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BaseX update persistence

Tuesday, 6 August 2013 · 5 messages · last reply 7 Aug 2013
E
ext-christopher.harper6 Aug 2013 10:36 #
Hi @ll, Re-sending from different address due to original message disappearing. When running BaseX as a server and connecting to it my update statements are successful but when using BaseX from a jar inside the JVM - Database creation works fine - the update statements don't get committed - not visible to other clients or after restart - to the database. Select queries work fine. Code that - no exception - fails is:
final String xQueryUpdate = String.format("for $tab in doc('db')//tabs/tab[@id='%s'] return replace node $tab/content with %s", tabId, value); //$NON-NLS-1$
try {
      synchronized (SESSION) {
            new ClientQuery(xQueryUpdate, SESSION, SESSION.getOutputStream()).close();
            // System.out.println(new XQuery(xQueryUpdate).execute(CONTEXT));
            SESSION.notify();
      }
} catch (final IOException ioex) {
      ioex.printStackTrace();
}
When trying to use XQuery - In comment - I get: org.basex.core.BaseXException: Improper use? Potential bug? Your feedback is welcome: Contact: basex-talk at mailman.uni-konstanz.de<mailto:basex-talk at mailman.uni-konstanz.de> Version: BaseX 7.6 Java: Oracle Corporation, 1.7.0_10-ea OS: Mac OS X, x86_64 Stack Trace: java.nio.channels.OverlappingFileLockException sun.nio.ch.SharedFileLockTable.checkList(FileLockTable.java:255) sun.nio.ch.SharedFileLockTable.add(FileLockTable.java:152) What might be the issue or have I misunderstood something? / Chris
JE
Jens Erat6 Aug 2013 11:05 #
Hi Chris, this *definitely* shouldn't happen. Could you try two things please: 1. Try with [BaseX 7.7 Beta] (close to release anyway) - we changed quite a bit with the logging, so chances are good that bug is gone anyway. As you're using BaseX as a jar, it should be a drop-in replacement. 2. Send me a complete example of the bug which I can execute (eg., including the SESSION declaration), so I can see what the problem was, anyway (and if it somehow could persist to the new version). Regards, Jens [BaseX 7.7 Beta]: http://files.basex.org/releases/latest/
-- Jens Erat [phone]: tel:+49-151-56961126 [mail]: mailto:email at jenserat.de [jabber]: xmpp:jabber at jenserat.de [web]: http://www.jenserat.de PGP: 350E D9B6 9ADC 2DED F5F2 8549 CBC2 613C D745 722B
Quoted text · ext-christopher.harper · 41 lines
Am 06.08.2013 um 10:36 schrieb <ext-christopher.harper at nokia.com>: > Hi @ll, > > Re-sending from different address due to original message disappearing. > > When running BaseX as a server and connecting to it my update statements are successful but when using BaseX from a jar inside the JVM – Database creation works fine – the update statements don't get committed – not visible to other clients or after restart – to the database. > > Select queries work fine. > > Code that – no exception – fails is: > > final String xQueryUpdate = String.format("for $tab in doc('db')//tabs/tab[@id='%s'] return replace node $tab/content with %s", tabId, value); //$NON-NLS-1$ > try { > synchronized (SESSION) { > new ClientQuery(xQueryUpdate, SESSION, SESSION.getOutputStream()).close(); > // System.out.println(new XQuery(xQueryUpdate).execute(CONTEXT)); > SESSION.notify(); > } > } catch (final IOException ioex) { > ioex.printStackTrace(); > } > > When trying to use XQuery - In comment – I get: > > org.basex.core.BaseXException: Improper use? Potential bug? Your feedback is welcome: > Contact: basex-talk at mailman.uni-konstanz.de > Version: BaseX 7.6 > Java: Oracle Corporation, 1.7.0_10-ea > OS: Mac OS X, x86_64 > Stack Trace: > java.nio.channels.OverlappingFileLockException > sun.nio.ch.SharedFileLockTable.checkList(FileLockTable.java:255) > sun.nio.ch.SharedFileLockTable.add(FileLockTable.java:152) > > What might be the issue or have I misunderstood something? > > / Chris > _______________________________________________ > BaseX-Talk mailing list > BaseX-Talk at mailman.uni-konstanz.de > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
CH
Christopher Harper6 Aug 2013 12:18 #
Hi Jens, I'll try the 7.6 version later today. This is a vaadin https://vaadin.com project which might be complex to set up Following are the BaseX specifics that are used to initialize the DB and session.
public static final DocumentBuilder	BUILDER;

public static final Context			CONTEXT	= new Context();
public static ClientSession			SESSION = null;
private static BaseXServer			SERVER	= null;

