Open Stack

Hello, Tom, 

Thanks for your mail to mention that some users out there that use
cells "to integrate multi-site / multi-vendor OpenStack instances into
one cloud with OpenStack API exposed.",.

Why do I think Cells using scale up methodology?

1, Use case 1: All cells using shared Cinder, Neutron, Glance as John Garbutt mentioned in the mail. In this use case, ,one Cinder, Neutron, Galnce intance to scale up for multi-sites, no multi-vendor cinder, neutron, glance, althoth it can integrate different vendor's driver/agent/plugin. This use case has unified north-bound OpenStack API

2, Use case 2, each child cells with seperate Cinder, Nova-Network. For this use case, No unified north-bound OpenStack API, multi-endpoints for upper layer.

3, Until now, only RPC used for inter-cell or api-cell communication. For multi-data center deployment, it leads to the risk of out of management: if one parent cell faild, no API or CLI is available to manage the child cells. RPC message interface is imposible being used to manage child cells.

4. Ok, suppose that Cells will add new driver to use REST API for  inter-cell or api-cell communication, then should it be done on Cinder/Neutron/Glance too? or still using shared Cinder/Neutron/Glance. If it's the the first choice, it is the same design as OpenStack cascading solution wants to do. If it's still using shared service, the RPC message acorss different data centers still exists, and it's still scale up methodology.

Best Regards

Chaoyi Huang ( joehuang )
________________________________________
From: Tom Fifield [tom at openstack.org]
Sent: 01 October 2014 15:19
To: openstack-dev at lists.openstack.org
Subject: Re: [openstack-dev] [all] [tc] Multi-clouds integration by OpenStack cascading

Hi Joe,

On 01/10/14 09:10, joehuang wrote:
> OpenStack cascading: to integrate multi-site / multi-vendor OpenStack instances into one cloud with OpenStack API exposed.
> Cells: a single OpenStack instance scale up methodology

Just to let you know - there are actually some users out there that use
cells "to integrate multi-site / multi-vendor OpenStack instances into
one cloud with OpenStack API exposed.", and this is their main reason
for using cells - not as a "scale up" methodology.


Regards,

Tom

_______________________________________________
OpenStack-dev mailing list
OpenStack-dev at lists.openstack.org
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev