Re: [ovirt-users] ovirt and gateway behavior

[Martin Sivak]

> This is expected behaviour, even if it’s not very bright. It’s being used as
> a way to detect network is operating correctly.

Correct, it is used to check whether users can reach the host and the
VM that runs on it. There aren't that many options to check that. All
require data exchange of some kind (ICMP req/res, TCP SYN/ACK, some
UDP echo..).

> It is insane as there are so many ways it breaks.  My network admin turns
> off ICMP responses and death to network.

ICMP is an important signaling mechanism.. seriously, it is usually a
bad idea to block it.

> I got this trying to install on a network with out a gateway.

How were your users accessing the VMs? Was this some kind of super
secure deployment with no outside connectivity?


Best regards

Martin Sivak

On Tue, Feb 6, 2018 at 4:32 PM, Ben De Luca  wrote:
> This is expected behaviour, even if it’s not very bright. It’s being used as
> a way to detect network is operating correctly.
>
> I got this trying to install on a network with out a gateway.
>
> It is insane as there are so many ways it breaks.  My network admin turns
> off ICMP responses and death to network.
>
> On Tue 6. Feb 2018 at 16:27, Alex K  wrote:
>>
>> Hi,
>>
>> I have seen hosts rendered unresponsive when gateway is lost.
>> I will be able to provide more info once I prepare an environment and test
>> this further.
>>
>> Thanx,
>> Alex
>>
>> On Tue, Feb 6, 2018 at 10:40 AM, Yaniv Kaul  wrote:
>>>
>>>
>>>
>>> On Feb 5, 2018 2:21 PM, "Alex K"  wrote:
>>>
>>> Hi all,
>>>
>>> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
>>> cluster is used to host several VMs.
>>> I have observed that when gateway is lost (say the gateway device is
>>> down) the ovirt cluster goes down.
>>>
>>>
>>> Is the cluster down, or just the self-hosted engine?
>>>
>>>
>>> It seems a bit extreme behavior especially when one does not care if the
>>> hosted VMs have connectivity to Internet or not.
>>>
>>>
>>> Are the VMs down?
>>> The hosts?
>>> Y.
>>>
>>>
>>> Can this behavior be disabled?
>>>
>>> Thanx,
>>> Alex
>>>
>>> ___
>>> Users mailing list
>>> Users@ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
>>
>> ___
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>
>
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Re: [ovirt-users] ovirt and gateway behavior

[Martin Sivak]

Hi,

ee use the ping check to see whether the host running hosted engine
has connectivity with the rest of the cluster and users. We kill the
VM in a hope that some other host will make the engine available to
users again.

We use the gateway by default as it is pretty common to have separate
network for data center, but you can change the address if your
topology is different.

Best regards

Martin Sivak

On Tue, Feb 6, 2018 at 4:27 PM, Alex K  wrote:
> Hi,
>
> I have seen hosts rendered unresponsive when gateway is lost.
> I will be able to provide more info once I prepare an environment and test
> this further.
>
> Thanx,
> Alex
>
> On Tue, Feb 6, 2018 at 10:40 AM, Yaniv Kaul  wrote:
>>
>>
>>
>> On Feb 5, 2018 2:21 PM, "Alex K"  wrote:
>>
>> Hi all,
>>
>> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
>> cluster is used to host several VMs.
>> I have observed that when gateway is lost (say the gateway device is down)
>> the ovirt cluster goes down.
>>
>>
>> Is the cluster down, or just the self-hosted engine?
>>
>>
>> It seems a bit extreme behavior especially when one does not care if the
>> hosted VMs have connectivity to Internet or not.
>>
>>
>> Are the VMs down?
>> The hosts?
>> Y.
>>
>>
>> Can this behavior be disabled?
>>
>> Thanx,
>> Alex
>>
>> ___
>> Users mailing list
>> Users@ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
>
> ___
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>
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Re: [ovirt-users] ovirt and gateway behavior

[Alex K]

Hi,

I have seen hosts rendered unresponsive when gateway is lost.
I will be able to provide more info once I prepare an environment and test
this further.

Thanx,
Alex

On Tue, Feb 6, 2018 at 10:40 AM, Yaniv Kaul  wrote:

>
>
> On Feb 5, 2018 2:21 PM, "Alex K"  wrote:
>
> Hi all,
>
> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
> cluster is used to host several VMs.
> I have observed that when gateway is lost (say the gateway device is down)
> the ovirt cluster goes down.
>
>
> Is the cluster down, or just the self-hosted engine?
>
>
> It seems a bit extreme behavior especially when one does not care if the
> hosted VMs have connectivity to Internet or not.
>
>
> Are the VMs down?
> The hosts?
> Y.
>
>
> Can this behavior be disabled?
>
> Thanx,
> Alex
>
> ___
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
>
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Re: [ovirt-users] ovirt and gateway behavior

[Darrell Budic]

I’ve seen this sort of happen on my systems, the gateway ip goes down for some 
reason, and the engine restarts repeatedly, rending it unusable, even though 
it’s on the same ip subnet as all the host boxes and can still talk to the 
VDSMs. In my case, it doesn’t hurt the cluster or DC, but it’s annoying and 
unnecessary in my environment where the gateway isn’t important for cluster 
communications..

