I'm working on a project where i have a window with a size of 4 days, with a step of 1 day
.timewindow(Time.days(4), Time.days(1))
and i have also a trigger
.trigger(new myTrigger)
onEventTime ---> Continue
onProccessingTime ---> Continue
clear ---> Purge
onElement---> (if element.isFinalTransaction) TriggerResult.FIRE_AND_PRUGE
isFinalTransaction is a boolean, when true it call FAP.
the mean question is how can i make it return true/false depending on if the element is the last in the window or not
is there any method that can tell us if the current element is the last one in the window?
is there any method that can tell us if the current window is done (before sliding) or not ?
From the abstract trigger class (https://github.com/apache/flink/blob/master//flink-streaming-java/src/main/java/org/apache/flink/streaming/api/windowing/triggers/Trigger.java)
The short answer is no. The method onElement is called for every element that gets added to the pane. When an element gets added it's impossible to know if it is the last element, because that information is not known until the next element comes (and we see if it was in this window or the next one).
However, one alternative would be to check if the element is sufficiently close to the end of the end of the window (because onElement has access to window e.g. if (timestamp > window.getEnd - delta) ...
However, I can not think of a use case in which I would recommend this. If you need access to the last element in the window, you should probably just use a WindowFunction and in the apply method get the last element of the input iterable (input.last).
Related
The "Assembler" should stop working for 2 hours after 10 assemblies are done.
How can I achieve that?
There are so many ways to do this depending on what it means to stop working and what the implications are for the incoming parts.. but here's one option
create a resourcePool called Machine, this will be used along with the technicians:
on the "on exit" action of the assembler do this (I use 9 instead of 10 because the out.count() doesn't count until the agent is completely out, so when it counts 9, it means that you have produced 10)
if(self.out.count()==9){
machine.set_capacity(0);
create_MyDynamicEvent(2, HOUR);
}
In your dynamice event (that you have to create) you will add the following code:
machine.set_capacity(1);
A second option is to have a variable countAssembler count the number of items produced... then
on exit you write countAssembler++;
on enter delay you write the following:
if(countAssembler==10){
self.suspend(agent);
create_MyDynamicEvent(2, HOUR,agent);
}
on the dynamic event you write:
assembler.resume(agent);
Don't forget to add the parameter needed in the dynamic event:
Create a variable called countAssembler of type int. Increment this as agents pass through the assembler. Also create a variable called assemblerStopTime. You also record the assembler stop time with assemblerStopTime=time()
Place a selectOutputOut block before the and let them in if countAssembler value is less than 10. Otherwise send to a Wait block.
Now, to maintain the FIFO rule, in the first selectOutputOut condition, you need to check also if there is any agent in the wait block and if the current time - assemblerStopTime is greater than 2. If there is, you free it and send to the assembler with wait.free(0) function. And send the current agent to wait. You also need to reset the countAssembler to zero.
Let's say I have 3 pairs of pickup and delivery(6 nodes), and their own time windows.
0-Node_start #Index(0)
1-Pickup, 2-Delivery #Index(1,2)
3-Pickup, 4-Delivery #Index(3,4)
5-Pickup, 6-Delivery #Index(5,6)
7-Node_end #Index(7)
How can I force my vehicle to go from node start to index_3, then continue with the rest of the route directly without changing the time window of a node in index_3, or changing the traveling time to 0 from node_0 to node_3? This should be possible regardless of the time taken from index_0 to index_3, as long as time windows allow.
Also, not sure if this is important in this case, but I use FirstSolutionStrategy.GLOBAL_CHEAPEST_ARC
I have found a solution that works for my case, hopeful it will work for others too. I used NextVar
consecutive_locations = [[1,3], [7,9]]
for location_index in consecutive_locations:
routing.solver().Add(routing.NextVar(location_index[0]) == location_index[1])
I used a loop because I have multiple vehicles, each vehicle has a specific starting point, and a location I want it to visit next after starting point.
The solution takes longer though, I think firstSolutionStrategy might be the issue(Not sure)
I call gtk_window_is_active(wnd) and always receive 0, even when I know for sure that wnd is active and receiving keyboard input. What is the cause and where is the remedy for this?
In fact, I run gtk_window_list_toplevels() and iterate over the list - and gtk_window_is_active() returns 0 for each of them!
When you create a GtkWindow it is still in the 'unrealized' state. You have to call show() on it and let the main loop run, then the window gets realized. So if you call gtk_window_is_active after creating the windows, but before the main loop has chances to run, you will get false.
