samba - Oct 2016 - a question about tdb record backup for ctdb failover

hello everyone:

I want to know if the lastest version of ctdb has the following mechanism:
when a record in tdb was added or upadted, if there are two same record in
different nodes.In other words, if ctdb need to backup a record on other node?

if not, do we plan to add this mechanism?

thank you !

________________________________
sunyekuan at outlook.com

On Mon, Oct 10, 2016 at 6:03 PM, sun yekuan via samba <samba at
lists.samba.org
> wrote:
> hello everyone:
>
> I want to know if the lastest version of ctdb has the following mechanism:
> when a record in tdb was added or upadted, if there are two same record in
> different nodes.In other words, if ctdb need to backup a record on other
> node?
>
> if not, do we plan to add this mechanism?
>
> thank you !
>
CTDB already replicates records to other nodes and performs database
recovery on failover.

What exactly are you trying to do?

Amitay.

OK, thank you!  I have another question:

what the current CTDB have done for transparent failover ? achieved  fully or
partially?
if CTDB has not achieved fully,  what else we should do ?

thank you!
best wishes!

From: Amitay Isaacs<mailto:amitay at gmail.com>
Date: 2016-10-11 13:43
To: sun yekuan<mailto:sunyekuan at outlook.com>
Subject: Re: Re: [Samba] a question about tdb record backup for ctdb failover
On Tue, Oct 11, 2016 at 3:34 PM, sun yekuan <sunyekuan at
outlook.com<mailto:sunyekuan at outlook.com>> wrote:
thank you for your answer!

    As i know, the latest record was stored in DMASTER node. When the LMASTER
and DMASTER are all dead because of some reasons,  TDB will not recovery to the
lastest.

    what i exactly want to know is that when a record was store in DMASTER,  can
other nodes have the copy of the record?

    can CTDB guarantee no data lose?

thank you very much!


Volatile database data model is designed to be lossy.

If a node goes away, all the SMB clients connected to that node also go away and
any changes made in TDB record are not relevant.

If you want persistent data, then you should use persistent database.

Amitay.

sun yekuan via samba <samba at lists.samba.org> writes:
> OK, thank you!  I have another question:
>
> what the current CTDB have done for transparent failover ? achieved  fully
or partially?
> if CTDB has not achieved fully,  what else we should do ?
Fully transparent failover not only a ctdb task. Samba is involved
too. We need persistent file handles with guarantees, a task that is not
done yet.

See https://wiki.samba.org/index.php/Samba3/SMB3#Persistent_File_Handles
for ideas.

With best regards,

Volker Lendecke