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https://issues.apache.org/jira/browse/DERBY-6107?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13945134#comment-13945134
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Knut Anders Hatlen commented on DERBY-6107:
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Hi Rick. Thanks for your comments. Here are my responses:
1) One does not have to use NATIVE authentication. It is enough to access a
database on the classpath with login timeouts enabled. This could result in
threads not finding databases that are in their context class loader, or
threads being able to access databases that are private to other threads. There
could be other scenarios as well, but I'm not aware of any other functionality
that depends on the context class loader of the thread that calls
getConnection().
2) Derby's current calls to getContextClassLoader() and setContextClassLoader()
are wrapped in try/catch blocks, and SecurityExceptions are silently ignored,
so one wouldn't notice if they failed. Those calls were added to fix
DERBY-3745, which could cause class loader leaks because Derby's daemon threads
would hold on to the context class loader of the application thread that
happened to boot the engine. The SecurityExceptions are ignored for backwards
compatibility so that existing applications that don't suffer from the class
loader leak aren't affected.
3) They are mentioned in the Developer's Guide, Running Derby under a security
manager, Granting permissions to Derby, in the optional section:
http://db.apache.org/derby/docs/10.10/devguide/cdevbabejgjd.html
4) The total number of threads at any given time will not be greater if the
keep alive timeout is set to 0. On the contrary, since idle threads are not
kept around for a while in the pool, the memory footprint will typically be
smaller if the keep alive timeout is 0. With timeout 0, the number of threads
in the pool will be equal to the number of callers currently waiting for
getConnection() to return. With the default, non-zero timeout, the number of
threads in the pool will be equal to the number of callers currently waiting
for getConnection() to return *plus* the number of idle threads that haven't
yet timed out.
> Investigate why setting a login timeout causes
> NativeAuthenticationServiceTest to fail when run in a suite
> ----------------------------------------------------------------------------------------------------------
>
> Key: DERBY-6107
> URL: https://issues.apache.org/jira/browse/DERBY-6107
> Project: Derby
> Issue Type: Bug
> Components: Test
> Affects Versions: 10.10.1.1
> Reporter: Rick Hillegas
> Assignee: Knut Anders Hatlen
>
> See DERBY-6094 for the details of this problem.
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