FreeLists / mylvmbackup / [mylvmbackup] Re: mylvmbackup

["Eric Bergen" <eric@xxxxxxxxxxxxxxxxx>]

Hi,

My comments on the flush tables change are inline.


On Mon, Mar 31, 2008 at 12:33 PM, Lenz Grimmer <lenz@xxxxxxxxxxx> wrote:
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>  Hi Pascal,
>
>  thanks for your message!
>
>  On 03/31/2008 06:05 PM, Pascal Borghino wrote:
>
>  > Hi Lenz, how are you doing?
>
>  Thanks, doing well! Had a relaxing weekend - hope you do well, too!
>
>  > hope everything is rolling after your easter vacations...I am real busy
>  > lately and I find it hard to catch up with everything....
>
>  Welcome to the Club ;)
>  The migration from MySQL to Sun is not really reducing the workload here,
>  either...
>
>  > This being said, let's talk about mylvmbackup :) it works like a
>  > charm...
>
>  Glad to hear that!
>
>  > I am going to customize it for my needs...
>
>  I'd love to hear more about this, would you like to join our mailing list
>  for discussing this?
>
>  You can subscribe to it via To subscribe, either enter your email address on
>  the mylvmbackup list information page
>  (http://www.freelists.org/list/mylvmbackup) or send an email with the subject
>  "subscribe" to mylvmbackup-request@xxxxxxxxxxxxxx
>
>  I copied my reply to the list, I hope you don't mind.
>  But this makes sure that others can chime in!
>
>  > I want to cut mylvmbackup into PERL modules to make it easier
>  > implementing the pre/post scripting phases.
>  >
>  > something like:
>  > mylvmbackup::confMgmt
>  > mylvmbackup::mySQLMgmt
>  > mylvmbackup::lvmMgmt
>  > mylvmbackup::bckcpMgmt
>  > ....
>  > with pre/post scripting...
>
>  I think that would make sense, the current script is quite monolithic and 
> hard
>  to expand.
>
>  > About the todo:
>  > 1. recovery my.cnf, not sure we need that if we have 1 config file for
>  > confMgmt.
>
>  Not sure what you mean by this, can you elaborate?
>
>  > 2. xfs_freeze, I will enforce at Y! the use of LVM2, so no problem for me.
>
>  Right, I guess calling xfs_freeze is no longer necessary nowadays.
>
>  > 3. sure !!! :p we go for modules
>
>  I blame my lack of Perl Fu for not having done that already :)
>
>  > 4. more backup method! definitely.
>  > ...
>  >
>  > I also want to add also a procedure that flush all table one after the
>  > other ( suppose to speed up the process ) instead of using "FLUSH
>  > TABLES WITH READ LOCK"...
>
>  Hmm, what exactly would you gain by that? Do you want to replace the initial
>  "FLUSH TABLES" that can be called before calling the "FLUSH TABLES WITH READ
>  LOCK afterwards?
>

I noticed two things with flush tables and mylvmbackup..

 First that mylvmbackup includes an extra_flush_tables to workaround
interactive timeouts. Is this referring to the mysql client
interactive timeout? Wouldn't it be better to have a mylvmbackup
option to adjust the interactive timeout instead of making the flush
(and thus the interference in mysql) take longer?

Have you benchmarked the flush each table then flush tables with read
lock method to see if it's faster? Internally any updates that were
waiting while the flush tables per table is being ran will try to run
and open those tables up again potentially make the flush tables with
read lock wait until they are done running so it an grab it's locks
and flush all the tables.


>  > ...
>  >
>  > I want to work also on a mylvmrecovery program... :)
>
>  That would be a nice supplement!
>
>  > So, what do you say? Interested by my help?
>
>  Certainly! Any improvements would be welcome. For the time being, your
>  overhaul should be done in a separate branch, I guess.
>
>  How can I assist you? My local SVN server does not really accommodate work on
>  separate branches and I don't want to become the roadblock for incorporating
>  your patches.
>
>  I wonder if I should convert the source tree to git or bzr and move it to a
>  public source code hosting site, to ease distributed work on this. Any
>  preferences? I was thinking of using either Launchpad or GitHub...
>
>  Bye,
>         LenZ
>  - --
>  - ------------------------------------------------------------------
>   Lenz Grimmer <lenz@xxxxxxxxxxx>                             -o)
>   [ICQ: 160767607 | Jabber: LenZGr@xxxxxxxxxx]                /\\
>   http://www.lenzg.org/                                       V_V
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