2:08 a.m.
Hi,
we got the following problem:
we create / start / stop
hole vms /data centers / storage etc
(basically: everything ovirt can handle
via REST-API)
But if you want to know e.g. the status
of a vm (or anything) you need to constantly
poll the API.
This is not what we desire to do, as it
does not scale very well (e.g. polling
100 vms).
Is there a standardized way of pushing information
from the engine?
--
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
2:18 a.m.
On 12/17/2013 03:08 AM, Sven Kieske wrote:
Hi,
we got the following problem:
we create / start / stop
hole vms /data centers / storage etc
(basically: everything ovirt can handle
via REST-API)
But if you want to know e.g. the status
of a vm (or anything) you need to constantly
poll the API.
This is not what we desire to do, as it
does not scale very well (e.g. polling
100 vms).
well, you can search events since last event you searched for, only for
the specific type of event you are interested in, then check which vm
its for.
Is there a standardized way of pushing information
from the engine?
well, the notification service which sends emails on these actually
polls for them every minute in order to send the emails.
we are discussing snmptraps here[1]
one of the options this could be implemented with is via log4j getting
all the audit log events, then you could use any log4j appender (db
table, jms queue, etc.)
[1] Bug 1032661 - Add SNMP trap as notification method to to
ovirt-engine-notification
2:24 a.m.
Note that you can usually get all the information you want using 1 API
call, which should still scale.
For instance, /ovirt-engine/api/vms will give you a list of all VMs and
their statuses, so you can just run an XPath and get the status of all of
them.
On Tue, Dec 17, 2013 at 10:18 AM, Itamar Heim <iheim(a)redhat.com> wrote:
On 12/17/2013 03:08 AM, Sven Kieske wrote:
> Hi,
>
> we got the following problem:
>
> we create / start / stop
> hole vms /data centers / storage etc
> (basically: everything ovirt can handle
> via REST-API)
>
> But if you want to know e.g. the status
> of a vm (or anything) you need to constantly
> poll the API.
>
> This is not what we desire to do, as it
> does not scale very well (e.g. polling
> 100 vms).
>
well, you can search events since last event you searched for, only for
the specific type of event you are interested in, then check which vm its
for.
> Is there a standardized way of pushing information
> from the engine?
>
>
>
well, the notification service which sends emails on these actually polls
for them every minute in order to send the emails.
we are discussing snmptraps here[1]
one of the options this could be implemented with is via log4j getting all
the audit log events, then you could use any log4j appender (db table, jms
queue, etc.)
[1] Bug 1032661 - Add SNMP trap as notification method to to
ovirt-engine-notification
_______________________________________________
Engine-devel mailing list
Engine-devel(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/engine-devel
4:47 a.m.
Hi,
thanks for your fast replies.
We are aware that we can poll this via API, but we don't want to poll
it, as it's not a good solution, from a design point of view.
We will maybe write a little python script, which runs on engine-node
via SDK which polls the API and let this script push the information
forward to external systems over network when a certain event occurs.
Something similar to this in oVirt would be useful.
You don't want to poll every second, or more often, for simple
events like "is the vm already up?".
This just creates unnecessary network traffic and load on the polling
system.
With this solution we can at least avoid the network traffic.
This is, why I asked for a pushing logic.
Maybe it's now more clear?
But thanks again for your help :-)
Am 17.12.2013 09:24, schrieb Liran Zelkha:
Note that you can usually get all the information you want using 1
API
call, which should still scale.
For instance, /ovirt-engine/api/vms will give you a list of all VMs and
their statuses, so you can just run an XPath and get the status of all of
them.
--
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
5:33 a.m.
You can use the DWH API to check these things.
The status is sampled and stored for most entities every 1 minute by default (and can be
set to less than that).
Yaniv
----- Original Message -----
From: "Sven Kieske" <S.Kieske(a)mittwald.de>
To: users(a)ovirt.org, engine-devel(a)ovirt.org
Sent: Tuesday, December 17, 2013 10:08:11 AM
Subject: [Engine-devel] Polling vs Pushing engine events
Hi,
we got the following problem:
we create / start / stop
hole vms /data centers / storage etc
(basically: everything ovirt can handle
via REST-API)
But if you want to know e.g. the status
of a vm (or anything) you need to constantly
poll the API.
This is not what we desire to do, as it
does not scale very well (e.g. polling
100 vms).
Is there a standardized way of pushing information
from the engine?
--
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
_______________________________________________
Engine-devel mailing list
Engine-devel(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/engine-devel
2:07 a.m.
Hi,
the following seems to be killing our
plans to use a pythonscript to fetch the list of vms:
This comes from the users list:
Am 17.12.2013 15:04, schrieb Sander Grendelman:> Fetching the list of
vms through the API with the python SDK
takes several seconds[1] with 100% cpu usage in the python script.
When I look at the engine log there is only one (fast) fetch from
the API. The rest of the time is spent in the SDK processing a
relatively small bit of XML data (only 26 VMs in my environment).
This seems an excessive amount of CPU for processing ~6KB of XML.
I've included some sample code [2] and output [3].
Attached is the cProfile output for this call and a visualization.
[1] ~6,5 seconds on an oVirt VM with 1 vcpu on older hardware,
~3,5 seconds on a fast physical machine with an i5 cpu.
Am 17.12.2013 15:31, schrieb Michael Pasternak:>
Hi Sander,
This is a known issue caused by generateDS python bindings we use,
it's extremely slow in python<->xml marshalling, and unable to recognize
cyclic referencing in the objects,
i'm planning to upgrade in 3.4 from 2.9a to 2.12, if it won't help, we may
consider other options.
This is no option for us at all:
We can't wait for a possible fix in 3.4
(which maybe even does not fix it).
Additionally we will have much higher amounts of vms to query.
--
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
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5 comments
4 participants
participants (4)
-
Itamar Heim -
Liran Zelkha -
Sven Kieske -
Yaniv Dary