I need a detail answer for this Kafka Orderering Services,
- Which Orderer node creates the block amoung the other orderers.
Try to take a look at this design document of Hyperledger Fabric Team.
This explains how it works and how they come up with this design.
https://docs.google.com/document/d/19JihmW-8blTzN99lAubOfseLUZqdrB6sBR0HsRgCAnY/edit
Related
We got a SaaS which is publishing it's events on AWS eventbridge (coulple of milion per day). We would love to consume those events and put them on our self hosted Kafka cluster. What would be the best methode to do this? We where thinking about lambda's, but the seem expensive for this use case and we don't to to manage to many other components. Does anyone have some good practices?
i was looking for a similar solution but in my case it is from eventbridge to MSK within AWS account. at this point looks like the only option is to use a lambda to feed into Kafka.
As per today, AWS only supports following Targets - https://docs.amazonaws.cn/en_us/eventbridge/latest/userguide/eb-targets.html#eb-console-targets
I have a similar use case where i need to send a message to AWS RabbitMQ or even to AWS Kafka as i need Priority Logic Implemented.
As AWS supports Lambda's, the message can be forwarded to the lambda from where it can be fed to any system
Zookeeper plays several roles in the open-source workflow framework dolphinscheduler, such as heartbeat detection among masters and workers, task queue，event listener and distributed lock.
dolphin-sche framework
Is it possible to replace it by using database (mysql)? The main reason is to simplify the project structure .
zookeeper in DS is mainly used as:
Task queue, for master sending tasks to worker
Lock, for the communication between host(masters and workers)
Event watcher. Master listens the event that worker added or removed
it costs to replace zk as mysql.
zk mainly assumes the responsibility of the registry and monitors the application status. zk is very mature in this area and is a recognized solution in the industry. If MySQL wants to do this, the technical implementation cost will be larger, and may not achieve the desired effect.
BTW, their team is currently working on the SPI development for the registry, and in later versions, perhaps you can use other components, such as etcd, to achieve similar functionality.
for now, MasterServer and the WorkerServer nodes in the system all use the Zookeeper for cluster management and fault tolerance. In addition, the system also performs event monitoring and distributed locking based on ZooKeeper. We have also implemented queues based on Redis, but we hope that DolphinScheduler relies on as few components as possible, so we finally removed the Redis implementation.
so now DolphinScheduler can't work fine without Zookeeper, maybe in the future.
DolphinScheduler System Architecture:
For more documents please refer: Official Document.
I could not found any broadcast or pub/sub pattern between Reliable Services in any documentation. Did I miss anything?
My use case is , we need to notify custom event to all the SF stateful service replica in cluster if there any state change in any primary replica.
I am aware of Reliable state manager events which triggers when any change in Reliable collections.
Is there any other broadcast , pub/sub events to communicate between services replicas of the cluster ?
Thanks,
Ashish
Did you see this oss project and package? It allows pub/sub messaging between services.
Why reinvent the wheel?
Service Fabric does not contains a brokered messaging engine because:
There are lot's of options already in the market available for this.
Would make your system tight coupled with service fabric runtime.
Why not just use Service Bus Pub\Sub Topics?
If the concern is latency, why not run RabitMQ, ActiveMQ or any other messaging system as a guest executable service or maybe inside a container.
If you had this feature on SF, you would have to write your services dependent on this feature, once you start adding external dependencies, you gonna face an integration challenge to forward these events to systems outside your cluster, having to create a service listening to these events just to forward it to another queue\topic.
It will just add extra work, complexity and maintenance to your solution.
There are scenario where you want to run a cluster of microservices in High-Availability but you would like just one of them to execute a specific operation (consuming from a queue, polling a database)
What are the best practices with relation to this use case? Should one use Zookeeper as a registry, or are there other suitable technologies?
There are a couple of technologies for service registration and discovery. Please see if the following articles help:
StackShare's comparison of Consul vs. ZooKeeper vs. Eureka
A nice paper for service-discovery and guide on how to make the choice
I want to know if it is possible to run kafka as a cloud-native application, and can I create a kafka cluster as a service on Pivotal Web Services. I don't want only client integration, I want to run the kafka cluster/service itself?
Thanks,
Anil
I can point you at a few starting points, there would be some work involved to go from those starting points to something fully functional.
One option is to deploy the kafka cluster on Cloud Foundry (e.g. Pivotal Web Services) using docker images. Spotify has Dockerized kafka and kafka-proxy (including Zookeeper). One thing to keep in mind is that PWS currently doesn't support apps with persistence (although this work is starting) so if you were to go this route right now, you would lose the data in kafka when the application is rolled. Looking at that Spotify repo, it looks like the docker images are generally run without any mounted volumes, so this persistence-less kafka seems like it may be a valid use case (I don't know enough about kafka to say).
The other option is to deploy kafka directly on some IaaS (e.g. AWS) using BOSH. BOSH can be hard if you're seeing it for the first time, but it is the ideal way to deploy any distributed software that you want running on VMs. You will also be able to have persistent volumes attached to your kafka VMs if necessary. Here is a kafka BOSH release which may work.
Once you have your cluster running, you have two ways to integrate your Cloud Foundry applications with it. The simplest is just to provide it to your applications as a "user-provided service", which lets you flow kafka cluster access info to your apps. The alternative would to put a service broker in front of your cluster, which would be especially useful if you have many different people who will be pushing apps that need to talk to the kafka cluster. Rather than you having to manually tell people the access info each time, they can do something simple like cf bind-service SOME_APP YOUR_KAFKA_SERVICE. Here is a kafka service broker along with more info about service brokers in general.
According to the 12-factor app description (https://12factor.net/processes), Kafka should not run as an application on top of Cloud Foundry:
Twelve-factor processes are stateless and share-nothing. Any data that needs to persist must be stored in a stateful backing service, typically a database.
Kafka is often considered a "distributed commit log" and as such carries a large amount of state. Many companies use it to keep all events flowing through their distributed system of micro services for a long (sometimes unlimited) amount of time.
Therefore I would strongly recommend to go for the second option in the accepted answer: Kafka topics should be bound to your applications in the form of stateful services.