We are a using a micro-service based pattern for our project where we have Users and their Orders. Users personal information (name, email, mobile) is stored in User table in relational database while we are storing Orders data of users in Orders collection in NoSql database. We want to develop an API to get a paginated list of all the orders placed with order details along with finer details of user associated like - user name, mobile, email along with each order. We are storing userId in Orders collection.
The problem is how do we get User details for each order in this list since both the resources are in different databases. We also thought of storing user name, email and mobile in Orders collection only but what if a user updates their profile, the Orders collection will have stale user data.
What is the best approach to address this issue?
You can use API gateway pattern, UI will call to API gateway endpoint and the Endpoint will call the both the API/services to get the result and aggregate it then returns aggregated response to the UI (caller)
https://microservices.io/patterns/apigateway.html
Well it mostly depends on scalability needs in terms of data size and number of requests. You may go with the API gateway if you don't have too much data and you don't get many requests to that service.
Otherwise if you really need something scalable then you should implement your own thought with an event based communication.
I already provided an answer for a similar situation you can take a look
https://stackoverflow.com/a/63957775/3719412
You have two services Orders and Users. You are requesting Orders service to get all Orders. It will return a response data which will contains ID of Users (each Order contains ID of User). Then, you will make a request to a Users service to get an information regarding User by ID which you got before. And finally, you can aggregate those results (if it is needed).
As guys mention, good solution will be to implement API Gateway here. As a client, you will send a request to a single port with endpoint (to a Gateway) and Gateway should create logic which I have described before.
Related
I am a nodejs developer. My server should ask every x ms and retrieve new orders. Notifications will be sent by the client part of the service to the seller. I need some fields of the order, I use the order api for most fields, the report api to retrieve the telephone number, which is not retrieved by the order api.
What I need now is the list of all the products of the seller, with the properties: SKU, weight
What api should I better use?
I also want to confirm the order shipment by sending to Amazon also a tracking code, but I did not fine this in the apis. Is there this feature?
What I do is periodically download orders into my own system using the reports API. I have the complete order with header information including all SKU's on the order. The Orders API is subject to throttling which may affect you.
To update Amazon that your order has shipped and to send a tracking number, you will use the Feeds API. Look at the Feed Types, specifically:
_POST_ORDER_FULFILLMENT_DATA_
In the link above, there is a flowchart explaining the process.
This is my first time reading about the microservices. Knowing that services is a subdivide system from a whole system which specialize in different domains. What about the data. I assumed all services using tradition db to store their data and data are stored distributed in different domain. What if there are data can belong in both of these domain services, what should I do with them.
E.g. A basket service (handling user shopping cart), and Payment service (handling payment of their order they have placed in the basket).
Maybe this isn't a great example, where do the product information to be stored.
In monolithic application, we have single database which stored the whole business data where each data will have reference to each other.
With the services we tend to ask one question who is source of truth?
In your case user adds item to the cart and there is service which keep tracks of what items the user has added (it may just have a itemid stored)
When this used to moves to checkout, there will be a checkout service which will then ask the cart service about the items in the users cart, apply in the cart logic.
Thing to note is checkout service knows and care about the checkout process and it has no idea where to get the data of the items. Its just calls the right service and get the stuff it wants and apply the logic.
For checkout to payment you pass along userid cartid and other info and payment can make use of these information to bloat the information as it sees fit and return a response back to checkout which may trigger an order service.
So if you see data is always available with one service and when ever you have a situation where you need data, instead of making a db call you make a service call
(Service responsibility is to give you this data with low latency and may be pulling in logic to cache or whatever)
Another point with respect to data is source of truth. For order service, which is called often we tend to keep a copy of all the information related to the order in it (Again we do that, their may be better approaches) and in doing so often during a return flow question which system to trust.You may query an order service to get an address on which order is supposed to be shipped, but this address might have been deleted by the user.
This is where Single source of truth comes into play. This is little tricky, for delivery service source of truth for delivery address is what it gets from order service and not the user service (however order service picked up the details from user service at time of placing orders)
At the same time, during return flow we consider the prices as stored in order service (again a snapshot of what was there during the time order was placed) not necessarily make a call to product service, however for payments we talk to payment service directly to check amount we have taken from the user (There may be multiple inward and outward flows)
So bottom line is
Have one database exposed via one service, and let other service connect to db via this service
Read more about Single Source of Truth. We decided on certain contracts like who is the SSOT for whom (I do not necessarily agree with this approach but it works well for us)
We are trying to develop a SCIM enabled Provisioning system for provisioning data from an Enterprise Cloud Subscriber(ECS) to Salesforce(Cloud Service Provider-CSP). We are following SCIM 1.1 standard.
