I have built an application that allows users to buy plane tickets, now I want to be able to set reminders in my application as in a script that continuously runs in the background checking the database.
Reminders should be sent via SMS a day before travel, I have covered the SMS part already. My problem now is generating a script that runs in the background and sends a reminder 1 day early to all customers. I have never implemented something like this before.
What I would do:
create a function to loop through your records and get the ones that are one day before take of. And set a cron job on that route
Then send emails to all that users
If you run the cron at night you can queue the mail job so mails will be send at a later time (morning).
Related
I've been thinking about how to design a system that supports user created scheduled alerts. My problem is once the alerts are created and inserted into a database, I don't know what the best way to go about scheduling those alerts. Polling the database to see which alerts need to go out next doesn't seem entirely right to me.
What are some ways this could be handled on a scale where say a million users could create their own custom alerts like change baby diaper at 3pm everyday?
This problem is very suitable for cloud platforms. For example, you could use GCP Cloud Scheduler to invoke a cloud function when the alert is supposed to be sent out. The cloud function then calls some API to alert the user.
If cloud platforms are not an option, you could have your application spawn a new thread when an alert is created, and sleep that thread for a certain duration. When it wakes up, it sends the alert. Less elegant and less scalable than the first solution, but it would still work.
I have created a dashboard which needs to be sent out via email report 3 times a day. How can I schedule the email report to be sent out multiple times a day?
Currently I only see the option to send it out at one time and I am not able to add more schedules to it.
Currently it is not possible to schedule email report to be sent out multiple times a day. An ugly workaround that I can think of is to replicate this dashboard 3 times and set different schedules for each copy of the dashboard.
I want to send notifications and emails to event participants one hour before an event. All data about events are stored in sql server database. It must work when for example some data in database will change - start time of event will change. One hour before event I want to send a reminder about the event. Information about event start also is only in database.
I have webapi in .net core 2.1 and I going to send emails and notification from there
You could use Hangfire to periodically go over your events and the send email if the event starts within the next hour. This would be a relatively easy thing to implement, but depending on the interval you choose might not send the email exactly one hour before an event.
Alternatively you could implement a service that will handle all creating, updating and deleting of events and then manage delayed jobs using Hangfire for sending email one hour before the event.
I want to inform the seller, that the buyer is coming soon (about 2 hours before pickup time) via mail.
I would normally do it the hard way with CRON and a database table. Checking hourly if I find an order with pickup time minus 2 hours, only then sending the mail out.
Now, I would like to know if you would recommend using Queueing Jobs for sending Mails out.
With
$when = now()->addDays(10); //I would dynamically set the date
Mail::to($order->seller())
->later($when, new BuyerIsComing($order));
I can delay the delivery of a queued email message.
But how safe would this be? Especially, if someone is ordering something but is picking it up in let us exaggerate two months?
Is the Laravel queueing system rigid enough to behave correctly after long delays (i.e. 2 months)?
Edit
I'm using Redis for Queueing
You actually have nothing to worry about. Sending mail usually increases the response time of your application, so it's a good thing you want to delay the sending.
Queues are the way to go and it's pretty easy to setup in Laravel. Laravel supports a couple of them out of the box. I would advise you start with database and then try beanstalk etc.
Lastly and somehow more importantly, use a process manager like Supervisor to monitor and maintain your queue workers...
Take a look at https://laravel.com/docs/5.7/queues for more insight.
Cheers.
If by safe, you mean reliable, then it would be little different than sending an email immediately. If there's ever a possibility that your server "hiccups" and doesn't send an email, that possibility would be the same now as 10 minutes from now. Once the job is in the queue, it is persisted until completion (unless you use a memory-based driver, like Redis, which could get reset if the server reboots).
If you are using a database queue driver or remote, the log of queued jobs will remain even if the server is unavailable for a short period of time. Your queue will be honored even if the exact time stamp for when you want to send the job has expired. For instance if you schedule to send an email at 1:00pm but your server is down at that exact moment, when it comes back online it will still see the job because it is stored as incomplete and the time for the job is in the past, which will trigger the execution of the job at the next time your queue worker checks the job list.
Of course, this assumes that you have your queue worker set up to always check jobs and automatically restart, even after a server failure, but that's a different discussion with lots of solutions...such as those shown here.
If you're using database driver with Laravel queues to process your email then you don't need to worry about anything.
Jobs are only removed from Jobs table if they are successfully completed otherwise their next attempt time is set which is few minutes in future and they are executed again (if your queue worker is online).
So its completely safe to use Laravel queues
I have an SaaS application where each paying customer may have thousands of members they may want to send emails to every now and then.
For now, simple BCC sending via AWS SES have done the trick, but now I am looking at sending personalized emails so I must be able to send the emails one by one.
SES does not have any queue system as per my knowledge, you must make an API call per email. In short, it takes forever to send a batch (my limit is 14 per second), and the user cannot close the page while it is executing (even AJAX calls stop executing if you leave the page, am I right?).
I was thinking of building a system where I store the emails in a database table and then either:
1) Use a CRON that executes every 5 seconds or so, grab a few emails and send them.
2) Execute an AJAX script each 5 seconds that grabs the emails for said logged in customer in a batch ONLY and send them out, but again, if the customer logs out while it executes chances are that specific a batch is interrupted (the remaining ones would still keep sending the next time the customer logs in).
Does any have any better ideas? Or, which of the two above would be preferred?
You should use templates and the SendBulkTemplatedEmail endpoint that AWS introduced a few months ago: https://aws.amazon.com/blogs/ses/introducing-email-templates-and-bulk-sending/.
That way you can send up to 50 personalized emails with a single SES API call. So 700 with 14 calls.
You shouldn't consider queuing them up in a user's browser and sending them by making a series of AJAX requests though. You should only send one Ajax request to start a job. In most server-side languages (any I can think of) you can respond to an HTTP request and still continue doing processing after responding. You can also implement a progress checker in a multitude of ways.
Use a cronjob that sends to the SES SMTP server. This way you can personalize the emails and also control how many emails to send. Your cronjob can sleep in between each batch of emails.
You can use celery to run background job. A user submits a request on a webpage which starts a background job through celery. The background job take care of sending emails. Once sending emails is completed, inform the user by email.
http://www.celeryproject.org/