Re: Data persistency - Mikael Ronström - com.mysql.lists.cluster

10 messages in com.mysql.lists.clusterRe: Data persistency

From	Sent On	Attachments
Richard Goh	18 Aug 2004 23:32
Mikael Ronström	19 Aug 2004 02:00
Devananda	19 Aug 2004 10:26
Mikael Ronström	20 Aug 2004 00:55
Devananda	20 Aug 2004 09:45
Devananda	20 Aug 2004 09:51
Mikael Ronström	20 Aug 2004 16:03
Devananda	20 Aug 2004 16:34
Clint Byrum	20 Aug 2004 17:22
Mikael Ronström	21 Aug 2004 00:46

Subject:	Re: Data persistency
From:	Mikael Ronström (mik...@mysql.com)
Date:	08/19/2004 02:00:58 AM
List:	com.mysql.lists.cluster

Hi Richard,

2004-08-19 kl. 08.32 skrev Richard Goh:

Hi,

I'd like to know where the data is being persisted. Is it to the disk or just in shared memory?

It's also to the disk with a slight delay.

What I really want to find out is what happens if there is power outage and there's no power backup at all? i.e., the servers are totally down when there is a lot of transaction going on. Will only the unfinished transactions be lost? Or those transactions that have just finished are also lost (because not persisted to the disk)

All unfinished transactions will be lost. The transactions completed will be safe on disk after the next global checkpoint which is run at configurable intervals (normally around 1-2 seconds).

Rgrds Mikael

Mikael Ronström, Senior Software Architect MySQL AB, www.mysql.com

Clustering: http://www.infoworld.com/article/04/04/14/HNmysqlcluster_1.html

http://www.eweek.com/article2/0,1759,1567546,00.asp