Hi Have you checked that startup times on a lightly used system are not inflating your response times ?
T On Mar 13, 3:05 pm, Patrick Twohig <[email protected]> wrote: > Hi, > > I asked once before, but I'm getting some painfully slow requests in my > app. Even on queries that I am certain only fetch a few entities, (5-10 max > under absolutely worst case circumstances). I also take advantage of memory > caching wherever possible, and I have confirmed (via logging) that I'm > pulling from the cache. Some requests are taking upwards of 2-3 seconds. > And given that my app right now is mostly a web service and not running in a > browser, there's quite a few things that are perplexing me. SO I have a few > questions: > > - I'm running JAX-RS (Jersey), a little Groovy, low level API (no JDO or > JPA), and Guice (yep, I'm a Google fanboy). I have identified where Groovy > is being slow, and came up with a workaround for that, so I'm not too > concerned. > - What's a reasonable number of entities I should fetch from the > datastore per request? I currently fetch at least one per request to > validate a user's login credentials, so no matter what I'm fetching at > least > one per request. Adding up the numbers in my head, I don't think that > - Even with aggressive caching, (all of my data objects get put in > memcache), it still behaves rather slowly? What is the penalty speed-wise > for using a transaction? I can't use caching with a transaction obviously > because I can't be guaranteed any consistency of data. If I start a > transaction and and commit it or roll it back and perform no operations in > it, what is the penalty? I'm certain this happens in my app, albeit very > infrequently. > - What's up with queries? They just tend to be really really slow. > - I know loading requests are a problem, but I'm not hitting many of > those according to the logs, so I can rule those out as being a > contributing > factor (unless there's something I don't know). I also don't use JSPs, > most > of it is static. > - How much of a performance difference does a bulk fetch/put cost versus > a bunch of individual ones? I haven't seen much of a difference, but maybe > I'm doing it wrong. > - There are zero use cases in my application where more than two users > write to the same entity group, except for a counter for which I use > sharding offloaded to the task queue. Is there a penalty for many users > reading from a single entity group at the same time? > > Thanks, > > -- > Patrick H. Twohig. > > Namazu Studios > P.O. Box 34161 > San Diego, CA 92163-4161 -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
