Merge pull request #7945 from hashicorp/docs-cronexpr-dst-fix

Document daylight saving handling

CHANGELOG.md

@@ -16,11 +16,14 @@ BUG FIXES:
 
  * api: validate scale count value is not negative [[GH-7902](https://github.com/hashicorp/nomad/issues/7902)]
  * api: autoscaling policies should not be returned for stopped jobs [[GH-7768](https://github.com/hashicorp/nomad/issues/7768)]
+ * client: Fixed a bug where an multi-task allocation maybe considered unhealthy if some tasks are slow to start [[GH-7944](https://github.com/hashicorp/nomad/issues/7944)]
  * core: job scale status endpoint was returning incorrect counts [[GH-7789](https://github.com/hashicorp/nomad/issues/7789)]
+ * core: Fixed bugs related to periodic jobs scheduled during daylight saving transition periods [[GH-7894](https://github.com/hashicorp/nomad/issues/7894)]
  * core: Fixed a bug where scores for allocations were biased toward nodes with resource reservations [[GH-7730](https://github.com/hashicorp/nomad/issues/7730)]
  * csi: Fixed checking of volume validation responses from plugins [[GH-7831](https://github.com/hashicorp/nomad/issues/7831)]
  * csi: Fixed counting of healthy and expected plugins after plugin job updates or stops [[GH-7844](https://github.com/hashicorp/nomad/issues/7844)]
  * csi: Added checkpointing to volume claim release to avoid unreleased claims on plugin errors [[GH-7782](https://github.com/hashicorp/nomad/issues/7782)]
+ * driver/docker: Fixed a bug preventing garbage collecting unused docker images [[GH-7947](https://github.com/hashicorp/nomad/issues/7947)]
  * jobspec: autoscaling policy block should return a parsing error multiple `policy` blocks are provided [[GH-7716](https://github.com/hashicorp/nomad/issues/7716)]
  * ui: Fixed a bug where exec popup had incorrect URL for jobs where name ≠ id [[GH-7814](https://github.com/hashicorp/nomad/issues/7814)]
 

website/pages/docs/job-specification/periodic.mdx

@@ -74,5 +74,15 @@ periodic {
 }
 ```
 
+## Periodic Jobs and Daylight Saving Time
+
+Though Nomad supports configuring time_zone, we strongly recommend that periodic
+jobs are specified with respect to UTC time_zone.
+
+Daylight saving changes may cause jobs to run in times unexpected to operator: A
+2.30am nightly job with `America/New_York` time zone will not run on the day
+daylight saving time start; a 1.30am nightly job will run twice on the day
+daylight saving time ends.
+
 [batch-type]: /docs/job-specification/job#type 'Batch scheduler type'
 [cron]: https://github.com/gorhill/cronexpr#implementation 'List of cron expressions'

website/pages/docs/upgrade/upgrade-specific.mdx

@@ -31,6 +31,17 @@ the bug fix will only minimally affect scoring.
 Feasability (whether a node is capable of running a job at all) is *not*
 affected.
 
+### Periodic Jobs and Daylight Saving Time
+
+Nomad 0.11.2 fixed a long outstanding bug affecting periodic jobs that are
+scheduled to run during daylight saving transition time.
+
+Nomad 0.11.2 provides a more defined behvior: nomad evaluates the cron
+expression with respect to specified time zone during transition. A 2.30am
+nightly job with `America/New_York` time zone will not run on the day daylight
+saving time start; similarly, a 1.30am nightly job will run twice on the day
+daylight saving time ends.
+
 ## Nomad 0.11.0
 
 ### client.template: `vault_grace` deprecation