Big Data

Constructing serverless occasion streaming functions with Amazon MSK and AWS Lambda

junho 27, 2025
techhdesign


As organizations construct trendy functions with event-driven architectures (EDA), they typically search options that decrease infrastructure administration overhead whereas maximizing developer productiveness. Amazon Managed Streaming for Apache Kafka (Amazon MSK) and AWS Lambda collectively present a serverless, scalable, and cost-efficient platform for real-time event-driven processing.

On this put up, we describe how one can simplify your event-driven software structure utilizing AWS Lambda with Amazon MSK. We exhibit how you can configure Lambda as a client for Kafka subjects, together with a cross-account setup and how you can optimize worth and efficiency for these functions.

Why use Lambda with Amazon MSK?

Prospects constructing event-driven functions have a number of key priorities relating to their structure decisions. They sometimes search to scale back their operational overhead by utilizing Amazon Net Providers (AWS) to deal with the advanced, underlying infrastructure parts so their groups can give attention to core enterprise logic. Moreover, builders desire a streamlined expertise that minimizes the necessity for repetitive boilerplate code, enabling them to be extra productive and give attention to creating worth. Moreover, these clients need to obtain each scalability and cost-effectiveness with out the burden of managing compute infrastructure instantly. Lambda integration with Amazon MSK successfully addresses these necessities, delivering a complete resolution that mixes the advantages of serverless computing with managed Kafka companies. For instance, an ecommerce firm can use Amazon MSK to gather real-time clickstream knowledge from its web site and course of these occasions utilizing AWS Lambda. With this integration, they will set off Lambda capabilities to replace advice fashions, ship personalised provides, or analyze consumer conduct immediately—with out provisioning or managing servers. The important thing advantages of utilizing Lambda with Amazon MSK embrace:

  1. Simplicity via native integration – AWS Lambda provides native integration with Amazon MSK via a connector useful resource known as occasion supply mapping. You need to use this integration to instantly affiliate a Kafka matter—whether or not it’s on Amazon MSK or a self-managed Kafka cluster—as an occasion supply for a Lambda perform with out writing customized client logic. With just some configuration steps, occasion supply mapping handles partition task, offset monitoring, and parallelized batch processing underneath the hood. It makes use of the Kafka client group protocol to distribute matter partitions throughout a number of concurrent Lambda invocations, helps batch windowing, and permits at-least-once supply semantics. Furthermore, it routinely commits offsets upon profitable perform execution whereas dealing with retries and dead-letter queue (DLQ) routing for failed data, considerably decreasing the operational overhead historically related to Kafka customers.
  2. Auto scaling and throughput controls – When utilizing AWS Lambda with Amazon MSK via occasion supply mapping, Lambda routinely scales by assigning a devoted occasion poller per Kafka partition, enabling parallel, partition-based processing. This enables the system to elastically deal with various site visitors with out guide intervention. For superior management, provisioned concurrency pre-initializes Lambda execution environments, eliminating chilly begins and delivering constant low-latency efficiency. Moreover, with provisioned occasion supply mapping, you possibly can configure the minimal and most variety of Kafka pollers, offering exact management over throughput and concurrency. That is perfect for functions with unpredictable site visitors patterns or strict latency necessities.
  3. Price-effectiveness – AWS Lambda makes use of a pay-per-use mannequin during which you solely pay for compute time and variety of invocations. When built-in with Amazon MSK, there are not any fees for idle time, making it perfect for bursty or low-frequency Kafka workloads. You may additional optimize prices by tuning batch dimension and batch window settings. For mission-critical workloads, provisioned concurrency supplies constant efficiency with managed pricing.
  4. Occasion filtering – AWS Lambda helps occasion filtering for Amazon MSK occasion sources, which implies you possibly can course of solely the Kafka data that match particular standards. This reduces pointless perform invocations and optimizes your perform prices. You may outline as much as 5 filters per occasion supply mapping (with the choice to request a rise to 10). Every filter makes use of a JSON-based sample to specify the circumstances a document should meet to be processed. Filters may be utilized utilizing the AWS Administration Console, AWS Command Line Interface (AWS CLI), or AWS Serverless Software Mannequin (AWS SAM) templates. For extra particulars and examples, check with the AWS Lambda documentation on occasion filtering with Amazon MSK.
  5. Dealing with Availability Zone outage in your client – Amazon MSK permits excessive availability in your Kafka brokers by distributing them throughout a number of Availability Zones inside a Area. To take care of excessive availability throughout your software, you equally want a client that provides excessive availability. AWS Lambda provides excessive availability and resilience by working your client capabilities throughout a number of Availability Zones in a Area. Which means that even when one Availability Zone experiences an outage, your Lambda perform will proceed to function in different wholesome Availability Zones. Whereas Lambda manages safety patching and Availability Zone failure situations, you possibly can focus in your software logic.
  6. Cross-account occasion processing – Cross-account connectivity between AWS Lambda and Amazon MSK permits a Lambda perform in a single AWS account to eat knowledge from an MSK cluster in one other account utilizing MSK multi-VPC non-public connectivity powered by AWS PrivateLink. This setup is especially useful for organizations that centralize Kafka infrastructure whereas sustaining separate accounts for various functions or groups.
  7. Help for JSON, Avro, Protobuf, and Schema Registries – AWS Lambda helps Kafka occasions in JSON, Avro and Protobuf codecs by way of occasion supply mapping. It integrates with AWS Glue Schema registry, Confluent Cloud Schema registry, and self-managed Confluent Schema registry , enabling native schema validation, filtering, and deserialization with out customized code.

