← Back to team overview

openstack team mailing list archive

Re: distributed and heterogeneous schedulers


What happens if a ZoneManager process dies? When the ZoneManager restarts, the compute nodes will send their attributes to the newly restarted ZoneManager and the in-memory list of attributes will be reconstructed, right?
The only downside to this approach is the (probably short) time that it takes for the restarted ZoneManager to reconstruct its in-memory db of host attributes.

As an unrelated side note, the folks over in Hadoop land use this sort of 'in-memory data-structures fed by heartbeats' approach with much success.

- Jagane
From: openstack-bounces+jagane=sundar.org@xxxxxxxxxxxxxxxxxxx [openstack-bounces+jagane=sundar.org@xxxxxxxxxxxxxxxxxxx] On Behalf Of Sandy Walsh [sandy.walsh@xxxxxxxxxxxxx]
Sent: Friday, April 15, 2011 2:24 PM
To: Jay Pipes; Ed Leafe
Cc: Mark Washenberger; openstack@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Openstack] distributed and heterogeneous schedulers

Each update from the services are atomic updates ... fully self contained.

Why does this need to be in a persistent store?

From: Jay Pipes [jaypipes@xxxxxxxxx]
>  you still need a persistent data store for attributes of the host. Just because you
> store a cached in-memory copy of instance attributes, doesn't mean you
> don't need a persistent data store. You still need a persistent data
> store regardless of whether it's a database table, a FLAG value, or
> /proc/cpuinfo.

Mailing list: https://launchpad.net/~openstack
Post to     : openstack@xxxxxxxxxxxxxxxxxxx
Unsubscribe : https://launchpad.net/~openstack
More help   : https://help.launchpad.net/ListHelp

Follow ups