Backoff delay duration less than minimum value - flutter

Back off delay duration less than minimum value in flutter download .
Notification keeps on loading

This is caused by the limitation of FlutterDownloaderPlugin.java
The minimum value is 10 seconds .i.e. The time gap between two consecutive downloads.
Set a duration of 10 seconds for the next download to occur.
The issue only occurs in andorid simulator, but it works in real device.

Related

What happens to Flutter Ticker if the UI misses frames due to bad performances?

I read on the the Ticker class documentation that:
"Ticker class calls its callback once per animation frame."
I am using createTicker(TickerCallback onTick) to implement a stopwatch. So I need the elapsed variable passed to the TickerCallback to be extremely precise (i.e. i need that after 5 seconds, the value of elapsed is exactly 5 seconds).
Now my question is: what happens if I have a sluggish UI very badly coded and that misses a lot of frame due to bad optimization? I can think of 2 cases:
The time of the stopwatch gets updated not at 60fps (because of my bad coding) but once it gets updated, the time being displayed is correct
The time displayed is wrong
Other?
Which is the case? And why (most importantly)? Also, considering the above, is it adviceable to use ticker for a stopwatch? Thanks
To answer your question(s):
1.The time of the stopwatch gets updated not at 60fps (because of my bad coding) but once it gets updated, the time being displayed is correct.
If phone works at 120 fps, does that mean it will forward time :)
Flutter aims to provide 60 frames per second (fps) performance, or 120 fps performance on devices capable of 120Hz updates. For 60fps, frames need to render approximately every 16ms. Jank occurs when the UI doesn't render smoothly.
So you may use ticker, and even if animation is sluggish, still it will display right time. Like on let say we have some delays on frames 500, they will be delays of animation not the time passed. Like on second 3 we have 1 second delay we will have 5 after that, it updates the screen, but timer will continue.
Also, considering the above, is it adviceable to use ticker for a stopwatch?
It is. At worst case you will have drop frames, jumping seconds but timer will be exact.

Google OR-Tools: Minimize Total Time

I am working on a VRPTW and want to minimize the total time (travel time + waiting time) cumulated for all vehicles. So if we have 2 vehicles one that starts at time 0 and returns at time 50 and one that starts at time 25 and returns at time 100, then the objective value would be 50+75=125.
Currently I have implemented the following code:
for i in range(data['num_vehicles']):
routing.AddVariableMinimizedByFinalizer(
time_dimension.CumulVar(routing.End(i)))
However, this seems like it is only minimizing the time we arrive back at the depot.
Also it results in very high waiting times.
How do I implement it correctly in Google OR tools?
This is called the span.
See the SetSpanCostCoefficientForVehicle method for one vehicle.
You can also set it for all vehicles.

reset chart to 0 in grafan

Below is a chart I have in grafana:
My problem is that if my chosen time range is say 5 minutes, the graph wont show only what happened in the last 5 minutes. So in the picture, nothing happened in the past 5 minutes so it's just showing the last points it has. How can I change this so that it goes back to zero if nothing has changed? I'm using a Prometheus counter for this, if that is relevant.
As explained in the Prometheus documentation, a counter value in itself is not of much use. It depends on when your job was last restarted and everything that happened since.
What's interesting about a counter is how much it changed over some period of time. I.e. either the average rate of change per second (e.g. 3 queries per second) or the increase over some time range (e.g. 10K queries in the last hour).
So instead of graphing something like e.g. http_requests, you should graph rate(http_requests[1m]) (the averate number of requests over the previous 1 minute) or increase(http_requests[1h]) (the total number of requests over the past hour). You can play with the range size until you get something which makes sense for your data. But make sure to use a range at least 2x your scrape interval (and ideally more, as Prometheus is somewhat daft in the way it computes rates/increases).

Detect an application that has not sent a message in the last 15 minutes using Kapacitor

We are writing a message count per application to InfluxDb every 10 seconds. I want to be able to generate an alert if that number has not changed in the last 15 minutes.
I tried derivative, but that gives the change for each data point. The unit parameter just scales the result. Derivative works well for our chattier apps where we can check if a message was sent every 10s, but the 15 minute window is not working.
I tried using spread with a batched query grouped by time, but that gives me the change in whole quarters of the hour (00 to 15, 15:01 to 30, 30:01 to 45...). I want to be able to check the last 15 minutes and check it every minute or so.
I tried using a windowed stream with spread, but it seems to be grabbing points outside the window since it is giving a non-zero answer.

iPhone - CLLocationManager stops updating while trying to acquire current location

I'm trying to acquire the current location on an iOS device (specifically, my iPhone).
I'm using this Apple example.
The timeout before I call stopUpdatingLocations is 60 seconds.
When I set the desiredAccuracy to be kCLLocationAccuracyHundredMeters, only 3 newLocations arrive to the didUpdateToLocation:fromLocation. The first one is the cached one, from long time ago. The next two ALSO have timestamps from more than 15 seconds, despite the fact that all 3 arrive within 5 seconds interval. All three of them contain bad horizontal accuracy.
On the other hand, when I set the desiredAccuracy to be kCLLocationAccuracyNearestTenMeters, newLocations continue to arrive until I get an appropriate, exact one.
My WiFi is off and I'm indoors.
My question is: why when using the kCLLocationAccuracyHundredMeters accuracy I stop receiving updates early?
Because when the location returned immediately satisfies the nearest accuracy, it stops? If this is not the case, can you show any logs or anything to further explain the situation if I have perhaps missed the point.