Re: [openstack-dev] [tripleo] Upgrade plans for RDO Manager - Brainstorming
On 09/09/2015 05:34 PM, Zane Bitter wrote: On 24/08/15 15:12, Emilien Macchi wrote: Hi, So I've been working on OpenStack deployments for 4 years now and so far RDO Manager is the second installer -after SpinalStack [1]- I'm working on. SpinalStack already had interested features [2] that allowed us to upgrade our customer platforms almost every months, with full testing and automation. Now, we have RDO Manager, I would be happy to share my little experience on the topic and help to make it possible in the next cycle. For that, I created an etherpad [3], which is not too long and focused on basic topics for now. This is technical and focused on Infrastructure upgrade automation. Feel free to continue discussion on this thread or directly in the etherpad. [1] http://spinalstack.enovance.com [2] http://spinalstack.enovance.com/en/latest/dev/upgrade.html [3] https://etherpad.openstack.org/p/rdo-manager-upgrades I added some notes on the etherpad, but I think this discussion poses a larger question: what is TripleO? Why are we using Heat? Because to me the major benefit of Heat is that it maintains a record of the current state of the system that can be used to manage upgrades. And if we're not going to make use of that - if we're going to determine the state of the system by introspecting nodes and update it by using Ansible scripts without Heat's knowledge, then we probably shouldn't be using Heat at all. I'm not saying that to close off the option - I think if Heat is not the best tool for the job then we should definitely consider other options. And right now it really is not the best tool for the job. Adopting Puppet (which was a necessary choice IMO) has meant that the responsibility for what I call "software orchestration"[1] is split awkwardly between Puppet and Heat. For example, the Puppet manifests are baked in to images on the servers, so Heat doesn't know when they've changed and can't retrigger Puppet to update the configuration when they do. We're left trying to reverse-engineer what is supposed to be a declarative model from the workflow that we want for things like updates/upgrades. That said, I think there's still some cause for optimism: in a world where every service is deployed in a container and every container has its own Heat SoftwareDeployment, the boundary between Heat's responsibilities and Puppet's would be much clearer. The deployment could conceivably fit a declarative model much better, and even offer a lot of flexibility in which services run on which nodes. We won't really know until we try, but it seems distinctly possible to aspire toward Heat actually making things easier rather than just not making them too much harder. And there is stuff on the long-term roadmap that could be really great if only we had time to devote to it - for example, as I mentioned in the etherpad, I'd love to get Heat's user hooks integrated with Mistral so that we could have fully-automated, highly-available (in a hypothetical future HA undercloud) live migration of workloads off compute nodes during updates. TBH I don't expect that using containers will significantly simplify (or make clearer) the upgrade process. It would work nicely if upgrade would mean just replacing one container with another (where a container is represented by a heat resource). But I'm convinced that a container replacement will actually involve a complex workflow of actions which have to be done before and after. In the meantime, however, I do think that we have all the tools in Heat that we need to cobble together what we need to do. In Liberty, Heat supports batched rolling updates of ResourceGroups, so we won't need to use user hooks to cobble together poor-man's batched update support any more. We can use the user hooks for their intended purpose of notifying the client when to live-migrate compute workloads off a server that is Unfortunately rolling_updates supports only "pause time" between update batches, so if any workflow would be needed between batches (e.g. pause before next batch until user validates that previous batch update was successful), we still have to use user hooks. But I guess adding hooks support to rolling_updates wouldn't be too difficult. about to upgraded. The Heat templates should already tell us exactly which services are running on which nodes. We can trigger particular software deployments on a stack update with a parameter value change (as we already do with the yum update deployment). For operations that happen in isolation on a single server, we can model them as SoftwareDeployment resources within the individual server templates. For operations that are synchronised across a group of servers (e.g. disabling services on the controller nodes in preparation for a DB migration) we can model them as a SoftwareDeploymentGroup resource in the parent template. And for chaining multiple sequential operations (e.g. disable services, migrate database, enable services
Re: [openstack-dev] [tripleo] Upgrade plans for RDO Manager - Brainstorming
