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From Wei Zhu <>
Subject Re: Estimating write throughput with LeveledCompactionStrategy
Date Wed, 06 Feb 2013 18:02:41 GMT
I have been struggling with the LCS myself. I observed that for the higher level compaction,(from
level 4 to 5) it involves much more SSTables than compacting from lower level. One compaction
could take an hour or more. By the way, you set the your SSTable size to be 100M?


 From: Ивaн Cобoлeв <>
Sent: Wednesday, February 6, 2013 2:42 AM
Subject: Estimating write throughput with LeveledCompactionStrategy
Dear Community,

Could anyone please give me a hand with understanding what am I
missing while trying to model how LeveledCompactionStrategy works:

Logs mostly contain something like this:
INFO [CompactionExecutor:2235] 2013-02-06 02:32:29,758 (line 221) Compacted to
2,255,863,073 to 1,908,460,931 (~84% of original) bytes for 36,868
keys at 14.965795MB/s.  Time: 121,614ms.

Thus spreadsheet is parameterized with throughput being 15Mb and
survivor ratio of 0.9.

1) Projected result actually differs from what I observe - what am I missing?
2) Are there any metrics on write throughput with LCS per node anyone
could possibly share?

Thank you very much in advance,
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