Hi Dinesh, AFAIR, we introduced a state to the cluster as CLUSTER_INMAINTAINENCE_MODE. So that cluster monitor will get paused until the cluster become active again. In that way, we can avoid autoscaler taking any additional decision. Do you think that we can re-use this state here when we apply the patches?
Thanks, Reka On Thu, Jul 24, 2014 at 12:13 PM, Dinesh Bandara <dine...@wso2.com> wrote: > > On Thu, Jul 24, 2014 at 11:26 AM, Sajith Kariyawasam <saj...@wso2.com> > wrote: > >> What I meant was "rebooting" the same instance [1] >> >> [1] >> http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-reboot.html >> >> While rebooting the instance, agent is down for sometime and AS will > terminate the instance assuming instance is a faulty member. then Stratos > will spawn a new cartridge instance. > Another disadvantage it will violate the high availability concept if we > only have a one instance. > >> >> On Thu, Jul 24, 2014 at 11:21 AM, Sajith Kariyawasam <saj...@wso2.com> >> wrote: >> >>> >>> On Mon, Jun 30, 2014 at 5:11 PM, Dinesh Bandara <dine...@wso2.com> >>> wrote: >>> >>>> Hi all, >>>> >>>> I have faced in to a situation that need to update existing cartridge >>>> instances without interrupt the process. AFAIU there are two types of >>>> updates that need to be applied. >>>> >>>> 1. OS level/ Security updates >>>> 2. Application level updates (Load balancer, PHP, MySQL) >>>> >>>> >>>> *Patching OS level/ Security updates* >>>> >>>> Since this is a mandatory update we have to shutdown the server and >>>> then need to restart it after successfully update the patch. But this will >>>> interrupt the whole process. >>>> Cartridge agent related updates can be consider as OS level update. >>>> >>>> *Solution* >>>> >>>> - Spawn a new instance and apply the updates. >>>> - Terminate exiting instance >>>> >>>> >>> Can't we think of restarting the same instance (After executing updates) >>> rather than terminating and spawning a new one? Because terminating and >>> starting a new one may incur additional cost, for eg, AFAIK Amazon EC2 >>> rates are based on per-hour, so if the instance terminate / re-spawn >>> happens in the middle of an hour, it will double the cost per instance >>> >>>> >>>> - >>>> - Repeat the above steps until spawn new instances on behalf of >>>> existing instances >>>> >>>> *Patching Application level updates* >>>> >>>> Status of the cartridge instance set into 'Maintenance' mode, apply >>>> updates and then set again as an 'Active' instance >>>> >>>> *Expose to user* >>>> >>>> Introduce new rest endpoint via SM which will provide the access to >>>> patch selected cluster. >>>> >>>> As the first step I would like to start with the "patching OS level >>>> updates". >>>> >>>> Highly appreciate your thoughts on this. >>>> >>>> Thanks, >>>> -- >>>> *Dinesh Bandara* >>>> Software Engineer >>>> WSO2 Inc.; http://wso2.com >>>> lean.enterprise.middleware >>>> >>>> >>> >>> >>> -- >>> *--* >>> *Sajith Kariyawasam* >>> *Mobile: +94772269575 <%2B94772269575>* >>> >> >> >> >> -- >> *--* >> *Sajith Kariyawasam* >> *Mobile: +94772269575 <%2B94772269575>* >> > > > > -- > *Dinesh Bandara* > Software Engineer > WSO2 Inc.; http://wso2.com > lean.enterprise.middleware > > -- Reka Thirunavukkarasu Senior Software Engineer, WSO2, Inc.:http://wso2.com, Mobile: +94776442007
