Discussion:
[Gluster-users] arbiter node on client?
Gandalf Corvotempesta
2018-05-06 11:15:32 UTC
Permalink
is possible to add an arbiter node on the client?

Let's assume a gluster storage made with 2 storage server. This is prone to
split-brains.
An arbiter node can be added, but can I put the arbiter on one of the
client ?

Can I use multiple arbiter for the same volume ? In example, one arbiter on
each client.
Dave Sherohman
2018-05-07 11:21:49 UTC
Permalink
Post by Gandalf Corvotempesta
is possible to add an arbiter node on the client?
I've been running in that configuration for a couple months now with no
problems. I have 6 data + 3 arbiter bricks hosting VM disk images and
all three of my arbiter bricks are on one of the kvm hosts.
Post by Gandalf Corvotempesta
Can I use multiple arbiter for the same volume ? In example, one arbiter on
each client.
I'm pretty sure that you can only have one arbiter per subvolume, and
I'm not even sure what the point of multiple arbiters over the same data
would be.

In my case, I have three subvolumes (three replica pairs), which means I
need three arbiters and those could be spread across multiple nodes, of
course, but I don't think saying "I want 12 arbiters instead of 3!"
would be supported.
--
Dave Sherohman
Gandalf Corvotempesta
2018-05-07 12:20:53 UTC
Permalink
Post by Dave Sherohman
I'm pretty sure that you can only have one arbiter per subvolume, and
I'm not even sure what the point of multiple arbiters over the same data
would be.
Multiple arbiter add availability. I can safely shutdown one hypervisor
node (where arbiter is located)
and still have a 100% working cluster with quorum.

Is possible to add arbiter on the fly or must be configured during the
volume creation ?
Ben Turner
2018-05-07 14:43:16 UTC
Permalink
One thing to remember with arbiters is that they need IOPs, not capacity as much. With a VM use case this is less impactful, but workloads with lots of smallfiles can become heavily bottlenecked at the arbiter. Arbiters only save metadata, not data, but metadata needs lots of small reads and writes. I have seen many instances where the the arbiter had considerably less IOPs than the other bricks and it lead to perf issues. With VMs you don't have thousands of files so its prolly not a big deal, but in more general purpose workloads its important to remember this.

HTH!

-b

----- Original Message -----
Sent: Monday, May 7, 2018 7:21:49 AM
Subject: Re: [Gluster-users] arbiter node on client?
Post by Gandalf Corvotempesta
is possible to add an arbiter node on the client?
I've been running in that configuration for a couple months now with no
problems. I have 6 data + 3 arbiter bricks hosting VM disk images and
all three of my arbiter bricks are on one of the kvm hosts.
Post by Gandalf Corvotempesta
Can I use multiple arbiter for the same volume ? In example, one arbiter on
each client.
I'm pretty sure that you can only have one arbiter per subvolume, and
I'm not even sure what the point of multiple arbiters over the same data
would be.
In my case, I have three subvolumes (three replica pairs), which means I
need three arbiters and those could be spread across multiple nodes, of
course, but I don't think saying "I want 12 arbiters instead of 3!"
would be supported.
--
Dave Sherohman
_______________________________________________
Gluster-users mailing list
http://lists.gluster.org/mailman/listinfo/gluster-users
Loading...