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From:Mikael Fridh Date:November 14 2003 9:57am
Subject:Re: CRASH AND ROLLBACK SIMULATION
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We used to have a fair amount of data in InnoDB.
Had a few crashes from power failures at a crappy hosting provider.
Everytime the InnoDB engine seemed to detect the crashes and read up its 
logfiles and recover.

I've never tried any "manual" InnoDB recovery / data extraction. Are there 
methods? so far it seems to me that InnoDB manages itself after a crash!?
innodb.com:
"InnoDB tables have automatic crash recovery. You do not need to repair your 
tables if the operating system or the database server crashes, when there is 
no disk image corruption"

Mike


On Thursday 13 November 2003 17.29, Nils Valentin wrote:
> Hi there,
>
> I am not sure I understood your question correctly. What exactly is it that
> you want to test ?
>
> a) the recovery possibility in case of power down
> b) the recovery possibility in case of client disconnection (network
> interruption, timeout etc.)
> c) Recovery possibilities in general accessing the data files directly and
> indirectly using command line and/or GUI tools.
>
> In case a) mysql would recover the data files itself in most cases next
> time when the server is started as long as the logfiles, datafiles, config
> files are all there in the original positions (talking about InnoDB).
>
> b) If the network connection times out or client is diconnected than all
> executed commands since the last commit,begin gets rolled back (will not be
> applied)
>
> c) If the Innodb files are damaged so that the mysql server does not
> startup than no client tool (command line or GUI) that uses the indirect
> access method can access any data.
>
> I know that there are tools in the mysql package which access and repair
> (My)ISAM tables directly (server doesnt need to run), but that isnt true
> for the InnoDB tables I believe. I am not sure if InnoDB Hotbackup can
> directly access the InnoDB tables.
>
> What I know is that there will be a book coming up in February from Paul
> Dubois (Certification Study Guide) which is already described on Amazon.
>
> When it comes out I believe that it  will be the best book on the market so
> far, answering many of those and similar questions. I had the honour to
> review one of those preprints, all I can say so far is "Very impressive",
> you will see for yourself..
>
> On Friday 14 November 2003 00:58, nm wrote:
> > Do you know how to test a crash and a rollback?
>
> --
> kind regards
>
> Nils Valentin
> Tokyo/Japan
>
> http://www.be-known-online.com/mysql/

-- 
Ongame E-Solutions AB
Mikael Fridh
Junior Systems Administrator
Smedsgränd 3, 753 20 Uppsala, Sweden
Mobile: +46 708 17 42 00
Office: +46 18 69 55 00
Fax: +46 18 69 44 11
e-mail: mikael.fridh@stripped
http://www.ongame.com/
Thread
CRASH AND ROLLBACK SIMULATIONnm13 Nov
  • Re: CRASH AND ROLLBACK SIMULATIONMartijn Tonies13 Nov
  • Re: CRASH AND ROLLBACK SIMULATIONNils Valentin13 Nov
    • Re: CRASH AND ROLLBACK SIMULATIONMikael Fridh14 Nov