incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Donal Zang <zan...@ihep.ac.cn>
Subject Re: insert slowdown with secondary indexes
Date Sat, 11 Jun 2011 11:40:03 GMT
On 11/06/2011 02:27, jodylandreneau@comcast.net wrote:
> I'm trying to understand why doing the inserts into a column family with indexes seems
to jam things up and am wondering if there are any settings that I could tweak to help. It
seems that the 4 node cluster should be able to handle 2 threads of data coming at it.  Has
anyone had any experience with this number of indexes per column family? Any insight or suggestions
would be appreciated.
Hi,
I used to post an email about this, see the mail list archive.
The secondary index now use hash method, and it causes an random I/O 
when do insertion(so lots of swap work). Also, the query based on it 
would be slow too.
So my advice would be : don't use the secondary index, at least for now 
(there are plans to build an bitmap index [1])
You can try Ed Uff 's method [2] to build an CF as your index, it's much 
faster than the secondary index. (this method may need the CompositeType 
[3])

[1] https://issues.apache.org/jira/browse/CASSANDRA-1472
[2] http://www.anuff.com/2010/07/secondary-indexes-in-cassandra.html
[3] https://issues.apache.org/jira/browse/CASSANDRA-2231

-- 
Donal Zang
Computing Center, IHEP
19B YuquanLu, Shijingshan District,Beijing, 100049
zangds@ihep.ac.cn
86 010 8823 6018



Mime
View raw message