I need to get the List of Partitions for an EventHub. I am trying to use EventProcessorClient from the Latest SDK. This does not seem to have a getRuntimeInformation method.
Is there any way I can get the list of partitions foa an EventHub using any API for a EventProcessorClient client.
The processor is intended to manage partitions on your behalf and without any explicit action on your part, so it does not expose any means to inspect the Event Hub or its properties.
To inspect your Event Hub and its partitions, you'll want to use the EventHubClientBuilder to create either a producer or consumer client to do so. I'd recommend taking a peek at GetEventHubMetadata.java from the client library samples, which demonstrates doing so.
Related
Can you elaborate on the differences between Pub/Sub and Firestore and provide some scenarios or use cases on which one to choose?
I'm not sure which one to use for building an app for a food delivery service that services real-time updates reflected as soon as they are added or changed to the database, ensuring that customers and drivers are aware of when food is ready for pickup and when food is in transit to their end destination such as UberEats.
The difference is quite simple:
Firestore (RealtimeDB) is for backend to frontend (customers/users) communication and realtime updates
Pubsub is a backend to backend message bus for async processing.
In your use case, you won't use PubSub to send notification to your users! Use realtimeDB to perform these updates.
Pub/Sub is like a notification system wherein you receive updates when something is added, changed or removed.
Firestore, on the other hand, is a NoSQL database for mobile (Android, iOS) and other web apps that can be directly access via native SDK. It can support many data types, from simple strings to complex objects. It also supports whatever data structure that works best for your app.
It is best to use Firestore for your app as it provides realtime updates.
You can check for the detailed documentation of Pub/Sub and Firestore.
For Firestore, you can either use either mobile/web client library or server client library.
Here's the link for Firestore, containing its benefits and key features.
I am building a Desktop-on-Demand solution using AWS Workspaces product and I am trying to understand what is the best AWS service to fit my requirements for managing state data for new users.
In a nutshell, solution will create a new AWS Workspace (virtual desktop instance) for a user when multiple conditions are met and checks are satisfied. These tasks would be satisfied by multiple lambda functions.
DynamoDB would be used as a central point for storing confguration data details like user data, user groups data and deployed virtual desktops data.
Logic for Desktops creation would be implemented using Step Functions like below:
Event hook comes from Identity Management system firing a lambda function that checks if user desktop already exists in DynamoDB table
If it does not exist, another lambda creates AWS AD connector
Once this is done, another lambda builds custom image for new desktop if needed
Another lambda pulls latest data from Identity Management system and updates DynamoDB table for users and groups.
Other lambda functions that may be fired up as a dependency
To ensure we have transactional mechanism, we only deploy new desktop when all conditions are met. I can think about few ways of implementing this check:
Use DynamoDB table for keeping State data. When all attributes in item are in expected state, desktop can be created. If any lambda fails or produces data that does not fit, dont' create desktop.
Just use Step Functions and design it's logic flow that all conditions must satisfy before desktop is created
Someone suggested using SQS queue but I don't see how this can be used for my purpose.
What is the best way to keep this data?
Step Functions is the method I would use for this. The DynamoDB solution would also work, but this seems like exactly the sort of thing Step Functions was designed to handle.
I agree that SQS would not be a correct solution.
I am trying to write a Kafka connector to fetch data from the facebook. The problems are,
How to fetch data from facebook through their API without exceeding the limit of API hit provided by facebook? The connector should call facebook API for data after a specific time interval so that the number of hits won't exceed.
Each user can hit the facebook API with their Access Token so users can't share the same topic partition. So how to handle this scenario. Do we have to create one partition for each user?
I read a few guides and blogs to understand Kafka connect and write a connector.
Confluent- https://docs.confluent.io/current/connect/index.html
Kafka Documentation- https://kafka.apache.org/documentation/#connect
Conceptually It gave me an idea about what is Kafka connect, how it works and what are the important classes to write a Kafka connector. But still, I am confused that practically how to write and run a connector. I tried to find step by step development guide but didn't get.
Any tutorial or pdf If you could suggest which have detailed step by step development guide to write and run Kafka connector.
The only "official guide" is in those links you have
https://docs.confluent.io/current/connect/devguide.html#developing-a-simple-connector
I personally have no experience with the Facebook API, but I assume it uses REST, so you could make start by forking the kafka-connect-rest project, but the simplest answer to not exceed the limit would be to not send more requests than you are allowed within a given time period (add a timer to the code that waits between requests)
Also, one connector would only have one set of access keys. How you create the ConnectRecord objects to ultimately partition the records is up to you, but I don't think having an access key per user will scale very well. It might make more sense to have one key tied to one application, then each user will accept that that application has access to read certain details from their account.
I am writing a publisher service that wants to publish events to a client event hub. Is it correct that by using RBAC, I can achieve without having to worry about SAS keys? If so, is there any sample code I can look at.
I have been looking at the github samples at https://github.com/Azure/azure-event-hubs/tree/master/samples/DotNet/Rbac/EventHubsSenderReceiverRbac/ but they seem to be using individual user accounts for RBAC.
I've just started messing around with AWS DynamoDB in my iOS app and I have a few questions.
Currently, I have my app communicating directly to my DynamoDB database. I've been reading around lately and people are saying this isn't the proper way to go about getting data from my database.
By this I mean is I just have a function in my code querying my Dynamo database and returning the result.
How I do it works but is there a better way I should be going about this?
Amazon DynamoDB itself is a highly-scalable service and standing up another server in front of it requires scaling the service also in line with the RCU/WCU configured for your tables, which we can and should avoid.
If your mobile application doesn't need a backend server and you can perform all the business functions from the mobile device, then you should probably think about
Using the AWS DynamoDB SDK for iOS devices to write your client application that runs on the mobile device
Use AWS Token Vending Machine to authenticate your mobile users to grant them credentials to be used to run operations on DynamoDB tables.
Control access (i.e what operations should be allowed on tables etc.,) using IAM policies.
HTH.
From what you say, I can guess that you are talking about a way you can distribute data to many clients (ios apps).
There are few integration patterns (a very good book on this: Enterprise Integration Patterns), one of which is called shared database. It is essentially about using a common database for multiple clients to share the data. Main drawback for that pattern (in your case) is that you are doing assumption about how the database schema looks like. It can potentially bring you some headache supporting the schema in the future, if your business logic changes.
The more advanced approach would be sending events on every change in your data instead of directly writing changes to the database from client apps. This way you can add additional processing to the events before the data they carry is written to the database. For example, you may want to change the event format in the new version of your app, but still want to support legacy users, so you add translation procedure which transforms both types of events to the format which fits the database schema. It's basically a question of whether to work with diffs vs snapshots.
You should be aware of added complexity of working with events, and it can be an overkill if your app is simple and changes in schema are unlikely.
Also consider that you can do data preprocessing using DynamoDB Streams, which gives you some advantages of using events still keeping it simple to implement.