netdev - Re: POHMELFS high performance network filesystem. Transactions, failover, performance.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080515011009.GA28687@shareable.org>
Date:	Thu, 15 May 2008 02:10:09 +0100
From:	Jamie Lokier <jamie@...reable.org>
To:	Evgeniy Polyakov <johnpol@....mipt.ru>
Cc:	Sage Weil <sage@...dream.net>, Jeff Garzik <jeff@...zik.org>,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: POHMELFS high performance network filesystem. Transactions, failover, performance.

Evgeniy Polyakov wrote:
> > It's possible that implementing server cloud protocol _and_ simple
> > client protocol may be more work than just server cloud protocol.  I'm
> > not sure.  Thoughts welcome.
> 
> Well, getting that client protocol is mostly ready, and its design
> allows infinite (blah!) extensions and extremely (blah!) flexible
> processing, we are close to just difficult server one :)

That's what I thought when I had my system working fine with just one
server.  The client was very simple. :-)

Since, I learned that my clients need to have parts of the complex
server protocol for fast, safe transactions (think ACID (or ACI)) over
relatively slow links, especially with multiple servers.

Also, efficiently recovering from a link/server failure, when clients
have large zero-latency caches (using leases), appears similar to the
synchronising protocol between recovering servers.

But, on the bright side, these things are only necessary for
performance in scenarios you might not encounter or care about :-)

I'm finding it's a really interesting but large problem.

-- Jamie
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html