cassandra-pr mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From michaelsembwever <...@git.apache.org>
Subject [GitHub] cassandra issue #147: [wip] CASSANDRA-10496
Date Sat, 09 Sep 2017 01:22:22 GMT
Github user michaelsembwever commented on the issue:

    https://github.com/apache/cassandra/pull/147
  
    @iksaif,
     continuing the conversation from [CASSANDRA-10496](https://issues.apache.org/jira/browse/CASSANDRA-10496).
    
    > What do you mean by "changing locations isn't supported" ?
    
    `switchCompactionLocation(..)` is a public method and can be called from other places,
when rows need to now be written to a new sstable in a new location. That's why [here](https://github.com/thelastpickle/cassandra/commit/a34a72391bb2847b3bd6ed93b4306199ddf3a991#diff-19359d40a9c932efdebc62a067ed4390R40)
i paired writers by their location, so if a location changes the writer can also change.
    
    > Currently it will create up to "minThreshold" sstables
    
    I'm not too sure I get that. The code you referenced is about which bucket is up for compaction,
not how many writers to use during a bucket's compaction.
    Marcus' idea was to only create two sstables per bucket, one that contains all the rows
that belong in the bucket, and another for old data that's been streamed in late. Therefore
SplittingTimeWindowCompactionWriter. writersByBounds` should be a fixed array of size 2. The
splitting approach as describe in  `SplittingTimeWindowCompactionWriter`'s class apidoc: splitting
in half, then half, down to 50Mb; is quite different to the original idea.
    
    > getBuckets() currently use maxTimestamp, , which isn't available (currently) in the
compaction task
    
    @krummas ?
    
    > Are you talking about sstables generated before this patch ?
    
    Yes.


---

---------------------------------------------------------------------
To unsubscribe, e-mail: pr-unsubscribe@cassandra.apache.org
For additional commands, e-mail: pr-help@cassandra.apache.org


Mime
View raw message