[PATCHSET] dbwrap, read only copies, lock order

Amitay Isaacs amitay at gmail.com
Fri Feb 7 01:05:41 MST 2014


On Thu, Feb 6, 2014 at 9:27 PM, Michael Adam <obnox at samba.org> wrote:

> Hi,
>
> attached find a patchset to samba's dbwrap system.
>
> The first part introduces a means to activate
> read only copies for the ctdb dbwrap backend.
> (These are like delegations/leases on db records.
>  In a cluster, under certain cenarios, the use
>  of these read only copies can reduce the record
>  ping-pong and hence prevent performance drops).
>
> This patchset then activates the read only
> for the netlogon_creds_cli DB, recently introduced
> by Metze.
>
> The second part of the patches does some
> cleanups and systematization to the lock-order
> code.
>
> This patchset is already reviewed, but we wanted
> to give a chance to comment before pushing.
>
> Cheers - Michael
>
>
Hi Michael,

Patches looks good.

Only question is:  Since the flag DBWRAP_FLAG_OPTIMIZE_READONLY_ACCESS is
meant to optimize the access, do we need fail db_open_ctdb if
SET_DB_READONLY control fails?  Database is attached successfully at this
stage and it will still work.

Amitay.


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