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From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: (unofficial) Community Poll for Production Operators : Repair
Date Wed, 15 May 2013 15:30:22 GMT
I have actually tested repair in many interesting scenarios:
Once I joined a node and forgot autobootstrap=true
So the data looked like this in the ring
left node
8GB
new node
0GB
right node
8GB

After repair
left node
10 GB
new node
13 gb
right node
12 gb

We do not run repair at all. It is better then the 0.6 and 0.7 days, but a
missed delete does not mean much to us. The difference between an 8gb
sstable and a 12 gb one could be major performance for us since we do
thousands of reads/sec.



On Wed, May 15, 2013 at 5:37 AM, André Cruz <andre.cruz@co.sapo.pt> wrote:

> On May 10, 2013, at 7:24 PM, Robert Coli <rcoli@eventbrite.com> wrote:
>
> > 1) What version of Cassandra do you run, on what hardware?
>
> 1.1.5 - 6 nodes, 32GB RAM, 300GB data per node, 900GB 10k RAID1, Intel(R)
> Xeon(R) CPU E5-2609 0 @ 2.40GHz.
>
> > 2) What consistency level do you write at? Do you do DELETEs?
>
> QUORUM. Yes, we do deletes.
>
> > 3) Do you run a regularly scheduled repair?
>
> Yes.
>
> > 4) If you answered "yes" to 3, what is the frequency of the repair?
>
> Every 2 days.
>
> > 5) What has been your subjective experience with the performance of
> > repair? (Does it work as you would expect? Does its overhead have a
> > significant impact on the performance of your cluster?)
>
> It works as we expect, it has some impact on performance, but it takes a
> long time. We used to run daily repairs, but they started overlapping. The
> reason for more frequent repairs is that we do a lot of deletes so we
> lowered the gc_grace_period otherwise the dataset would grow too large.
>
> André
>
>

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