OSQLNonBlockingQuery not working

[temilmg]

Steps to reproduce the problem

Expected behavior and actual behavior

I tried using OSQLNonBlockingQuery but i get different errors when actually using the returned odocument (see below).

    OrientGraph graph = graphFactory.getTx();           
    try {

        OSQLNonBlockingQuery<Object> test = new OSQLNonBlockingQuery<Object>("select * from Prod where pid = '421'", new OCommandResultListener() {
              int resultCount = 0;
              @Override
              public boolean result(Object iRecord) {
                resultCount++;

                ODocument odoc = ((ODocument)iRecord);

                for(String name : odoc.fieldNames()) {     //  <----------- PROBLEM
                    System.out.println("Name:"+name);
                }

                System.out.println("callback "+resultCount+" invoked");
                return resultCount > 20 ? false : true;
              }

              @Override
              public void end() {
              }
            });

        Future future = graph.command(test).execute();
            System.out.println("query executed");
    } catch (Exception e) {
        e.printStackTrace();
    } finally {

        if (graph != null) {
            graph.shutdown(); // <------- If i remove this bit it wont throw the last exception but how do I then release resources
        }
    }

java.lang.UnsupportedOperationException: Trying to iterate over a non-blocking query result
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery$ONonBlockingQueryFuture.iterator(OSQLNonBlockingQuery.java:102)
at com.tinkerpop.blueprints.impls.orient.OrientGraphCommand.execute(OrientGraphCommand.java:51)
at com.myapp.Endpoint.main(Endpoint.java:57)

May 17, 2016 11:14:40 AM com.orientechnologies.common.log.OLogManager log
WARNING: Error deserializing record with id #38:235 send this data for debugging: 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
Exception in thread "Thread-3" com.orientechnologies.orient.core.exception.ODatabaseException: Database 'remote:orientdb:2424/mydb' is closed
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.checkOpeness(ODatabaseDocumentTx.java:2920)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.getMetadata(ODatabaseDocumentTx.java:793)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.getMetadata(ODatabaseDocumentTx.java:121)
at com.orientechnologies.orient.core.record.impl.ODocument.setClassNameIfExists(ODocument.java:1917)
at com.orientechnologies.orient.core.record.impl.ODocument.fillClassIfNeed(ODocument.java:2180)
at com.orientechnologies.orient.core.record.impl.ODocumentInternal.fillClassNameIfNeeded(ODocumentInternal.java:64)
at com.orientechnologies.orient.core.serialization.serializer.record.binary.ORecordSerializerBinaryV0.deserialize(ORecordSerializerBinaryV0.java:159)
at com.orientechnologies.orient.core.serialization.serializer.record.binary.ORecordSerializerBinary.fromStream(ORecordSerializerBinary.java:74)
at com.orientechnologies.orient.core.record.impl.ODocument.deserializeFields(ODocument.java:1817)
at com.orientechnologies.orient.core.record.impl.ODocument.checkForFields(ODocument.java:2416)
at com.orientechnologies.orient.core.record.impl.ODocument.fieldNames(ODocument.java:736)
at com.myapp.Endpoint$1.result(Endpoint.java:42)
at com.orientechnologies.orient.client.remote.OStorageRemote.command(OStorageRemote.java:1214)
at com.orientechnologies.orient.client.remote.OStorageRemoteThread.command(OStorageRemoteThread.java:453)
at com.orientechnologies.orient.core.sql.query.OSQLQuery.run(OSQLQuery.java:72)
at com.orientechnologies.orient.core.query.OQueryAbstract.execute(OQueryAbstract.java:33)
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery.access$001(OSQLNonBlockingQuery.java:47)
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery$1.run(OSQLNonBlockingQuery.java:258)
at java.lang.Thread.run(Thread.java:745)

Important Questions

If I dont do a graph.shutdown() it will print the fieldnames and not throw the last exception but then how do I release my resources?

