Some questions about ctdb availability when some node is crashed

[Christopher R. Hertel]

Az,

The command you are executing is:

  ctdb pstore test.tdb /tmp/test /tmp/test

So are you using the file pathname ("/tmp/test") as the key?  I think that
makes sense, but it is a little confusing to read.

I find it interesting that the pstore subcommand is not listed in the man
page for ctdb.  It was added in 2010, I believe.

Chris -)-----

On 11/16/2012 10:02 AM, XW Huang wrote:
> Dear martin,
> 
> Thanks for your reply!
> 
> In my tests, the IPs hosted by the failed node was moved to other nodes
> correctly.
> But all records in test.tdb can not be fetched on all nodes, i.e. {node-0,
> node-1, node-2, node-3}.
> It seems hanging when doing ctdb_fetch_lock:force_migration
> when node-0, node-2, node-3 tries to fetch the record from test.tdb.
> Is there any mechanism to revoke __transaction_lock__?
> 
> Thanks again. I really appreciate receiving any input from smart people
> like you guys.
> 
> az
> 
> 2012/11/16 Martin Schwenke <martin at meltin.net>
> 
>> On Sun, 11 Nov 2012 15:23:02 +0800, XW Huang <xwhuang123 at gmail.com>
>> wrote:
>>
>>> A record (/tmp/test) is stored in a persistent tdb (test.tdb) by this
>>> command.
>>>
>>> $sudo ctdb pstore test.tdb /tmp/test /tmp/test
>>>
>>> This record is fetched again and again on node-1.
>>> Then, node-1's network interface was turned down to simulate it is
>> crashed
>>> by this command.
>>>
>>> $sudo ifconfig eth0 down
>>> [...]
>>
>>> [...]
>>> However, the records in test.tdb can not be fetched anymore.
>>> But "ctdb getdbstatus" says test.tdb is healthy
>>> and "ctdb catdb" can dump its content:
>>> [...]
>>
>> It sounds like you are still trying to fetch the record on node 1.
>> That won't work.  CTDB isn't available on that node.
>>
>> If you are providing a CIFS service using Samba/CTDB then when a node
>> fails, the IPs hosted by the failed node will be moved to other nodes
>> so that they can continue to provide the CIFS service. Then any data
>> that Samba needs from CTDB can be fetched on those other nodes.
>>
>> Does that help?  :-)
>>
>> peace & happiness,
>> martin
>>

-- 
"Implementing CIFS - the Common Internet FileSystem" ISBN: 013047116X
Samba Team -- http://www.samba.org/     -)-----   Christopher R. Hertel
jCIFS Team -- http://jcifs.samba.org/   -)-----   ubiqx development, uninq.
ubiqx Team -- http://www.ubiqx.org/     -)-----   crh at ubiqx.mn.org
OnLineBook -- http://ubiqx.org/cifs/    -)-----   crh at ubiqx.org