[RFC] Use mutexes by default in db_open()
slow at samba.org
Wed May 31 07:11:52 UTC 2017
On Wed, May 31, 2017 at 04:12:18PM +1000, Amitay Isaacs wrote:
> On Wed, May 31, 2017 at 3:29 PM, Ralph Böhme <slow at samba.org> wrote:
> > Hi Amitay
> > On Mon, May 29, 2017 at 12:21:50PM +1000, Amitay Isaacs wrote:
> > > Here's the summary of what I would like to propose:
> > > 1. CTDB ignores tdb_flags specified in DB_ATTACH controls, tdb flags are
> > > calculated based on the database model (or specific DB_ATTACH control)
> > > 2. For volatile databases, mutexes will be enabled by default
> > > (TDBMutexEnabled=1) when samba enables mutexes by default
> > > (dbwrap_tdb_mutexes:*=true)
> > sorry, but I fail to understand how 1 and 2 could work together. If,
> > according
> > to 1, ctdb ignores the tdb_flags in the DB_ATTACH control, how is
> > disabling of
> > mutexes handled in step 2 when dbwrap_tdb_mutexes:*=false is set in
> > smb.conf
> > (while TDBMutexEnabled=1 still set for ctdb) ?
> > *scratches head*
> Obviously you have not ready my fully. Here's the statement you missed from
> previous email.
> As a result, in clustered samba case, dbwrap_tdb_mutexes settings will be
> ignored for clustered (volatile) databases.
huh, sorry but for me this still doesn't combine with clause 2. Let me try to
2. Whether mutexes are enabled or disabled for volatile databases is determined by
2.1. smb.conf dbwrap_tdb_mutexes setting on a standalone Samba server, or
2.2. ctdb tunable TDBMutexEnabled in a ctdb cluster
With 4.7 we change both defaults to yes and 1 respectively.
Got it? :)
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