When you look in the logs please let me know if you see this error…
https://issues.apache.org/jira/browse/CASSANDRA-4223

I look at nodetool compactionstats (for the Merkle tree phase),  nodetool netstats for the streaming, and this to check for streaming progress:

while true; do date; diff <(nodetool -h localhost netstats) <(sleep 5 && nodetool -h localhost netstats); done

Or use Data Stax Ops Centre where possible http://www.datastax.com/products/opscenter

Cheers


-----------------
Aaron Morton
Freelance Developer
@aaronmorton

On 8/05/2012, at 2:15 PM, Ben Coverston wrote:

Check the log files for warnings or errors. They may indicate why your repair failed.

On Mon, May 7, 2012 at 10:09 AM, Bill Au <bill.w.au@gmail.com> wrote:
I restarted the nodes and then restarted the repair.  It is still hanging like before.  Do I keep repeating until the repair actually finish?

Bill


On Fri, May 4, 2012 at 2:18 PM, Rob Coli <rcoli@palominodb.com> wrote:
On Fri, May 4, 2012 at 10:30 AM, Bill Au <bill.w.au@gmail.com> wrote:
> I know repair may take a long time to run.  I am running repair on a node
> with about 15 GB of data and it is taking more than 24 hours.  Is that
> normal?  Is there any way to get status of the repair?  tpstats does show 2
> active and 2 pending AntiEntropySessions.  But netstats and compactionstats
> show no activity.

As indicated by various recent threads to this effect, many versions
of cassandra (including current 1.0.x release) contain bugs which
sometimes prevent repair from completing. The other threads suggest
that some of these bugs result in the state you are in now, where you
do not see anything that looks like appropriate activity.
Unfortunately the only solution offered on these other threads is the
one I will now offer, which is to restart the participating nodes and
re-start the repair. I am unaware of any JIRA tickets tracking these
bugs (which doesn't mean they don't exist, of course) so you might
want to file one. :)

=Rob

--
=Robert Coli
AIM&GTALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb




--
Ben Coverston
DataStax -- The Apache Cassandra Company