Well you might not agree but you are not the one who has to explain to his customers why is the CB cluster down when everything is working perfectly. We are running on 4 x SSDsRAID 10 and I can’t configure my system to use disk only for oler items or remove the non-used elements from Memcached. If it runs out of Memcached memory it just starts to throw temporary failures instead of more aggressive ejection.
You also not the one who spent 4 days on debugging why is CB returning 503s. After reading your documentation -that is btw. incorrect so many places that I lost count- finally came to the conclusion that you did not give too much control over what is kept in memory so if your system reaches this limit it starts to fail and the only thing what I can do is to give more memory of more nodes.
Now, you admitted that this is a problem by introducing more control over the metadata in 3.0. If it was not a problem why is that feature added?
We can disagree about how these distributed systems should work, but at least you have to be upfront about it like Riak is. I was aware of the trade offs of the different data stores just by reading through their documentation that is correct and comprehensive compare to CB.
I have run into roughly ~5-8 major bugs since I was forced to use CB and non of them are fun, but this one is the most annoying one of them all. This problem itself would be enough reason for me not to consider CB for anything serious.
Talking about other bugs:
node managements is FUBAR, if need to add or remove nodes we tear down the entire cluster wipe out all of the data and rebuild, this became our official policy to deal with CB
iterating over a view where you can’t do startkey and endkey is getting slow by every iteration because the seek time for skip=N ~ N, so if you have 10000000 keys you can’t use this feature
your documentation states that you can configure the low and the high watermark for the memcahced with percentage but unfortunately it is in bytes so you just trolling anybody who is new to this system at such extent that is outrageous
rebalancing failed, this is my favorite. I am not sure why am in the business of telling a data system that it needs to rebalance itself but once you have this feature it should probably work
Thanks for your support, now I can just use this little thread to go to management and justify why we are going to rip out CB from our production infrastructure and never put it back.