Hey Ivo, The qualification for a hot key is a key that receives over 100 QPS in the memcache, as our docs say [1]. You have had a few hot keys over the course of the past few days, from our investigation. These ought to have been displayed. We've taken note of this and created an internal issue to track work on it. You can follow this public issue [2] for updates.
Cheers, Nick Cloud Platform Community Support [1] https://cloud.google.com/appengine/docs/standard/java/memcache/using#monitoring_memcache [2] https://issuetracker.google.com/36103562 On Friday, March 3, 2017 at 6:00:20 AM UTC-5, Ivo Bellin Salarin wrote: > > Hi all, > > I have two questions concerning memcache and its performances. > > I was reading the page > https://cloud.google.com/appengine/articles/best-practices-for-app-engine-memcache#distribute_load_across_the_keyspace, > > where I found > *The Memcache viewer in the administration console displays a list of top > keys, which can be used to identify bottlenecks* > > In my administration console, this section is empty. (i.e. 'No hot keys') > But yes, I am sure that there are hot keys, since among the stackdriver > insights I can see the following messages > Slow memcache calls. Your app made 1 remote procedure calls to memcache > that took more than 50 ms and the slowest call took 66 ms. Consider > reducing the value of max_concurrent_requests for your app. > 1) Thus, where can I find the hottest keys of my dedicated memcache? > > In the meanwhile, according to the messages I can find in StackDriver, the > longest (thus, probably, hottest) memcache.get(s) are made by ndb.get(). In > the code of ndb.get I can see that the cache keys are **not** distributed > across the keyspace (as recommended by the page above). > I think that not using memcache (use_memcache=False) would be a worse > solution. > 2) Is there a way to force a better key distribution for NDB, apart from > monkey patching > /gcloud/platform/google_appengine/google/appengine/ext/ndb/context.py::Context._memcache_prefix > > with a time dependent % operation? :-) > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/555801c2-75f1-47c9-8470-a9df33520f2a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
