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From Michal Michalski <mich...@opera.com>
Subject Re: Hinted handoff
Date Thu, 07 Mar 2013 13:06:59 GMT
I think it's still true, but not because of network-related issues, but 
because of the maintenance problems it will cause during per-node 
operations. For example in my case running 'upgradesstables' on ~300GB 
node takes about 30+ hours. The other IO-intensive operations will 
probably be a pain too.

M.

W dniu 07.03.2013 13:59, Kanwar Sangha pisze:
> <Do you have 9.5TB on a single node ?>
> In the normal case it's best to have around 300 to 500GB per node. With that much data
is will take a week to run repair or replace a failed node.
>
> Hi Aaron - This was true for pre 1.2 but with 1.2 and virtual nodes, does this still
hold ? 1 TB at 1Gb/s will take roughly 2.2hrs assume we stream from say 100 nodes...
>
>
> From: aaron morton [mailto:aaron@thelastpickle.com]
> Sent: 06 March 2013 23:47
> To: user@cassandra.apache.org
> Subject: Re: Hinted handoff
>
> Check the IO utilisation using iostat
>
> You *really* should not need to make HH run faster, if you do there is some thing bad
going on. I would consider dropping the hints and running repair.
>
> Data is ~9.5 TB
> Do you have 9.5TB on a single node ?
> In the normal case it's best to have around 300 to 500GB per node. With that much data
is will take a week to run repair or replace a failed node.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 6/03/2013, at 1:22 PM, Kanwar Sangha <kanwar@mavenir.com<mailto:kanwar@mavenir.com>>
wrote:
>
>
> Is this correct ?
>
> I have Raid 0 setup for 16 TB across 8 disks. Each disk is 7.2kRPM with IOPS of 80 per
disk. Data is ~9.5 TB
>
> So 4K * 80 * 9.5 = 3040 KB ~  23.75 Mb/s.
>
> So basically I am limited at the disk rather than the n/w
>
> From: Kanwar Sangha [mailto:kanwar@mavenir.com<http://mavenir.com>]
> Sent: 06 March 2013 15:11
> To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
> Subject: RE: Hinted handoff
>
> After trying to bump up the "hinted_handoff_throttle_in_kb" to 1G/b per sec, It still
does not go above 25Mb/s.  Is there a limitation ?
>
>
>
> From: Kanwar Sangha [mailto:kanwar@mavenir.com]
> Sent: 06 March 2013 14:41
> To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
> Subject: RE: Hinted handoff
>
> Got the param. thanks
>
> From: Kanwar Sangha [mailto:kanwar@mavenir.com]
> Sent: 06 March 2013 13:50
> To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
> Subject: Hinted handoff
>
> Hi - Is there a way to increase the hinted handoff throughput ? I am seeing around 8Mb/s
(bits).
>
> Thanks,
> Kanwar
>
>


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