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Posted to derby-user@db.apache.org by Kristian Waagan <kr...@oracle.com> on 2010/08/02 09:51:10 UTC
Re: Shutting down a database that is already shut down
On Fri, Jul 30, 2010 at 02:30:34PM -0700, David Van Couvering wrote:
> Do I have to worry about ensuring that a database is running before I try to
> shut it down, or is it OK to get a connection with URL ";shutdown=true" on a
> database that's not booted.
>
> If I were to do that, does it boot the database and then shut it down again, or
> does it do nothing?
Hi David,
Derby won't boot the database, but you will get a database not found
exception. The exception may also be written to derby.log, which casues
the file to grow a lot faster if you issue a lot of shutdown requests
for non-booted databases.
You get the exception because the getConnection call must either
return a valid connection or throw an exception. Since we haven't shut
down the database (it wasn't booted), we cannot throw an exception
saying we did so. Getting database not found seems a bit odd too, but
maybe Derby currently has to boot a database to confirm that it exists?
Regards,
--
Kristian
>
> Thanks,
>
> David
>
> --
> David W. Van Couvering
>
> http://www.linkedin.com/in/davidvc
> http://davidvancouvering.blogspot.com
> http://twitter.com/dcouvering
Socket Closed Exception when pinging NetworkServerControl
Posted by Pavel Bortnovskiy <PB...@Jefferies.com>.
Hello:
I am getting intermittent (rare, but causing fatal shutdown) exceptions
when pinging NetworkServerControl:
2010-08-02 15:31:25,491 [ApacheDerbyServer] INFO
components.DerbyServerComponent - 2010-08-02 19:31:25.491 GMT : Error on
client socket:Socket closed
2010-08-02 15:31:25,492 [ApacheDerbyServer] INFO
components.DerbyServerComponent - 2010-08-02 19:31:25.492 GMT : Socket
closed
2010-08-02 15:31:25,492 [ApacheDerbyServer] INFO
components.DerbyServerComponent - java.net.SocketException: Socket closed
2010-08-02 15:31:25,492 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
java.net.SocketInputStream.socketRead0(Native Method)
2010-08-02 15:31:25,493 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
java.net.SocketInputStream.read(SocketInputStream.java:129)
2010-08-02 15:31:25,493 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
java.net.SocketInputStream.read(SocketInputStream.java:90)
2010-08-02 15:31:25,493 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
org.apache.derby.impl.drda.NetworkServerControlImpl.fillReplyBuffer(Unknown
Source)
2010-08-02 15:31:25,494 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
org.apache.derby.impl.drda.NetworkServerControlImpl.readResult(Unknown
Source)
2010-08-02 15:31:25,494 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
org.apache.derby.impl.drda.NetworkServerControlImpl.pingWithNoOpen(Unknown
Source)
2010-08-02 15:31:25,494 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
org.apache.derby.impl.drda.NetworkServerControlImpl.ping(Unknown Source)
2010-08-02 15:31:25,495 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
org.apache.derby.drda.NetworkServerControl.ping(Unknown Source)
2010-08-02 15:31:25,495 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
com.jefco.fi.geni.components.DerbyServerComponent.run(DerbyServerComponent.java:142)
2010-08-02 15:31:25,495 [ApacheDerbyServer] INFO
components.DerbyServerComponent - at
java.lang.Thread.run(Thread.java:619)
2010-08-02 15:31:25,496 [ApacheDerbyServer] ERROR
components.DerbyServerComponent - Error while pinging
NetworkServerControl:
java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at java.net.SocketInputStream.read(SocketInputStream.java:90)
at
org.apache.derby.impl.drda.NetworkServerControlImpl.fillReplyBuffer(Unknown
Source)
at
org.apache.derby.impl.drda.NetworkServerControlImpl.readResult(Unknown
Source)
at
org.apache.derby.impl.drda.NetworkServerControlImpl.pingWithNoOpen(Unknown
Source)
at
org.apache.derby.impl.drda.NetworkServerControlImpl.ping(Unknown Source)
at org.apache.derby.drda.NetworkServerControl.ping(Unknown Source)
My code pings the NSC in two places - there is one thread which implements
run() method like this:
final public void run() {
final Thread currentThread = Thread.currentThread();
try {
m_server = new NetworkServerControl(m_host, m_port);
m_server.start(new PrintWriter(new LoggingOutputStream(logger,
Level.INFO), true));
try {
while (m_thread == currentThread) {
try {
Thread.sleep(m_sleep);
if (logger.isTraceEnabled()) {
logger.trace("Pinging NetworkServerControl on
[" + m_host + ":" + m_port + "]");
}
---> m_server.ping(); <--- Exception Thrown
} catch (InterruptedException e) {
logger.info(toString() + " sleep has been
interrupted");
}
}
} catch (Exception e) {
logger.error("Error while pinging NetworkServerControl:",
e);
}
logger.info("Stopping NetworkServerControl on [" + m_host +
":" + m_port + "]");
m_server.shutdown();
} catch (Exception e) {
logger.error("Error while starting/stopping
NetworkServerControl:", e);
}
}
And another "validating" thread calls this method at regular intervals:
final public String isRuntimeValid() {
final StringBuilder builder = new StringBuilder();
builder.append(super.isRuntimeValid());
if (m_server == null) builder.append("\n\t").append("Server is
null");
if (m_thread == null) builder.append("\n\t").append("Thread is
null");
try {
m_server.ping();
} catch (Exception e) {
builder.append("\n\t").append("Server cannot be pinged");
}
return builder.toString();
}
Can there be any problem if those two are called at around the same time?
This is probably the only scenario which could, I imagine, cause a
problem...
Would anyone have any other thoughts or suspicions?
Much appreciated,
Pavel.
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Re: Shutting down a database that is already shut down
Posted by David Van Couvering <da...@vancouvering.com>.
OK, thanks. I'll work to ensure that I only shut down a database that is
currently up, just to keep my life simple and the log empty of kruft.
David
On Mon, Aug 2, 2010 at 12:51 AM, Kristian Waagan <kristian.waagan@oracle.com
> wrote:
> On Fri, Jul 30, 2010 at 02:30:34PM -0700, David Van Couvering wrote:
> > Do I have to worry about ensuring that a database is running before I try
> to
> > shut it down, or is it OK to get a connection with URL ";shutdown=true"
> on a
> > database that's not booted.
> >
> > If I were to do that, does it boot the database and then shut it down
> again, or
> > does it do nothing?
>
> Hi David,
>
> Derby won't boot the database, but you will get a database not found
> exception. The exception may also be written to derby.log, which casues
> the file to grow a lot faster if you issue a lot of shutdown requests
> for non-booted databases.
>
> You get the exception because the getConnection call must either
> return a valid connection or throw an exception. Since we haven't shut
> down the database (it wasn't booted), we cannot throw an exception
> saying we did so. Getting database not found seems a bit odd too, but
> maybe Derby currently has to boot a database to confirm that it exists?
>
>
> Regards,
> --
> Kristian
>
> >
> > Thanks,
> >
> > David
> >
> > --
> > David W. Van Couvering
> >
> > http://www.linkedin.com/in/davidvc
> > http://davidvancouvering.blogspot.com
> > http://twitter.com/dcouvering
>
--
David W. Van Couvering
http://www.linkedin.com/in/davidvc
http://davidvancouvering.blogspot.com
http://twitter.com/dcouvering