System alarm recurrence - windows-phone-7

Windows Phone allows you to create and register system alarms with the ScheduledActionService. The options for recurrenceType are daily, weekly, etc.
I am trying to get alarms set for specific days. This is not possible using the recurrenceType enum. The only way I can see to achieve this is to create an alarm for each day specified. This way, for a single alarm that is created I will have to create a copy of it on every day I wish it to recur.
The only issue with this is displaying them. They cannot be given a 'Name' property and so there is no way to logically group these alarms in to a single "master" alarm.
has anyone encountered this issue? Is there a way to set alarms without using this scheduler service? I cannot think of a way around this and would appreciate any guidance.

The only example I'm aware of where someone was in a similar situation resulted in them not using the scheduler at all.
As they required a complex scheduling pattern they instead chose to not use any of the built in functionality but rather to create individual alarms as appropriate. They already had an existing BackgroundAgent and added functionality there to ensure that the next two alarms were always queued up.
Your exact requirements may make this possible.
I'd think carefully about adding an agent just for this though.

Related

GA3 Event Push Neccesary fields in Request

I am trying to push a event towards GA3, mimicking an event done by a browser towards GA. From this Event I want to fill Custom Dimensions(visibile in the user explorer and relate them to a GA ID which has visited the website earlier). Could this be done without influencing website data too much? I want to enrich someone's data from an external source.
So far I cant seem to find the minimum fields which has to be in the event call for this to work. Ive got these so far:
v=1&
_v=j96d&
a=1620641575&
t=event&
_s=1&
sd=24-bit&
sr=2560x1440&
vp=510x1287&
je=0&_u=QACAAEAB~&
jid=&
gjid=&
_u=QACAAEAB~&
cid=GAID&
tid=UA-x&
_gid=GAID&
gtm=gtm&
z=355736517&
uip=1.2.3.4&
ea=x&
el=x&
ec=x&
ni=1&
cd1=GAID&
cd2=Companyx&
dl=https%3A%2F%2Fexample.nl%2F&
ul=nl-nl&
de=UTF-8&
dt=example&
cd3=CEO
So far the Custom dimension fields dont get overwritten with new values. Who knows which is missing or can share a list of neccesary fields and example values?
Ok, a few things:
CD value will be overwritten only if in GA this CD's scope is set to the user-level. Make sure it is.
You need to know the client id of the user. You can confirm that you're having the right CID by using the user explorer in GA interface unless you track it in a CD. It allows filtering by client id.
You want to make this hit non-interactional, otherwise you're inflating the session number since G will generate sessions for normal hits. non-interactional hit would have ni=1 among the params.
Wait. Scope calculations don't happen immediately in real-time. They happen later on. Give it two days and then check the results and re-conduct your experiment.
Use a throwaway/test/lower GA property to experiment. You don't want to affect the production data while not knowing exactly what you do.
There. A good use case for such an activity would be something like updating a life time value of existing users and wanting to enrich the data with it without waiting for all of them to come in. That's useful for targeting, attribution and more.
Thank you.
This is the case. all CD's are user Scoped.
This is the case, we are collecting them.
ni=1 is within the parameters of each event call.
There are so many parameters, which parameters are neccesary?
we are using a test property for this.
We also got he Bot filtering checked out:
Bot filtering
It's hard to test when the User Explorer has a delay of 2 days and we are still not sure which parameters to use and which not. Who could help on the parameter part? My only goal is to update de CD's on the person. Who knows which parameters need to be part of the event call?

Laravel Schedule One-Off Events

Users are able to set up a marketing email send time within my app for random dates as they need them. It is crucial that the emails start to go out exactly when they are scheduled. So, the app needs to create something that fires one time for a specific group of emails at a specific date and time down to the minute. There will be many more dates for other sends in the future, but they are all distinct (so need something other than 'run every xxx date')
I could have a Scheduler task that runs every minute that looks at the dates of any pending tasks in the database and moves to the command that sends those that need sending. But I'm running a multi-tenanted app -- likely not overlap, but seems like a huge hit to multiple databases every minute for every tenant to search through potentially thousands of records per tenant.
What I need (I think) is a way to programmatically set a schedule for each send date, and then remove it. I liked this answer or perhaps using ->between($startMin, $endMin), without the every xxx instruction, or even using the cron function within Scheduler to set up one single time for each group that needs to be sent. Not sure I'm using this the way it was intended though?
Would this even work? I programmatically created a schedule from within a test method, and it was added to the schedule queue based on the dump of the $schedule I created, showing all schedules - but it did not show up via this method found from this answer:
$schedule = app()->make(\Illuminate\Console\Scheduling\Schedule::class);
$events = collect($schedule->events())->filter(function (\Illuminate\Console\Scheduling\Event $event) {
return stripos($event->command, 'YourCommandHere');
});
It also did not output anything, so I'm wondering if programmatically creating a schedule outside of Kernel.php is not the way to go.
Is there another way? I don't know scheduler well enough to know if these one-off schedules permanently remain somewhere, are they deleted after their intended single use, taking up memory, etc?
Really appreciate any help or guidance.

What is a good way to store arbitrary schedule data?

