1:12 a.m.
On 29/04/15 21:53, Dan Yasny wrote:
There is always room for improvement, but think about it: ever since
SolidICE, there has been a demand to minimize the amount of hardware used in a
minimalistic setup, thus the hosted engine project. And now that we have it, all of a
sudden, we need to provide a way to make multiple engines work in active/passive mode? If
that capability is provided, I'm sure a new demand will arise, asking for
active/active engines, infinitely scalable, and so on.
of course you wan't active/active clusters for an enterprise product,
rather sooner than later
The question really is, where the line is drawn. The engine downtime can be a few
minutes, it's not that critical in setups of hundreds of hosts. oVirt's raison
d'etre is to make VMs run, everything else is just plumbing around that.
I
disagree:
ovirt is a provider of critical infrastructure
(vms and their management) for modern it business.
imagine a large organisation just using ovirt for their virtualization,
with lots of different departments which at will can spawn their own
vms, maybe even from different countrys with different time zones (just
like red hat ;) ).
of course, if just the engine service is down for some reason and you
can just restart it with an outage of some seconds, or maybe a minute -
fine.
but everything above a minute could become critical for large orgs
relying on the ability to spawn vms at any given time.
or imagine critical HA vms running on ovirt:
you can't migrate them, when the engine is not running.
you might not even want a downtime of a single second for them, that's
why you implemented things like live migration in the first place.
the bottom line is:
if you manage critical infrastructure, the tools to manage
this infrastructure have to be as reliable as the infrastructure itself.
--
Mit freundlichen Grüßen / Regards
Sven Kieske
Systemadministrator
Mittwald CM Service GmbH & Co. KG
Königsberger Straße 6
32339 Espelkamp
T: +49-5772-293-100
F: +49-5772-293-333
https://www.mittwald.de
Geschäftsführer: Robert Meyer
St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen
Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen
3:09 a.m.
New subject: [ovirt-users] oVirt HA.
On Thu, Apr 30, 2015 at 8:12 AM, Sven Kieske <s.kieske(a)mittwald.de> wrote:
but everything above a minute could become critical for large orgs
relying on the ability to spawn vms at any given time.
or imagine critical HA vms running on ovirt:
you can't migrate them, when the engine is not running.
you might not even want a downtime of a single second for them, that's
why you implemented things like live migration in the first place.
the bottom line is:
if you manage critical infrastructure, the tools to manage
this infrastructure have to be as reliable as the infrastructure itself.
If there is any interest I can revamp a testbed similar to what already
done about one year ago with CentOS 6.5 and oVirt 3.3.3
See for summary about my configuration here:
http://lists.ovirt.org/pipermail/users/2014-March/022176.html
At that time I configured the cluster with Pacemaker/cman and the resource
split on the two-node cluster was something like this
Last updated: Wed Mar 5 18:07:51 2014
Last change: Wed Mar 5 18:07:51 2014 via crm_resource on
ovirteng01.localdomain.local
Stack: cman
Current DC: ovirteng01.localdomain.local - partition with quorum
Version: 1.1.10-14.el6_5.2-368c726
2 Nodes configured
14 Resources configured
Online: [ ovirteng01.localdomain.local ovirteng02.localdomain.local ]
Master/Slave Set: ms_OvirtData [OvirtData]
Masters: [ ovirteng01.localdomain.local ]
Slaves: [ ovirteng02.localdomain.local ]
Resource Group: ovirt
ip_OvirtData (ocf::heartbeat:IPaddr2): Started
ovirteng01.localdomain.local
lvm_ovirt (ocf::heartbeat:LVM): Started ovirteng01.localdomain.local
fs_OvirtData (ocf::heartbeat:Filesystem): Started
ovirteng01.localdomain.local
pgsql_OvirtData (lsb:postgresql): Started
ovirteng01.localdomain.local
ovirt-engine (lsb:ovirt-engine): Started
ovirteng01.localdomain.local
ovirt-websocket-proxy (lsb:ovirt-websocket-proxy): Started
ovirteng01.localdomain.local
httpd (ocf::heartbeat:apache): Started
ovirteng01.localdomain.local
Clone Set: p_lsb_nfs-clone [p_lsb_nfs]
Started: [ ovirteng01.localdomain.local ovirteng02.localdomain.local ]
Clone Set: p_exportfs_root-clone [p_exportfs_root]
Started: [ ovirteng01.localdomain.local ovirteng02.localdomain.local ]
there were some customizations I had to do related to ovirt-engine service
init script and to setup HA for POstgreSQL.
