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Posted to user@cassandra.apache.org by myreasoner <my...@gmail.com> on 2011/09/20 20:30:26 UTC
Column family has more SSTables than threshold but no
minorcompaction is running
Column Family: CF_1
SSTable count: 249
Space used (live): 15120496328
Space used (total): 15120496328
Number of Keys (estimate): 18860800
Memtable Columns Count: 0
Memtable Data Size: 0
Memtable Switch Count: 2483
Read Count: 442
Read Latency: NaN ms.
Write Count: 208741548
Write Latency: NaN ms.
Pending Tasks: 0
Key cache capacity: 200000
Key cache size: 2395
Key cache hit rate: NaN
Row cache capacity: 200000
Row cache size: 221
Row cache hit rate: NaN
Compacted row minimum size: 104
Compacted row maximum size: 73457
Compacted row mean size: 394
Current compaction thresholds: min = 4, max = 32
As shown above, the # of SStables exceeds the max, the node load is light
but it's not running minor compaction on this Column family. I don't want
to run major compaction manually from time to time. Is there anything I can
tune?
--
View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Column-family-has-more-SSTables-than-threshold-but-no-minorcompaction-is-running-tp6813230p6813230.html
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Re: Column family has more SSTables than threshold but no minorcompaction is running
Posted by aaron morton <aa...@thelastpickle.com>.
yes in 0.8 the compaction thresholds are for buckets of files.
Files are put into buckets where the size of each file is +/- half the size of the average size. Files smaller than 50MB (from memory) are all put in the first bucket.
You can change the compaction thresholds via nodetool, and trigger a minor compaction by flushing. Again via node tool.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 21/09/2011, at 9:34 AM, Konstantin Naryshkin wrote:
> I believe that minor compactions work on tables of same or similar size, so as long as your tables do not fall within a small range of each other in terms of size, Cassandra does not see an opportunity to run a minor compaction.
>
> ----- Original Message -----
> From: "myreasoner" <my...@gmail.com>
> To: cassandra-user@incubator.apache.org
> Sent: Tuesday, September 20, 2011 2:30:26 PM
> Subject: Column family has more SSTables than threshold but no minorcompaction is running
>
> Column Family: CF_1
> SSTable count: 249
> Space used (live): 15120496328
> Space used (total): 15120496328
> Number of Keys (estimate): 18860800
> Memtable Columns Count: 0
> Memtable Data Size: 0
> Memtable Switch Count: 2483
> Read Count: 442
> Read Latency: NaN ms.
> Write Count: 208741548
> Write Latency: NaN ms.
> Pending Tasks: 0
> Key cache capacity: 200000
> Key cache size: 2395
> Key cache hit rate: NaN
> Row cache capacity: 200000
> Row cache size: 221
> Row cache hit rate: NaN
> Compacted row minimum size: 104
> Compacted row maximum size: 73457
> Compacted row mean size: 394
>
> Current compaction thresholds: min = 4, max = 32
>
> As shown above, the # of SStables exceeds the max, the node load is light
> but it's not running minor compaction on this Column family. I don't want
> to run major compaction manually from time to time. Is there anything I can
> tune?
>
> --
> View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Column-family-has-more-SSTables-than-threshold-but-no-minorcompaction-is-running-tp6813230p6813230.html
> Sent from the cassandra-user@incubator.apache.org mailing list archive at Nabble.com.
Re: Column family has more SSTables than threshold but no minorcompaction is running
Posted by Konstantin Naryshkin <ko...@a-bb.net>.
I believe that minor compactions work on tables of same or similar size, so as long as your tables do not fall within a small range of each other in terms of size, Cassandra does not see an opportunity to run a minor compaction.
----- Original Message -----
From: "myreasoner" <my...@gmail.com>
To: cassandra-user@incubator.apache.org
Sent: Tuesday, September 20, 2011 2:30:26 PM
Subject: Column family has more SSTables than threshold but no minorcompaction is running
Column Family: CF_1
SSTable count: 249
Space used (live): 15120496328
Space used (total): 15120496328
Number of Keys (estimate): 18860800
Memtable Columns Count: 0
Memtable Data Size: 0
Memtable Switch Count: 2483
Read Count: 442
Read Latency: NaN ms.
Write Count: 208741548
Write Latency: NaN ms.
Pending Tasks: 0
Key cache capacity: 200000
Key cache size: 2395
Key cache hit rate: NaN
Row cache capacity: 200000
Row cache size: 221
Row cache hit rate: NaN
Compacted row minimum size: 104
Compacted row maximum size: 73457
Compacted row mean size: 394
Current compaction thresholds: min = 4, max = 32
As shown above, the # of SStables exceeds the max, the node load is light
but it's not running minor compaction on this Column family. I don't want
to run major compaction manually from time to time. Is there anything I can
tune?
--
View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Column-family-has-more-SSTables-than-threshold-but-no-minorcompaction-is-running-tp6813230p6813230.html
Sent from the cassandra-user@incubator.apache.org mailing list archive at Nabble.com.