my app has list of events with start time (date and time). I want to make a scheduled task to send reminder via email to all user participate in event 1 hour before event start. (Note: Admin can change time of event).
I currently use celery to send email to list of participants when admin change the time of event.
Please suggest me some solution for this. Thanks.
Here's a recent(ish) discussion where a potential solution is proposed for celery: https://github.com/celery/celery/issues/4522.
I built Posthook to make solving these kinds of problems easier for developers. In your case, when a new event is created or the event time changes you can schedule a request back to your app for 1 hour before the start time. Then when you get the request from Posthook you can send out the reminder after validating that it still needs to be sent out.
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So I have notification system in place.For example when sending a task to user, user get a notification within my system. Right now I have only "instant" notifications. so when I send a task to someone, a notification is created in the db, and via web-socket the user is notified with the data of the notification.
With the Reminder I have the problem, that the notification I want to send here is not necessarily "instant". I want to set the date to next Monday on 9 am. so User should receive the notification on Monday 9 am.
Question: Is there an extension in django (or onboard methods) where I can execute stuff delayed? For example, send notification with the following data on Monday 9 am.
Celery can be used to schedule and defer tasks.
Here's and example of how to schedule for a specific time. https://docs.celeryq.dev/en/latest/userguide/calling.html#eta-and-countdown
I have different REST-API views where I either send a mail (if an account exists) or do not send a mail.
For example, the user can input the email in the forgot-password form and a mail is sent if the account exists.
I am using from django.core.mail import send_mail to send the mail.
The problem is, that this takes some time, and so requests for valid emails are generally longer than requests for non-exiting emails.
This allows an attacker to compare the request times to find out if an account exists or not.
Is there any way that I can call send_mail() without sending the mail?
Or what would be the fix to make request times equally long for both cases?
Note: I could check how long send_mail() needs on average and wait this time if I do not send the mail. As the app runs on different servers with different configs, this can not be generally done in my case. I would rather not store the average execution time per server in a database to solve this.
It's a common practice to use celery for tasks that require some time to be finished. Celery will run a task in a separate thread and a user doesn't need to wait while it is finished. In your specific case what will happen if you use celery:
You send a task send_mail to celery and immediately return a successful response to a user.
Celery receives a task and runs it in a separate thread.
In this way, the response time for both cases will be the same.
So this is something similar to an issue I had, and my solution was actually to always send the email, but the email reads something like You tried to reset your password, but this email isn't registered to an account with us. if they don't have an account.
From a user's perspective, it can be annoying to have to wait for an email that may or may not arrive, and spend time checking spam/junk etc. Telling them they don't have an account with that email address is quicker and cleaner for them.
We saw a big drop in users enquiring with us about why they hadn't received a PW reset email.
(Sorry for not actually answering the question, I dislike it when people do this on SO but since I experienced the same issue, I thought I'd weigh in.)
I have a django app where the user sends a request, and the server does some SQL lookup, followed by computation on results and finally showing the results to the user.
The SQL lookup and the computation afterwards can take a long time, maybe 30+ minutes. I have seen some webpages ask for email in such cases then send you the URL later. But I'm not sure how this can be done in django or whether there are other options for this situation. Any pointer will be very helpful.
(I'm sorry but as I said it's a rather general question, I don't know how can I provide a min runnable code for this)
One way to accomplish this would be to use something like Celery, which is a distributed task queue. The processing task would go into the queue (synchronously or asynchronously), and it would call a function to send an email to the user alerting them it is ready when the task is complete.
Documentation: https://docs.celeryproject.org/en/stable/django/first-steps-with-django.html
I've been working on a Dialogflow chatbot that calls a webhook which can often take more than the 5s delay to process and answer the user's request. So, following this post, my webhook sends a response containing a followup event if the processing is too long, and will be able to answer the following request sent by the intent triggered by the event.
Now, while this approach is working great, I have two questions :
Is there any way to send a message ("Please wait, I'm processing your request") to the user on every followup event ?
Since I'm using the Dialogflow-Messenger integration, is there any way to display the three dots "typing" animation while the webhook is processing the request ?
Thanks !
When developing a chatbot, you should keep in mind that you are trying to duplicate how 2 humans interact. You are developing a conversation and in the conversation, we should not keep other person waiting. All your requests should be completed within 4-5 seconds (to avoid timeout by the platform) to have a better UX.
So there is no way to show either Please Wait or animated 3 dots!
Write a good backend code to fetch response faster or tweak and cache your response. Dialogflow is currently designed for 1-1 conversation and cannot provide multiple delayed responses. If you need it that way, you will require to develop your own NLP engine.
I want incorporate a timed based reminder email of the events for the day in django. Basically I have a model which has all the events (including the date of the event). I want to send emails to concerned people at around 8.00 AM in the morning of each day about the events for the day. How do I incorporate this is django?
Thanks
I reckon a custom management command to send the alerts, commanded by django-chronograph should do the trick
I wrote a database-backed email queue, to send out emails from a single django install and not have to worry about SMTP throttling and whatnot. It's dead simple -- one model class for the email with a sendit() method, and a command-line script to flush the queue, which I run with cron.
http://gist.github.com/629663