check_time=get_datetime("2100-01-01 00:00:00")))
 		self.assertTrue(
 			schedule_jobs_based_on_activity(
@@ -68,19 +73,21 @@ class TestScheduler(TestCase):
 		job = get_test_job(method="frappe.tests.test_scheduler.test_method", frequency="Daily")
 		job.execute()
 		job_log = frappe.get_doc("Scheduled Job Log", dict(scheduled_job_type=job.name))
-		job_log.db_set("creation", add_days(frappe.db.get_last_created("Activity Log"), 5))
+		job_log.db_set(
+			"modified", add_days(_get_last_modified_timestamp("Activity Log"), 5), update_modified=False
+		)
 
 		# inactive site with recent job, don't run
 		self.assertFalse(
 			schedule_jobs_based_on_activity(
-				check_time=add_days(frappe.db.get_last_created("Activity Log"), 5)
+				check_time=add_days(_get_last_modified_timestamp("Activity Log"), 5)
 			)
 		)
 
 		# one more day has passed
 		self.assertTrue(
 			schedule_jobs_based_on_activity(
-				check_time=add_days(frappe.db.get_last_created("Activity Log"), 6)
+				check_time=add_days(_get_last_modified_timestamp("Activity Log"), 6)
 			)
 		)
 

frappe/utils/scheduler.py

@@ -18,7 +18,7 @@ import schedule
 # imports - module imports
 import frappe
 from frappe.installer import update_site_config
-from frappe.utils import get_sites, now_datetime
+from frappe.utils import get_datetime, get_sites, now_datetime
 from frappe.utils.background_jobs import get_jobs
 
 DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"
@@ -146,7 +146,7 @@ def schedule_jobs_based_on_activity(check_time=None):
 	Returns True for inactive sites once in 24 hours"""
 	if is_dormant(check_time=check_time):
 		# ensure last job is one day old
-		last_job_timestamp = frappe.db.get_last_created("Scheduled Job Log")
+		last_job_timestamp = _get_last_modified_timestamp("Scheduled Job Log")
 		if not last_job_timestamp:
 			return True
 		else:
@@ -162,7 +162,7 @@ def schedule_jobs_based_on_activity(check_time=None):
 
 
 def is_dormant(check_time=None):
-	last_activity_log_timestamp = frappe.db.get_last_created("Activity Log")
+	last_activity_log_timestamp = _get_last_modified_timestamp("Activity Log")
 	since = (frappe.get_system_settings("dormant_days") or 4) * 86400
 	if not last_activity_log_timestamp:
 		return True
@@ -171,6 +171,14 @@ def is_dormant(check_time=None):
 	return False
 
 
+def _get_last_modified_timestamp(doctype):
+	timestamp = frappe.db.get_value(
+		doctype, filters={}, fieldname="modified", order_by="modified desc"
+	)
+	if timestamp:
+		return get_datetime(timestamp)
+
+
 @frappe.whitelist()
 def activate_scheduler():
 	if is_scheduler_disabled():