On Tue, May 17, 2011 at 10:13 PM, Robert Kluin <robert.kl...@gmail.com>wrote:
> Hi Greg, > I'm looking forward to seeing the scheduler improvements in the > coming weeks. Overall this looks promising, I'm actually pretty happy > to see that the API calls 'with checks' will be included and just > billed by time consumed. Is the 4x cost relative to a master-slave > (M/S) or high-replication (HR) apps? Certainly if that is relative to > M/S then it is not that bad, HR is totally worth it. ;) > Good point! It is relative to M/S. > Thanks for listening to and addressing the community's feedback. > We're trying our best, thanks for hanging in there :) > > > > Robert > > > > > > > > On Wed, May 18, 2011 at 00:49, Gregory D'alesandre <gr...@google.com> > wrote: > > Hello All! > > As you've likely heard, when Google App Engine leaves Preview in the > second > > half of 2011, the pricing model will change. Prices are listed here: > > http://www.google.com/enterprise/appengine/appengine_pricing.html. But > that > > leaves a lot of questions unanswered, this FAQ is intended to help answer > > some of the frequently asked questions about the new model. We are > > interested in hearing additional thoughts and comments you have based on > > this. Once it is relatively stable I'll add it to our official docs. If > > you find there is something you want to know but it is not yet answered, > > just ask and I'll try to answer it as clearly as possible. We've made > some > > changes based on the feedback we've gotten (from this group in > particular), > > they are bolded below but not updated on the external pages yet. There > are > > still blanks to fill in and I will be sending that information to this > group > > first in order as it is available. Finally, thank you for your questions > > and bearing with us as we are ironing out details, I and the whole App > > Engine team very much appreciate it. > > Greg D'Alesandre > > Senior Product Manager, Google App Engine > > > > ------------------- > > Definitions > > Instance: A small virtual environment to run your code with a reserved > > amount of CPU and Memory. > > Frontend Instance: An Instance running your code and scaling dynamically > > based on the incoming requests but limited in how long a request can run. > > Backend Instance: An Instance running your code with limited scaling > based > > on your settings and potentially starting and stopping based on your > > actions. > > Scheduler: Part of the App Engine infrastructure that determines which > > Instance should serve a request including whether or not a new Instance > is > > needed. > > > > Serving Infrastructure > > Q: What’s an Instance? > > A: When App Engine starts running your code it creates a small virtual > > environment to run your code with a reserved amount of CPU and Memory. > For > > example if you are running a Java app, we will start a new JVM for you > and > > load your code into it. > > > > Q: Is an App Engine Instance similar to a VM from infrastructure > providers? > > A: Yes and no, they both have a set amount of CPU and Memory allocated to > > them, but GAE instances don’t have the overhead of operating systems or > > other applications running, so a much larger percentage of the CPU and > > memory is considered “usable.” They also operate against high-level APIs > and > > not down through layers of code to virtual device drivers, so it’s more > > efficient, and allows all the services to be fully managed. > > > > Q: How does GAE determine the number of Frontend Instances to run? > > A: For each new request, the Scheduler decides whether there is an > available > > Instance for the request, the request should wait, or a new Instance > should > > be created to service the request. It looks at the number of Instances, > the > > throughput of the Instances, and the number of requests waiting. Based > on > > that it predicts how long it will take before it can serve the request > (aka > > the Pending Latency). If it predicts the delay will be over 1 second, a > new > > Instance is created. If it looks like an Instance is no longer needed, > it > > will take that Instance down. > > > > Q: Should I assume I will be charged for the number of Instances > currently > > being shown in the Admin console? > > A: No, we are working to change the Scheduler to optimize the utilization > of > > instances, so that number should go down somewhat. If you are using > Java, > > you can also make your app threadsafe and take advantage of handling > > concurrent requests. You can look at that as an upper bound on how many > > Instances you will be charged for. > > > > Q: How can I control the number of instances running? > > A: With the new Scheduler you’ll have the ability to choose a set of > > parameters that will help you specify how many instances are spun up to > > serve your traffic. More information about the specific parameters and > how > > they will affect the Scheduler will be available on this within a few > weeks. > > > > Q: What can I control in terms of how many requests an Instance can > handle? > > A: The single largest factor is your application’s latency in handling > the > > request. If you service requests quickly, a single instance can handle a > > lot of requests. Also, Java apps support concurrent requests, so it can > > handle