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What to expect during a dry-run
In preparation of the DHS move we will conduct a number of general dry-runs. During these system sessions Dry-runs are system sessions to simulate the DHS behaviour during the DHS Move. During a dry-run read access to the main DHS in Reading will be closed and instead essential data necessary to continue all critical activities during the move will be provided by a temporary DHS in Bologna.
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At the start of the system session, all active/queued MARS retrieve requests (MARS) or and ECFS get operations (ECFS) on the DHS will fail. This is to switch MARS & ECFS to the dry-run configuration. After such failure, we encourage users to re-run requests/scripts once, to experience the expected behaviour expected during the DHS Move:
- Requests for essential/recent data should be satisfied from the temporary DHS.
- Requests for historical data should fail with an explanatory message. We encourage users to re-run those requests after the system session is overhas ended.
Timetable of System Session on
| Time (UTC) |
|---|
| Event / Impact | User action |
|---|---|
| 8:00 | Change configuration of all services using MARS/ECFS to use the temporary DHS in |
| Bologna. | |
| 8:00 - 8:30 | Drain all MARS/ECFS activity in Reading |
| : All active/queued MARS retrieve requests and ECFS get operations on the DHS in Reading will fail |
| . | Please re-run to test behaviour expected during DHS Move. |
| 8:30 - 17:30 |
| Dry-run mode: Behaviour as expected during the DHS Move. | |
| 18:00 | Revert to use DHS infrastructure in Reading |
| : Short interruption. |
Please re-run all failed requests/scripts. Longer than usual turn-around time should be expected. |
Example of execution
Available tools
MARS
Data available during the dry-run is listed in the Catalogue of the temporary DHS. To monitor the status of your requests during the dry-run, please, visit the Temporary DHS server activity
ECFS
Add Relevant user information/commands re temporary DHS for ECFS
How to report a problem
If your activity is critical and we have missed to identify it as such, please , do get in touch with User Services raise a support ticket, see below, and we will look at your specific requirements.
If your request does not behave as explained aboveas described, please, provide as much information as possible so analysts can investigate, for example:
- Service/Tool you are using (mars client, metview, web api, verify, etc...)
- Version of the tool you are using
- Host (ecgb, ATOS, cca, your workstation, ...)
Temporary DHS
MARS
During a dry-run, access will be limited to essential data. The available data is listed in the Catalogue of the temporary DHS.
To monitor the status of your requests, please, visit the Temporary DHS server activity
ECFS
Add Relevant user information/commands re temporary DHS for ECFSPlease report all issues via our Support Portal, mentioning "dhs dry-run" in the title of your computing problem ticket.