openstack team mailing list archive

["Reddin, Tim (Cloud Services)" <Tim.Reddin@xxxxxx>]

Jay wrote:



>>

FYI, some folks have done some performance testing of Glance with

Swift backends. It was determined that using SSL caused a dramatic

performance degradation (roughly decreased the network I/O throughput

by half, with a queuing behvaiour showing up on GET requests as well.)



The solution was to disable zlib compression in SSL on the Glance API

server box.

<<



Our initial tests used an image dervied from /dev/urandom which was an absolute worst case for  compression.


We found subsequently that using ZLIB with real images did provide “some” benefit  (up to ~30 – but depends on image content). We also tried using LZO which gave up to 400% with a stock Ubuntu image (1.45GB). We will publish something on this when we have a more complete picture.

As Jay points out – replacing the compression algorithm is not easy.


Tim



-----Original Message-----
From: openstack-bounces+tim.reddin=hp.com@xxxxxxxxxxxxxxxxxxx [mailto:openstack-bounces+tim.reddin=hp.com@xxxxxxxxxxxxxxxxxxx] On Behalf Of Jay Pipes
Sent: 19 September 2011 16:39
To: Kuo Hugo
Cc: openstack@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Openstack] Load Balancers for Swift Proxy-servers ----why Pound ?



On Mon, Sep 19, 2011 at 7:47 AM, Kuo Hugo <tonytkdk@xxxxxxxxx> wrote:

> btw , most of articles just using HTTP instead of HTTPS.   Does Pound better

> than Nginx under HTTPS?



FYI, some folks have done some performance testing of Glance with

Swift backends. It was determined that using SSL caused a dramatic

performance degradation (roughly decreased the network I/O throughput

by half, with a queuing behvaiour showing up on GET requests as well.)



The solution was to disable zlib compression in SSL on the Glance API

server box.



There aren't a whole lot of easy ways to do this in OpenSSL 0.9.8, but

you may find the discussion in this article interesting:



http://journal.paul.querna.org/articles/2011/04/05/openssl-memory-use/



Cheers,

jay



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