3 messages in com.mysql.lists.clusterRe: cluster load balancer| From | Sent On | Attachments |
|---|---|---|
| Saul Waizer | 16 Jun 2006 09:40 | |
| Geert Vanderkelen | 16 Jun 2006 10:06 | |
| Geert Vanderkelen | 16 Jun 2006 23:59 |
| Subject: | Re: cluster load balancer |
|---|---|
| From: | Geert Vanderkelen (gee...@mysql.com) |
| Date: | 06/16/2006 11:59:33 PM |
| List: | com.mysql.lists.cluster |
Hi Saul,
(Please reply to the mailinglist too)
Saul Waizer wrote:
Geert,
I have a php web application that uses a regular connection string to the mysql node1, I have no idea how to really “use” the cluster, right now everything is being sent to one node, but if that node fails there is no true redundancy unless I point the connection to the second node
NODE1 <----> NODE2 | | V APPLICATION
Check out this URL and the diagram there: http://dev.mysql.com/doc/refman/5.0/en/mysql-cluster-overview.html
What you probably have is:
DATANODE <---> DATANODE | | MYSQL NODE | | Application
According to this diagram if node one fails the application will fail as well because the connection string is directed to node1
You can't make your Application connect to a particular data node, only to a MySQL node. It's important to always mention what kind of node you are talking about, as there are 3 types :)
Your application is connecting to a 'MySQL node' (or 'API Node'). This MySQL node will then connect to one of the 'data nodes'. If you have 2 data nodes and NoOfReplicas=2, then you data nodes are redundant: if one fails, your cluster will still be up! No need to do much here.
Again, you will need to do some load balancing or fail-over on MySQL nodes level. Add a second MySQL node and make it connect to the cluster. Then you have couple of options: - your application connects to one, if the connection fails to the first MySQL node, it should use the second one. - you run your application on both machines where MySQL nodes are running, and load balance between them - you load balance between the MySQL nodes and make your application only connect to the load balancer, which should handle also the fail-over.
I would use second option, as you have your application redundant as well then.
Cheers,
Geert
-- Geert Vanderkelen, Support Engineer MySQL GmbH, Germany, www.mysql.com
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