Re: Xen, application servers and going forward

[Jason]

On Tue, 2007-04-03 at 12:03 -0500, Mike McGrath wrote:
>  I'm working on getting our first production xen instance up and
> running 
>  for things like koji, smolt, bodhi and the package database.  Here are 
>  some guidelines I'd like to put on the wiki as well as some changes I'd 
>  like to make.
>  
>  
>  1) xen dom0 - RHEL5 (its just a black box, lets set it up and forget 
>  about it) 
>  2) after we update our RHEL4 boxes to RHEL5 We will maintain two
> types 
>  of servers, RHEL5 and FC6 (this is because not all required packages are 
>  in EPEL, and ultimately the FC6 boxes will probably become FC7,8,9 
>  boxes.  I'd like to keep just two types so we can create an appa[1-9] 
>  and an appb[1-9].  I'd like to put appa and appb behind a vip that gets 
>  balanced 1-9 RR.  This will allow us to choose where we want to put our 
>  apps, stable environments vs cutting edge. 
this makes a lot of sense and would help ease admin/maintenance tasks.


>  3) test and production xen guests will exist only on test and
> production 
>  xen hosts.  (basically no mixing of production and test).  Obviously 
>  emergencies are one thing but in general this is just for organizational 
>  purposes and because we may create a test network later and they won't 
>  be able to mix. 
production and test *should* never mix :) bad things tend to happen and
tracking the cause down gets waaay complicated.

>  4) xen instances will be named by hostname.  Naming by purpose is 
>  getting confusing. 
less confusion is good, if this is what does it.. 

>  5) We will probably start mixing hardware.  Unlike before where we
> had 
>  builder hardware and app hardware, we'll be bluring this line as the 
>  need requires.  I plan on building out a few more wiki instances before 
>  the F7 release.
>  6) Kickstarts - I'm working on a xen-host and xen-guest kickstart 
>  script.  All of our boxes will be based off of one of these two scripts 
>  (they'll be sent to the list soon for examination / suggestions).  
>  Beyond that configuration will happen with puppet.  Note: puppet can 
>  pull in config files, install packages and restart services.
>  7) Monitoring - I'm working on a monitoring piece (basically a web page) 
>  that will list exactly what xen guests are running on what xen hosts, if 
>  they are pingable, etc. 
good ideas, on a side note just curious how do updates get pulled/pushed
once the servers and apps are in place?


-Jason