Thanks to Emmanuele Bassi, Gnome Foundation staff, I figured it out: the problem is that my focus-in-event handler returned 1 (TRUE), and thus prevented the default GTK behaviour. It turned out (something not obvious) that keeping track of the active window is part of that default behavior that i unknowingly overrode.
So, I changed focus-in-event handler of my windows to return FALSE (0), and ever since gtk_window_is_active() works like a clock.
I came to realize an unhelpful (to my task) detail: gtk_window_is_active() only works AFTER all focus-in-event handlers have completed working. Well, I have a mouse click handler that activates some other window, and then needs to check if a certain window is active (these things belong to different objects and different modules, yet are executed within one click hadler invocation). In my case gtk_window_is_active() is useless: it returs FALSE for the active window until after my click handler has finished and the focus-in-handlers (mine and the default) have finished, too.
I have flink stream and I am calucating few things on some time window say 30 seconds.
here what happens it is giving me result my aggregating previous windows as well.
say for first 30 seconds I get result 10.
next thiry seconds I want fresh result, instead I get last window result + new
and so on.
so my question is how I get fresh result for each window.
You need to use a purging trigger. What you want is FIRE_AND_PURGE (emit and remove window content), what the default flink trigger does is FIRE (emit and keep window content).
input
.keyBy(...)
.timeWindow(Time.seconds(30))
// The important part: Replace the default non-purging ProcessingTimeTrigger
.trigger(new PurgingTrigger[..., TimeWindow](ProcessingTimeTrigger))
.reduce(...)
For a more in depth explanation have a look into Triggers and FIRE vs FIRE_AND_PURGE.
A Trigger determines when a window (as formed by the window assigner) is ready to be processed by the window function. Each WindowAssigner comes with a default Trigger. If the default trigger does not fit your needs, you can specify a custom trigger using trigger(...).
When a trigger fires, it can either FIRE or FIRE_AND_PURGE. While FIRE keeps the contents of the window, FIRE_AND_PURGE removes its content. By default, the pre-implemented triggers simply FIRE without purging the window state.
The functionality you describe can be found in Tumbling Windows: https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/windows.html#tumbling-windows
A bit more detail and/or code would help :)
I'm little late into this question but I encountered the same issue with OP's. What I found out later was a bug in my own code. FYI my mistake could be good reference for your problem.
// Old code (modified to be an example):
val tenSecondGrouping: DataStream[MyCustomGrouping] = userIdsStream
.keyBy(_.somePartitionedKey)
.window(TumblingProcessingTimeWindows.of(Time.of(10, TimeUnit.SECONDS)))
.trigger(ProcessingTimeTrigger.create())
.aggregate(new MyCustomAggregateFunc(new MyCustomGrouping()))
Bug happened at new MyCustomGrouping: I unintentionally created a singleton MyCustomGrouping object and reusing it in MyCustomAggregateFunc. As more tumbling windows created, the later aggregation results grow crazy! The fix was to create new MyCustomGrouping each time MyCustomAggregateFunc is triggered. So:
// New code, problem solved
...
.aggregate(new MyCustomAggregateFunc(() => new MyCustomGrouping()))
// passing in a func to create new object per trigger
Guys help me to understand the timeouts usage. The documentation gives quite a couple of words about them:
popTimeout- Retrieves the previous timeout value from a stack, restores it as the current timeout value, and returns it.
pushTimeout - Stores the current timeout value on a stack and sets a new timeout value.
They also provide some code:
target = UIATarget.localTarget();
target.pushTimeout(2);
// attempt element access
target.popTimeout();
But I don't exactly understand how and when to use them. Can anybode give an example?
During automation testing, some elements might not become visible right away. so instruments uses a timeout (default 5 seconds) to wait for requested elements. They call this the grace period.
Sometimes the default grace period might not be what you need, so you can change the timeout to a shorter or longer value.
Using the pushTimeout and popTimeout makes sure that the previous grace period is restored after calling popTimeout, without the need to remember the previous grace period.
For example: in one of my tests, I don't want to wait for a popover to become active, but I just want to know if there is a popover active, and dismiss it if there is:
target.pushTimeout(0.0);
if ( target.isDeviceiPad() && ! isNull( popOver= app.mainWindow().popover() ) )
{
UIALogger.logDebug(" dismiss popup by tapping somewhere");
popOver.dismiss();
target.delay(0.2);
}
target.popTimeout();
BTW, the isNull() is a custom function I made, but you probably understand what is going on.