...except that even with steady traffic, appengine seems to be restarting some Java apps all the time. I get a steady 30-60 requests/min and I'm looking at 20 restarts in the last 4 hours.
Jeff On Mon, Jan 18, 2010 at 11:44 PM, Gary B <gary.b...@gmail.com> wrote: > The App Engine team recently blogged about loading request performance > in Java: > http://googleappengine.blogspot.com/2009/12/request-performance-in-java.html > If your application has a steady stream of traffic, then loading > requests are infrequent and should not contribute significantly to the > cost of running your application. > > I also tested loading request times using simple "Hello World" > applications. Here are the times that I found in App Engine CPU ms: > > Python 85 > Java 525 > Clojure 2955 > > The Java and Clojure applications used precompilation..The source is > available here: http://github.com/garyburd/app-eng-cold-start-test > > On Jan 18, 9:23 pm, Locke <locke2...@gmail.com> wrote: >> Out of curiosity, I decided to implement "hello world" in the two >> official, and one unofficial, languages that run on AppEngine. These >> apps make no use of the datastore or any services. They just print >> "hello world." >> >> The methodology was simply to run the app three times, waiting for >> about a minute for AppEngine to unload my app between each request. >> >> All times are in "wall time." Google typically bills you for "CPU >> time," which is greater than wall time. The units are seconds. >> >> --- jruby + rack: >> 15.5 >> 18.0 >> 13.8 >> average: 15.8 seconds >> >> --- python + google's "webapp" micro-framework: >> 0.127 >> 0.170 >> 0.079 >> average: .0.125 seconds >> >> --- java: >> 0.911 >> !! canceled after 10 seconds with "Request was aborted after waiting >> too long to attempt to service your request." !! >> 2.4 >> 4.2 >> average: 2.5 seconds not counting the fatal error >> >> In all three cases, the apps respond in about one tenth those times if >> they were already loaded. >> >> And yes, Java performance is all over the map! My simple "hello world" >> java app was killed by AppEngine. It was merely running the template >> code that came with the java SDK. >> >> My test shows that Python on AppEngine is excellent--some of the >> fastest web app execution I've seen on any host anywhere. AppEngine's >> Java support, on the other hand, should very much be considered a >> "preview release" product. When "hello world" is killed by AppEngine >> for taking too long to respond, you know there are some major problems >> to work out. Bot both java and jruby, once loaded, run at quite >> acceptable speeds. Unfortunately, they are reloaded after mere seconds >> without hits, and those reloads can sporadically end in 500s. Based on >> these numbers, I would not enable billing or AppEngine Java, nor would >> I use it for "production" applications at this time. But AppEngine >> Java hasn't been around nearly as long as the Python version, so >> perhaps this is understandable. >> >> (the java crash error follows) >> >> 01-18 08:50PM 42.121 /helloappengine 500 10085ms 0cpu_ms 0kb Mozilla/ >> 5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) Gecko/20091221 >> Firefox/3.5.7 (.NET CLR 3.5.30729),gzip(gfe) >> [myip] - - [18/Jan/2010:20:50:52 -0800] "GET /helloappengine HTTP/1.1" >> 500 0 - "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) >> Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729),gzip(gfe)" "[myapp]" >> W 01-18 08:50PM 52.206 >> Request was aborted after waiting too long to attempt to service your >> request. Most likely, this indicates that you have reached your >> simultaneous dynamic request limit. This is almost always due to >> excessively high latency in your app. Please >> seehttp://code.google.com/appengine/docs/quotas.htmlfor more details. > > -- > 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-appeng...@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. > > > >
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