Sam Hutchins created DERBY-7116:
-----------------------------------
Summary: Meta-data for unknown could not be accessed to read
Key: DERBY-7116
URL: https://issues.apache.org/jira/browse/DERBY-7116
Project: Derby
Issue Type: Bug
Affects Versions: 10.14.2.0
Environment: Windows 10
Reporter: Sam Hutchins
Hi,
I'm afraid I don't have a reproducible case for this, but it's an issue we've
seen in the wild on customer's machines. I'd guess it's specific to Windows, as
other platforms don't support exclusive locks, and we've only ever seen it
reported from Windows users.
The `ConcurrentCache` in the stacktrace makes me wonder if Derby is able to
lock itself out of the database under the right conditions. Here's the trace:
{code:java}
Caused by: java.sql.SQLException: Meta-data for unknown could not be accessed
to read
C:\Users\USER\.ScreamingFrogSEOSpider\ProjectInstanceData\6b422f28-46c9-492e-bbde-aeb5bc1e6307\results_10505723-008c-4b06-aa69-2c676ef858c8\sql\seg0\c71.dat
at
org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(SQLExceptionFactory.java)
at
org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(SQLExceptionFactory.java)
at org.apache.derby.impl.jdbc.Util.seeNextException(Util.java)
at
org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(TransactionResourceImpl.java)
at
org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(TransactionResourceImpl.java)
at
org.apache.derby.impl.jdbc.EmbedConnection.handleException(EmbedConnection.java)
at
org.apache.derby.impl.jdbc.ConnectionChild.handleException(ConnectionChild.java)
at
org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(EmbedPreparedStatement.java)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeQuery(EmbedPreparedStatement.java)
at
uk.co.screamingfrog.seospider.db.AbstractDuplicateTableOperations.getSpiderUrls(AbstractDuplicateTableOperations.java:152)
... 17 more
Caused by: ERROR XSDG3: Meta-data for unknown could not be accessed to read
C:\Users\USER\.ScreamingFrogSEOSpider\ProjectInstanceData\6b422f28-46c9-492e-bbde-aeb5bc1e6307\results_10505723-008c-4b06-aa69-2c676ef858c8\sql\seg0\c71.dat
at
org.apache.derby.iapi.error.StandardException.newException(StandardException.java)
at
org.apache.derby.impl.jdbc.SQLExceptionFactory.wrapArgsForTransportAcrossDRDA(SQLExceptionFactory.java)
... 28 more
Caused by: java.io.FileNotFoundException:
C:\Users\USER\.ScreamingFrogSEOSpider\ProjectInstanceData\6b422f28-46c9-492e-bbde-aeb5bc1e6307\results_10505723-008c-4b06-aa69-2c676ef858c8\sql\seg0\c71.dat
(The process cannot access the file because it is being used by another
process)
at java.base/java.io.RandomAccessFile.open0(Native Method)
at java.base/java.io.RandomAccessFile.open(Unknown Source)
at java.base/java.io.RandomAccessFile.<init>(Unknown Source)
at java.base/java.io.RandomAccessFile.<init>(Unknown Source)
at
org.apache.derby.impl.io.DirRandomAccessFile.<init>(DirRandomAccessFile.java)
at org.apache.derby.impl.io.DirFile.getRandomAccessFile(DirFile.java)
at
org.apache.derby.impl.store.raw.data.RAFContainer.run(RAFContainer.java)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at
org.apache.derby.impl.store.raw.data.RAFContainer.openContainer(RAFContainer.java)
at
org.apache.derby.impl.store.raw.data.RAFContainer4.openContainer(RAFContainer4.java)
at
org.apache.derby.impl.store.raw.data.FileContainer.setIdent(FileContainer.java)
at
org.apache.derby.impl.store.raw.data.FileContainer.setIdentity(FileContainer.java)
at
org.apache.derby.impl.services.cache.ConcurrentCache.find(ConcurrentCache.java)
at
org.apache.derby.impl.store.raw.data.BaseDataFileFactory.openContainer(BaseDataFileFactory.java)
at
org.apache.derby.impl.store.raw.data.BaseDataFileFactory.openContainer(BaseDataFileFactory.java)
at org.apache.derby.impl.store.raw.xact.Xact.openContainer(Xact.java)
at
org.apache.derby.impl.store.access.btree.OpenBTree.init(OpenBTree.java)
at
org.apache.derby.impl.store.access.btree.BTreeScan.init(BTreeScan.java)
at
org.apache.derby.impl.store.access.btree.index.B2IForwardScan.init(B2IForwardScan.java)
at org.apache.derby.impl.store.access.btree.index.B2I.openScan(B2I.java)
at
org.apache.derby.impl.store.access.RAMTransaction.openScan(RAMTransaction.java)
at
org.apache.derby.impl.store.access.RAMTransaction.openScan(RAMTransaction.java)
at
org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getDescriptorViaIndexMinion(DataDictionaryImpl.java)
at
org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getDescriptorViaIndex(DataDictionaryImpl.java)
at
org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getTableDescriptorIndex1Scan(DataDictionaryImpl.java)
at
org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getUncachedTableDescriptor(DataDictionaryImpl.java)
at
org.apache.derby.impl.sql.catalog.NameTDCacheable.setIdentity(NameTDCacheable.java)
at
org.apache.derby.impl.services.cache.ConcurrentCache.find(ConcurrentCache.java)
at
org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getTableDescriptor(DataDictionaryImpl.java)
at
org.apache.derby.impl.sql.compile.QueryTreeNode.getTableDescriptor(QueryTreeNode.java)
at
org.apache.derby.impl.sql.compile.FromBaseTable.bindTableDescriptor(FromBaseTable.java)
at
org.apache.derby.impl.sql.compile.FromBaseTable.bindNonVTITables(FromBaseTable.java)
at org.apache.derby.impl.sql.compile.FromList.bindTables(FromList.java)
at
org.apache.derby.impl.sql.compile.SelectNode.bindNonVTITables(SelectNode.java)
at
org.apache.derby.impl.sql.compile.DMLStatementNode.bindTables(DMLStatementNode.java)
at
org.apache.derby.impl.sql.compile.DMLStatementNode.bind(DMLStatementNode.java)
at
org.apache.derby.impl.sql.compile.CursorNode.bindStatement(CursorNode.java)
at
org.apache.derby.impl.sql.GenericStatement.prepMinion(GenericStatement.java)
at
org.apache.derby.impl.sql.GenericStatement.prepare(GenericStatement.java)
at
org.apache.derby.impl.sql.GenericPreparedStatement.rePrepare(GenericPreparedStatement.java)
at
org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java)
at
org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java)
... 21 more {code}
The exception message mentions "another process", but it's possible to get
exactly this error message in a single Java application:
{code:java}
public static void main(
final String[] args) throws Exception
{
final Path path = Path.of("lock");
path.toFile().createNewFile();
try (final FileChannel channel = FileChannel.open(path,
StandardOpenOption.APPEND))
{
channel.lock(0, Long.MAX_VALUE, false);
System.out.println("Locked");
final FileInputStream fis = new FileInputStream(path.toFile());
fis.readAllBytes();
System.out.println("Done");
}
} {code}
On Windows, this will throw a similar exception.
If, however, it is a problem caused by some other piece of software (such as
antivirus or backup software), is there a way for Derby to use this same
locking mechanism to lock out those other applications?
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