additional requests while waiting for other requests to complete. > > This can significantly lower the number of Instances your app requires. > > > > Q: Will there be a solution for Python concurrency? Will this require > any > > code changes? > > Python concurrency will be handled by our release of Python 2.7 on App > > Engine. We’ve heard a lot of feedback from our Python users who are > worried > > that the incentive is to move to Java because of its support for > concurrent > > requests, so we’ve made a change to the new pricing to account for that. > > While Python 2.7 support is currently in progress it is not yet done so > we > > will be providing a half-sized instance for Python (at half the price) > until > > Python 2.7 is released. > > > > Q: How many requests can an average instance handle? > > A: Single-threaded Instances (python or java) can currently handle 1 > > concurrent request. Single-threaded Instances (python or java) can > > currently handle 1 concurrent request. Therefore there is a direct > > relationship between the latency and number of requests which can be > handled > > on the instance per second, for instance: 10ms latency = 100 > > request/second/Instance, 100ms latency = 10 request/second/Instance, etc. > > Multi-Threaded Instances can handle many concurrent requests. Therefore > > there is a direct relationship between the cpu consumed and the number of > > requests/second. For instance, for a B4 (approx 2.4GHz) instance: > consuming > > 10 Mcycles/request = 240 request/second/Instance, 100 Mcycles/request = > 24 > > request/second/Instance, etc. These numbers are the ideal case but they > are > > pretty close to what you should be able to accomplish on an Instance. > > Multi-Threaded instances are currently only supported for Java; we are > > planning support for Python later this year. > > > > Q: Why is Google charging for instances rather than CPU as in the old > model? > > Were customers really asking for this? > > A: CPU time only accounts for a portion of the resources used by App > Engine. > > When App Engine runs your code it creates an Instance, this is a maximum > > amount of CPU and Memory that can be used for running a set of your code. > > Even if the CPU is not currently working due to waiting for responses, > the > > instance is still resident and considered “in use” so, essentially, it > still > > costs Google money. Under the current model, apps that have high latency > > (or in other words stay resident for long periods of time without doing > > anything) are not able to scale because it would be cost-prohibitive to > > Google. So, this change is designed to allow developers to run any sort > of > > application they would like but pay for all of the resources that are > being > > used. > > > > Q: What does this mean for existing customers? > > A: Many customers have optimized for low CPU usage to keep bills low, but > in > > turn are often using a large amount of memory (by having high latency > > applications). This new model will encourage low latency applications > even > > if it means using larger amounts of CPU. > > > > Q: How will always-on work under the new model? > > A: Still determining how this will work, answer coming very soon (no > > seriously, we are almost done). > > > > Q: What is the difference between On-demand Instances and Reserved > > Instances? > > A: On-demand Instances have no pre-commitment in terms of the number that > > will be used. You pay for them as you use them. Reserved Instances are > > pre-commitment to a certain number of Instance Hours in a week. They are > > cheaper but you must pay for all the Instance Hours that you have > > pre-committed to whether you use them or not. This does not mean they > have > > to be running the whole time. > > > > Q: Wait, so Reserved instances don’t mean you have to keep them running > the > > whole time? > > A: No, it is just a way to get cheaper instance-hours by pre-committing > to > > them. > > > > Q: What is the time granularity of the instance pricing? ie if I have an > > instance up for 5 minutes, what am I charged, $0.08 / 60*5? > > A: Instances are charged for their uptime and until they are idle for 15 > > minutes (when the scheduler takes them down). So if you have an > on-demand > > Instance only serving traffic for 5 minutes, you will pay for 5+15 > minutes, > > or $0.08 / 60 * 20 = 2.6 cents. > > > > Q: You seem to be trying to account for RAM in the new model. Will I be > > able to purchase Frontend Instances that use different amounts of memory? > > A: We are only planning on having one size of Frontend Instance. > > > > Q: Do Frontend instances handle Task Queues and Cron? > > A: Yes. > > > > Q: Can the experimental Go Runtime handle concurrent requests? > > A: Not currently. > > > > Costs > > Q: Is the $9/app/month a fee or a minimum spend? > > A: Based on the feedback we’ve received we are changing this $9 fee to be > a > > minimum spend rather than a fee a originally listed. In other words you > > will still have to spend $9/month in order to scale but you won’t pay an > > additional $9 for your first $9 worth of usage each month. The > > $500/account/month will still be a fee as it covers the cost of > operational > > support. > > > > Q: Will most customers have to move to Paid Apps? > > A: No, we