Ikai,

I had that full hour and a half gap.

I have a chained task that runs like this (in fact, there is nothing else
running in the day for my app except this single background task):

1.  After the task's primary work is done, it calculates a delay like so:

now = datetime.today()
seconds = 60*(now.minute) + now.second
delay = 300 - seconds%300

2. It adds a task to the queue with a delay = the delay calculated above.

The expected result is that the task should run at the next 5 minute mark.

A task successfully ran at 10:30 AM PST, and presumably added a task with a
delay that would have the next one start at 10:35 AM PST.

Instead, nothing at all happens in my logs or on my dashboard or anywhere
until 11:53 AM PST when the task runs successfully and resumes the once
every 5 minutes chained process.

I know that the 11:53 AM task that ran is the expected 10:35 AM task since
they use numeric task names and it is the next task in the sequence.

So, there are two probable explanations:

1. The task was sitting in the queue and was scheduled to run at 10:35 AM
PST.. but was not executed until 11:53 AM PST for unknown reasons.
2. Somehow the delay ended up being equal to about 4800 seconds.

Pretty much, option 2 is impossible.  Even if datetime.now() returned some
wildly wrong value.. seconds%300 will always return some value less than
300.  thus the delay is going to be between 300 and 1.

So, the task should always start within 300 seconds (or 5 minutes) if the
delay setting works for task.add().

Even though I did not view the Task Queue during this delay, I feel fairly
confident that.. there was a task sitting in my default queue (and, in fact,
was the only task scheduled for my entire app during that time) for over
4,800 seconds that had a delay setting that was less than 300 seconds.

On Fri, Sep 17, 2010 at 11:45 AM, Ikai Lan (Google) <
[email protected] <ikai.l%[email protected]>> wrote:

> It looks like there was a period of time when tasks were not executing. It
> shouldn't have been an hour and a half, but I'll double check.
>
>
> On Fri, Sep 17, 2010 at 11:18 AM, Tom Wu <[email protected]> wrote:
>
>> +1, me too.
>>
>>
>> 2010/9/17 Francois Masurel <[email protected]>
>>
>> Yep, I can confirm this tasks and cron gap shows in my dashboard.
>>>
>>> On Sep 16, 11:50 pm, Eli Jones <[email protected]> wrote:
>>> > I second this report.
>>> >
>>> > I have an app that has a chained task that executes every 5 minutes.
>>>  Each
>>> > time the task completes it enqueues the next task to be executed (the
>>> next
>>> > task is always scheduled for the next 5 minute mark).
>>> >
>>> > From looking at the logs.. the task ran fine at 10:30 AM PST.. then
>>> just did
>>> > nothing (no errors no nothing) until 11:53 AM PST when it just started
>>> > running again.
>>> >
>>> > So, there was pretty much an hour and a half gap.. with nothing
>>> happening.
>>> >
>>> > This chained task has been running fine for the past 9 months with no
>>> > mysterious gaps like this.
>>> >
>>> >
>>> >
>>> > On Thu, Sep 16, 2010 at 2:57 PM, Chris Vaughn <[email protected]>
>>> wrote:
>>> > > According to the app engine system stats page everything is running
>>> > > fine but I'm seeing an issue that I can't figure out.
>>> >
>>> > > I have an app that relies heavily on task queues.  Every minute or so
>>> > > a payload comes in and is broken into 1 or many (depending on the
>>> size
>>> > > of the payload) schedule tasks and added to the "schedule-queue".
>>>  For
>>> > > the last 1h 15m nothing in my schedule-queue has been executed.  I
>>> see
>>> > > no errors in the logs and it has stayed at 0 run in the last minute.
>>> > > Here's a screenshot from my admin page of that one queue.
>>> > >http://skitch.com/chris.vaughn/dabtu/task-queues-appspot.com
>>> >
>>> > > I've found another user on Twitter reporting similar behavior at the
>>> > > same time.
>>> > >http://twitter.com/bjschnei/status/24685776803
>>> >
>>> > > Chris
>>> >
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