General
Q: What is Apache Kafka?
Q: What is streaming data?
Q: What are Apache Kafka’s primary capabilities?
- Apache Kafka stores streaming data in a fault-tolerant way as a continuous series of records and preserves the order in which the records were produced.
- Apache Kafka acts as a buffer between data producers and data consumers. Apache Kafka allows many data producers (e.g. websites, IoT devices, Amazon EC2 instances) to continuously publish streaming data and categorize this data using Apache Kafka topics. Multiple data consumers (e.g. machine learning applications, Lambda functions) read from these topics at their own rate, similar to a message queue or enterprise messaging system.
- Data consumers process data from Apache Kafka topics on a first-in-first-out basis, preserving the order data was produced.
Q: What are the key concepts of Apache Kafka?
Q: When should I use Apache Kafka?
Apache Kafka is used to support real-time applications that transform, deliver, and react to streaming data, and for building real-time streaming data pipelines that reliably get data between multiple systems or applications.
Q: What does Amazon MSK do?
Amazon MSK makes it easy to get started and run open-source versions of Apache Kafka in AWS with high availability and security while providing integration with AWS services without the operational overhead of running an Apache Kafka cluster. Amazon MSK allows you to use and configure open-source versions of Apache Kafka while the service manages the setup, provisioning, AWS integrations, and on-going maintenance of Apache Kafka clusters.
With a few clicks in the console, you can provision an Amazon MSK cluster. From there, Amazon MSK replaces unhealthy brokers, automatically replicates data for high availability, manages Apache ZooKeeper nodes, automatically deploys hardware patches as needed, manages the integrations with AWS services, makes important metrics visible through the console, and will support Apache Kafka version upgrades when more than one version is supported so you can take advantage of improvements to the open-source version of Apache Kafka.
Q: What Apache Kafka versions does Amazon MSK support?
For supported Kafka versions, see the Amazon MSK documentation.
Q: Are Apache Kafka APIs compatible with Amazon MSK?
Yes, all data plane and admin APIs are natively supported by Amazon MSK.
Q: Is the Apache Kafka AdminClient supported by Amazon MSK?
Yes.
Data production and consumption
Q: Can I use Apache Kafka APIs to get data in and out of Apache Kafka?
Yes, Amazon MSK supports the native Apache Kafka producer and consumer APIs. Your application code does not need to change when clients begin to work with clusters within Amazon MSK.
Q: Can I use Apache Kafka Connect, Apache Kafka Streams, or any other ecosystem component of Apache Kafka with Amazon MSK?
Yes, you can use any component that leverages the Apache Kafka producer and consumer APIs, and the Apache Kafka AdminClient. Tools that upload .jar files into Apache Kafka clusters are currently not compatible with Amazon MSK.
Migrating to Amazon MSK
Version upgrades
Q: How will the upgrade process work under the hood?
When you deploy a new Apache Kafka version, Amazon MSK will use a rolling upgrade process that upgrades one broker or Apache ZooKeeper node at a time before moving on to the next resource. Throughout the upgrade process your cluster will be in an ‘Updating’ state and will transition to an ‘Active’ state when finished. It’s important to note that if you chose to not replicate data to multiple brokers within a cluster that is being upgraded, your cluster will experience downtime.
Clusters
You can create your first cluster with a few clicks in the AWS management console or using the AWS SDKs. First, in the Amazon MSK console select an AWS region to create an Amazon MSK cluster in. Choose a name for your cluster, the VPC you want to run the cluster with, a data replication strategy for the cluster, and the subnets for each AZ. Next, pick a broker instance type and quantity of brokers per AZ, and click create.
Each cluster contains broker instances, provisioned storage, and Apache ZooKeeper nodes.
You can choose EC2 T3.small or instances within the EC2 M5 instance family. Please refer to the pricing page for the full list of instances.
Q: Does Amazon MSK offer Reserved Instance pricing?
No, not at this time.
No, each broker you provision includes boot volume storage managed by the Amazon MSK service.
Some resources, like elastic network interfaces (ENIs), will show up in your Amazon EC2 account. Other Amazon MSK resources will not show up in your EC2 account as these are managed by the Amazon MSK service.
You need to provision broker instances and broker storage with every cluster you create. You do not provision Apache ZooKeeper nodes as these resources are included at no additional charge with each cluster you create.
Unless otherwise specified, Amazon MSK uses the same defaults specified by the open-source version of Apache Kafka. The default settings are documented here.
Q: Can I provision brokers such that they are imbalanced across AZs (e.g. 3 in us-east-1a, 2 in us-east-1b, 1 in us-east-1c)?
No, Amazon MSK enforces the best practice of balancing broker quantities across AZs within a cluster.
Amazon MSK uses Apache Kafka’s leader-follower replication to replicate data between brokers. Amazon MSK makes it easy to deploy clusters with multi-AZ replication and gives you the option to use a custom replication strategy by topic. By default with each of the replication options, leader and follower brokers will be deployed and isolated using the replication strategy specified. For example, if you select a 3 AZ broker replication strategy with 1 broker per AZ cluster, Amazon MSK will create a cluster of three brokers (1 broker in three AZs in a region), and by default (unless you choose to override the topic replication factor) the topic replication factor will also be 3.
Q: Can I change the default broker configurations or upload a cluster configuration to Amazon MSK?
Yes, Amazon MSK allows you to create custom configurations and apply them to new and existing clusters. For more information on custom configurations, see the configuration documentation.
Topics
Networking
Connecting to the VPC
Q: How do I connect to my AWS MSK cluster outside of the VPC?
