Re: Question about node tool repair

2014-01-22 Thread Artur Kronenberg

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) 
<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





RE: Question about node tool repair

2014-01-21 Thread Logendran, Dharsan (Dharsan)
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) 
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



Re: Question about node tool repair

2014-01-21 Thread Robert Coli
On Mon, Jan 20, 2014 at 2:47 PM, Logendran, Dharsan (Dharsan) <
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


Re: Question about node tool repair

2014-01-20 Thread sankalp kohli
Can you give the logs of both the machines. Logs will tell why it is taken
so long.

On a side note, you are using 2500 Cfs. I think you need to redesign this
schema.

Also 2 node cluster with RF=2, you might want to add a machine if it is
prod.


On Mon, Jan 20, 2014 at 2:47 PM, Logendran, Dharsan (Dharsan) <
dharsan.logend...@alcatel-lucent.com> wrote:

>  Hi,
>
>
>
> 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?.
>
>
>
> Thanks
>
> Dharsan
>
>


Question about node tool repair

2014-01-20 Thread Logendran, Dharsan (Dharsan)
Hi,

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?.

Thanks
Dharsan