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Sorry for the delay. You've got an interesting problem, and we were all quite busy last week with the summit.

First, the standard caveat: Your performance is going to be highly dependent on your particular workload and your particular hardware deployment. 3500 req/sec in two different deployments may be very different based on the size of the requests, the spread of the data requested, and the type of requests. Your experience may vary, etc, etc.

However, for an attempt to answer your question...

6 proxies for 3500 req/sec doesn't sound unreasonable. It's in line with other numbers I've seen from people and what I've seen from other large scale deployments. You are basically looking at about 600 req/sec/proxy.

My first concern is not the swift workload, but how keystone handles the authentication of the tokens. A quick glance at the keystone source seems to indicate that keystone's auth_token middleware is using a standard memcached module that may not play well with concurrent connections in eventlet. Specifically, sockets cannot be reused concurrently by different greenthreads. You may find that the token validation in the auth_token middleware fails under any sort of load. This would need to be verified by your testing or an examination of the memcache module being used. An alternative would be to look at the way swift implements it's memcache connections in an eventlet-friendly way (see swift/common/memcache.py:_get_conns() in the swift codebase).

--John



On Oct 11, 2012, at 4:28 PM, Alejandro Comisario <alejandro.comisario at mercadolibre.com> wrote:

> Hi Stackers !
> This is the thing, today we have a 24 datanodes (3 copies, 90TB usables) each datanode has 2 intel hexacores CPU with HT and 96GB of RAM, and 6 Proxies with the same hardware configuration, using swift 1.4.8 with keystone.
> Regarding the networking, each proxy / datanodes has a dual 1Gb nic, bonded in LACP mode 4, each of the proxies are behind an F5 BigIP Load Balancer ( so, no worries over there ).
> 
> Today, we are receiving 5000 RPM ( Requests per Minute ) with 660 RPM per Proxies, i know its low, but now ... with a new product migration, soon ( really soon ) we are expecting to receive about a total of 90.000 RPM average ( 1500 req / s ) with weekly peaks of 200.000 RPM ( 3500 req / s ) to the swift api, witch will be 90% public gets ( no keystone auth ) and 10% authorized PUTS (keystone in the middle, worth to know that we have a 10 keystone vms pool, connected to a 5 nodes galera mysql cluster, so no worries there either ) 
> 
> So, 3500 req/s divided by 6 proxy nodes doesnt sounds too much, but well, its a number that we cant ignore.
> What do you think about this numbers? does this 6 proxies sounds good, or we should double or triple the proxies ? Does anyone has this size of requests and can share their configs ?
> 
> Thanks a lot, hoping to ear from you guys !
> 
> -----
> alejandrito
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