Wontfix on need max-idle instances 0, but my single idle instance won't go away.

[Tim Hoffman]

Hi

Just got the email saying issue "We need to be able to set "Max-Idle-Instance" to 0" 

http://code.google.com/p/googleappengine/issues/detail?id=5764 wont be fixed.

In that case there is a problem with the scheduler not shutting down idle instances.

My app your-pond, has a single instance that has been running for over 10 hours, serviced 11 requests during that time and the last one

was about an hour ago.

Total number of instances	Average QPS*	Average Latency*	Average Memory
1 total	0.000	Unknown ms	51.0 MBytes

Instances 

QPS*	Latency*	Requests	Errors	Age	Memory	Availability
0.000	0.0 ms	11	0	10:59:52	51.0 MBytes	Dynamic

Request graph for the last 6 hours.

Instances graph for the same period

Notice the graph of instances actually only shows instances for the periods when requests where made, however the instances view

tells a different story. That the instance has been around for 10 hours. Do I believe the graph or the instances view ?

This instance does not have billing enabled. This behavior means the free quota will be used up keeping a single instance alive

rather than used for actual work.  (I will be turning billing on for this instance but that shouldn't matter to the behaviour).  

The startup time is neglible for this particular app and it is on HR, so it seems reasonable that any idle instance should be shut down after 15 minutes.

Regards

Tim Hoffman

[Barry Hunter]

From what Jon said in another thread ("min instace time is 24 hours?"), instances may be left hanging around (as they happen to be on a fortuitous machine) 

But you are not changed for these. ie its the lines on the graphs that actully affect billing (see Jons equations in the same thread) 

... i.e. you get a instance sitting around ready to serve a request at a moments notice. For free. Bonus. 

(or another way, its better for Google to not bother tearing it down, only to have to put it back later) 

--
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/-/xfDJsIK6W-IJ.
To post to this group, send email to google-a...@googlegroups.com.
To unsubscribe from this group, send email to google-appengi...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.

[Tim Hoffman]

Hi Barry 

Thanks for pointing out that thread.

I am still not 100% convinced from what Jon said is the whole picture

He did say that they may not kill of idle instances and the graph shows that.

But he also says that max-idle-instances=1  equates to 24 billable hours.  So I am inclined to conclude

that his comment about not killing off idle instances refers to idle instances >1 , rather than the single idle instance.

His last point was that

(e) billable-instances-rate = min(active-instances-rate +

max-idle-instances, total-instances-rate) = min(0.0033 + 1, 1) = 1

So if I have absolutely no activity for 20 hours, but 24 instance hours activity in 4 hours, based on those

calculations if I have a single instance idle for the 20 hours as well. I would expect to billed for 

What do you think ?

Rgds

Tim

[Dani Shaulov]

But he also says that max-idle-instances=1  equates to 24 billable hours.

He did not say that. He clearly said that an instance will not be billed after 15 mins of inactivity.

You will get 24 billable hours if you ping(make a request) the system at a rate of at least 1 time every 15 minuets.

You are billed by the data on the graph (3 bursts of 15 minuets each = 45 instance minuets or 0.75 hours in the time period the graph shows)

You better wait 3 days and see the billing history for today - and will be able to see under the expected new billing prices that there was no use of 10 hours.

I had and instance that seemed to run for 2 straight days (age was 2 days). now i have a billing history of that day and it only shows a few hours NOT 24

[Dani Shaulov]

And, your total-instance-rate is the blue line in the graph. As you can see it is 0 most of the time not 1. So in the formula you put 0 for most of the idle hours.

[Tim Hoffman]

Ok, where he said that was in the context of someone pinging every minute rather than as

a general statement.

It would be good if the instances view showed billable instance hours against each instance.  

I might have to wait more than 3 days to see the billing, I am currently 4 days behind on all of my billing statements.

Rgds

Tim

[Jon McAlister]

Hi Tim,

As Dani explained, if there are no instances that have received a
request in the last 15 minutes, then the billable-instances-rate for
that time period is indeed 0. So, in your last example, the
billable-instances for the day would be 4. I'm happy to walk through
other scenarios if you'd like me to.

Also, we've been working hard to speed up the delivery of the billing
reports. We'll get it down to <1-day reporting hopefully this week.

Also agreed that a graph for billable-instances-rate is a good idea. I
believe there is an issue filed for it.

> --
> 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/-/nNxTrJHQAHgJ.

[Tim Hoffman]

Hi Jon

Thanks for the update.

Faster billing will help a lot.

I don't envy the person who gets to write up all these billing behaviours in a

clean concise fashion.  A job for an good technical writer.

See ya

T