On 29/03/12 12:13, Itamar Heim wrote:
On 03/29/2012 11:59 AM, Doron Fediuck wrote:
On 29/03/12 10:54, Itamar Heim wrote:
On 03/29/2012 10:05 AM, Muli Salem wrote:
Thanks for the comments, I updated the wiki page accordingly: http://www.ovirt.org/wiki/Features/ReloadableConfiguration
1. Instead of the new DB column is_reloadable --> Annotation to ConfigValues. 2. Found a way to update the Quartz jobs, at least basic issues such as interval size. 3. The values will be reloaded upon admin's decision to do so - with a new command in the engine-config CLI, since that is where admins make the changes.
just wondering - how will the CLI do this at the technical level (via REST API? signal to service, etc.)?
Basically we need a script using the REST sdk to trigger re-configuration This script will need the engine's IP so it'll know where to find it. The thing is, REST also needs the admin's user and password to run...
We can get it in 2 options:
1. Store Admin's user+pass in the engine's conf file. 2. Use engine-config to fetch the credentials.
Once we have credentials, we can use it with a new script to trigger configuration reload. We can also incorporate this script into engine-config so admin won't need to know another script, and simply use a 'reload' verb.
I'm not keen on storing the credentials in a conf' file, but (unfortunately) it wouldn't be a first time. Any better alternative is welcome (just as patches ;-).
true.
A simple alternative to the whole credentials and IP need, is a simple periodic reload, as suggested initially.
Any thoughts on this?
/d
isn't there some way to send a process signal or something like that (not allowing remote access, but i think it uses the db crednetials from a local file anyway, and i don't think running config remotely is a must)
other options: 1. require user to provide user/password (kind of funny for running manage-domains utility, but possible This will make service xxx reload pointless, unless we decide to drop it and reduce to a simple
Simply signaling a process such as "kill TRAP PID" is problematic since: - The engine core is a web-app on top of JBoss, how do we know which pid to trigger? - What happens if JBoss isn't running / using nohup / ... ? script (embedded or not in the config utility).
2. use a way on the host to send a signal (change a file, process signal, etc.) Great. This means we need to poll a folder or similar (DB)... sounds familiar? See above the periodic reload. We can do it better if we look for a key in the DB (enableReconfigure=true), to avoid reloading in the middle of an update process of several keys. We still need to be careful from concurrency, but I have solutions for this as well (do not allow updates to vdc_options until the key becomes false again, also set it to false on initial boot).
3. Write a simple public reload servlet (maybe limit to local host only?), which we can call using simple curl http://xxx/reload? As I see it now, I'd go for one of the following (in this order)- 2: periodically poll DB, reload only when allowed. 3: local servlet. Thoughts? Better solutions?