What are we able to do:
We are able to perform CRUD operations on User object using Salesforce auto-generated userId field
Exact Problem:
We are not able to update/delete User object using externalId provided by ECS.
Tried something as below... But it is not working, Unknown_Exception is thrown...
XXX/my.salesforce.com/services/scim/v1/Users/701984?fields=externalId
Please note that it is not possible to store Salesforce userId in ECS's database due to some compliance reasons. So we have to completely depend upon externalId only.
Possible Workaround:
Step1: Read the userId based on externalId from Salesforce
Step2: Update the User object using the salesforce UserId obtained in Step1.
But this two step process would definitely degrade the performance.
Is there any way to update/delete the User by externalId
Could you please guide us on this..
Thanks so much....
I realize this is old thread but wanted to note that you CAN update Users from REST using an external ID. The endpoint in above question is incorrect. Following is how it should be set, send as a PATCH request:
[instance]/services/data/v37.0/sobjects/user/[external_id__c]/[external id value]
Instance = your instance i.e. https://test.salesforce.com/
external_id__c = API name of your custom external Id field on User
external id value = whatever the value of the user's external Id
NOTES:
Salesforce responds with an HTTP 204 status code with No Content in the body, this isn't usual for patch requests, but it is 'success' response
The external id on user has to be a custom field, make sure it is set
as UNIQUE
Ensure the profile/permission set of the user that is making the call
has the Manage Users permission & has access to the external id field
It is pretty common pattern for other applications, too, to search first and then perform on update on the returned object. Your workaround seems fine to me. What performance problem are you concerned about? Are you concerned about Salesforce not being able to process more requests or are you concerned about the higher response time in your application because you need to make multiple requests? Have you actually measured how much an extra call costs?
I am building a web app that will use an auto-complete/suggestions for the end user as they type their information in. This will be specifically for entering Country, Province, City information.
Do a wild card search on the database on each keystroke:
SELECT CityName
FROM City
WHERE CityName LIKE '%#CityName%'
Return a list of all Cities to a given Province to the client and have the client do the matching:
SELECT CityName
FROM City
WHERE ProvinceID = #ProvinceID
These would be returned to the client as a JSON string via an ajax call to a web service. My thoughts are that javascript would be able to handle the list of 100+ entries via JSON faster than the database would be able to do a wildcard search, but I'd like the communities input.
In the past, I have used both techniques. If you are talking about 100 or so entries, and assuming each entry is very small, it will likely be faster to do the autocomplete filter on the client side. That will provide you with better response time (although probably negligible) and will reduce the load on your server.
Google actually does a live search while the user is typing, and it seems to be pretty responsive from the user's point of view. This is an example where the query must be executed server-side because the dataset is far too large to transfer to the client.
One thing you might do is wait until the user types two keystrokes before fetching the list from the server, thus narrowing down the results initially. Of course, that adds complexity - you would then need to refresh the list if the user changes either of the first two keystrokes.
We have implemented same functionality using ajax auto complete control we wait the user type three keystroke before fetching the list from server we have not done any coding at client side we just assigned web services method which return list to ajax control and its start working
In the end user's interest, it is always better to handle this client-side.
The Telerik Autocomplete controller allows for both ways.
Of course under load client-side autocomplete is likely to make the application crawl.
I have an Account entity that has a facebook id.
Sometimes, the client might send all facebook ids (the clients facebook friends) to the server.
We want to select all Accounts IN the facebook ids the client provided.
Looping and calling get on each facebook id seems rather slow, considering people might have 1000+ friends. Further more, GAE is limited to 30 queries with IN clause.
Has anyone had a similar situation? How did you handle it?
Thanks!
You can set up a model that uses the facebook ID as a key which allows you to use Model. get_by_key_name(key_names=fb_ids) to fetch all the models with keys in fb_ids at once.
e.g.
class FBModel(db.Model):
account = db.ReferenceProperty(reference_class=Account)
When creating the model:
model = FBModel(key_name=fb_id)