expect the majority of current active apps will still fall > under > > the free quota. > > > > Q: Will existing apps be grandfathered in and continue under today’s > billing > > model? > > A: No, existing apps will fall under the new billing model once App > Engine > > is out of preview. > > > > Q: Will most customers’ bills increase? If so, why is Google increasing > the > > price for App Engine? > > A: Yes, most paying customers will see higher bills. During the preview > > phase of App Engine we have been able to observe what it costs to run the > > product as well as what typical use patterns have been. We are changing > the > > prices now because GAE is going to be a full product for Google and > > therefore needs to have a sustainable revenue model for years to come. > > > > APIs > > Q: How were the APIs priced? > > A: For the most part the APIs are priced similarly to what they cost > today, > > but rather than charging for CPU hours we are charging for operations. > For > > instance the Channel API is $0.01/100 channels. This is approximately > what > > users pay today (although it would be paid as a fraction of a CPU hour). > > The datastore API is the most significantly changed and is described > below. > > > > Q: For the items under APIs on the pricing page that just have a check, > what > > does that mean? > > A: Those items come free with using App Engine. > > > > Q: For XMPP, how does the new model work? How much do presence messages > > cost? > > A: For XMPP we will only be charging an operation fee for outgoing > stanzas. > > Incoming stanzas are just considered requests similar to any other > request > > and so we’ll charge for the bandwidth used as well as whatever it takes > to > > process the request in terms of Instance Hours. We don’t charge for > > presence messages other than the bandwidth it consumes. This is almost > > exactly how it works today with the exception that your bill would show > CPU > > hours as opposed to Stanzas. > > > > Q: For Email, how much do incoming emails cost? > > A: Incoming emails will just be considered requests similar to any other > > request and so we’ll charge for the bandwidth used as well as whatever it > > takes to process the request in terms of Instance Hours. This is in > essence > > how it works today. > > > > Q: Will the Front End Cache feature ever be formalized as an expected, > > documented part of the service offering? > > A: We are currently looking at various options, but don’t yet have any > plans > > for when this would happen. > > > > Q: What is being charged for in terms of Datastore operations? What do > you > > expect the ratio to be between the new pricing metric and the Datastore > API > > calls metric we have today? > > A: Today we charge for the CPU consumed per entity written, index > written, > > entity read, query index scanned, and query result read. Under the new > > model we will charge per operation rather than CPU, and we will no longer > > charge for query index scans. This means the cost of your queries will > be > > tied exclusively to the size of your result set. We expect the cost of > > these operations will be approximately 4x the cost of the equivalent CPU > > under today’s model, but for apps that make heavy use of indexes, this > will > > be somewhat offset by the fact that we will no longer be charging for > query > > index scans. The admin console today shows total Datastore API Calls, > but > > this is not a good gauge of how many operations you will be charged for > > under the new model. Your costs will be highly dependent on the types > and > > contents of your API calls, not the number of calls themselves, which is > > what we currently display. For example a single get() API call may > retrieve > > 1 Entity or 100 Entities, and a beginTransaction() API call doesn’t > consume > > any billable resources. > > > > Q: Could emails sent to admins be cheaper or free? > > A: That’s a possibility that we can look into. > > > > Usage Types > > Q: What does the Premier cost of "$500/account" mean? Per Google Apps > > Account? Per Developer Account, Per Application Owner Account? > > A: It is per Organization (which would translate into per Google Apps > > account if you are currently a Google Apps customer). So, for instance > if > > you are working at gregco.com and you signed up for a Premier account, > > gregco.com users will be able to create apps which are billed to the > > gregco.com account. > > > > Q: Will there be special programs for non-profit usage? > > A: Possibly, we are currently looking into this. > > > > Q: Will there be special programs for educational usage? > > A: Possibly, we are currently looking into this. > > > > Q: Will there be special programs for open-source projects? > > A: Possibly, we are currently looking into this. > > > > Usage Limits > > Q: If I migrate to HR Datastore, does that mean I have a "newly created" > > application, and will get the new, lower, free quota for email? Could > you > > grandfather in migrated apps at the old 2000 limit? > > A: Yes, we can grandfather in the email quota for HRD apps that are > > migrating from M/S apps. > > > > -- > > 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. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. 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