On Wed, Aug 8, 2012 at 4:10 AM, Jeff Schnitzer <j...@infohazard.org> wrote:
> If you've been reading various threads on this list you know that > Richard has been having trouble getting his mobile game to run > smoothly on GAE. It's a little unusual because timing is coordinated > precisely: > > * At T+0, all clients submit scores > * At T+5s, a reaper process aggregates the scores and builds a result set > * At T+10s, all clients fetch scores > > The question is: Where to submit the score data so that the reaper > can fetch and aggregate it? > > Here's some answers that didn't work: > > * The datastore. Eventual consistency is too eventual to query for > all the scores and get them. > * Pull queues. There's too much of a delay between task insertion > and when it appears for leasing. > * A single backend. One backend cannot handle more than ~80qps. > > He eventually got a system working reliably, sharded across ten B1 > instances, at a cost (beyond other charges) of ~$600/mo. It can > collect a couple thousand scores within the 5s deadline (barely). > > I thought this was insane, so I built a few experiments to see what > other technologies can do, using the exact program logic of Richard's > collector. Here are the results: > > The environment: 256MB Rackspacecloud VPS running Ubuntu 10.04.4 LTS > The cost: $11/mo > The command: ab -c 10000 -n 10000 -r http://theurl (that's 10k > requests, all concurrent). > > Node.js: ~2500 qps. Rock solid through multiple test runs, all > complete before the deadline. > Java SimpleHTTP: ~2100 qps. Had to bump heap up to 128MB. > Python Twisted: ~1600 qps. Failed a lot of requests on most test runs. > Python Tornado: ~1500 qps, but rock solid through multiple test runs. > > So basically, an $11/mo VPS server running Javascript vastly exceeds > the capabilities of 10 backends at $60/mo each. > Hi Jeff, Can you share your test methodology ? I would like to reproduce this testing on my side before escalating the results. In particular I'm wondering if are you calling ab on the backends directly, or on App Engine frontend that urlfetch to the backend in an handler? Thanks in advance. > > Jeff > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to google-appengine@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- Johan Euphrosine (proppy) Developer Programs Engineer Google Developer Relations -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
