db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-4741) Make Derby work reliably in the presence of thread interrupts
Date Tue, 02 Nov 2010 09:54:26 GMT

    [ https://issues.apache.org/jira/browse/DERBY-4741?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12927345#action_12927345
] 

Knut Anders Hatlen commented on DERBY-4741:
-------------------------------------------

The sane jars are not intended for production use, so I wouldn't worry too much about a performance
loss that we only see with them. Unless it's getting so slow that it takes an unreasonably
long time to run the regression tests with them, that is.

I'm guessing that the extra performance loss seen with sane jars is caused by the assert in
InterruptStatus.restoreIntrFlagIfSeen(LanguageConnectionContext), which makes us look up the
lcc in the context stack. Twice, actually. Perhaps it would help a little to store the result
from getContextOrNull() in a local variable so that we get away with a single call. Or perhaps
it's the unconditional string concatenation for the message text that's costly. In any case,
that assert is the only place I can see that the patch would have a different performance
impact on sane and insane.

> Make Derby work reliably in the presence of thread interrupts
> -------------------------------------------------------------
>
>                 Key: DERBY-4741
>                 URL: https://issues.apache.org/jira/browse/DERBY-4741
>             Project: Derby
>          Issue Type: Bug
>          Components: Store
>    Affects Versions: 10.2.1.6, 10.2.2.0, 10.3.1.4, 10.3.2.1, 10.3.3.0, 10.4.1.3, 10.4.2.0,
10.5.1.1, 10.5.2.0, 10.5.3.0, 10.6.1.0
>            Reporter: Dag H. Wanvik
>            Assignee: Dag H. Wanvik
>         Attachments: derby-4741-a-01-api-interruptstatus.diff, derby-4741-a-01-api-interruptstatus.stat,
derby-4741-a-02-api-interruptstatus.diff, derby-4741-a-02-api-interruptstatus.stat, derby-4741-a-03-api-interruptstatus.diff,
derby-4741-a-03-api-interruptstatus.stat, derby-4741-all+lenient+resurrect.diff, derby-4741-all+lenient+resurrect.stat,
derby-4741-nio-container+log+waits+locks+throws.diff, derby-4741-nio-container+log+waits+locks+throws.stat,
derby-4741-nio-container+log+waits+locks-2.diff, derby-4741-nio-container+log+waits+locks-2.stat,
derby-4741-nio-container+log+waits+locks.diff, derby-4741-nio-container+log+waits+locks.stat,
derby-4741-nio-container+log+waits.diff, derby-4741-nio-container+log+waits.stat, derby-4741-nio-container+log.diff,
derby-4741-nio-container+log.stat, derby-4741-nio-container-2.diff, derby-4741-nio-container-2.log,
derby-4741-nio-container-2.stat, derby-4741-nio-container-2b.diff, derby-4741-nio-container-2b.stat,
derby.log, derby.log, MicroAPITest.java, xsbt0.log.gz
>
>
> When not executing on a small device VM, Derby has been using the Java NIO classes java.nio.clannel.*
for file io.
> If thread is interrupted while executing blocking IO operations in NIO, the ClosedByInterruptException
will get thrown. Unfortunately, Derby isn't current architected to retry and complete such
operations (before passing on the interrupt), so the Derby database can be left in an inconsistent
state and we therefore have to return a database level error. This means the applications
can no longer access the database without a shutdown and reboot including a recovery.
> It would be nice if Derby could somehow detect and finish IO operations underway when
thread interrupts happen before passing the exception on to the application. Derby embedded
is sometimes embedded in applications that use Thread.interrupt to stop threads.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message