From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nivedita Singhvi Subject: Re: RFC: "local" communications Date: Wed, 15 Jun 2005 14:31:10 -0700 Message-ID: <42B09E1E.3060709@us.ibm.com> References: <42B08E8A.9090609@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <42B08E8A.9090609@us.ibm.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Anthony Liguori Cc: Lon Hohberger , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Anthony Liguori wrote: > Rik van Riel wrote: > >> Hi, >> >> When combining clustering with cluster storage, the situation >> arises where virtual machines are not only managed by the cluster >> software, but also need to participate in the cluster software >> themselves... >> >> In order for this to work better, it would be good if there >> was a way for software in a domU to communicate with software >> on the local dom0 - so after being migrated elsewhere, a guest >> would start talking to the new dom0 automatically. Rik, is this a heartbeat kind of protocol or some such thing? Is there value to making it be a generic solution that would work when communicating in a non-xen environment? >> Should it be some virtual device analogous to the virtual >> network driver, or should we have some other kind of socket >> for node local communications ? Using protocols like TCP for node-local comms is undesirable as TCP is engineered for the heavy machinery of the Internet. UDP or raw sockets will be somewhat better, although AF_UNIX would be best of all (albeit with its own constraints). >> What kind of approach would the Xen community (that's you, if >> you read this far) prefer ? >> >> > I can only speak for myself, but I'd personally like to see a small > userspace library that established a datagram connection between two > domains (using an event channel and a shared page) that could be reused > for many applications. Which datagram service, Anthony? Having a small lib like this would be a good idea, although the benefit would be in the details, and of course, depending on how many apps we need to support that we don't want to modify... > If it could be used with normal read/write calls that would be even > better (although first thought is that that would require a daemon). Probably don't want to do that... thanks, Nivedita