[GT-152] timeout causes ssm to crash

[Sae126V]

When we make use of AmsHttpRequests provided by the AMS itself, pull_sub. is a POST request and it under the hood uses _retry_make_request() where it tries to make an attempt for retries.

In our case, retry =3:
If enabled (retry > 0), multiple subscription pulls will be tried in case of problems/glitches with the AMS service.

Because we are using the ArgoMessagingService class under the hood, it is making use of requests lib. So timeouts (one of the API error status, requests.exceptions.ReadTimeout) from AMS (HTTP 408) or load balancer (HTTP 408 and 504) should be handled by AmsBalancerException, AmsConnectionException, AmsTimeoutException.

Resolves #214 .

[gregcorbett]

Looks good

Can you rebase away 84151b4 and 5022943?

I would shorten the line codeclimate has identified as being too long.

I don't think the Travis CI being stuck in the "Expected" state is caused by this PR, other recent PRs have this behaviour as well.

[gregcorbett]

Working through https://stackoverflow.com/a/70994400 may resolve the weirdness of this PR showing already merged commits, it worked for GOCDB/gocdb#447.

[Sae126V]

'Applied Rebase' - Squashed the commits into one.

[tofu-rocketry]

So timeouts ... should be handled by AmsBalancerException, AmsConnectionException, AmsTimeoutException.

But this clearly isn't the case if you look at the log in #214. The exception type raised is requests.exceptions.ReadTimeout. This won't be a subclass of any of the AMS exception types, right? So trying to catch an AMS exception type won't help. We need to catch the ReadTimeout.

[Sae126V]

Note:

Findings' shows that it seems there is an issue with older version of AMS when ReadTimeout Exception occurs. But, Newer versions was able to catch these errors. So, We have decided to catch the issues with what New version of ARGO AMS library is offering.

For ref:
https://github.com/ARGOeu/argo-ams-library/releases/tag/v.0.6.0-1

[tofu-rocketry]

If you address my comment, and rebase the code, then I should be able to slip this into version 3.3.0. 👍🏻

[tofu-rocketry]

I've double checked that these exceptions are available in the AMS lib 0.5.4 and 0.5.1, as used on apel-preprod and apel prod, respectively.

[tofu-rocketry]

@Sae126V Do check that you've pulled the latest from dev before you rebase. (I've sorted it out for this PR.)