About repairs,
we encountered a similar problem with our setup where repairs would take
ages to complete. Based on your setup you can try loading data into page
cache before running repairs. Depending on how much data you can hold in
cache, this will speed up your repairs massively.
-- artur
On 21/01/14 20:33, Logendran, Dharsan (Dharsan) wrote:
Thanks Rob,
Dharsan
*From:*Robert Coli [mailto:rc...@eventbrite.com]
*Sent:* January-21-14 2:26 PM
*To:* user@cassandra.apache.org
*Subject:* Re: Question about node tool repair
On Mon, Jan 20, 2014 at 2:47 PM, Logendran, Dharsan (Dharsan)
<dharsan.logend...@alcatel-lucent.com
<mailto:dharsan.logend...@alcatel-lucent.com>> wrote:
We have a two node cluster with the replication factor of 2. The db
has more than 2500 column families(tables). The nodetool -pr repair
on an empty database(one or table has a litter data) takes about 30
hours to complete. We are using Cassandra Version 2.0.4. Is there
any way for us to speed up this?.
Cassandra 2.0.2 made aspects of repair serial and therefore logically
much slower as a function of replication factor. Yours is not the
first report I have heard of >= 2.0.2 era repair being unreasonably slow.
https://issues.apache.org/jira/browse/CASSANDRA-5950
You can use -par (not at all confusingly named with -pr!) to get the
old parallel behavior.
Cassandra 2.1 has this ticket to improve repair with vnodes.
https://issues.apache.org/jira/browse/CASSANDRA-5220
But really you should strongly consider how much you need to run
repair, and at very least probably increase gc_grace_seconds from the
unreasonably low default of 10 days to 32 days, and then run your
repair on the first of each month.
https://issues.apache.org/jira/browse/CASSANDRA-5850
IMO it is just a complete and total error if repair of an actually
empty database is anything but a NO-OP. I would file a JIRA ticket,
were I you.
=Rob