On 24/08/15 15:12, Emilien Macchi wrote: Hi, So I've been working on OpenStack deployments for 4 years now and so far RDO Manager is the second installer -after SpinalStack [1]- I'm working on. SpinalStack already had interested features [2] that allowed us to upgrade our customer platforms almost every months, with full testing and automation. Now, we have RDO Manager, I would be happy to share my little experience on the topic and help to make it possible in the next cycle. For that, I created an etherpad [3], which is not too long and focused on basic topics for now. This is technical and focused on Infrastructure upgrade automation. Feel free to continue discussion on this thread or directly in the etherpad. [1] http://spinalstack.enovance.com [2] http://spinalstack.enovance.com/en/latest/dev/upgrade.html [3] https://etherpad.openstack.org/p/rdo-manager-upgrades I added some notes on the etherpad, but I think this discussion poses a larger question: what is TripleO? Why are we using Heat? Because to me the major benefit of Heat is that it maintains a record of the current state of the system that can be used to manage upgrades. And if we're not going to make use of that - if we're going to determine the state of the system by introspecting nodes and update it by using Ansible scripts without Heat's knowledge, then we probably shouldn't be using Heat at all. I'm not saying that to close off the option - I think if Heat is not the best tool for the job then we should definitely consider other options. And right now it really is not the best tool for the job. Adopting Puppet (which was a necessary choice IMO) has meant that the responsibility for what I call "software orchestration"[1] is split awkwardly between Puppet and Heat. For example, the Puppet manifests are baked in to images on the servers, so Heat doesn't know when they've changed and can't retrigger Puppet to update the configuration when they do. We're left trying to reverse-engineer what is supposed to be a declarative model from the workflow that we want for things like updates/upgrades. That said, I think there's still some cause for optimism: in a world where every service is deployed in a container and every container has its own Heat SoftwareDeployment, the boundary between Heat's responsibilities and Puppet's would be much clearer. The deployment could conceivably fit a declarative model much better, and even offer a lot of flexibility in which services run on which nodes. We won't really know until we try, but it seems distinctly possible to aspire toward Heat actually making things easier rather than just not making them too much harder. And there is stuff on the long-term roadmap that could be really great if only we had time to devote to it - for example, as I mentioned in the etherpad, I'd love to get Heat's user hooks integrated with Mistral so that we could have fully-automated, highly-available (in a hypothetical future HA undercloud) live migration of workloads off compute nodes during updates. In the meantime, however, I do think that we have all the tools in Heat that we need to cobble together what we need to do. In Liberty, Heat supports batched rolling updates of ResourceGroups, so we won't need to use user hooks to cobble together poor-man's batched update support any more. We can use the user hooks for their intended purpose of notifying the client when to live-migrate compute workloads off a server that is about to upgraded. The Heat templates should already tell us exactly which services are running on which nodes. We can trigger particular software deployments on a stack update with a parameter value change (as we already do with the yum update deployment). For operations that happen in isolation on a single server, we can model them as SoftwareDeployment resources within the individual server templates. For operations that are synchronised across a group of servers (e.g. disabling services on the controller nodes in preparation for a DB migration) we can model them as a SoftwareDeploymentGroup resource in the parent template. And for chaining multiple sequential operations (e.g. disable services, migrate database, enable services), we can chain outputs to inputs to handle both ordering and triggering. I'm sure there will be many subtleties, but I don't think we *need* Ansible in the mix. So it's really up to the wider TripleO project team to decide which path to go down. I am genuinely not bothered whether we choose Heat or Ansible. There may even be ways they can work together without compromising either model. But I would be pretty uncomfortable with a mix where we use Heat for deployment and Ansible for doing upgrades behind Heat's back. cheers, Zane. [1] http://www.zerobanana.com/archive/2014/05/08#heat-configuration-management __ OpenStack Development Mailing List
Re: [openstack-dev] [tripleo] Upgrade plans for RDO Manager - Brainstorming
On 08/24/2015 03:12 PM, Emilien Macchi wrote: > Hi, > > So I've been working on OpenStack deployments for 4 years now and so far > RDO Manager is the second installer -after SpinalStack [1]- I'm working on. > > SpinalStack already had interested features [2] that allowed us to > upgrade our customer platforms almost every months, with full testing > and automation. > > Now, we have RDO Manager, I would be happy to share my little experience > on the topic and help to make it possible in the next cycle. > > For that, I created an etherpad [3], which is not too long and focused > on basic topics for now. This is technical and focused on Infrastructure > upgrade automation. > One week without discussion or thoughts in the etherpad. Can anyone who cares about upgrades participate to the thread? Thank you, -- Emilien Macchi signature.asc Description: OpenPGP digital signature __ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
[openstack-dev] [tripleo] Upgrade plans for RDO Manager - Brainstorming
Hi, So I've been working on OpenStack deployments for 4 years now and so far RDO Manager is the second installer -after SpinalStack [1]- I'm working on. SpinalStack already had interested features [2] that allowed us to upgrade our customer platforms almost every months, with full testing and automation. Now, we have RDO Manager, I would be happy to share my little experience on the topic and help to make it possible in the next cycle. For that, I created an etherpad [3], which is not too long and focused on basic topics for now. This is technical and focused on Infrastructure upgrade automation. Feel free to continue discussion on this thread or directly in the etherpad. [1] http://spinalstack.enovance.com [2] http://spinalstack.enovance.com/en/latest/dev/upgrade.html [3] https://etherpad.openstack.org/p/rdo-manager-upgrades -- Emilien Macchi signature.asc Description: OpenPGP digital signature __ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
