You have a mild conceptual misunderstanding - you are always using entity groups whenever you use the datastore, both for M/S and HR. If you do nothing special, every entity will go into its own entity group so you can write to each one at 1/sec. But this involves tradeoffs WRT transactions and eventual consistency.
Another alternative is to put your entire database in a single entity group, which gives you perfect consistency and transactionality but limits you to 1 write per second. Obviously this is pretty preposterous, so in reality you will need to create a balance of entity grouping. The rule of thumb of "one user's data" is not a bad one, but it's not a hard and fast rule. Jeff On Fri, Oct 21, 2011 at 1:03 PM, Philip <[email protected]> wrote: > So that's what seems odd to me. The HR datastore is best used with > entity groups and yet there is such a huge limit on its throughput. > > Since we can't rely on memcached values staying around (since they > might be purged at any time), there seems to be no decent workaround > for having immediately consistent reads (in case memcache is purged) > without being limited to 1 write per second. > > Do I have that write (pun intended)? > > On Oct 21, 12:32 pm, Steve Sherrie <[email protected]> wrote: > > This just refers to the entity group write limit that is the same in > > both MS and HR datastores. > > > > On 11-10-21 03:30 PM, Philip wrote: > > > > > > > > > > > > > > > > > I am concerned about the statement: > > > > > "This allows queries on a single guestbook to be strongly consistent, > > > but also limits changes to the guestbook to * 1 write per second * > > > (the supported limit for entity groups)." > > >http://code.google.com/appengine/docs/python/datastore/hr/overview.html > . > > > > > Is it true that writes are limited to 1 per second when using the high > > > replication datastore or is this an old limitation? > > -- > 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. > > -- 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.
