# Kafka
> 43 posts about Kafka, summarised, each linking to the original.

## Articles

### [Data First, SLA Always](https://yomu.fyi/post/data-first-sla-always.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Johan Kok
- Published: Aug 1, 2019

Grab's Data Engineering team transitioned from periodic batch ETL ingestion to a real-time change data capture architecture called Trailblazer after dataset sizes exceeded the petabyte mark. The previous system caused severe JDBC timeouts and heavy CPU loads when executing chunked or full-scan queries on unindexed upstream MySQL tables. To solve this, MySQL binary logs are captured via Debezium on Kafka Connect, buffered in Kafka, and ingested into a data lake using Spark Structured Streaming. Checkpoints are decoupled from local storage and persisted in a Redis cluster to simplify ingestion offset overrides and handle ephemeral compute clusters. The system incorporates extensive health monitoring across Airflow, Datadog, and custom services to maintain stream liveliness and avoid Kafka retention breaches.


### [How We Simplified Our Data Ingestion & Transformation Process](https://yomu.fyi/post/how-we-simplified-our-data-ingestion-transformation-process.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Yichao Wang
- Published: Mar 3, 2019

Grab evolved its real-time data ingestion pipeline after an initial architecture built on Spark Streaming and Python encountered operational complexity, node failures, and data loss from S3 eventual consistency. Because the streaming workload primarily handled event partitioning and ORC file generation, the team consolidated these tasks directly into an existing Golang processing service. They implemented sharded concurrent maps for high-throughput partitioning and optimized heap allocations to resolve memory bottlenecks. This refactor removed intermediate Avro conversions and intermediate storage hops. The simplified Go pipeline eliminated data loss and reduced processing lag from up to 13 minutes down to approximately 1 minute.


### [How We Designed the Quotas Microservice to Prevent Resource Abuse](https://yomu.fyi/post/how-we-designed-the-quotas-microservice-to-prevent-resource-abuse.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Jim Zhan
- Published: Aug 10, 2018

As Grab migrated from a monolith to hundreds of microservices, managing global rate limiting became essential to prevent cascading failures and resource exhaustion. To avoid putting a rate limiting service on the critical path of every API call, Grab built Quotas, an asynchronous rate limiting system. Client services use a lightweight SDK and middleware to read rate limiting decisions from local in-memory caches and stream usage metrics asynchronously via Apache Kafka. The Quotas service aggregates usage data locally, flushes stats to Redis periodically, and publishes updated rate limiting decisions back over Kafka topics. In production, Quotas successfully handles 200k peak transactions per second with decision enforcement delays capped at 200 milliseconds.


[Newer posts](https://yomu.fyi/topic/kafka/page/2.md)