AWS SNS主题数限制

Question

There will be number of users. Each users may have number of areas. I want to send email alerts of 3 categories for each area. Each category will have number of email endpoints.

So creating a topic for each category feasible?

for example - if my each area has 3 categories, I'll have to create a topic for each category. so each area will have three tpoics and each topic will have some subscribers.

I want to ask, is this the correct way or are there better options?

Answer 1

About the scenario, you mentioned, I guess Filter policy for SNS suits best. You can also follow this AWS tutorial ' Filter Messages Published to Topics ' for this.

The idea of filter policy is very simple,
When publishing message to topic, you also include some attributes(metadata) in your message for example area=2, category=3
Now this message will be only sent to those subscribers who has this key-value pair mentioned in their subscription policy(attributes) or to all those who don't have any policy at all.

You define subscription policy(attributes), while making subscribe request in your code from client side.

Sample message to publish (Note MessageAttributes in the message):

{
  "Type" : "Notification",
  "MessageId" : "e3c4e17a-819b-5d95-a0e8-b306c25afda0",
  "TopicArn" : "arn:aws:sns:us-east-1:111122223333:MySnsTopic",
  "Message" : message body with transaction details . . .
  "Timestamp" : "2017-11-07T23:28:01.631Z",
  "SignatureVersion" : "1",
  "Signature" : signature . . .
  "UnsubscribeURL" : unsubscribe URL . . .
  "MessageAttributes" : {
    "customer_interests" : {"Type":"String.Array","Value":"[\"soccer\", \"rugby\", \"hockey\"]"},
    "store" : {"Type":"String","Value":"example_corp"},
    "event" : {"Type":"String","Value":"order_placed"},
    "price_usd" : {"Type":"Number","Value":210.75}
  }
}

Sample subscriber policy:

{
    "store": ["example_corp"],
    "event": [{"anything-but":"order_cancelled"}],
    "customer_interests": ["rugby", "football", "baseball"],
    "price_usd": [{"numeric":[">=", 100]}]
}

About Limits:
By default, SNS offers 10 million subscriptions per topic, and 100,000 topics per account. To request a higher limit, please contact Support. Link

I hope this answer puts you in the right direction to now think/move in