New subject: Bugreport: org.basex.server.ClientQuery.cache(ClientQuery.java:81)

8 Mar 2013


      Hi all,
I apologize for the german post on this english mailinglist...So here we go
in english:
I have recently migrated my BaseX application from version 7.2 to 7.6 (and
7.6.1 Beta). The BaseX lib throws exceptions while running concurrent XQuery
queries and updates (based on a threadpool), see the exceptions attached
below (the specific numeric error-code changes slightly but the error occurs
every time on the same line of code). The error itself seems to happen unter
heavy concurrency (sequential queries have no problem) and not every time
query executes.
The application code is as follows (class
de.infabswissarmy.control.XMLDBManagerBaseX.query):
public ArrayList<String> query(String inQuery, String[][] inArgs){
ClientSession mySession = null; ClientQuery myQuery = null;
ArrayList<String> tmpString = new ArrayList<String>();
    try {
    	mySession = getClientSession();
    	myQuery = mySession.query(inQuery);
// bind variable
    	if (inArgs != null){
    	  for (int i=0; i < inArgs.length; i++){
    		myQuery.bind("$" + inArgs[i][0], inArgs[i][1]);
    	  }
    	}
    	
    	while (myQuery.more()){  // **exception is in this line **
    	  tmpString.add(myQuery.next());
    	}
    } catch (IOException e) {
    	// TODO Auto-generated catch block
    	e.printStackTrace();
    } finally {
    	if (myQuery != null){
    		try {
    			myQuery.close();
    		} catch (BaseXException e) {
    			// ignore
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    	}
    }
return tmpString;
}
To be complete this is the used helper function:
private static ClientSession getClientSession() throws IOException {
    ClientSession mySession = new ClientSession("localhost", 1984,
"admin", "admin");
    return mySession;
}
Version 7.2 is running without problems. In version 7.6 I have seen some
rare Java heap space errors at the same location, and once I even saw a
massive growth of the DB > 1GB (normal size would be 1MB), but this may be
another error and I cannot reproduce it. I will try to deliver a
selfcontained min-example, but this could be quite an effort to do (it will
take some time to produce it). So I hope that you might find the problem
with the delivered information.
Many thanks once again for this great XML-DB and thanks in advance for your
help!
Bodo
-- attached error stack with version 7.6.1 (in 7.6 the error occurs in row
79 instead of 81)
org.basex.core.BaseXException: -146032
    at org.basex.server.ClientQuery.cache(ClientQuery.java:81)
    at org.basex.server.Query.more(Query.java:74)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.query(XMLDBManagerBaseX.java:86)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.queryDoc(XMLDBManagerBaseX.java:
121)
    at de.infabswissarmy.control.QueryTask.httpQuery(QueryTask.java:180)
    at de.infabswissarmy.control.QueryTask.run(QueryTask.java:271)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown
Source)
    at java.lang.Thread.run(Unknown Source)
org.basex.core.BaseXException: 0
    at org.basex.server.ClientQuery.cache(ClientQuery.java:81)
    at org.basex.server.Query.more(Query.java:74)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.query(XMLDBManagerBaseX.java:86)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.queryDoc(XMLDBManagerBaseX.java:
121)
    at de.infabswissarmy.control.QueryTask.httpQuery(QueryTask.java:180)
    at de.infabswissarmy.control.QueryTask.run(QueryTask.java:271)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown
Source)
    at java.lang.Thread.run(Unknown Source)
org.basex.core.BaseXException: java.lang.ArrayIndexOutOfBoundsException
    at org.basex.server.ClientQuery.cache(ClientQuery.java:81)
    at org.basex.server.Query.more(Query.java:74)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.query(XMLDBManagerBaseX.java:86)
    at
de.infabswissarmy.control.XMLDBManagerBaseX.queryDoc(XMLDBManagerBaseX.java:
121)
    at de.infabswissarmy.control.QueryTask.httpQuery(QueryTask.java:180)
    at de.infabswissarmy.control.QueryTask.run(QueryTask.java:271)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown
Source)
    at java.lang.Thread.run(Unknown Source)

Re: [basex-talk] Bugreport: org.basex.server.ClientQuery.cache(ClientQuery.java:81)