How Mercado Libre rebuilt its observability platform on ClickHouse Cloud with 50x faster trace queries

Summary

Mercado Libre rebuilt its O11y events observability platform to answer granular business-level questions such as why a payment failed across a large microservice environment. The previous storage-layer design performed transformation, filtering, and aggregation at query time, causing queries to run longer than five minutes and making high-cardinality analysis expensive. The team moved storage to ClickHouse Cloud on AWS while retaining its existing ingestion path, and shifted heavy work into the database with materialized views, layered retention, and a dedicated lookup table for high-cardinality filtering. O11y events uses OpenTelemetry instrumentation with business-flow attributes and samples all traffic for critical applications. The resulting system reduced trace-query time to about four seconds, a 50x speedup, achieved up to 89% compression, and scaled from 7 million to 400 million spans per minute in ClickHouse.

Takeaways

1. 1

   ClickHouse materialized views shifted transformation, filtering, and aggregation from query clients into the database.

2. 2

   O11y events uses a dedicated lookup table for high-cardinality filtering on identifiers such as payment IDs and user IDs.

3. 3

   The platform reports about four-second trace queries, up to 89% compression, and growth from 7 million to 400 million spans per minute in ClickHouse.