I already have as a task to dig into cluster changes for CentOS 7.1 and so
I can try to see how it adapts with oVirt 3.5 too.
Gianluca
8:14 a.m.
New subject: [ovirt-users] oVirt HA.
----- Original Message -----
From: "Sven Kieske" <s.kieske(a)mittwald.de>
To: devel(a)ovirt.org
Cc: users(a)ovirt.org
Sent: Thursday, April 30, 2015 2:12:55 AM
Subject: Re: [ovirt-users] oVirt HA.
On 29/04/15 21:53, Dan Yasny wrote:
> There is always room for improvement, but think about it: ever since
> SolidICE, there has been a demand to minimize the amount of hardware used
> in a minimalistic setup, thus the hosted engine project. And now that we
> have it, all of a sudden, we need to provide a way to make multiple
> engines work in active/passive mode? If that capability is provided, I'm
> sure a new demand will arise, asking for active/active engines, infinitely
> scalable, and so on.
of course you wan't active/active clusters for an enterprise product,
rather sooner than later
No doubt there, however, that's not *just* HA any longer :)
>
> The question really is, where the line is drawn. The engine downtime can be
> a few minutes, it's not that critical in setups of hundreds of hosts.
> oVirt's raison d'etre is to make VMs run, everything else is just plumbing
> around that.
I disagree:
ovirt is a provider of critical infrastructure
(vms and their management) for modern it business.
imagine a large organisation just using ovirt for their virtualization,
with lots of different departments which at will can spawn their own
vms, maybe even from different countrys with different time zones (just
like red hat ;) ).
of course, if just the engine service is down for some reason and you
can just restart it with an outage of some seconds, or maybe a minute -
fine.
but everything above a minute could become critical for large orgs
relying on the ability to spawn vms at any given time.
I think you're getting away from the point here. If the hosted engine's HA
isn't fast enough, you can cluster the engine in other ways, that were available way
before hosted engine came to be.
or imagine critical HA vms running on ovirt:
you can't migrate them, when the engine is not running.
you might not even want a downtime of a single second for them, that's
why you implemented things like live migration in the first place.
the bottom line is:
if you manage critical infrastructure, the tools to manage
this infrastructure have to be as reliable as the infrastructure itself.
--
Mit freundlichen Grüßen / Regards
Sven Kieske
Systemadministrator
Mittwald CM Service GmbH & Co. KG
Königsberger Straße 6
32339 Espelkamp
T: +49-5772-293-100
F: +49-5772-293-333
https://www.mittwald.de
Geschäftsführer: Robert Meyer
St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen
Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
8:36 a.m.
New subject: [ovirt-users] oVirt HA.
On 30/04/15 15:14, Dan Yasny wrote:
No doubt there, however, that's not *just* HA any longer :)
sorry for being a nitpick and to quote wikipedia but:
"There are three principles of high availability engineering. They are
1. Elimination of single points of failure. This means adding redundancy
to the system so that failure of a component does not mean failure of
the entire system.[..]"
e.g active/active clusters ;)
I promise this will be my last mail to this thread :-)
--
Mit freundlichen Grüßen / Regards
Sven Kieske
Systemadministrator
Mittwald CM Service GmbH & Co. KG
Königsberger Straße 6
32339 Espelkamp
T: +49-5772-293-100
F: +49-5772-293-333
https://www.mittwald.de
Geschäftsführer: Robert Meyer
St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen
Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen
3278
days inactive
3278
days old
3 comments
3 participants
participants (3)
-
Dan Yasny -
Gianluca Cecchi -
Sven Kieske