I posted this logic once before but people only listen when they are ranting.
You can only change an entity once per second. You can however maintain a data store "Cache" that will save you money, writes, and prevent you from ever seeing write limits. By maintaining a Small DataStore of "Writes To commit" things you want to write to data store permanently can be put in to a data store which you increment the task on. When you do a Read from the datastore you check that the writes to commit don't supersede the data in the main data store. This will save you on indexing operations, and reduce your write throttling and if done correctly can even move most of your reads to Memory rather than DataStore. This will increase your number of reads. Which will increase your Costs slightly over MS, but likely is better than having MS down or MS Read OnlyTime. From: google-appengine@googlegroups.com [mailto:google-appengine@googlegroups.com] On Behalf Of Andrius A Sent: Tuesday, December 06, 2011 3:44 PM To: google-appengine@googlegroups.com Subject: Re: [google-appengine] Re: DeadlineExceeded errors haunting every now and then In docs it says that HRD is more costly "The High Replication Datastore costs more due to the additional replication (see billing page for pricing details). Due to the higher cost, we recommend High Replication Datastore primarily for those developers building critical App Engine applications that require the highest availability". It also says "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). Therefore, writing to a single entity group per guestbook is not ideal when high usage is expected. If your app is likely to encounter heavy write usage, consider using another means. For example, you can put recent posts in memcache with an expiration, and then display a mix of recent posts from memcache and posts retrieved from the datastore." How could we trust by putting data to memcache if we know it can be evicted any time? To use HRD is not viable for applications which need strong consistency for high rate of puts. At the moment MS is perfect what it does but bloody thing keeps dying.. I can't believe there is no way to improve MS and you are switching to HRD. In long term HRD can cause more problems for applications parts were it wasn't aticipating to receive higher rate of inserts, and having a limit of 1 write per second is a disastrous. On 6 December 2011 23:29, Gregory D'alesandre <gr...@google.com> wrote: Hi Kenneth, We are planning to add blobstore migration at some point but it won't likely be until the middle of Q1 at the earliest. Greg On Tue, Dec 6, 2011 at 3:27 PM, Kenneth <kennet...@aladdinschools.com> wrote: Hi Greg, Can you give us some indication if the migration tool is ever going to include blobstore migration? That's the only thing holding me back. I know I can do it myself but I'd rather not. I see now that it has gone ga, have you stuck a fork in it and called it done? Thanks -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/f7KzNP-pCuwJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com <mailto:google-appengine%2bunsubscr...@googlegroups.com> . 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 google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com <mailto:google-appengine%2bunsubscr...@googlegroups.com> . 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 google-appengine@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. -- 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-appengine@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.
