Catch CDS down

[robmarkcole]

The CDS status is currently DOWN and materialize enters a loop of

Recovering from connection error [HTTPSConnectionPool(host='cds.climate.copernicus.eu', port=443): Max retries exceeded with url: /api/catalogue/v1/messages (Caused by ConnectTimeoutError(<urllib3.connection.HTTPSConnection object at 0x3042e1b50>, 'Connection to cds.climate.copernicus.eu timed out. (connect timeout=60)'))], attempt 1 of 500
Retrying in 120 seconds
Recovering from HTTP error [500 Internal Server Error], attempt 2 of 500

Possibly we want to check the status before a request, and log to the user if it is down. Ideally I would proceed with the rest of materialize then rerun CDS when it is back up?

[robmarkcole]

After a couple of hours downloads resumed, even though the status page shows DOWN, perhaps the page is a bit unreliable