On Sat, 2002-03-23 at 18:44, Chris McDonough wrote:
Chris, how high of an rps would you expect a nicely powered (say, dual Athlon 2000+, 1-2GB RAM) ZEO Server to handle, roughly speaking?
Depending on the type of site it was (writes are much more expensive than reads in almost all contexts), and how well the code was written, I'd imagine that a single Zope backended by ZEO could crank out on the order of 30 - 90 r/s. But the ZEO server isn't the bottleneck here, it's Zope.
Right, I want to determine if anyone knows what the ZEO Server's limit is.
The ZEO server I mentioned that spikes the processor is fronted by 10 ZEO clients, but each appserver is only capable of delivering a nominal 7 requests/sec due to a lack of app optimization. After caching, the ZEO server ends up servicing somewhere on the order of 5 transactions per second or so during normal load, but I can imagine that it's serving about 5X that number during peak periods.
OK, so I'll use TPS then. :) So, the aforementioned ZSS is peaking (estimated) at ~25 TPS. We can safely assume that it could handle ~90 TPS (as in the case of a single Zope Server connected to it. Basically, I'm looking at it like this: Assuming good code, an emphasis on reads, and several hundred Zope Server front ends, at what point, measured in TPS, could I expect my ZSS to fall over? Not RPS for the whole site overall, but transactions per second for the storage server. Through ZEO, Zope has awesome potential to scale, but we will eventually hit a limit when it comes to a single ZEO Storage Server. It would be good to know that limit. -- Bill Anderson Linux in Boise Club http://www.libc.org Amateurs built the Ark, professionals built the Titanic. Amateurs build Linux, professionals build Windows(tm).