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From: John Sanda <john.sanda@gmail.com>
Date: Thu, 1 Dec 2016 18:54:13 -0500
Message-ID: <CA+BDQ7yXF49=p_1R1ib7dpC4iQP_ezrxGHL1VoQXdW=voS2w5g@mail.gmail.com>
Subject: empty buckets with STCS
To: user <user@cassandra.apache.org>
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archived-at: Thu, 01 Dec 2016 23:54:21 -0000

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I have 2.2.1 Cassandra node that does not appear to be compacting
SSTables.  The table is currently configured with STCS. I turned on some
debug logging and when the compaction checks run, they log:

Compaction buckets are []

I have been going over SizeTieredCompactionStrategy.java and looking in
particular at the getNextBackgroundTables method since that is where the
above message is logged. Assuming I am reading the logs correctly, what if
anything besides all SSTables being blacklisted would result in empty
buckets? As I understand the code if an SSTable falls outside the threshold
of all existing buckets, it will be added to a new bucket.


- John

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<div dir=3D"ltr">I have 2.2.1 Cassandra node that does not appear to be com=
pacting SSTables.=C2=A0 The table is currently configured with STCS. I turn=
ed on some debug logging and when the compaction checks run, they log:<div>=
<br></div><div><span style=3D"color:rgb(51,51,51);font-family:monospace;fon=
t-size:11px;background-color:rgb(248,248,248)">Compaction buckets are []</s=
pan></div><div><font color=3D"#333333" face=3D"monospace"><span style=3D"fo=
nt-size:11px"><br></span></font></div><div>I have been going over SizeTiere=
dCompactionStrategy.java and looking in particular at the getNextBackground=
Tables method since that is where the above message is logged. Assuming I a=
m reading the logs correctly, what if anything besides all SSTables being b=
lacklisted would result in empty buckets? As I understand the code if an SS=
Table falls outside the threshold of all existing buckets, it will be added=
 to a new bucket. =C2=A0<font color=3D"#333333" face=3D"monospace"><span st=
yle=3D"font-size:11px"><br clear=3D"all"></span></font><div><br></div><div =
class=3D"gmail_signature"><br>- John</div>
</div></div>

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