How Lambda processes messages out of your Kafka matter

Lambda makes use of occasion supply mappings to course of data from Amazon MSK by actively polling Kafka subjects via occasion pollers that invoke Lambda capabilities with batches of data. These mappings are Lambda managed sources designed for high-throughput, stream-based processing. By default, Lambda detects the OffsetLag for all partitions in your Kafka matter and routinely scales pollers primarily based on site visitors. For prime-throughput functions, you possibly can allow provisioned mode to outline minimal and most pollers, and your occasion supply mapping auto scales between the minimal and most outlined values. Within the provisioned mode, every poller can course of as much as 5 MBps and helps concurrent Lambda invocations.

After Lambda processes every batch, it commits the offsets of the messages in that batch. In case your perform returns an error for a message in a batch, Lambda retries the entire batch of messages till processing succeeds or the messages expire. You may ship data that fail all retry makes an attempt to an on-failure vacation spot for later processing. To take care of ordered processing inside a partition, Lambda limits the utmost occasion pollers to the variety of partitions within the matter. When organising Kafka as a Lambda occasion supply, you possibly can specify a client group ID to let Lambda be a part of an current Kafka client group. If different customers are energetic in that group, Lambda will obtain solely a part of the subject’s messages. If the group exists, Lambda begins from the group’s dedicated offset, ignoring the StartingPosition. The next diagram illustrates this stream.

Walkthrough: Construct a serverless Kafka app with AWS Lambda

Comply with these steps to construct a serverless software that consumes messages from an MSK cluster utilizing AWS Lambda:

  1. Create an Amazon MSK cluster. Use the AWS Administration Console or AWS CLI to create your MSK cluster. When the cluster is up, create your Kafka matter(s). For detailed directions, check with the Amazon MSK documentation.
  2. Create a Lambda perform utilizing the AWS Administration Console or the AWS CLI. To be taught extra about making a Lambda perform, check with Create your first Lambda perform. The Lambda perform’s execution function must have the next permissions:
    1. Entry to hook up with your MSK cluster
    2. Permissions to handle elastic community interfaces in your VPC
  3. To attach Lambda to Amazon MSK as a client, arrange occasion supply mapping to hyperlink your MSK matter with the Lambda perform. This enables Lambda to routinely ballot for brand spanking new messages and course of them. Comply with the information on how you can configure occasion supply mapping.

For reference, configuring occasion supply mapping entails three steps:

  1. Community setup – Within the default occasion supply mapping mode, you must configure a networking setup utilizing a PrivateLink endpoint or NAT gateway for occasion supply mapping to invoke Lambda capabilities. In provisioned mode, no networking configuration is required (and also you don’t incur the price of networking parts).
  2. Occasion supply mapping parameter configuration – This entails setting vital configuration parameters for the occasion supply mapping to have the ability to ballot messages out of your Kafka cluster. This consists of the MSK cluster, matter title, client group ID, authentication technique, and optionally, schema registry, scaling mode. You may configure the scaling mode for provisioned throughput, together with batch dimension, batch window, and occasion filtering in your occasion supply mapping.
  3. Entry permissions – This entails configuring required permissions to entry the required AWS sources, and consists of configuring permissions for the perform to execute the code, permissions for the occasion supply mapping to entry your MSK cluster, and permissions for Lambda to entry your VPC sources.

The next screenshot reveals the console setup for configuring Amazon MSK occasion supply mapping, together with the Amazon MSK set off associated fields.

