Hi,
We,re running cassandra 1.0.3.
I've done some testing with 2 nodes (node A, node B), replication factor 2.
I take node A down, writing some data to node B and then take node A up.
Sometimes hints aren't delivered when node A comes up.

I've done some debugging in org.apache.cassandra.db.HintedHandOffManager and sometimes node B ends up in a strange state in method
org.apache.cassandra.db.HintedHandOffManager.deliverHints(final InetAddress to), where org.apache.cassandra.db.HintedHandOffManager.queuedDeliveries already has node A in it's Set and therefore no hints will ever be delivered to node A.
The only reason for this that I can see is that in org.apache.cassandra.db.HintedHandOffManager.deliverHintsToEndpoint(InetAddress endpoint) the hintStore.isEmpty() check returns true and the endpoint (node A)  isn't removed from org.apache.cassandra.db.HintedHandOffManager.queuedDeliveries. Then no hints will ever be delivered again until node B is restarted.
During what conditions will hintStore.isEmpty() return true?
Shouldn't the hintStore.isEmpty() check be inside the try {} finally{} clause, removing the endpoint from queuedDeliveries in the finally block?

public void deliverHints(final InetAddress to)
{
        logger_.debug("deliverHints to {}", to);
        if (!queuedDeliveries.add(to))
            return;
        .......
}

private void deliverHintsToEndpoint(InetAddress endpoint) throws IOException, DigestMismatchException, InvalidRequestException, TimeoutException,
{
        ColumnFamilyStore hintStore = Table.open(Table.SYSTEM_TABLE).getColumnFamilyStore(HINTS_CF);
        if (hintStore.isEmpty())
            return; // nothing to do, don't confuse users by logging a no-op handoff
    try
    {
        ......              
    }
    finally
    {
            queuedDeliveries.remove(endpoint);
    }
}

Regards
/Fredrik