Details
Minor Description
I recently saw case where a user was seeing the following error in the derby.log when trying to shutdown their database.
New exception raised during cleanup null
java.lang.NullPointerException
at org.apache.derby.impl.store.raw.log.LogToFile.flush(LogToFile.java:3964)
at org.apache.derby.impl.store.raw.log.LogToFile.flush(LogToFile.java:1781)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.flush(BaseDataFileFa
at org.apache.derby.impl.store.raw.data.CachedPage.writePage(CachedPage.java:761
at org.apache.derby.impl.store.raw.data.CachedPage.clean(CachedPage.java:610)
at org.apache.derby.impl.services.cache.ConcurrentCache.cleanAndUnkeepEntry(Conc
at org.apache.derby.impl.services.cache.ConcurrentCache.cleanCache(ConcurrentCac
at org.apache.derby.impl.services.cache.ConcurrentCache.cleanAll(ConcurrentCache
at org.apache.derby.impl.services.cache.ConcurrentCache.shutdown(ConcurrentCache
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.stop(BaseDataFileFac
at org.apache.derby.impl.services.monitor.TopService.stop(TopService.java:405)
at org.apache.derby.impl.services.monitor.TopService.shutdown(TopService.java:34
at org.apache.derby.impl.services.monitor.BaseMonitor.shutdown(BaseMonitor.java:
at org.apache.derby.impl.db.DatabaseContextImpl.cleanupOnError(DatabaseContextIm
at org.apache.derby.iapi.services.context.ContextManager.cleanupOnError(ContextM
at org.apache.derby.impl.jdbc.TransactionResourceImpl.cleanupOnError(Transaction
at org.apache.derby.impl.jdbc.EmbedConnection.<init>(EmbedConnection.java:584)
at org.apache.derby.jdbc.Driver40.getNewEmbedConnection(Driver40.java:68)
at org.apache.derby.jdbc.InternalDriver.connect(InternalDriver.java:238)
at org.apache.derby.jdbc.AutoloadedDriver.connect(AutoloadedDriver.java:119)
at java.sql.DriverManager.getConnection(DriverManager.java:316)
at java.sql.DriverManager.getConnection(DriverManager.java:273)
It ended up that some of the log files did not have proper write permissions because some operation on the database had been performed by root. They had subsequently deleted their db.lck file so the database did not boot READ ONLY as it would if the root owned db.lck file still existed and the symptom was that they got this error on shutdown.
Clearly this was user error, but it would have been good if we gave a better error message. To reproduce on Linux:
As a user with umask 0022, run the program
java MakeDB
this will make the databases wombat and create a table.
su root
with umask 0022, run the program to insert data and remove the db.lck file:
java InsertALot
rm wombat/db.lck
go back to the original user
run the program:
java ConnectAndShutdown
The application gets the normal shutdown exception but if you look in derby.log you will see the exception.
java.lang.NullPointerException
at org.apache.derby.impl.store.raw.log.LogToFile.flush(LogToFile.java:3964)
...
I will attach the files.