There are several methods to connect to your AWS MSK clusters outside of your VPC: VPN, VPC Peering, VPC Transit Gateway, AWS Direct Connect. You can also use a REST proxy on an instance running within your VPC. REST proxies allow your producers and consumers to communicate to the cluster through HTTP API requests.
Encryption
Yes, Amazon MSK uses Amazon EBS server-side encryption and AWS KMS keys to encrypt storage volumes.
Yes, by default new clusters have encryption in-transit enabled via TLS for inter-broker communication. You can opt-out of using encryption in-transit when a cluster is created.
Yes, by default in-transit encryption is set to TLS only for clusters created from the CLI or AWS Console. Additional configuration is required for clients to communicate with clusters using TLS encryption. You can change the default encryption setting by selecting the TLS/plaintext or plaintext settings. Read More: MSK Encryption
No, the default version of Apache Zookeeper bundled with Apache Kafka does not support encryption. However it is important to note that communications between Apache Zookeeper and Apache Kafka brokers is limited to broker, topic, and partition state information.
Monitoring, metrics, logging, tagging
Q: How do I monitor the performance of my clusters or topics?
You can monitor the performance of your clusters using the Amazon MSK console, Amazon CloudWatch console, or you can access JMX and host metrics using Open Monitoring with Prometheus, an open source monitoring solution.
Q: What is the cost for the different CloudWatch monitoring levels?
The cost of monitoring your cluster using Amazon CloudWatch is dependent on the monitoring level and the size of your Apache Kafka cluster. Amazon CloudWatch charges per metric per month and includes a free tier; see Amazon CloudWatch pricing for more information. For details on the number of metrics exposed for each monitoring level, see Amazon MSK monitoring documentation.
Q: What monitoring tools are compatible with Open Monitoring with Prometheus?
Tools that are designed to read from Prometheus exporters are compatible with Open Monitoring, like: Datadog, Lenses, New Relic, Sumologic, or a Prometheus server. For details on Open Monitoring, see Amazon MSK Open Monitoring documentation.
Q: How do I monitor the health and performance of clients?
You can use any client-side monitoring supported by the Apache Kafka version you are using.
Q: Can I tag Amazon MSK resources?
Yes, you can tag Amazon MSK clusters from the AWS CLI or Console.
Q: How do I monitor consumer lag?
Topic level consumer lag metrics are available as part of the default set of metrics that Amazon MSK publishes to Amazon CloudWatch for all clusters. No additional setup is required to get these metrics. To get partition level metrics (partition dimension), you can enable enhanced monitoring (PER_PARTITION_PER_TOPIC) on your cluster. Alternatively, you can enable Open Monitoring on your cluster, and use a Prometheus server, to capture partition level metrics from the brokers in your cluster. Consumer lag metrics are available at port 11001, just as other Kafka metrics.
Q: How much does it cost to publish the consumer lag metric to Amazon CloudWatch?
Topic level metrics are included in the default set of Amazon MSK metrics, which are free of charge. Partition level metrics are charged as per Amazon CloudWatch pricing.
Apache ZooKeeper
Q: What is Apache ZooKeeper?
From https://zookeeper.apache.org/: “Apache ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. All of these kinds of services are used in some form or another by distributed applications,” including Apache Kafka.
Q: Does Amazon MSK use Apache ZooKeeper?
Yes, Amazon MSK uses Apache ZooKeeper and manages Apache ZooKeeper within each cluster as a part of the Amazon MSK service. Apache ZooKeeper nodes are included with each cluster at no additional cost.
Q: How do my clients interact with Apache ZooKeeper?
Your clients can interact with Apache ZooKeeper through an Apache ZooKeeper endpoint provided by the service. This endpoint is provided in the AWS management console or using the DescribeCluster API.
Scaling
Q: How can I scale up storage in my cluster?
You can scale up storage in your cluster using the AWS Management Console or the AWS CLI.
Q. Can I scale the number of brokers in an existing cluster?
Yes. You can scale out, or increase, the number of brokers for existing Amazon MSK clusters.
Q. Can I scale a broker instance size in an existing cluster?
No. Scaling the instance size of brokers in an existing cluster is not currently supported by Amazon MSK, but is on our roadmap.
Pricing and availability
Q: How does Amazon MSK pricing work?
Pricing is based is per Apache Kafka broker-hour, and per provisioned storage-hour. AWS data transfer rates apply for data transfer in and out of Amazon MSK. For more information, visit our pricing page.
Q: Do I pay for data transfer as a result of data replication?
No, all in-cluster data transfer is included with the service at no additional charge.
Q: How does data transfer pricing work?
You will pay standard AWS data transfer charges for data transferred in and out of an Amazon MSK cluster. You will not be charged for data transfer within the cluster in a region, including data transfer between brokers and data transfer between brokers and Apache ZooKeeper nodes.
Service Level Agreement
Our Amazon MSK SLA guarantees a Monthly Uptime Percentage of at least 99.9% for Amazon MSK.
Q: How do I know if I qualify for a SLA Service Credit?
You are eligible for a SLA credit for Amazon MSK under the Amazon MSK SLA if Multi-AZ deployments on Amazon MSK have a Monthly Uptime Percentage of less than 99.9% during any monthly billing cycle.
Get started with Amazon MSK

Learn how to set up your Apache Kafka cluster on Amazon MSK in this step-by-step guide.

Start running your Apache Kafka cluster on Amazon MSK. Log in to the Amazon MSK console.