Testing netsplit in Riak

Andrey Ershov andrershov at gmail.com
Wed Feb 22 13:06:06 EST 2017


Hi, guys!

I'm testing netsplit in Riak and can not achieve satisfiable behaviour.
I've just two nodes cluster and bucket with the following settings n=3,
w=2, r=2. And I have just a couple of entries.
Basically I have two problems:
1) After the split, writes on one side of the partition start lagging hard.
It takes more than 1 minute for the first write to be become successful. I
understand that this is related to the process of setting up backup vnodes
in Riak, but is any way to speed up the process?  Which configuration
parameters influence that?
2) More weird problem is after netsplit. "riak-admin transfers" command
immediately reports that there should 5 partition transfers from one node
to another and 5 partition transfers in the opposite direction. But active
transfers output is empty!
I've put a watch on this command and active transfers are always empty.
Finally, it takes several minutes for Riak to finish hinted handoff.
Several minutes just for several keys!
What Riak is doing all this time? Anyway to speed up the process?
3) The reason why I'm concerned about hinted-handoff speed is because, I
noticed that until this process finishes, I read stale data on both sides
of ex-netsplit.


-- 
Thanks,
Andrey
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.basho.com/pipermail/riak-users_lists.basho.com/attachments/20170222/09c2760e/attachment-0002.html>


More information about the riak-users mailing list