[
https://issues.apache.org/jira/browse/DERBY-2911?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Knut Anders Hatlen updated DERBY-2911:
--------------------------------------
Attachment: d2911perf.java
I have written a small test which can be used to measure performance
improvements in this issue. It is a multi-threaded test which performs
primary-key lookups. Each thread has its own table to work on to avoid
contention on latches (which is a scalability issue separate from the one we're
trying to solve in this JIRA issue).
It's a standalone Java program for now since our JUnit framework doesn't
support multi-threaded tests yet, as far as I can see. To run the test, use
this command line:
java d2911perf <DB-URL> <THREADS> <WARMUP> <COLLECT>
The test will have a warm-up phase of <WARMUP> seconds and collect results for
<COLLECT> seconds.
> Implement a buffer manager using java.util.concurrent classes
> -------------------------------------------------------------
>
> Key: DERBY-2911
> URL: https://issues.apache.org/jira/browse/DERBY-2911
> Project: Derby
> Issue Type: Improvement
> Components: Performance, Services
> Affects Versions: 10.4.0.0
> Reporter: Knut Anders Hatlen
> Assignee: Knut Anders Hatlen
> Priority: Minor
> Attachments: d2911-unused.diff, d2911-unused.stat, d2911perf.java
>
>
> There are indications that the buffer manager is a bottleneck for some types
> of multi-user load. For instance, Anders Morken wrote this in a comment on
> DERBY-1704: "With a separate table and index for each thread (to remove latch
> contention and lock waits from the equation) we (...) found that
> org.apache.derby.impl.services.cache.Clock.find()/release() caused about 5
> times more contention than the synchronization in LockSet.lockObject() and
> LockSet.unlock(). That might be an indicator of where to apply the next push".
> It would be interesting to see the scalability and performance of a buffer
> manager which exploits the concurrency utilities added in Java SE 5.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
