How to set up an e-commerce messaging solution using ably.io - publish-subscribe

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.

Related

Hangouts Chat bot to post timed message

I can see from this, that a bot can send a message in chat, and if supplied a thread ID that does not exist, will start a new thread and post there. I am wondering if there is a way, given the current REST API or any other compatible with Hangouts, to send a message to a room at a given time of day, rather than when the bot is called or interacted with.
I am working in NodeJS, deploying my project in the GCP.
My apologies for the ambiguity of my question, I am trying to wrap my mind around the GCP environment.
In the bots documentation there are described the three ways in which a bot can send a message to a room. Those are:
Every time the bot is mentioned.
When the bot enters a room for the first time.
When the bot is taken out of the room.
Unfortunately, none of them is a daily message at a given time. If you still have questions, please ask them freely.
We have a working bot (NodeJS based) which sends messages freely. Just use this endpoint https://developers.google.com/hangouts/chat/reference/rest/v1/spaces.messages/create .
Your bot must be invited to the particular space/room for this. You can create threads as well with new and subsequent messages.
We also have bots written in Google Apps Script and there it is also possible.

Facebook Messenger Send Api - send to a big amount of users

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

Facebook real time inbox messages with Graph API v2

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...

Facebook Graph - What is the limit to send private messages from page to users?

I am developing a chat robot that works with private messages on facebook. The person sends a private message to a page that I own, and then I will send an answer for each message.
Everything is working, but I need to be sure facebook won't complain about the amount of messages I will send. This application will receive a lot of interactions at the same time, but in some early tests one of my messages were received like that:
http://cl.ly/image/1C1n0Z2L0R05
I am now using Batch Requests to send all messages, on an interval of 15s.
Do someone know some way to test it with multiple users and multiple messages at the same time? How the process of identification of spam messages work on facebook? How many messages can I send at the same time and in what time range to prevent that kind of behaviour?
Thanks.
There is no set limit or guideline on volume.
But really volume should not be the issue. There's a huge number of factors that is taken into account to determine if a message is spam... too many to discuss here. But you can assume basics: the content of the messages, the volume per user in a given time period, the content variation per user, has this app been flagged as spammy before, by how many users, etc. I would say its reasonable to assume your test user is probably going to be triggered as spammy because you're likely using it far far more than the average user would.
So, in short: it depends entirely on what exactly you're doing every 15 seconds.
Tip (although I cannot verify it): if you are trying to batch send a message to a number of users at once, without them very recently contacting you, you're probably gonna be flagged as spammy.

GAE channel API chat

Currently im trouble shooting some code that I wrote to create a chat room. I will include the code if necessary but for now I just wanted to hear some possibilities for the problem im having. So basically I have client1 that is listening to a channel and then when clien2 sends a message to the server the message is then sent from the server to all available users. What is happening is that client 2 will send the message and it will be displayed on his browser but client 1 will not receive the message until he refreshes the page or types in a message of his own. So I would think that user presence is being detected fine since the message eventually gets sent to all available users but im not sure? Thoughts?
The Google App Engine blog has a nice case study that talks about how to do this.
They store a list of channel ID's in memcache and send update messages to each of them. They mention that race conditions make memcache not ideal, but it worked well enough for their demo.