Failed to generate dynamic type objectdb.java.util.ArrayList

Ran into this error recently on a deployment server.

Any thougths?

[ObjectDB 2.2.8_06] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) Server VM 1.6.0_26 (on Linux 2.6.39.1-linode34).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList
com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList
at com.objectdb.o.MSG.d(MSG.java:74)
at com.objectdb.o.ACL.e(ACL.java:185)
at com.objectdb.o.STL.j(STL.java:130)
at com.objectdb.o.STL.i(STL.java:108)
at com.objectdb.o.TYM.ax(TYM.java:1019)
at com.objectdb.o.MUT.<init>(MUT.java:101)
at com.objectdb.o.CLT.<init>(CLT.java:38)
at com.objectdb.o.MUT.w(MUT.java:322)
at com.objectdb.o.TYS.m(TYS.java:202)
at com.objectdb.o.TYS.l(TYS.java:136)
at com.objectdb.o.TYM.ac(TYM.java:485)
at com.objectdb.o.TYM.<init>(TYM.java:232)
at com.objectdb.o.MST.aJ(MST.java:181)
at com.objectdb.o.SHN.X(SHN.java:287)
at com.objectdb.o.SHN.W(SHN.java:245)
at com.objectdb.o.SHN.J(SHN.java:113)
at com.objectdb.o.HND.run(HND.java:133)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.LinkageError: loader (instance of  com/objectdb/o/STL): attempted  duplicate class definition for name: "objectdb/java/util/ArrayList"
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at com.objectdb.o.ACL.e(ACL.java:174)
... 16 more

It seems as a class loading conflict.

It could be the result of using multiple Eclipse plugins with ObjectDB (see this issue).

I just got the same LinkageError myself for both the ArrayList and HashSet classes. We are not using any Eclipse Plugins (we run NetBeans in house) and this occurs when running in a standalone environment. I get two stack traces (one for each class) that are identical to the one posted above. Any other ideas on what might cause this?

[ObjectDB 2.2.8] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) Client VM 1.6.0_26 (on Windows XP 5.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.HashSet
com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.HashSet

[ObjectDB 2.2.8] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) Client VM 1.6.0_26 (on Windows XP 5.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList
com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList

Could you please post the stack traces?

If you are not using exactly the same build - the stack traces might be similar but not identical and that additional info could help.

No problem. Shortly after making my post earlier I updated to 2.2.9 and the problem seems to be resolved, I have not had the exceptions occur since then.

[ObjectDB 2.2.8] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) Client VM 1.6.0_26 (on Windows XP 5.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList
com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.ArrayList
at com.objectdb.o.MSG.d(MSG.java:74)
at com.objectdb.o.ACL.e(ACL.java:185)
at com.objectdb.o.STL.j(STL.java:130)
at com.objectdb.o.STL.i(STL.java:108)
at com.objectdb.o.TYM.ax(TYM.java:1019)
at com.objectdb.o.MUT.<init>(MUT.java:101)
at com.objectdb.o.CLT.<init>(CLT.java:38)
at com.objectdb.o.TYS.n(TYS.java:257)
at com.objectdb.o.TYM.ac(TYM.java:495)
at com.objectdb.o.TYM.aa(TYM.java:441)
at com.objectdb.o.TYM.am(TYM.java:760)
at com.objectdb.o.TYM.aq(TYM.java:845)
at com.objectdb.o.EPR.Un(EPR.java:77)
at com.objectdb.o.UML.w(UML.java:544)
at com.objectdb.o.MMM.ad(MMM.java:975)
at com.objectdb.o.UTY.visitRefs(UTY.java:1143)
at com.objectdb.o.TVS.j(TVS.java:169)
at com.objectdb.o.TVS.cascade(TVS.java:146)
at com.objectdb.o.STA.Q(STA.java:476)
at com.objectdb.o.STM.D(STM.java:393)
at com.objectdb.o.OBM.bH(OBM.java:884)
at com.objectdb.jdo.PMImpl.bH(PMImpl.java:2186)
at com.objectdb.o.OBM.bG(OBM.java:800)
at com.objectdb.o.OBM.bE(OBM.java:715)
at com.objectdb.jpa.EMImpl.commit(EMImpl.java:274)
at nuwc.iof.data.AbstractObjectDBDatabase.processCommands(AbstractObjectDBDatabase.java:320)
at nuwc.iof.data.AbstractInformationObjectDatabase$CommandProcessingTask.call(AbstractInformationObjectDatabase.java:290)
at nuwc.iof.data.AbstractInformationObjectDatabase$CommandProcessingTask.call(AbstractInformationObjectDatabase.java:278)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.LinkageError: loader (instance of  com/objectdb/o/STL): attempted  duplicate class definition for name: "objectdb/java/util/ArrayList"
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at com.objectdb.o.ACL.e(ACL.java:174)
... 31 more

[ObjectDB 2.2.8] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) Client VM 1.6.0_26 (on Windows XP 5.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.HashSet
com.objectdb.o.UserException: Failed to generate dynamic type objectdb.java.util.HashSet
at com.objectdb.o.MSG.d(MSG.java:74)
at com.objectdb.o.ACL.e(ACL.java:185)
at com.objectdb.o.STL.j(STL.java:130)
at com.objectdb.o.STL.i(STL.java:108)
at com.objectdb.o.TYM.ax(TYM.java:1019)
at com.objectdb.o.MUT.<init>(MUT.java:101)
at com.objectdb.o.CLT.<init>(CLT.java:38)
at com.objectdb.o.TYS.n(TYS.java:257)
at com.objectdb.o.TYM.ac(TYM.java:495)
at com.objectdb.o.TYM.aa(TYM.java:441)
at com.objectdb.o.TYM.am(TYM.java:760)
at com.objectdb.o.TYM.aq(TYM.java:845)
at com.objectdb.o.TYW.writeElement(TYW.java:212)
at nuwc.iof.persistence.MetaDataBean.__odbWriteContent(MetaDataBean.java:1)
at peoiws5.track.persistence.TrackMetaDataBean.__odbWriteContent(TrackMetaDataBean.java:1)
at com.objectdb.o.MMM.af(MMM.java:1025)
at com.objectdb.o.UTY.aF(UTY.java:1185)
at com.objectdb.o.UTY.aE(UTY.java:1174)
at com.objectdb.o.ENH.a(ENH.java:46)
at com.objectdb.o.STA.T(STA.java:512)
at com.objectdb.o.STM.D(STM.java:408)
at com.objectdb.o.OBM.bH(OBM.java:884)
at com.objectdb.jdo.PMImpl.bH(PMImpl.java:2186)
at com.objectdb.o.OBM.bG(OBM.java:800)
at com.objectdb.o.OBM.bE(OBM.java:715)
at com.objectdb.jpa.EMImpl.commit(EMImpl.java:274)
at nuwc.iof.data.AbstractObjectDBDatabase.processCommands(AbstractObjectDBDatabase.java:320)
at nuwc.iof.data.AbstractInformationObjectDatabase$CommandProcessingTask.call(AbstractInformationObjectDatabase.java:290)
at nuwc.iof.data.AbstractInformationObjectDatabase$CommandProcessingTask.call(AbstractInformationObjectDatabase.java:278)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.LinkageError: loader (instance of  com/objectdb/o/STL): attempted  duplicate class definition for name: "objectdb/java/util/HashSet"
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at com.objectdb.o.ACL.e(ACL.java:174)
... 32 more

Actually I cannot think about anything in version 2.2.9 that could fix the problem. It seems that the exception might be thrown because of a missing synchronized - build 2.2.9_03 includes an attempt to fix it.