I can understand why using the ip of the gateway became a test as a proxy for 
network connectivity, but it seems like it’s something that isn’t always valid 
and maybe the local admin should have a choice of how it’s used. Something like 
the current fencing option for “50% hosts down” as a double check, if you can 
still reach the vdsm hosts, don’t restart the engine vm.

  -Darrell
> From: Yaniv Kaul <yk...@redhat.com>
> Subject: Re: [ovirt-users] ovirt and gateway behavior
> Date: February 6, 2018 at 2:40:14 AM CST
> To: Alex
> Cc: Ovirt Users
> 
> 
> 
> On Feb 5, 2018 2:21 PM, "Alex K" <rightkickt...@gmail.com 
> <mailto:rightkickt...@gmail.com>> wrote:
> Hi all, 
> 
> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The 
> cluster is used to host several VMs. 
> I have observed that when gateway is lost (say the gateway device is down) 
> the ovirt cluster goes down. 
> 
> Is the cluster down, or just the self-hosted engine? 
> 
> 
> It seems a bit extreme behavior especially when one does not care if the 
> hosted VMs have connectivity to Internet or not. 
> 
> Are the VMs down? 
> The hosts? 
> Y. 
> 
> 
> Can this behavior be disabled?
> 
> Thanx, 
> Alex
> 
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> <http://lists.ovirt.org/mailman/listinfo/users>
> 
> 
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Re: [ovirt-users] ovirt and gateway behavior

[Yaniv Kaul]

On Feb 5, 2018 2:21 PM, "Alex K"  wrote:

Hi all,

I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
cluster is used to host several VMs.
I have observed that when gateway is lost (say the gateway device is down)
the ovirt cluster goes down.


Is the cluster down, or just the self-hosted engine?


It seems a bit extreme behavior especially when one does not care if the
hosted VMs have connectivity to Internet or not.


Are the VMs down?
The hosts?
Y.


Can this behavior be disabled?

Thanx,
Alex

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Re: [ovirt-users] ovirt and gateway behavior

[Alex K]

Hi Edward,

So this is not an expected behavior?
I will collect logs as soon as I reproduce it.

Thanx,
Alex

On Tue, Feb 6, 2018 at 9:36 AM, Edward Haas  wrote:

> Hi Alex,
>
> Please provide Engine logs from when this is occurring and mention the
> date/time we should focus at.
>
> Thanks,
> Edy.
>
>
> On Mon, Feb 5, 2018 at 2:19 PM, Alex K  wrote:
>
>> Hi all,
>>
>> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
>> cluster is used to host several VMs.
>> I have observed that when gateway is lost (say the gateway device is
>> down) the ovirt cluster goes down.
>>
>> It seems a bit extreme behavior especially when one does not care if the
>> hosted VMs have connectivity to Internet or not.
>>
>> Can this behavior be disabled?
>>
>> Thanx,
>> Alex
>>
>> ___
>> Users mailing list
>> Users@ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
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Re: [ovirt-users] ovirt and gateway behavior

[Edward Haas]

Hi Alex,

Please provide Engine logs from when this is occurring and mention the
date/time we should focus at.

Thanks,
Edy.


On Mon, Feb 5, 2018 at 2:19 PM, Alex K  wrote:

> Hi all,
>
> I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
> cluster is used to host several VMs.
> I have observed that when gateway is lost (say the gateway device is down)
> the ovirt cluster goes down.
>
> It seems a bit extreme behavior especially when one does not care if the
> hosted VMs have connectivity to Internet or not.
>
> Can this behavior be disabled?
>
> Thanx,
> Alex
>
> ___
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
___
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[ovirt-users] ovirt and gateway behavior

[Alex K]

Hi all,

I have a 3 nodes ovirt 4.1 cluster, self hosted on top of glusterfs. The
cluster is used to host several VMs.
I have observed that when gateway is lost (say the gateway device is down)
the ovirt cluster goes down.

It seems a bit extreme behavior especially when one does not care if the
hosted VMs have connectivity to Internet or not.

Can this behavior be disabled?

Thanx,
Alex
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