Sounds great. Would it be reasonable to expect that read latencies would be slightly better due to the datastore being more highly replicated?
On 6 January 2011 10:17, Ikai Lan (Google) <[email protected]<ikai.l%[email protected]> > wrote: > By the way, I should mention that there is no Java SDK. This is *almost* > completely a server side change. > > The Python SDK ships with migration tools for migrating an existing > application to an HR instance. As of right now, there are no Java tools - > please use the Python SDK if you need this functionality. > > > -- > Ikai Lan > Developer Programs Engineer, Google App Engine > Blogger: http://googleappengine.blogspot.com > Reddit: http://www.reddit.com/r/appengine > Twitter: http://twitter.com/app_engine > > > > On Wed, Jan 5, 2011 at 3:15 PM, Ikai Lan (Google) < > [email protected] <ikai.l%[email protected]>> wrote: > >> Hey everyone, >> >> If you don't already subscribe to our blog in your RSS reader, I advise >> that you do so: >> >> >> http://googleappengine.blogspot.com/2011/01/announcing-high-replication-datastore.html >> >> I've embedded the post below. This is a feature that I'm very excited >> about. Feel free to post to this thread if you have any questions. >> >> Announcing the High Replication Datastore for App >> Engine<http://googleappengine.blogspot.com/2011/01/announcing-high-replication-datastore.html> >> >> When App Engine launched over two years ago, we offered a Datastore that >> was designed for quick, strongly consistent reads. It was based on a >> Master/Slave replication topology, designed for fast writes while still >> allowing applications to see data immediately after it was written. For the >> past six months, as you are probably aware, we’ve been struggling with some >> reliability >> issues<http://googleappengine.blogspot.com/2010/06/datastore-performance-growing-pains.html> >> with >> the App Engine Datastore. Over the course of the past few months, we’ve made >> major strides in fixing these issues. However, our experience with these >> issues has made us rethink some of our design assumptions. As we promised >> you in some of our outage >> reports<https://groups.google.com/group/google-appengine-downtime-notify/msg/e9414ee6493da6fb?pli=1> >> earlier >> this year, we wanted to give you a more fundamental solution to the problem. >> >> Today I’m proud to announce the availability of a new Datastore >> configuration option, the High Replication Datastore. The High Replication >> Datastore provides the highest level of availability for your reads and >> writes, at the cost of increased latency for writes and changes in >> consistency guarantees in the API. The High Replication Datastore increases >> the number of data centers that maintain replicas of your data by using the >> Paxos >> algorithm <http://labs.google.com/papers/paxos_made_live.html> to >> synchronize that data across datacenters in real time. One of the most >> significant benefits is that all functionality of your application will >> remain fully available during planned maintenance periods, as well as during >> most unplanned infrastructure issues. A more detailed comparison between >> these two options is available in our >> documentation<http://code.google.com/appengine/docs/python/datastore/hr/> >> . >> >> From now on, when creating a new application, you will be able to select >> the Datastore configuration for your application. While the current >> Datastore configuration default remains Master/Slave, this may change in the >> future. >> <http://2.bp.blogspot.com/_dLfQMJsmsaI/TSTL4Cwfg3I/AAAAAAAAAI8/LR_gHxATJto/s1600/hr.png> >> Datastore configuration options when creating an app. >> >> The datastore configuration option can not be changed once an application >> is created, and all existing applications today are using the Master/Slave >> configuration. To help existing apps migrate their data to an app using the >> High Replication Datastore, we are providing some migration tools to assist >> you. First, we have introduced an option in the Admin Console that allows an >> application toserve in read-only >> mode<http://code.google.com/appengine/docs/adminconsole/applicationsettings.html#Disable_Datastore_Writes> >> so >> that the data may be reliably copied between apps. Secondly, we are >> providing a migration tool with the Python SDK that allows you to copy from >> one app to another. Directions on how to use this tool for Python and Java >> apps is documented >> here<http://code.google.com/appengine/docs/adminconsole/datastoreadmin.html#Copying_Entities_to_Another_Application> >> . >> >> Now, a word on pricing: Because the amount of data replication >> significantly increases with the High Replication datastore, the price of >> this datastore configuration is different. But because we believe that this >> new configuration offers a significantly improved experience for some >> applications, we wanted to make it available to you as soon as possible, >> even though we haven’t finalized the pricing details. Thus, we are releasing >> the High Replication Datastore with introductory pricing of 3x that of the >> Master/Slave Datastore until the end of July 2011. After July, we expect >> that pricing of this feature will change. We’ll let you know more about the >> pricing details as soon as they are available, and remember, you are always >> protected when pricing changes occur by our Terms of >> Service<http://code.google.com/appengine/terms.html>. >> Due to the higher cost, we thus recommend the High Replication Datastore >> primarily for those developers building critical applications on App Engine >> who want the highest possible level of availability for their application. >> >> Thank you, everyone, for all the work you’ve put into building >> applications on App Engine for the past two years. We’re excited to have >> High Replication Datastore as the first of many exciting launches in the new >> year, and hope you’re excited about the other things we’ve got in store for >> App Engine in 2011. >> Posted by Kevin Gibbs, The App Engine Team >> >> >> >> -- >> Ikai Lan >> Developer Programs Engineer, Google App Engine >> Blogger: http://googleappengine.blogspot.com >> Reddit: http://www.reddit.com/r/appengine >> Twitter: http://twitter.com/app_engine >> >> > -- > 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]<google-appengine%[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.
