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From Wei Zhu <wz1...@yahoo.com>
Subject Re: sstable size change
Date Thu, 25 Jul 2013 00:49:27 GMT
what is output of show keyspaces from cassandra-cli, did you see the new value?

  Compaction Strategy: org.apache.cassandra.db.compaction.LeveledCompactionStrategy
      Compaction Strategy Options:
        sstable_size_in_mb: XXX


________________________________
 From: Keith Wright <kwright@nanigans.com>
To: "user@cassandra.apache.org" <user@cassandra.apache.org> 
Sent: Wednesday, July 24, 2013 3:44 PM
Subject: Re: sstable size change
 


Hi all,

   This morning I increased the SSTable size for one of my LCS via an alter command and
saw at least one compaction run (I did not trigger a compaction via nodetool nor upgrades
stables nor removing the .json file).  But so far my data sizes appear the same at the default
5 MB (see below for output of ls –Sal as well as relevant portion of cfstats).   Is this
expected?  I was hoping to see at least one file at the new 256 MB size I set.

Thanks

SSTable count: 4965
SSTables in each level: [0, 10, 112/100, 1027/1000, 3816, 0, 0, 0]
Space used (live): 29062393142
Space used (total): 29140547702
Number of Keys (estimate): 195103104
Memtable Columns Count: 441483
Memtable Data Size: 205486218
Memtable Switch Count: 243
Read Count: 154226729

-rw-rw-r--  1 cassandra cassandra 5247564 Jul 18 01:33 users-shard_user_lookup-ib-97153-Data.db
-rw-rw-r--  1 cassandra cassandra 5247454 Jul 23 02:59 users-shard_user_lookup-ib-109063-Data.db
-rw-rw-r--  1 cassandra cassandra 5247421 Jul 20 14:58 users-shard_user_lookup-ib-103127-Data.db
-rw-rw-r--  1 cassandra cassandra 5247415 Jul 17 13:56 users-shard_user_lookup-ib-95761-Data.db
-rw-rw-r--  1 cassandra cassandra 5247379 Jul 21 02:44 users-shard_user_lookup-ib-104718-Data.db
-rw-rw-r--  1 cassandra cassandra 5247346 Jul 21 21:54 users-shard_user_lookup-ib-106280-Data.db
-rw-rw-r--  1 cassandra cassandra 5247242 Jul  3 19:41 users-shard_user_lookup-ib-66049-Data.db
-rw-rw-r--  1 cassandra cassandra 5247235 Jul 21 02:44 users-shard_user_lookup-ib-104737-Data.db
-rw-rw-r--  1 cassandra cassandra 5247233 Jul 20 14:58 users-shard_user_lookup-ib-103169-Data.db

From:  sankalp kohli <kohlisankalp@gmail.com>
Reply-To:  "user@cassandra.apache.org" <user@cassandra.apache.org>
Date:  Tuesday, July 23, 2013 3:04 PM
To:  "user@cassandra.apache.org" <user@cassandra.apache.org>
Subject:  Re: sstable size change


"Will Cassandra force any newly compacted files to my new setting as compactions are naturally
triggered" 
Yes. Let it compact and increase in size. 



On Tue, Jul 23, 2013 at 9:38 AM, Robert Coli <rcoli@eventbrite.com> wrote:

On Tue, Jul 23, 2013 at 6:48 AM, Keith Wright <kwright@nanigans.com> wrote:
>
>Can you elaborate on what you mean by "let it take its own course organically"?  Will
Cassandra force any newly compacted files to my new setting as compactions are naturally triggered?
>
>
>You see, when two (or more!) SSTables love each other very much, they sometimes decide
they want to compact together..
>
>
>But seriously, "yes." If you force all existing SSTables to level 0, it is as if you just
flushed them all. Level compaction then does a whole lot of compaction, using the active table
size.
>
>
>=Rob
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