ref(crons): Add new timestamps to check-ins (#84990)

Co-authored-by: Josh Ferge <[email protected]>

Author: evanpurkhiser

migrations_lockfile.txt

@@ -15,7 +15,7 @@ remote_subscriptions: 0003_drop_remote_subscription
 
 replays: 0004_index_together
 
-sentry: 0828_add_platform_to_grouphash_metadata
+sentry: 0829_add_additional_timestamps_to_checkins
 
 social_auth: 0002_default_auto_field
 

src/sentry/migrations/0829_add_additional_timestamps_to_checkins.py

@@ -0,0 +1,39 @@
+# Generated by Django 5.1.5 on 2025-02-11 20:06
+
+import django.utils.timezone
+from django.db import migrations, models
+
+from sentry.new_migrations.migrations import CheckedMigration
+
+
+class Migration(CheckedMigration):
+    # This flag is used to mark that a migration shouldn't be automatically run in production.
+    # This should only be used for operations where it's safe to run the migration after your
+    # code has deployed. So this should not be used for most operations that alter the schema
+    # of a table.
+    # Here are some things that make sense to mark as post deployment:
+    # - Large data migrations. Typically we want these to be run manually so that they can be
+    #   monitored and not block the deploy for a long period of time while they run.
+    # - Adding indexes to large tables. Since this can take a long time, we'd generally prefer to
+    #   run this outside deployments so that we don't block them. Note that while adding an index
+    #   is a schema change, it's completely safe to run the operation after the code has deployed.
+    # Once deployed, run these manually via: https://develop.sentry.dev/database-migrations/#migration-deployment
+
+    is_post_deployment = False
+
+    dependencies = [
+        ("sentry", "0828_add_platform_to_grouphash_metadata"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="monitorcheckin",
+            name="date_clock",
+            field=models.DateTimeField(null=True),
+        ),
+        migrations.AddField(
+            model_name="monitorcheckin",
+            name="date_created",
+            field=models.DateTimeField(default=django.utils.timezone.now, null=True),
+        ),
+    ]

src/sentry/monitors/models.py

@@ -501,6 +501,25 @@ class MonitorCheckIn(Model):
     Represents the time the checkin was made. This CAN BE back-dated in some
     cases, and does not necessarily represent the insertion time of the row in
     the database.
+
+    This date comes from the time relay reiceved the envelope containing the
+    check-in.
+    """
+
+    date_clock = models.DateTimeField(null=True)
+    """
+    Represents the "clock time" that this check in was recorded at. Since the
+    stream of check-ins is processed within the context of a clock that only
+    moves forward as we process kafka messages, this time represents the time
+    at which we processed this check-in, in relation to all other tasks (such
+    as detecting misses)
+    """
+
+    date_created = models.DateTimeField(default=timezone.now, null=True)
+    """
+    Represents when the check-in was actually recorded into the database. This
+    is a real wall-clock time and is not tied to the "clock" time that
+    check-ins are processed in the contenxt of.
     """
 
     date_updated = models.DateTimeField(default=timezone.now)