In the event I get the non-blocking query working is it possible to return results in batches (I suspect otherwise I will get into trouble with latency given Im using a remote connection)?

Runninng Mode

• Remote

OrientDB Version

• v2.1.17

Operating System

• Linux

Java Version

• 8

[wolf4ood]

hi @temilmg

about the closed exception,
you cannot release the graph in the finally since the graph is used in the async query.
You could release the graph in the end method

@Override
public void end() {
   graph.makeActive();
   graph.shutdown();
}

Let me know if it works

Thanks

[temilmg]

Hi maggiolo00,
Thanks for looking into this.

I get two exceptions when adding your two lines of code, see stack-trace below.
For some reason the end() method is called twice. The exceptions are thrown the second time inside end().

Also the documentations says: "... That means that in the meantime you can close your db instance and keep on receiving callbacks from the query result." Maybe its a silly question but I thought that meant I could release the graph resources right away? Or does it mean I should do graphFactory.getDatabase().close(); in the finally block?

com.orientechnologies.orient.core.exception.ODatabaseException: Database instance is not set in current thread. Assure to set it with: ODatabaseRecordThreadLocal.INSTANCE.set(db);
at com.orientechnologies.orient.core.db.ODatabaseRecordThreadLocal.get(ODatabaseRecordThreadLocal.java:51)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.checkIfActive(ODatabaseDocumentTx.java:3130)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.close(ODatabaseDocumentTx.java:1168)
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery$1.run(OSQLNonBlockingQuery.java:267)
at java.lang.Thread.run(Thread.java:745)
Exception in thread "Thread-5" com.orientechnologies.orient.core.exception.ODatabaseException: Database 'remote:orientdb:2424/mydb' is closed
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.checkOpeness(ODatabaseDocumentTx.java:2867)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.getMetadata(ODatabaseDocumentTx.java:799)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.getMetadata(ODatabaseDocumentTx.java:121)
at com.orientechnologies.orient.core.sql.query.OSQLQuery.run(OSQLQuery.java:75)
at com.orientechnologies.orient.core.query.OQueryAbstract.execute(OQueryAbstract.java:33)
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery.access$001(OSQLNonBlockingQuery.java:47)
at com.orientechnologies.orient.core.sql.query.OSQLNonBlockingQuery$1.run(OSQLNonBlockingQuery.java:258)
at java.lang.Thread.run(Thread.java:745)

[temilmg]

Had a peek into the code (OSQLNonBlockingQuery) seems like the db is being closed automatically. So Im thinking I shouldnt do anything to release resources. Can anyone confirm?
Maybe this is not a bug but just slightly misleading documentation.

Actually there is still the problem with the end() method, it probably shouldn't be invoked twice.

[tglman]

Hi,
This should be fixed now, is going to be out for 2.2.4, closing.

[temilmg]

I have tried to run it again, the same way as the documentation, and in 2.2.13 its still not working. This time it doesn't call into the method
@OverRide public boolean result(Object iRecord) {}
Could anybody please provide a working code example so I can see how to use nonblocking queries, because I can't get it to work at all?

[tglman]

hi @temilmg,

I add the proper test cases ad fixed all the related issues, now it should work.

check the commit the test case is a working example now.

Bye

[temilmg]

Hi tglman, thank you for looking into this issue and fixing it.
I did some testing and it seems to work for my purpose. I did wonder about the Object getResult() method, now it never actually calls into it!

[tglman]

hi @temilmg,

As return of a non blocking query there is a Future if you call the get of the future that will call the getResult()
here is an exampe of future : https://github.com/orientechnologies/orientdb/blob/master/tests/src/test/java/com/orientechnologies/orient/test/database/auto/NonBlockingQueryTest.java#L64

[temilmg]

Ok I see, thank you:-)

[tglman]

hi @temilmg,

Can we close this again ? now there is the test case to prove it works ;)

[temilmg]

Yes I think this one can be closed (I did open a related issue for deleting and updating with OSQLNonBlockingQuery)