Well, my money are on AWS Elasticache, see if bypassing their proxy will do any good. It's probably a good idea to do so in testing environment with high load targeting elasticache and nothing else. Also it might be a good idea to write to AWS too, maybe there're other people with the same problem out there.
> On 6 Dec 2016, at 18:03, Andreas Kuhne <[email protected]> wrote: > > The way it is set up there are 2 cache nodes in a cluster - a primary and a > secondary. Then I have a seperate address to connect to the cache cluster - > so there probably is some sort of proxy there, but I can't manipulate it - > it's in the AWS Elasticache offering. I don't want to bypass the proxy, > because if the primary goes down, it won't automatically failover if I don't > use it. I could however test to bypass it just to see if that changes > anything. > > Also I have setup the sessions backend via the PyPI package > django-redis-sessions - so it handles the connections for me. I don't know if > it reuses the connections or not - however looking at the monitoriing of the > redis server, it doesn't have that many connections - I think the > django-redis-sessions plugin has a short timeout value. > > However this has worked perfectly until just a month ago, so I don't really > see why these changes have come now. > > Med vänliga hälsningar, > > Andréas Kühne > Software Development Manager > Suitopia Scandinavia AB > > 2016-12-06 15:46 GMT+01:00 GMail <[email protected] > <mailto:[email protected]>>: > You didn't answer about proxy. Also, do you reuse connections to > redis.example.com <http://redis.example.com/>? Or create a new one for every > request? If you aren't reusing them, maybe you should add timeout for > connection creation and retry creating after timeout has exceeded. I know > this doesn't solve the problem, but at least you wouldn't have to wait for > server timeout. > > I still think something is proxying your request to redis.example.com > <http://redis.example.com/> and this something is what gives you timeouts and > connection errors. > >> On 6 Dec 2016, at 17:41, Andreas Kuhne <[email protected] >> <mailto:[email protected]>> wrote: >> >> Hi, >> >> Thanks for you answer - I don't think the problem is with django either, but >> thought that maybe someone else has run into the same issues on AWS. My >> cache cluster worked fine for over 2 year as well, but now, not so much :-) >> >> 2016-12-06 14:35 GMT+01:00 GMail <[email protected] >> <mailto:[email protected]>>: >> Hi! >> >> Do you by any chance have any proxy on top of Redis? Seems like Django has >> nothing to do with it, though. >> >> I don't know anything about dynamodb really, but I think implementing Django >> cache with dynamo as backend should work. I've implemented Redis Cluster >> cache for my project and it works fine. Here're the docs about session >> engines: >> https://docs.djangoproject.com/en/1.10/topics/http/sessions/#using-cached-sessions >> >> <https://docs.djangoproject.com/en/1.10/topics/http/sessions/#using-cached-sessions> >> >>> On 6 Dec 2016, at 15:55, Andreas Kuhne <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> Hi, >>> >>> We are having a strange problem with our redis elasticache instances on >>> AWS. We have our sessions stored in a redis cluster on AWS. Our webservers >>> sometimes get a: >>> * Error connecting to redis.example.com:6379 >>> <http://redis.example.com:6379/>. timed out >>> * Timeout reading from socket >>> >>> (I haven't included our real domain for the redis servers :-)) >>> >>> Both of these are related to our webservers connecting to our redis server. >>> This started about a month ago, and worked perfectly for nearly 2 years >>> before that. I really don't understand why this is happening. I know that >>> the webservers have access to the redis servers, so I really can't >>> understand the problem. Has anyone else experienced a similar problem? >>> >>> That was the first part of my question, my second is related to this >>> though. For costsaving I would really like to dump the redis cluster and >>> change to a dynamodb based session store. I have found a pypi package that >>> works for the implementation, but when I tried it about 2 years ago, it >>> failed miserably. We ended up having people get new sessions all the time >>> and the sessions weren't being persisted corrrectly (each request ended up >>> generating a new session). >>> >>> Has anyone successfully implemented a session store on dynamodb? With 2 >>> webservers behind an loadbalancer? >>> >>> Also, has anyone any ideas of how to move the sessions from our redis store >>> to the dynamodb database? >>> >>> Any tips / tricks would be very appreciated. >>> >>> Regards, >>> >>> Andréas >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Django users" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected] >>> <mailto:[email protected]>. >>> To post to this group, send email to [email protected] >>> <mailto:[email protected]>. >>> Visit this group at https://groups.google.com/group/django-users >>> <https://groups.google.com/group/django-users>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/CALXYUb%3D89GTJ33FgE_DpjofdgOn2fYqVoctzo00NOq5K26Twmw%40mail.gmail.com >>> >>> <https://groups.google.com/d/msgid/django-users/CALXYUb%3D89GTJ33FgE_DpjofdgOn2fYqVoctzo00NOq5K26Twmw%40mail.gmail.com?utm_medium=email&utm_source=footer>. >>> For more options, visit https://groups.google.com/d/optout >>> <https://groups.google.com/d/optout>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at https://groups.google.com/group/django-users >> <https://groups.google.com/group/django-users>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/13E0B717-29E6-43D5-AAD9-0FD4A4424186%40gmail.com >> >> <https://groups.google.com/d/msgid/django-users/13E0B717-29E6-43D5-AAD9-0FD4A4424186%40gmail.com?utm_medium=email&utm_source=footer>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at https://groups.google.com/group/django-users >> <https://groups.google.com/group/django-users>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/CALXYUbkum1Ou5x6yTqFxz-T1pG2%3D9_Km-_XbWBiFur34dVnXyg%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/django-users/CALXYUbkum1Ou5x6yTqFxz-T1pG2%3D9_Km-_XbWBiFur34dVnXyg%40mail.gmail.com?utm_medium=email&utm_source=footer>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/django-users > <https://groups.google.com/group/django-users>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/E58F1469-2A35-45DC-8F5D-7DC9D6E61650%40gmail.com > > <https://groups.google.com/d/msgid/django-users/E58F1469-2A35-45DC-8F5D-7DC9D6E61650%40gmail.com?utm_medium=email&utm_source=footer>. > > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/django-users > <https://groups.google.com/group/django-users>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/CALXYUbm_zJa48VbEj%2BSevZQ%3DX%3DT-tR6%3DL%2Bf9Hby95Ahhpm2CHQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/django-users/CALXYUbm_zJa48VbEj%2BSevZQ%3DX%3DT-tR6%3DL%2Bf9Hby95Ahhpm2CHQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Django users" group. 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