Hi guys,
while working on the repair() function, iI found something very
interesting.
When we update a partition, at the end, we call the sync() method which
writes down on disk all the updates which are pending in memory. This
sync() method itself sync all the indexes :
/**
* This method is called when the synch thread is waking up, to write
* the modified data.
*
* @throws Exception on failures to sync database files to disk
*/
public synchronized void sync() throws Exception
{
if ( !initialized )
{
return;
}
// Sync all system indices
for ( Index<?, String> idx : systemIndices.values() )
{
idx.sync();
}
// Sync all user defined userIndices
for ( Index<?, String> idx : userIndices.values() )
{
idx.sync();
}
// Sync the master table
( ( JdbmMasterTable ) master ).sync();
}
Sadly, the rdnIndex is *never* flushed explicitely - so it's done only
periodically (every 2000 updates, the default):
/**
* Commit the modification on disk
*
* @param recordManager The recordManager used for the commit
*/
private void commit( RecordManager recordManager ) throws IOException
{
if ( commitNumber.incrementAndGet() % 2000 == 0 )
{
sync();
}
}
This is *BAD*. That means we may have some pending modifications of this
RDN index that are not written on disk when we stop the server or when
we have a crash :/
Adding a rdnIdx.sync() might be just enough to eliminate the corruptions
we see...
In any case, we still need the repair tool.
