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From: Wei Liu <wei.liu2@citrix.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jonathan Davies <jonathan.davies@citrix.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Jon Ludlam <jonathan.ludlam@citrix.com>,
	Euan Harris <euan.harris@citrix.com>,
	Dave Scott <dave@recoil.org>,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH 0/7] oxenstored: improve transaction conflict handling
Date: Fri, 18 Mar 2016 16:36:21 +0000	[thread overview]
Message-ID: <20160318163621.GC23307@citrix.com> (raw)
In-Reply-To: <20160318143335.GD27285@char.us.oracle.com>

On Fri, Mar 18, 2016 at 10:33:35AM -0400, Konrad Rzeszutek Wilk wrote:
> On Thu, Mar 17, 2016 at 05:51:08PM +0000, Jonathan Davies wrote:
> > This patch series makes a substantial improvement to oxenstored's transaction
> > handling.
> > 
> > The original design of oxenstored assumed that a transaction would only ever
> > span a small subtree. In practice this is rarely the case and means that other
> > xenstore traffic overlapping with a transaction can cause it to fail with
> > EAGAIN. This leads to significant performance problems with toolstack operations
> > when there is a certain level of xenstore traffic coming from other sources.
> > 
> > Instead, we observe that, although the transaction may span a large subtree, it
> > is very unlikely to read or write the same keys as other xenstore traffic. This
> > observation leads to an improved transaction conflict-handling algorithm in
> > which the transaction is replayed to check it is serializable. This approach is
> > superior in performance.
> > 
> > The sixth patch is the main one that changes the way transaction conflicts are
> > handled. The first five patches prepare the way by performing some refactoring
> > and addition of infrastructure that allows for transactions to be replayed. The
> > seventh patch adds some extra logging.
> 
> All the patches have quite the Reviewed-by list already so I would think
> these can go in now?
> 

We need an ack from Dave.

But, FWIW, the result is impressive, and the changes are only internal
to oxenstored, so I think it's pretty safe interface-wise or
protocol-wise.

Wei.

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  parent reply	other threads:[~2016-03-18 16:36 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-17 17:51 [PATCH 0/7] oxenstored: improve transaction conflict handling Jonathan Davies
2016-03-17 17:51 ` [PATCH 1/7] oxenstored: refactor putting response on wire Jonathan Davies
2016-03-17 17:51 ` [PATCH 2/7] oxenstored: remove some unused parameters Jonathan Davies
2016-03-17 17:51 ` [PATCH 3/7] oxenstored: refactor request processing Jonathan Davies
2016-03-24 22:22   ` Boris Ostrovsky
2016-03-24 22:49     ` Andrew Cooper
2016-03-24 23:57       ` Boris Ostrovsky
2016-03-29  9:08         ` Jonathan Davies
2016-03-29 12:45           ` Boris Ostrovsky
2016-03-29 16:38           ` Wei Liu
2016-03-29 19:41             ` David Scott
2016-03-30 15:46               ` Jonathan Davies
2016-03-30 15:53                 ` Wei Liu
2016-03-17 17:51 ` [PATCH 4/7] oxenstored: keep track of each transaction's operations Jonathan Davies
2016-03-17 17:51 ` [PATCH 5/7] oxenstored: move functions that process simple operations Jonathan Davies
2016-03-17 17:51 ` [PATCH 6/7] oxenstored: replay transaction upon conflict Jonathan Davies
2016-03-17 17:51 ` [PATCH 7/7] oxenstored: log request and response during transaction replay Jonathan Davies
2016-03-18 14:33 ` [PATCH 0/7] oxenstored: improve transaction conflict handling Konrad Rzeszutek Wilk
2016-03-18 16:21   ` Jonathan Davies
2016-03-18 16:36   ` Wei Liu [this message]
2016-03-19 11:30     ` David Scott

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