[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] ocaml oxenstored2 (forwarded message)

Forwarded with Dave Scott's permission, here is an email about some
work that has been going on to advance the state of oxenstored.

I think this sounds really interesting and I'm looking forward to
seeing the actual patches.  Dave, if there's anything we can do,
please let us know.


--- Begin Message ---
Hi Wei,

I have been working on oxenstored recently. It's all open-source, and I intend 
to send an email to xen-devel about it soon :-)

So far I've made the following changes:

1. it can now use libev to handle events (instead of just calling select()). 
This is all transparent now that I'm using a library called "lwt" ("light 
weight threads")
2. it can be built as either a stubdom (via Mirage[1]) or as a Unix user-space 
process (as before)
3. it supports a new transaction coalesce algorithm which avoids unnecessary 
conflicts when starting VMs -- this helps "VM bootstorms" a lot
4. it has an improved quota mechanism which works for driver domains (a driver 
domain will need a higher quota than a regular domU)
5. all of its configuration parameters (eg logging config) can be changed live, 
by writing to special nodes in the tree (like linux /proc). This helps a lot 
when debugging since you can just turn on read logging without needing to 
reboot and it makes sense in a stubdom where there is no config file...
6. it has a large unit test suite, to check all those annoying corner-cases: 
this makes refactoring much easier

I've been working on the code in github:


There's still a fair amount of work to do, but it's working pretty well.

I've got some design documentation lying around which I'll either add to a 
public repo or stick on the xen wiki. After that I'll start a thread on 


[1] http://www.openmirage.org/ -- a set of tools and libraries for building xen 
kernels (stubdoms etc)

> -----Original Message-----
> From: Wei Liu [mailto:Wei.Liu2@xxxxxxxxxx]
> Sent: 02 January 2013 4:35 PM
> To: Dave Scott
> Cc: Wei Liu; Roger Pau Monne
> Subject: Asking about oxenstored2
> Hi Dave
> I'm Wei Liu and I work for platform team. We currently have an issue about
> scalability of (o)xenstored and xenconsoled. They use select() to handle
> events, which is not desirable when we have thousands of domains.
> We want to fix this issue.
> I was told that you're working on oxenstored2 to deal with similar issue. Can
> you tell me about the progress of oxenstored2? Is there any plan to open
> source it?
> Thanks
> Wei.

--- End Message ---
Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.