static {
	try {
		BUILDER = DocumentBuilderFactory.newInstance().newDocumentBuilder();
		if (SESSION == null) {
			SERVER = new BaseXServer();
			SESSION = new ClientSession("localhost", 1985, "admin", "admin");
//$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
			try {
				SESSION.execute(new Open("db")); //$NON-NLS-1$
			} catch (final BaseXException bxexNoDBCreatedYet) {
				final File emptyDB = getDB(new
File(System.getProperty("catalina.base"))); //$NON-NLS-1$
				SESSION.execute(new CreateDB("db", emptyDB.getPath())); //$NON-NLS-1$
				SESSION.execute(new Open("db")); //$NON-NLS-1$
			}
		}
	} catch (final IOException ioex) {
		throw new RuntimeException("Failed to initialize the BaseX server and a
session to it.", ioex); //$NON-NLS-1$
	} catch (final ParserConfigurationException pcex) {
		throw new RuntimeException("Failed to initialize the document builder.",
pcex); //$NON-NLS-1$
	}
}
I'll let you know how the new version tests go. What i forgot to mention is that the same statement executed from the BaseX UI work as expected. / Chris
Quoted text · Jens Erat · 83 lines
On 06/08/2013 12:05, "Jens Erat" <jens.erat at uni-konstanz.de> wrote: >Hi Chris, > >this *definitely* shouldn't happen. > >Could you try two things please: > >1. Try with [BaseX 7.7 Beta] (close to release anyway) - we changed quite >a bit with the logging, so chances are good that bug is gone anyway. As >you're using BaseX as a jar, it should be a drop-in replacement. >2. Send me a complete example of the bug which I can execute (eg., >including the `SESSION` declaration), so I can see what the problem was, >anyway (and if it somehow could persist to the new version). > >Regards, >Jens > >[BaseX 7.7 Beta]: http://files.basex.org/releases/latest/ > >-- >Jens Erat > > [phone]: tel:+49-151-56961126 > [mail]: mailto:email at jenserat.de >[jabber]: xmpp:jabber at jenserat.de > [web]: http://www.jenserat.de > > PGP: 350E D9B6 9ADC 2DED F5F2 8549 CBC2 613C D745 722B > > > >Am 06.08.2013 um 10:36 schrieb <ext-christopher.harper at nokia.com>: > >> Hi @ll, >> >> Re-sending from different address due to original message disappearing. >> >> When running BaseX as a server and connecting to it my update >>statements are successful but when using BaseX from a jar inside the JVM >>­ Database creation works fine ­ the update statements don't get >>committed ­ not visible to other clients or after restart ­ to the >>database. >> >> Select queries work fine. >> >> Code that ­ no exception ­ fails is: >> >> final String xQueryUpdate = String.format("for $tab in >>doc('db')//tabs/tab[@id='%s'] return replace node $tab/content with %s", >>tabId, value); //$NON-NLS-1$ >> try { >> synchronized (SESSION) { >> new ClientQuery(xQueryUpdate, SESSION, >>SESSION.getOutputStream()).close(); >> // System.out.println(new >>XQuery(xQueryUpdate).execute(CONTEXT)); >> SESSION.notify(); >> } >> } catch (final IOException ioex) { >> ioex.printStackTrace(); >> } >> >> When trying to use XQuery - In comment ­ I get: >> >> org.basex.core.BaseXException: Improper use? Potential bug? Your >>feedback is welcome: >> Contact: basex-talk at mailman.uni-konstanz.de >> Version: BaseX 7.6 >> Java: Oracle Corporation, 1.7.0_10-ea >> OS: Mac OS X, x86_64 >> Stack Trace: >> java.nio.channels.OverlappingFileLockException >> sun.nio.ch.SharedFileLockTable.checkList(FileLockTable.java:255) >> sun.nio.ch.SharedFileLockTable.add(FileLockTable.java:152) >> >> What might be the issue or have I misunderstood something? >> >> / Chris >> _______________________________________________ >> BaseX-Talk mailing list >> BaseX-Talk at mailman.uni-konstanz.de >> https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk >
CG
Christian Grünin reply to ext-christopher.harper, 6 Aug 2013, 10:367 Aug 2013 00:05 #
Hi Christoph, two little observations that might help you to improve your queries:
Quoted text · ext-christopher.harper · 2 lines
> new ClientQuery(xQueryUpdate, SESSION, > SESSION.getOutputStream()).close();
You need to execute your query, otherwise, this will be a no-op operation:
   ClientQuery cq = SESSION.query(xQueryUpdate);
   cq.execute();
   cq.close();
Quoted text · ext-christopher.harper · 2 lines
> // System.out.println(new > XQuery(xQueryUpdate).execute(CONTEXT));
In this line, you are a circumventing the client/server context, which could lead to your error message. If you manage to create a minimized example, that’d be helpful. Best, Christian
CH
Christopher Harper7 Aug 2013 07:53 #
Hi Christian, Thanks, that sorted the issue! What threw me was that queries that do a select don't need the execute call in order to work:
final String xQuery = String.format("for $tab in
doc('db')//tabs/tab[@id='%s'] return data($tab/content/h3)", //$NON-NLS-1$
    this.tabId);
final ClientQuery checkQuery = new ClientQuery(xQuery, SSCCE.SESSION,
SSCCE.SESSION.getOutputStream());
try {
	if (checkQuery.more()) {
		System.out.println(checkQuery.next());
	}
} finally {
	checkQuery.close();
}
So likely more calls execute... I sent a SSCCE to Jens yesterday. / Chris
Quoted text · Christian Grün · 24 lines
On 07/08/2013 01:05, "Christian Grün" <christian.gruen at gmail.com> wrote: >Hi Christoph, > >two little observations that might help you to improve your queries: > >> new ClientQuery(xQueryUpdate, SESSION, >> SESSION.getOutputStream()).close(); > >You need to execute your query, otherwise, this will be a no-op operation: > > ClientQuery cq = SESSION.query(xQueryUpdate); > cq.execute(); > cq.close(); > >> // System.out.println(new >> XQuery(xQueryUpdate).execute(CONTEXT)); > >In this line, you are a circumventing the client/server context, which >could lead to your error message. > >If you manage to create a minimized example, that¹d be helpful. > >Best, >Christian

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