Add exception catch for redis connection failure #1261
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Codecov Report
@@ Coverage Diff @@
## master #1261 +/- ##
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+ Coverage 93.84% 95.01% +1.16%
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Files 22 43 +21
Lines 2341 5841 +3500
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+ Hits 2197 5550 +3353
- Misses 144 291 +147
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rq/worker.py
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| except redis.exceptions.ConnectionError as conn_err: | ||
| self.log.error('Could not connect to Redis instance: %s ' | ||
| 'Retrying...', conn_err) | ||
| time.sleep(1) |
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maybe would be better to use an exponential backoff approach here instead of trying each 1 second?
| self.log.error('Could not connect to Redis instance: %s ' | ||
| 'Retrying...', conn_err) | ||
| time.sleep(connection_wait_time) | ||
| connection_wait_time *= self.exponential_backoff_factor |
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Let's limit the connection_wait_time to 60 seconds max. So it'll try every 1, 2, 4, 8 ... up to 60 seconds.
rq/worker.py
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| @@ -567,14 +567,15 @@ def dequeue_job_and_maintain_ttl(self, timeout): | |||
| self.set_state(WorkerStatus.IDLE) | |||
| self.procline('Listening on ' + qnames) | |||
| self.log.debug('*** Listening on %s...', green(qnames)) | |||
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| connection_wait_time = 1.0; | |||
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Please remove the use of semicolons.
rq/worker.py
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| time.sleep(connection_wait_time) | ||
| connection_wait_time *= self.exponential_backoff_factor | ||
| else: | ||
| connection_wait_time = 1.0; |
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Please remove the use of semicolons.
rq/worker.py
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| @@ -591,6 +592,13 @@ def dequeue_job_and_maintain_ttl(self, timeout): | |||
| break | |||
| except DequeueTimeout: | |||
| pass | |||
| except redis.exceptions.ConnectionError as conn_err: | |||
| self.log.error('Could not connect to Redis instance: %s ' | |||
| 'Retrying...', conn_err) | |||
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Please add Retrying in <wait_time> seconds...
rq/worker.py
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| @@ -1,4 +1,4 @@ | |||
| # -*- coding: utf-8 -*- | |||
| #wait_time_after_connection_failure -*- coding: utf-8 -*- | |||
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Why does this line need to be changed?
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Hi @selwin rq workers are not automatically retrying to connect when connect is lost/redis-server is restarted for maintenance. So until rq worker is restarted, it keeps raising ConnectionError resulting in failure. Lately this is becoming serious issue in production. Hoping this PR can fix it. |
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@Asrst because my comments haven't been addressed. |
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@selwin Is there anything we can do since it is in this state from Jun 20 ? |
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Yes, if my comments on this PR is addressed, this is also something I'd like to see merged in. |
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I think I have resolved the issues now, please let me know if there is anything else! |
Resolves #1153
Resolves (Maybe?) #998