

Twitter experiences major, 2-hour+ outage - seldo
http://status.twitter.com/post/699623494/site-availability-issues-due-to-failed-enhancement-of

======
jazzychad
This is a perfect storm. Many twitter clients automatically retry posting
tweets when there is a non 200 return code from the Twitter API (including
humans posting on the website seeing errors). Unfortunately, Twitter has been
returning 5xx codes while successfully posting tweets. This, plus the apparent
fact that duplicate tweet detection is failing/turned off means that all of
the duplicate posts get through. Mayhem ensues...

~~~
akent
#firstworldproblems

------
ErrantX
This happened the other day as well (probably on a shorter timescale, I'm not
sure). I'm not sure if it was a 5xx error code - it seemed more like
connections were hanging.

It showed me the danger of working on someone else's platform, cue warning
story:

I had something that queried Twitter in php (Curl) but it never really
occurred to me to time out the connection (this was ages ago, I forgot about
the project till the other day). For some reason I assumed the host would kill
long running PHP scripts..

Apparently not because my whole account got disabled for too many open
connections.... oops.

------
rykov
"..failed enhancement of a new approach to timeline caching"

I hope this is not a testament to scalability of Cassandra or Redis.

Ref: [http://engineering.twitter.com/2010/02/link-cassandra-at-
twi...](http://engineering.twitter.com/2010/02/link-cassandra-at-twitter.html)
<http://github.com/twitter/haplocheirus>

~~~
codahale
At this point, neither Cassandra nor Redis are in the critical path of their
timeline service.

------
Osiris
I noticed I kept getting Internal Server Error messages, so I kept trying to
post, until I checked my timeline and saw it showed my post 4 times. Then I
saw someone I follow post the same message about 20 times in a row.

It kind of reminds me of the Win32 exception with a result code of 0,
"Operation completed successfully." but backwards.

------
Spoutingshite
Never before has a free service been relied upon by so many diverse people,
from business people, to students and demonstrators. Long live Twitter!

~~~
humbledrone
google.com

