While thinking through a system design for real-time chat, I am curious what kind queue whatsapp or FB messenger is using on Server side to deliver the message to recipient. What I was thinking was there is a per-person queue/kafka-topic, so when a new message need to be deliver to user A, the message is enqueue to A's queue.
However, there may be billions of users (FB has 2 billion users), does that mean we need 2 billion queues/topics(in kafka term)? If so, which queue can handle this performantly.
Any comment is welcome!
Thank you!
Related
I would like to know that we are having a lead generation campaign running on Facebook but few of the times our staff isn't available to answer the query on Facebook messenger, so based on that short-coming I am thinking to devise a mechanism that "If within 1 hour of user's message no one replies to him then an automated BOT message should get sent to him."
Please don't deprecate this question as it is based entirely on knowledge. And if perhaps someone has hints or links on how to achieve this thing then I will really appreciate it.
Thanks.
Some options:
You can query your /conversations edge every X minutes to detect when there is a message from a user which has not been replied to, then you would send the automated message using Send API.
https://developers.facebook.com/docs/graph-api/reference/v10.0/conversation
https://developers.facebook.com/docs/messenger-platform/reference/send-api/
You can use webhook data for incoming messages to create a task that will run at received_time + 60 minutes, find the thread in your conversations edge based on PSID and then check if there has been a reply
Alternatively you can check out Handover Protocol which allows a Page to simultaneously use a Messenger Bot and Live chat agent to handle messaging
https://developers.facebook.com/docs/messenger-platform/handover-protocol/
I have an e-commerce website and I want to implement a messaging solution between my clients, using ably.io. I am new to ably.io and also to pub/sub message pattern and need some advice to put me on the right track.
Let’s say I have 75,000 users on my website. Users can create an advertisement... if anyone is interested in the advertisement they should be able to message the advertiser.
This is the solution that comes to my mind after reading ably's documentation:
Since I have 75,000 users, I create 75,000 channels, 1 channel per user.
An user named Brian creates an advertisement on the website. Brian subscribes to BrianChannel to receive all messages on his own channel. Now Amy and Tom have seen Brian's advertisement and want to contact him, they publish a message on BrianChannel and Brian would receive the messages.
I am not sure if the above solution is the right approach?
If the above solution is the right way, I have 2 further questions:
Let's Brian uses JavaScript to subscribe to BrianChannel. Now Brian is obviously not online 24/7 - how should I handle his messages while he is offline?
I have 75,000 users registered on my website. At any point of time 5,000 users are online. Out of these 5000 users online, 20 users are actually messaging each other. Using my solution above, I should have 5,000 active channels for all the online users... Is there a way to reduce the number of active channels? Perhaps by periodically polling the channels?
This is Srushtika, Dev Advocate at Ably.
Your approach is correct and is in-fact the most commonly implemented one. i.e, each of your 75,000 users will have their own channels to which only they will be subscribed to. Any other client who wishes to send them a message, will attach to 'their' channel and publish messages to it. Since all users are always subscribed to their own channels, they will be able to receive any messages intended for them.
If any of your subscriber clients are not online at the time a message is to be sent to them, Ably's Realtime platform will, by default, retain it for 2min after which, if the subscriber client is still offline, the messages will be discarded. However, using the Persisted History feature, you can increase the time for which messages are retained to 24-72hrs.
Unfortunately, as of now, Ably doesn't offer a mechanism to detach from channels with no activity while the client is still online. But, this feature is coming soon. Keep an eye on our Engineering blog where we post all such updates.
Hope that answers your question.
all.
On the last week we are facing a problem in messages order, in Facebook Messenger.
When user is interacting with our bot, on most of the cases Messenger send random messages that it has sent before in the conversation. This old messages are not triggered by our bot, they simply appear, which makes us to think it is a Messenger thing. After a while, when user leave the conversation for some seconds and get back to it later, the bot is ok again. Sometimes user has to say "hi" to bot, so it gets back to the right point of conversation.
It also happens with messages that were sent by user, not only by our bot.
We have never get this problem using it on web platform. It seems to occur only in Android devices (Android massenger app), until this point.
When we check the conversation from the fan page side, it is all ok, and it is hard to determine where the problem occured just by looking from the fan page perspective. It seems there is no problem. But if you are the one who is interacting with the bot is very bad, it is like a "crazy" conversation for the end user.
It is a different case from the listed on other topics. We have an information thread that sends lots of messages, and in this case for example, it has never failed in order. It just happens when there is an user-bot interaction.
Is anybody here facing this kind of problem with messages order?
Thank you in advance.
we have seen the same behavior in android
On further investigation, we found that the messages which we assumed are delivered to the users were actually not delivered.
What we did was started listening to delivery notification and read receipts documentation link. We saved every message at our end and then mapped with seq number and it turns out that there is connectivity issues in android for fb messenger (reference).
When fb messenger is running in background and there is poor network connection then messages are not being received. This is what I have observed when I have poor network connection.
I have a bot over Facebook which people are subscribing for sports updates.
I have 1,000 - 10,000 users I want to send out an update to.
Currently, in small scales like 20 messages , I would use a Facebook Batch request.
But, i'm not sure what would be the best way to send my messages in a large scale.
My two options are:
Batch - limited to 50 requests per batch request.
I don't really know if I should expect a delay in the execution of the request.
Regular calls - I will iterate through my receivers and send each of them a message separately.
I'm afraid Facebook might block me for thinking i'm spamming, or I will exceed the rate limits.
I have to say I was expecting a more generic method coming from Facebook since they are allowing users to subscribe for update through my bot, hence, I was expecting them to provide a guide on what are the best practices for sending the update users subscribed for.
You should definitely use Facebook Messenger Broadcast API for this. This will broadcast your message to all user subscribed to the bot.
Caveats:
You have to apply for this permission. (pages_messaging and pages_messaging_subscriptions.Takes about 1-2 days, but
can test on Admin/Test users of the app)
Each broadcast has to be a separate broadcast. (e.g. you can't send image and a text together, each has to be its own individual broadcast).
Have some kind of un-subscription option as well. FB user might think you are spamming even if you clearly say in the messages that your bot will send updates.
Use custom labels to create targetted sends. So you can either subdivide who you will send updates to about specific issues or just label people if they unsubscribe to your broadcast or not.
Basic workflow:
Get permission to broadcast.
Create message_creative_id via POST to endpoint
Use message_creative_id to POST a broadcast_messages
On a successful send you will get back broadcast_id
Does anyone know a way to fetch a user/page inbox messages in real time?
I've found this link, but there is no mention about inbox messages.
The Real-time updates are about... -updates-. That means you will only get notified about changes in the fields described in that link (not regarding the Payments API, that's a different case).
So, you can't get real-time inbox messages.
You can subscribe to the notifications, but I'm not really sure if Messages notifications are included in those...