[
https://issues.apache.org/jira/browse/CASSANDRA-1825?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12968393#action_12968393
]
Jonathan Ellis commented on CASSANDRA-1825:
-------------------------------------------
the easy solution that fits nicely w/ existing design is to just make the
check-cache logic a separate stage (thread pool).
> Separation of Data (Cached/Non-Cached)
> --------------------------------------
>
> Key: CASSANDRA-1825
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1825
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Chris Goffinet
> Fix For: 0.8
>
>
> At the moment Cassandra goes through the ROW-READ stage to fetch data from
> the page cache, and if it's not in the page cache, it goes to disk.
> Data that is currently hot (in page cache) will block if all I/O threads are
> busy reading from disk. We should seriously look at implementing a buffer
> pool similar to MySQL for storing data in-memory, and our I/O threads be
> dedicated to just going to disk. I suggest studying how InnoDB does
> scheduling as well, they have good lessons to learn from.
> Scaling I/O by thread's isn't going to be a good solution here either. I
> would argue that going past 64 threads for I/O is just going to hurt overall
> performance based on context switching.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