I am working on a project where the objective is to keep track of whether a client has uploaded data within their expected time-window or not. These windows can occur daily, weekly, bi-weekly, bi-monthly, quarterly... etc. I'm currently using the CRON syntax to describe these schedules which kind-of works, but it falls short in some scenarios, for example the bi-weekly one.
I was wondering if there is some industry standard way to efficiently describe and store schedules that I don't know of. I tried to educate myself via Google, but when I put the word schedule into the mix, it always assumes I'm trying to schedule some task, but I only want to calculate dates based on these schedule definitions and compare the incoming file dates with them.
Thank you

Compensating Events on CQRS/ES Architecture

So, I'm working on a CQRS/ES project in which we are having some doubts about how to handle trivial problems that would be easy to handle in other architectures
My scenario is the following:
I have a customer CRUD REST API and each customer has unique document(number), so when I'm registering a new customer I have to verify if there is another customer with that document to avoid duplicity, but when it comes to a CQRS/ES architecture where we have eventual consistency, I found out that this kind of validations can be very hard to address.
It is important to notice that my problem is not across microservices, but between the command application and the query application of the same microservice.
Also we are using eventstore.
My current solution:
So what I do today is, in my command application, before saving the CustomerCreated event, I ask the query application (using PostgreSQL) if there is a customer with that document, and if not, I allow the event to go on. But that doesn't guarantee 100%, right? Because my query can be desynchronized, so I cannot trust it 100%. That's when my second validation kicks in, when my query application is processing the events and saving them to my PostgreSQL, I check again if there is a customer with that document and if there is, I reject that event and emit a compensating event to undo/cancel/inactivate the customer with the duplicated document, therefore finishing that customer stream on eventstore.
Altough this works, there are 2 things that bother me here, the first thing is my command application relying on the query application, so if my query application is down, my command is affected (today I just return false on my validation if query is down but still...) and second thing is, should a query/read model really be able to emit events? And if so, what is the correct way of doing it? Should the command have some kind of API for that? Or should the query emit the event directly to eventstore using some common shared library? And if I have more than one view/read? Which one should I choose to handle this?
Really hope someone could shine a light into these questions and help me this these matters.
For reference, you may want to be reviewing what Greg Young has written about Set Validation.
I ask the query application (using PostgreSQL) if there is a customer with that document, and if not, I allow the event to go on. But that doesn't guarantee 100%, right?
That's exactly right - your read model is stale copy, and may not have all of the information collected by the write model.
That's when my second validation kicks in, when my query application is processing the events and saving them to my PostgreSQL, I check again if there is a customer with that document and if there is, I reject that event and emit a compensating event to undo/cancel/inactivate the customer with the duplicated document, therefore finishing that customer stream on eventstore.
This spelling doesn't quite match the usual designs. The more common implementation is that, if we detect a problem when reading data, we send a command message to the write model, telling it to straighten things out.
This is commonly referred to as a process manager, but you can think of it as the automation of a human supervisor of the system. Conceptually, a process manager is an event sourced collection of messages to be sent to the command model.
You might also want to consider whether you are modeling your domain correctly. If documents are supposed to be unique, then maybe the command model should be using the document number as a key in the book of record, rather than using the customer. Or perhaps the document id should be a function of the customer data, rather than being an arbitrary input.
as far as I know, eventstore doesn't have transactions across different streams
Right - one of the things you really need to be thinking about in general is where your stream boundaries lie. If set validation has significant business value, then you really need to be thinking about getting the entire set into a single stream (or by finding a way to constrain uniqueness without using a set).
How should I send a command message to the write model? via API? via a message broker like Kafka?
That's plumbing; it doesn't really matter how you do it, so long as you are sure that the command runs within its own transaction/unit of work.
So what I do today is, in my command application, before saving the CustomerCreated event, I ask the query application (using PostgreSQL) if there is a customer with that document, and if not, I allow the event to go on. But that doesn't guarantee 100%, right? Because my query can be desynchronized, so I cannot trust it 100%.
No, you cannot safely rely on the query side, which is eventually consistent, to prevent the system to step into an invalid state.
You have two options:
You permit the system to enter in a temporary, pending state and then, eventually, you will bring it into a valid permanent state; for this you could allow the command to pass, yield CustomerRegistered event and using a Saga/Process manager you verify against a uniquely-indexed-by-document-collection and issue a compensating command (not event!), i.e. UnregisterCustomer.
Instead of sending a command, you create&start a Saga/Process that preallocates the document in a uniquely-indexed-by-document-collection and if successfully then send the RegisterCustomer command. You can model the Saga as an entity.
So, in both solution you use a Saga/Process manager. In order for the system to be resilient you should make sure that RegisterCustomer command is idempotent (so you can resend it if the Saga fails/is restarted)
You've butted up against a fairly common problem. I think the other answer by VoicOfUnreason is worth reading. I just wanted to make you aware of a few more options.
A simple approach I have used in the past is to create a lookup table. Your command tries to register the key in a unique constraint table. If it can reserve the key the command can go ahead.
Depending on the nature of the data and the domain you could let this 'problem' occur and raise additional events to mark it. If it is something that's important to the business/the way the application works then you can deal with it either manually or at the time via compensating commands. if the latter then it would make sense to use a process manager.
In some (rare) cases where speed/capacity is less of an issue then you could consider old-fashioned locking and transactions. Admittedly these are much better suited to CRUD style implementations but they can be used in CQRS/ES.
I have more detail on this in my blog post: How to Handle Set Based Consistency Validation in CQRS
I hope you find it helpful.

Windows Phone recurring alarms on specific weekdays

I'm working on an app where the user needs to be able to create alarms on Windows Phone. The issue I'm hitting is that we want to provide the functionality for an alarm to repeat on specific days (e.g. only mon-fri).
The RecurrenceInterval class doesn't seem to offer options to suit this (even though the it is possible in the native alarm app), only daily, weekly, etc...
Do I need to create a seperate alarm for each weekday and set them to repeat weekly?
Enumeration does not allow specifying days in a week for alarms - so I would go with separate alarm for each weekday and repeat weekly. To make alarams easier to find, I would just use namming convention for alarms, something like "AlarmName_[n]", where n=1..6 - depending on how many days you have when alarm needs to go off, and then you can enumerate from 1 until there are no alarms with specified name.

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