Arbitrator and Bandwidth

MySQL & MariaDB Percona XtraDB Cluster 5.x
1

Hello,
I am trying to do a two nodes cluster with an arbitrator as third node.

What i understood about abritror is that it is a fake node but do not store any data.

But what about bandwidth, does my arbitrator need the same bandwidth as my two nodes?

I use an arbitrator to limit the cost of a real three nodes cluster. Maybe it is not a good idea if the bandwith consumed is consequent.

Thanks for your replies.

2

@oliver,

Arbitrator is just used for quorum(polling) purpose, this arbitrator node uses few KBps only for checking the cluster health.

but using a real node is much better than arbitrator, as it will help recovering the cluster faster!.

3

Hello, i tried to install a two node cluster with an arbitrator to get an idea of the difference between bandwith consumption between a node and an arbitrator. In understood that an arbitrator may consume less bandwith than a node. But it seems the volume of data transfered (kilobytes measured at interface) is quite the same for the arbitrator or the node.

Is there something to configure to avoid this useless bandwidth consumption?

System used: Ubuntu 12.04 + Percona 5.6.15-25.2-645.precise

4

No, the arbitrator needs to still receive the whole traffic that other nodes do. The only difference is that it does not store anything on disk. So make sure you have a good network link between both data and arbitrator nodes.
[url]http://www.codership.com/wiki/doku.php?id=galera_arbitrator[/url]

5

Oh,I thought arbitrator is used only for polling!, then arbitrator is useless unless you really want to save some GB’s!.

6

Arbitrator may be a lightweight way to better manage the cluster quorum. It needs less memory and needs no disk as opposed to normal nodes. But also it can’t serve SST requests, backups, etc.