fuel-dev team mailing list archive

[Bogdan Dobrelya <bdobrelia@xxxxxxxxxxxx>]

On 02/04/2014 08:21 AM, Matthew Mosesohn wrote:
> One major element to consider is # of transactions per second we need
> to anticipate, rather than volume in mb/gb/tb. No matter how small a
> transaction is, it creates overhead. Yes, storage capacity is
> important, but you have to be functional in order to fill the disk up
> with Ceilometer events.
> What we ought to do is determine is the breaking point. How many
> nova/neutron/glance DB transactions per minute cause too much
> API/Galera traffic + Ceilometer traffic that it starts to interfere
> with normal user requests?
> 
> I'm still working on sizing for Galera/SQLAlchemy, and that breaking
> point will raise for environments with many CPUs and lots of memory,
> but it won't go away.
> I vote for Ceilometer + MongoDB as a role and on a separate node if we
> have over 50 nodes.
> 
+1, I vote for make roles as much atomic as possible. I believe, the
best practice for enterprise clusters (i.e. HA and large scaled ones) is
to separate roles, not to combine them.
> 
> 
> On Tue, Feb 4, 2014 at 9:55 AM, Mike Scherbakov
> <mscherbakov@xxxxxxxxxxxx> wrote:
>> Some numbers can be found here for large amount of instances (20k) and
>> volumes (20k):
>> https://docs.google.com/a/mirantis.com/spreadsheet/ccc?key=0AtziNGvs-uPudDhRbEJJOHFXV3d0ZGc1WE9NLTVPX0E#gid=0
>>
>> According to this table, it generates 339Mb/hour, or ~8Gb/day, or
>> ~0.25Tb/month. Even on such a scale, it should survive on existing
>> controller nodes, if we allocate dedicated disks, does not it?
>>
>>
>>
>> On Tue, Feb 4, 2014 at 9:44 AM, Mike Scherbakov <mscherbakov@xxxxxxxxxxxx>
>> wrote:
>>>
>>> +David, Nadya
>>>
>>> Hi Max,
>>> as we discussed verbally there is a major concern behind - about placement
>>> of MongoDB. As I understand right, it is expected that there is a huge disk
>>> IO consumption in case of larger deployments (let's say >50 nodes).
>>> If it is the case, then I would agree that we may not want to use shared
>>> disks for MongoDB and other OpenStack components. I see two options here:
>>>
>>> Make sure MongoDB uses dedicated disk(s) on the server where it's
>>> installed, and it can be part of existing controller role then
>>>
>>> Nailgun can make default allocation in a way that MongoDB has dedicated
>>> disk by default, if there is more than one disk on the server (which is 100%
>>> of real cases, I assume)
>>> User's experience would be simply to enable Ceilometer installation by
>>> clicking on checkbox. In simple mode, ceilometer + mongo will be installed
>>> on controller node. In HA mode, ceilometer + mongo will be installed on all
>>> 3 controllers under pacemaker control
>>>
>>> Make sure MongoDB is installed on a separated server
>>>
>>> In UI, user will have to:
>>>
>>> enable ceilometer checkbox ("Install Ceilometer")
>>> don't forget to add "ceilometer-db" (mongodb) role to one of the
>>> unallocated nodes
>>>
>>> UI must ensure that this role should not intersect with any other
>>> UI must ensure that this role is assigned to at least one node in the env,
>>> if ceilometer checkbox is enabled
>>> UI must ensure that this role is assigned to at least 3 different
>>> unallocated nodes in case of HA deployment mode, to ensure that we will have
>>> Ceilometer HA (we can skip this, but add logic that if we have more than one
>>> mongo - we must build cluster)
>>>
>>> In terms of simplicity and ease of use, I would vote for option #1, while
>>> leaving ability to place MongoDB on a separate server via Fuel CLI for
>>> customized deployments. #1 solves the issue with disk IO by providing
>>> dedicated disk(s).
>>>
>>>> Do we need HA Cluster with non-HA Mongo?
>>> For consistency over Fuel story, I vote for HA for all OpenStack
>>> components, if HA mode is chosen. So my opinion is no - we do not need such
>>> a case.
>>>
>>>> Puppet manifest are  finished
>>> Great! Please pull request them asap - we will need time for reviews. I
>>> hope we can complete manifests for HA story by the end of the week too.
>>>
>>> Thanks,
>>>
>>>
>>> On Mon, Feb 3, 2014 at 5:37 PM, Max Mazur <mmaxur@xxxxxxxxxxxx> wrote:
>>>>
>>>> Hi!
>>>>
>>>>
>>>> I'd like to add to Fuel the following options:
>>>>
>>>> 1. Simple install
>>>>  - Ceilometer with MongoDB or Ceilometer wit If customer selected Mongo
>>>> it is necessary to deploy one more node with MongoDB
>>>> Puppet manifest are  finished
>>>>
>>>> 2. HA Mode
>>>>  - Ceilometer with MongoDB replica set.  In this case we need 3 MongoDB
>>>> nodes to build HA replica set.
>>>> Puppet manifests are in progress now
>>>>
>>>>
>>>> Do we need HA Cluster with non-HA Mongo?
>>>>
>>>> Best Regards,
>>>> Max Mazur
>>>>
>>>>
>>>>
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>>>
>>>
>>>
>>>
>>> --
>>> Mike Scherbakov
>>> #mihgen
>>
>>
>>
>>
>> --
>> Mike Scherbakov
>> #mihgen
>>
>> --
>> Mailing list: https://launchpad.net/~fuel-dev
>> Post to     : fuel-dev@xxxxxxxxxxxxxxxxxxx
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>> More help   : https://help.launchpad.net/ListHelp
>>
> 


-- 
Best regards,
Bogdan Dobrelya.