On 17.01.12 03:14, Pavel Bortnovskiy wrote:
Hello, all
can someone please also shed light on the following:
In addition to the problems described in the previous email (below), I also get
intermittent " Database 'memory:test' not found" errors while shutting down
Derby:
Hi Pavel,
I don't know what's causing this intermittent error. The first thing
that comes to mind is concurrent attempts to boot and/or drop the
database. I don't know if this could be happening in you application?
Regarding the errors you are seeing when dropping the database, I think
that's what you have to expect from Derby at this time when you have
active connections at the time of the drop/shutdown. I don't think this
is limited to the in-memory back end.
The only way to avoid these errors popping up is to coordinate the
shutdown/drop from the application layer.
As a side note, I did some work on a mechanism that you may find useful.
You can read the description of it under DERBY-4447 [1].
Regards,
--
Kristian
[1] https://issues.apache.org/jira/browse/DERBY-4447
Error while shutting down:
java.sql.SQLException: Database 'memory:test' not found.
at
org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.newSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.EmbedConnection.handleDBNotFound(Unknown
Source)
at org.apache.derby.impl.jdbc.EmbedConnection.<init>(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection30.<init>(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection40.<init>(Unknown Source)
at org.apache.derby.jdbc.Driver40.getNewEmbedConnection(Unknown Source)
at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
Caused by: java.sql.SQLException: Database 'memory:test' not found.
at
org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at
org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown
Source)
... 21 more
This error doesn't happen all the time, it's intermittent and I suspect that it
might have be somehow connected to other problems I've been having trying to
shutdown in-memory Derby DB gracefully.
Can someone please help me understand what's causing this particular problem?
My code that's shutting down Derby is quite simple, and oddly it works most of the times,
but sometimes it throws this " Database 'memory:test' not found " error!
Here is the excerpt of my shutdown code:
private static final String DB_DROP_URL =
"jdbc:derby:memory:%DB_NAME%;drop=true";
private static final String DB_SHUTDOWN_URL = "jdbc:derby:;shutdown=true";
private static class ShutdownAction {
final private String m_url;
final private int m_errorCode;
final private String m_sqlState;
private ShutdownAction(final String url, final int errorCode, final
String sqlState) {
m_url = url;
m_errorCode = errorCode;
m_sqlState = sqlState;
}
private void doAction(final String dbName) {
final String url = m_url.replace("%DB_NAME%", dbName);
logger.info("Executing Derby Shutdown Command: " + url);
try {
DriverManager.getConnection(url);
} catch (SQLException e) {
if ((e.getErrorCode() != m_errorCode) ||
(!m_sqlState.equals(e.getSQLState()))) {
logger.error("Error while shutting down:", e);
}
}
}
}
private static final ShutdownAction[] ACTIONS = {
new ShutdownAction(DB_DROP_URL, 45000, "08006"),
new ShutdownAction(DB_SHUTDOWN_URL, 50000, "XJ015")
};
private String m_dbName;
private String m_dbCreateURL;
private NetworkServerControlPinger m_derbyServerControl;
@Override
final public void shutdown() {
for (final ShutdownAction action : ACTIONS) {
action.doAction(m_dbName);
}
m_derbyServerControl.shutdown();
}
-----Original Message-----
From: Pavel Bortnovskiy [mailto:[email protected]]
Sent: Friday, January 13, 2012 10:01 AM
To: Derby Discussion
Subject: RE: Shutting down in-memory Derby gracefully
Hello, Bryan:
Thank you for your prompt response. I will report it as per guidelines.
Would you be able to suggest anything that I could do in the meantime?
We have watchdog processes monitoring error files and when the error files get
populated with these messages, the watchdog raises all kinds of alarms.
This is more than just a nuisance, as it's causing havoc in some cases.
Thank you,
Pavel.
-----Original Message-----
From: Bryan Pendleton [mailto:[email protected]]
Sent: Friday, January 13, 2012 9:58 AM
To: Derby Discussion
Subject: Re: Shutting down in-memory Derby gracefully
While our application is shutting down, it is possible that some of
its components may continue execution or even begin execution of the
queries on the in-memory Derby DB. In such situation, Derby starts throwing all
kinds of exceptions, including a Null Pointer Exception (pls see excerpt from
our log below).
That looks like a bug to me, and worthy of reporting to the Derby developers.
http://db.apache.org/derby/DerbyBugGuidelines.html
thanks,
bryan
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this email you may not copy, forward, disclose or otherwise use it or any part
of it in any form whatsoever. This email may be produced at the request of
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