Rails - Nov 2014 - Mysql2::Error: This connection is still waiting for a result, try again once you have the result

Rails-talk, 

Last night I got a slew (around 2000) of these exceptions raised in my
production app between 4:03 AM and 7:30 AM (eastern time).

They all had the same pattern:

ActiveRecord::StatementInvalid: Mysql2::Error: This connection is still waiting
for a result, try again once you have the result: SELECT `spree_buckets`.* FROM
`spree_buckets` WHERE `spree_buckets`.`slug` = 'gallery' LIMIT 1
(The SQL query was different for many, but the Mysql2::Error: This connection is
still waiting for a result, try again once you have the result part was the
same)

I called Amazon RDS support and they said the underlying database looked fine,
we are well below our IOPS threshold, and our queue depth looks healthy.

I think perhaps just 1 Unicorn worker choked up with a single MySQL call,
resulting in all subsequent calls from that Unicorn worker to produce this error
(for 3 hours!)

Does anyone else have any best practice advice for this error? Should I simply
catch for this exception and close & reconnect any active MySQL connections
? Can someone share some examples of how to do that as cleanly as possible?

Thanks,
Jason




----

Jason Fleetwood-Boldt
tech-eJ8lBn5LdNBhbmWW9KSYcQ@public.gmane.org
http://www.jasonfleetwoodboldt.com/writing

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/0C92E483-8F51-4AAF-A210-D5243246CE6C%40datatravels.com.
For more options, visit https://groups.google.com/d/optout.