The next screenshot reveals occasion poller configuration.

The next screenshot reveals further settings you need to use, relying in your use case.

Optimizing AWS Lambda for stream processing with Amazon MSK

When constructing real-time knowledge processing pipelines with Amazon MSK and AWS Lambda, it’s vital to tune your setup for each efficiency and cost-efficiency. Lambda provides highly effective serverless compute capabilities, however to get essentially the most out of it in a streaming context, you must make just a few key optimizations:

  1. Allow provisioned concurrency for low-latency processing – For workloads which might be delicate to latency—chilly begins can introduce undesirable delays. By enabling provisioned concurrency, you possibly can pre-warm a specified variety of Lambda cases so that they’re at all times able to deal with site visitors instantly. This eliminates chilly begins and supplies constant response instances, which is essential for latency-critical use instances.
  2. Allow provisioned mode for occasion supply mapping for high-throughput processing – For Kafka workloads with stringent throughput necessities, activate the provisioned mode. The optimum configuration of minimal and most occasion pollers in your Kafka occasion supply mapping is dependent upon your software’s efficiency necessities. Begin with the default minimal occasion pollers to baseline the efficiency profile and modify occasion pollers primarily based on noticed message processing patterns and your software’s efficiency necessities. For workloads with spiky site visitors and strict efficiency wants, improve the minimal occasion pollers to deal with sudden surges. You may fine-tune the minimal occasion pollers by evaluating your required throughput, your noticed throughput, which is dependent upon elements such because the ingested messages per second and common payload dimension, and utilizing the throughput capability of 1 occasion poller (as much as 5 MB/s) as reference. To take care of ordered processing inside a partition, Lambda caps the utmost occasion pollers on the variety of partitions within the matter.
  3. Optimize message batching utilizing dimension and windowing – By integrating Lambda with Amazon MSK, you possibly can management how messages are batched earlier than they’re despatched to your perform. Tuning parameters corresponding to batch dimension (the variety of data per invocation: 1–10,000 data) and most batching window (how lengthy to attend for a full batch: 0–300 seconds) can considerably affect efficiency. Bigger batches imply fewer invocations, which reduces overhead and improves throughput. Nonetheless, it’s vital to strike a steadiness—too giant a batch or window would possibly introduce undesirable processing delays. Monitor your stream’s conduct and modify these settings primarily based on throughput necessities and acceptable latency.
  4. Apply filters to scale back pointless invocations – Not each document in your Kafka matter would possibly require processing. To keep away from pointless Lambda invocations (and related prices), apply filtering logic instantly when configuring the occasion supply mapping. With Lambda, you possibly can outline filtering (as much as 10 filters) standards in order that solely related data set off your perform. This helps scale back compute time, decrease noise, and optimize your finances, particularly when coping with high-throughput subjects with combined content material. For Amazon MSK, Lambda commits offsets for matched and unmatched messages after efficiently invoking the perform.

Conclusion

By combining Amazon MSK with AWS Lambda, you possibly can seamlessly construct trendy, serverless event-driven functions. This integration eliminates the necessity to handle client teams, compute infrastructure, or scaling logic so groups can give attention to delivering enterprise worth sooner.

Whether or not you’re integrating Kafka into microservices, remodeling knowledge pipelines, or constructing reactive functions, Lambda with Amazon MSK is a strong and versatile serverless resolution. For detailed documentation on how you can configure Lambda with Amazon MSK, check with the AWS Lambda Developer Information. For extra serverless studying sources, go to Serverless Land.

Concerning the Authors

Tarun Rai Madan is a Principal Product Supervisor at Amazon Net Providers (AWS). He makes a speciality of serverless applied sciences and leads product technique to assist clients obtain accelerated enterprise outcomes with event-driven functions, utilizing companies like AWS Lambda, AWS Step Capabilities, Apache Kafka, and Amazon SQS/SNS. Previous to AWS, he was an engineering chief within the semiconductor trade, and led growth of high-performance processors for wi-fi, automotive, and knowledge middle functions.

Masudur Rahaman Sayem is a Streaming Information Architect at AWS with over 25 years of expertise within the IT trade. He collaborates with AWS clients worldwide to architect and implement subtle knowledge streaming options that tackle advanced enterprise challenges. As an knowledgeable in distributed computing, Sayem makes a speciality of designing large-scale distributed programs structure for max efficiency and scalability. He has a eager curiosity and fervour for distributed structure, which he applies to designing enterprise-grade options at web scale.