---
title: Downtimes
#tags:
#keywords:
last_updated: 28 June 2019
#summary: "Merlin 6 cluster overview"
sidebar: merlin6_sidebar
permalink: /merlin6/downtimes.html
---

On the first Monday of each month the Merlin6 cluster might be subject to interruption due to maintenance. 
Users will be informed with at least one week in advance when a downtime is scheduled for the next month.

Downtimes will be informed to users through the <merlin-users@lists.psi.ch> mail list. Also, a detailed description 
for the nexts scheduled interventions will be available in [Next Scheduled Downtimes](/merlin6/downtimes.html#next-scheduled-downtimes)).

---

## Scheduled Downtime Draining Policy

Scheduled downtimes mostly affecting the storage and Slurm configurantions may require draining the nodes.
When this is required, users will be informed accordingly. Two different types of draining are possible:

* **soft drain**: new jobs may be queued on the partition, but queued jobs may not be allocated nodes and run from the partition. 
Jobs already running on the partition continue to run. This will be the **default** drain method.
* **hard drain**: no new jobs may be queued on the partition (job submission requests will be denied with an error message), 
but jobs already queued on the partition may be allocated to nodes and run. 

Unless explicitly specified, the default draining policy for each partition will be the following: 

* The **daily** and **general** partition will be soft drained 24h before the downtime.
* The **hourly** partition will be soft drained 1 hour before the downtime.
* The **gpu** partition will be soft drained 1 hour before the downtime.

Finally, **remaining running jobs will be killed** by default when the downtime starts. In some specific rare cases jobs will be 
just *paused* and *resumed* back when the downtime finished.

### Draining Policy Summary

The following table contains a summary of the draining policies during a Schedule Downtime:

| **Partition**   | **Drain Policy**  | **Default Drain Type** | **Default Job Policy**           |
|:---------------:| -----------------:| ----------------------:| --------------------------------:|
| **general**     | 24h before the SD | soft drain             | Kill running jobs when SD starts |
| **daily**       | 24h before the SD | soft drain             | Kill running jobs when SD starts |
| **hourly**      |  1h before the SD | soft drain             | Kill running jobs when SD starts |
| **gpu**         |  1h before the SD | soft drain             | Kill running jobs when SD starts |

---

## Next Scheduled Downtimes

The table below shows a description for the next Scheduled Downtime:

| From             | To               | Affected Service/s             | Description                                                           |
| :------------:   | ---------        | :----------------------------- | :-----------------------------------------------------------------    |
| *02.03.2020 9h*  | *02.03.2020 10h* | merlin-l-01, merlin-l-001      | Outage. YFS (AFS) update and reboot                                   |
| *02.03.2020 9h*  | *02.03.2020 17h* | Merlin5 computing nodes        | Outage. O.S. update, OFED drivers update, YFS (AFS) update.           |


* **Note**: An e-mail will be sent when the login nodes are fully available. An e-mail will be sent when Merlin5 computing nodes are back.
