Re: HA, failover and load balancing / howto?

I will have to look into slony.. not much into db admin yet...
OK.. so
1. lets stick with complete duplicates in each region
identical
2. what opensource/free rdbms are there that can do this better?

Hmm got an answer from Ben but didnt see my post on the list...

Ben wrote:
> You should take it up on the slony list to be sure, but it sure sounds
> like you should be able to use Slony-I for this. Slony hasn't worked for
> my situations yet, but for you, it sounds like you can have seperate
> schemas for each region, and then have the master for each region
> replicate to the other regions. Combine these regional schemas with
> views, and you should have a working system.
>
> On Sun, 5 Aug 2007, hanasaki wrote:
>
>> Single master point subsets wasn't the plan but is doable. Each
>> geographic region should have a local read copy.
>>
>> Ben wrote:
>>> Are those geographical copies, or geographical subsets? Multi-master
>>> replication is hard with postgres (read: probably not going to happen)
>>> but if you can partition your data up so that you have one writer for a
>>> subset of records, that could work quite well. Especially if you have
>>> rich clients that can afford fast links between your regional servers.
>>>
>>> On Sat, 4 Aug 2007, hanasaki wrote:
>>>
>>>> I have some web applications and rich clients that need to
>>>> geographically localized copies (for network latency reasons) of a
>>>> database (East Coast, Central, West Coast and Japan) These will be
>>>> mostly read however there will be full CRUD activities going on. I
>>>> think this means that there will be a cluster in each region to deal
>>>> with load and single failures and when a whole region perhaps dies,
>>>> clients will fall back to another region.
>>>>
>>>> ex:
>>>> 4 servers for load East Coast
>>>> - db and webservers
>>>> 4 servers for load Central USA Coast
>>>> - db and webservers
>>>> 4 servers for load West Coast
>>>> - db and webservers
>>>>
>>>> The web applications (Java, tomcat, ejb3, jboss4, php) If one one, or
>>>> more web or db servers die, the others in the region are still used
>>>> (ie:
>>>> just 'degraded') If all the db servers die in a region, the web server
>>>> and applications will hit the db servers in another region)
>>>>
>>>> How can all of this be setup and configured and how can failed db
>>>> servers be brought back online and updated to sync into the clusters?
>>>>
>>>> Also looking at the pro/con of doing this in Postgres vs mysql
>>>>
>>>> ---------------------------(end of
>>>> broadcast)---------------------------
>>>> TIP 4: Have you searched our list archives?
>>>>
>>>> http://archives.postgresql.org/
>>>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 9: In versions below 8.0, the planner will ignore your desire to
>> choose an index scan if your joining column's datatypes do not
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>>