InvalidClassException in IndexedDiskCache

[naoliv]

Clicked to load one IBGE layer and saw this:

[ERROR] IndexedDiskCache - Region [TMS] Problem loading keys for file TMS <java.io.InvalidClassException: org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskElementDescriptor; local class incompatible: stream classdesc serialVersionUID = 7685317388573182052, local class serialVersionUID = -3029163572847659450>java.io.InvalidClassException: org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskElementDescriptor; local class incompatible: stream classdesc serialVersionUID = 7685317388573182052, local class serialVersionUID = -3029163572847659450
	at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:617)
	at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1622)
	at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1517)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1350)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
	at java.util.HashMap.readObject(HashMap.java:1180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)
	at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1893)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1798)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1350)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
	at org.apache.commons.jcs.utils.serialization.StandardSerializer.deSerialize(StandardSerializer.java:83)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDisk.readObject(IndexedDisk.java:118)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCache.loadKeys(IndexedDiskCache.java:332)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCache.initializeStoreFromPersistedData(IndexedDiskCache.java:285)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCache.initializeKeysAndData(IndexedDiskCache.java:249)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCache.<init>(IndexedDiskCache.java:182)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCache.<init>(IndexedDiskCache.java:154)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCacheFactory.createCache(IndexedDiskCacheFactory.java:60)
	at org.apache.commons.jcs.auxiliary.disk.indexed.IndexedDiskCacheFactory.createCache(IndexedDiskCacheFactory.java:33)
	at org.openstreetmap.josm.data.cache.JCSCacheManager.getCacheInner(JCSCacheManager.java:162)
	at org.openstreetmap.josm.data.cache.JCSCacheManager.getCache(JCSCacheManager.java:149)
	at org.openstreetmap.josm.gui.layer.AbstractCachedTileSourceLayer.getCache(AbstractCachedTileSourceLayer.java:90)
	at org.openstreetmap.josm.gui.layer.AbstractCachedTileSourceLayer.<init>(AbstractCachedTileSourceLayer.java:66)
	at org.openstreetmap.josm.gui.layer.TMSLayer.<init>(TMSLayer.java:50)
	at org.openstreetmap.josm.gui.layer.ImageryLayer.create(ImageryLayer.java:163)
	at org.openstreetmap.josm.actions.AddImageryLayerAction.actionPerformed(AddImageryLayerAction.java:84)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
	at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
	at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
	at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
	at java.awt.Component.processMouseEvent(Component.java:6516)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3312)
	at java.awt.Component.processEvent(Component.java:6281)
	at java.awt.Container.processEvent(Container.java:2229)
	at java.awt.Component.dispatchEventImpl(Component.java:4872)
	at java.awt.Container.dispatchEventImpl(Container.java:2287)
	at java.awt.Component.dispatchEvent(Component.java:4698)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
	at java.awt.Container.dispatchEventImpl(Container.java:2273)
	at java.awt.Window.dispatchEventImpl(Window.java:2719)
	at java.awt.Component.dispatchEvent(Component.java:4698)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:747)
	at java.awt.EventQueue.access$300(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:706)
	at java.awt.EventQueue$3.run(EventQueue.java:704)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.awt.EventQueue$4.run(EventQueue.java:718)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:717)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

JOSM

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2015-07-27 01:32:05
Last Changed Author: wiktorn
Revision: 8621
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Relative URL: ^/trunk
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2015-07-27 00:01:30 +0200 (Mon, 27 Jul 2015)
Last Changed Rev: 8621

Identification: JOSM/1.5 (8621 pt_BR) Linux Debian GNU/Linux unstable (sid)
Memory Usage: 247 MB / 4029 MB (149 MB allocated, but free)
Java version: 1.7.0_79, Oracle Corporation, OpenJDK 64-Bit Server VM
Java package: openjdk-7-jre:amd64-7u79-2.5.5-1
VM arguments: [-Dawt.useSystemAAFontSettings=on]

Plugins:
- AddrInterpolation (31241)
- Create_grid_of_ways (31241)
- FastDraw (31265)
- FixAddresses (31241)
- OpeningHoursEditor (31241)
- PicLayer (31241)
- SimplifyArea (31241)
- buildings_tools (31361)
- download_along (31241)
- editgpx (31241)
- geotools (31126)
- graphview (31241)
- jts (31126)
- measurement (31289)
- merge-overlap (31241)
- opendata (31241)
- pdfimport (31241)
- poly (31241)
- reverter (31241)
- tagging-preset-tester (31241)
- todo (29154)
- turnrestrictions (31241)
- undelete (31241)
- utilsplugin2 (31241)

[wiktorn]

Do you have any way to reproduce this error? There was no changes to IndexElementDescriptor class, so you couldn't have older version of the class. So I suspected disk or RAM corruption.

When I tried converting both values in Windows Calculator to binary form, I've got the same value. When I used Java Long.toBinaryString(), I got a bit different values. I do not know how longs are stored in memory in Java, nor how they are serialized, but disk or RAM corruption might be the case.

It might be rowhammer:
​https://github.com/google/rowhammer-test

Or silent disk corruption.

[naoliv]

Doesn't seem to be rowhammer nor a disk/filesystem issue.
Could it be caused by JOSM getting closed unproperly or some kind of issue when upgrading from an older version?

[wiktorn]

Upgrading from an older version should not result in such error.

Closing forcibly could result in such error, but if this was a bit-flip, that changed the value from positive to negative, then it is of low probability, that this error was due to forcibly closing. If this was random junk, then yes - closing forcibly could result in such error.

[naoliv]

Maybe some kind of overflow making the value negative?
But anyway, since it's not a reproducible problem I guess we can close it.

[wiktorn]

Then this would be then some Java bug. I'm closing this then.