On Tue, Oct 9, 2012 at 9:47 AM, Thomas Mortagne
<[email protected]> wrote:
> On Fri, Oct 5, 2012 at 6:20 PM, Paul Libbrecht <[email protected]> wrote:
>> The story evolved down here.
>>
>> I have crafted an extra observer that listens to notifications and checks if
>> the values are the same when in event and one second later in a spawned
>> thread. They're not.
>>
>> The code is copied below, it is inspired from the nice tutorial about
>> observation.
>>
>> Since about 36h, the observation listener below has reported 967 saves. From
>> them, 145 indicate the warning at the end of this code.
>
> Couldn't it be that you did several saves very quickly so when you
> received the remote event the database was changed again already ?
I mean during the 1s you waited.
>
>>
>> This warning indicates that the title, number of a objects of a particular
>> class (where we observed the bug first), or version differ:
>> - when pulled from the source of the event (XWikiDocument or
>> LazyXWikiDocument)
>> - or when pulled one second later with xwiki.getXWiki().getDocument().
>>
>> However, and that's the crusty bit.
>> Somehow, the attempt to reproduce the bug have almost all failed since that
>> time as well.
>> (no systematic way to reproduce the bug has been found, neither has there
>> been a page that stayed different between the two nodes). We're on hold but
>> this is a rather good surprise!
>>
>> Paul
>>
>>
>>>> It was the request of previous versions which has failed.
>>>>
>>>> All that seems quite curriki specific in there is a simple listener, using
>>>> the old-style-notification, which analyzes the document and indexes it and
>>>> maybe "related" documents (for example reindexes the user-document so as
>>>> to display the count of contributions, or reindexes all of the resources
>>>> of the user if the user has changed his name...). The IndexUpdater of the
>>>> LucenePlugin does not seem to care for this (but then, it doesn't seem to
>>>> measure differences).
>>> OK will try with 50 and see what I get. Not sure how this could be
>>> related unless it makes the LazyXWikiDocument fail to get the document
>>> from the database for some weird reason.
>>
>>
>> // {{groovy}}
>> // This page should be Util.TryObservation
>> //
>> import org.xwiki.observation.*
>> import org.xwiki.observation.event.*
>> import com.xpn.xwiki.web.*
>> import com.xpn.xwiki.*
>> import org.xwiki.bridge.event.DocumentUpdatedEvent
>> import com.xpn.xwiki.doc.XWikiDocument
>> import org.apache.commons.logging.Log
>> import org.apache.commons.logging.LogFactory
>> import com.xpn.xwiki.util.AbstractXWikiRunnable
>> import org.xwiki.observation.remote.RemoteObservationManagerContext
>>
>> class TryObservation implements EventListener
>> {
>>
>>
>> static final Log LOG =
>> LogFactory.getLog("groovyPages.Sandbox.TryObservation");
>> boolean DEBUG = LOG.isDebugEnabled();
>>
>> XWiki xwiki
>> XWikiContext xcontext
>>
>> TryObservation(xwiki, xcontext)
>> {
>> this.xwiki = xwiki
>> this.xcontext = xcontext
>> }
>>
>> String getName()
>> {
>> // The unique name of this event listener
>> return "Changes-Version-Checker"
>> }
>>
>> List<Event> getEvents()
>> {
>> // The list of events this listener listens to
>> return Arrays.asList(new DocumentUpdatedEvent())
>> }
>>
>> // Called by the Observation Manager when an event matches the list of
>> events returned
>> // by getEvents()
>> void onEvent(Event event, Object source, Object data)
>> {
>> XWikiDocument xdoc = source;
>> LOG.warn("Received event: " + event + ", source: " + source);
>> LOG.warn("Title of changed document " + xdoc.getTitle())
>> LOG.warn("Version of changed document " + xdoc.getVersion())
>> int count = 0;
>> List o = xdoc.getObjects("CurrikiCode.SubAssetClass");
>> if(o!=null) count = o.size()
>> LOG.warn("Number of children: " + count);
>>
>> LOG.warn("Is remote? " +
>> Utils.getComponent(RemoteObservationManagerContext.class).isRemoteState());
>>
>> Thread obs = new Thread(new DelayedObserver(xwiki, xcontext,
>> xdoc.getFullName(), xdoc.getTitle(), xdoc.getVersion(), count),"delayed
>> obs");
>> obs.start();
>> LOG.warn("started obs " + obs);
>> // Prevent infinite recursion since in this example we log to wiki
>> page which
>> // triggers a document change... :)
>> /* if (source.fullName != "Sandbox.TryObservation") {
>> def document = xwiki.getDocument("Sandbox.TryObservation")
>>
>> document.setContent("${document.getContent()}\n${source.fullName} has
>> changed")
>> document.save("Logging event", true)
>> } */
>> }
>>
>> public static class DelayedObserver extends AbstractXWikiRunnable {
>>
>> public DelayedObserver(XWiki xwiki, XWikiContext context, String
>> fullName, String inEventTitle, String inEventVersion, int inEventCount) {
>> super(XWikiContext.EXECUTIONCONTEXT_KEY, context.clone());
>> LOG.warn("(delayed) delayed observer initting. ")
>> this.xwiki = xwiki;
>> this.fullName = fullName;
>> this.context = context;
>> this.inEventTitle = inEventTitle;
>> this.inEventVersion = inEventVersion;
>> this.inEventCount = inEventCount;
>> }
>>
>> private XWiki xwiki;
>> private XWikiContext context;
>> private String fullName, inEventTitle, inEventVersion;
>> private int inEventCount;
>>
>> public void runInternal() {
>> try {
>> Thread.currentThread().setName("delayed observer " +
>> fullName);
>> LOG.warn("(delayed) delayed observer starting. ")
>> Thread.sleep(1000);
>> XWikiDocument doc = xwiki.getDocument(fullName, context);
>> LOG.warn("(delayed) Title of changed document " +
>> doc.getTitle())
>> LOG.warn("(delayed) Version of changed document " +
>> doc.getVersion())
>> int count = 0;
>> List o = doc.getObjects("CurrikiCode.SubAssetClass");
>> if(o!=null) count = o.size()
>> LOG.warn("(delayed) Number of children: " + count);
>> LOG.warn("(delayed) Is remote? " +
>> Utils.getComponent(RemoteObservationManagerContext.class).isRemoteState());
>> if(!(inEventVersion==doc.getVersion() &&
>> inEventTitle==doc.getTitle() && count == inEventCount)) {
>> LOG.error("(delayed) WARNING: inEvent and and delayed do
>> not match!!");
>> }
>> } catch (Exception ex) {
>> LOG.warn("Exception at the delayed bit: "+ ex, ex);
>> }
>> }
>> }
>>
>> }
>>
>> // Register against the Observation Manager
>>
>> def observation = Utils.getComponent(ObservationManager.class)
>> observation.removeListener("Changes-Version-Checker")
>> def listener = new TryObservation(xwiki.getXWiki(), xcontext.getContext())
>> observation.addListener(listener)
>>
>> // {{/groovy}}
>> _______________________________________________
>> devs mailing list
>> [email protected]
>> http://lists.xwiki.org/mailman/listinfo/devs
>
>
>
> --
> Thomas Mortagne
--
Thomas Mortagne
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