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Posted to user@cassandra.apache.org by Kanwar Sangha <ka...@mavenir.com> on 2013/02/20 15:47:00 UTC
SSTable Num
Hi - I have around 6TB of data on 1 node and the cfstats show 32 sstables. There is no compaction job running in the background. Is there a limit on the size per sstable ? Or will the sstable compaction continue and eventually we will have 1 file ?
Thanks,
Kanwar
Re: SSTable Num
Posted by aaron morton <aa...@thelastpickle.com>.
> Ok. So for 10 TB, I could have at least 4 SStables files each of 2.5 TB ?
You will have many sstables, in your case 32.
Each bucket of files (files that are within 50% of the average size of files in a bucket) will contain 3 or less files.
This article provides com back ground, but it's working correctly as you have described it
http://www.datastax.com/dev/blog/when-to-use-leveled-compaction
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 22/02/2013, at 6:39 AM, Kanwar Sangha <ka...@mavenir.com> wrote:
> No.
> The default size tiered strategy compacts files what are roughly the same size, and only when there are more than 4 (default) of them.
>
> Ok. So for 10 TB, I could have at least 4 SStables files each of 2.5 TB ?
>
> From: aaron morton [mailto:aaron@thelastpickle.com]
> Sent: 21 February 2013 11:01
> To: user@cassandra.apache.org
> Subject: Re: SSTable Num
>
> Hi – I have around 6TB of data on 1 node
> Unless you have SSD and 10GbE you probably have too much data on there.
> Remember you need to run repair and that can take a long time with a lot of data. Also you may need to replace a node one day and moving 6TB will take a while.
>
> Or will the sstable compaction continue and eventually we will have 1 file ?
> No.
> The default size tiered strategy compacts files what are roughly the same size, and only when there are more than 4 (default) of them.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 21/02/2013, at 3:47 AM, Kanwar Sangha <ka...@mavenir.com> wrote:
>
>
> Hi – I have around 6TB of data on 1 node and the cfstats show 32 sstables. There is no compaction job running in the background. Is there a limit on the size per sstable ? Or will the sstable compaction continue and eventually we will have 1 file ?
>
> Thanks,
> Kanwar
>
RE: SSTable Num
Posted by Kanwar Sangha <ka...@mavenir.com>.
No.
The default size tiered strategy compacts files what are roughly the same size, and only when there are more than 4 (default) of them.
Ok. So for 10 TB, I could have at least 4 SStables files each of 2.5 TB ?
From: aaron morton [mailto:aaron@thelastpickle.com]
Sent: 21 February 2013 11:01
To: user@cassandra.apache.org
Subject: Re: SSTable Num
Hi - I have around 6TB of data on 1 node
Unless you have SSD and 10GbE you probably have too much data on there.
Remember you need to run repair and that can take a long time with a lot of data. Also you may need to replace a node one day and moving 6TB will take a while.
Or will the sstable compaction continue and eventually we will have 1 file ?
No.
The default size tiered strategy compacts files what are roughly the same size, and only when there are more than 4 (default) of them.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 21/02/2013, at 3:47 AM, Kanwar Sangha <ka...@mavenir.com>> wrote:
Hi - I have around 6TB of data on 1 node and the cfstats show 32 sstables. There is no compaction job running in the background. Is there a limit on the size per sstable ? Or will the sstable compaction continue and eventually we will have 1 file ?
Thanks,
Kanwar
Re: SSTable Num
Posted by aaron morton <aa...@thelastpickle.com>.
> Hi – I have around 6TB of data on 1 node
Unless you have SSD and 10GbE you probably have too much data on there.
Remember you need to run repair and that can take a long time with a lot of data. Also you may need to replace a node one day and moving 6TB will take a while.
> Or will the sstable compaction continue and eventually we will have 1 file ?
No.
The default size tiered strategy compacts files what are roughly the same size, and only when there are more than 4 (default) of them.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 21/02/2013, at 3:47 AM, Kanwar Sangha <ka...@mavenir.com> wrote:
> Hi – I have around 6TB of data on 1 node and the cfstats show 32 sstables. There is no compaction job running in the background. Is there a limit on the size per sstable ? Or will the sstable compaction continue and eventually we will have 1 file ?
>
> Thanks,
> Kanwar
>