---
title: "ClickHouse at FOSDEM 2026"
description: "The ClickHouse community and development team participated in FOSDEM 2026 in Brussels, hosting a community dinner and delivering technical presentations across multiple developer tracks. Presentations covered a range of engineering topics, including building geospatial analytical applications with Leaflet and ClickHouse, as well as integrating LLVM XRay to dynamically hot-patch production logging without redeployments. Additional ClickHouse sessions addressed the engineering challenges of integrating Rust libraries into large C++ codebases, optimizing low-level memcpy routines, and implementing specialized inverted indexes for large-scale text processing. Contributed community sessions detailed workflows for upstream patches in MariaDB and Postgres, alongside WebShield, an open-source Python daemon that streams web accelerator access logs into ClickHouse for bot analysis."
---

# ClickHouse at FOSDEM 2026

[Clickhouse](https://yomu.fyi/company/clickhouse) · Tyler Hannan · Apr 8, 2026

**Type:** Announcement

## Summary

The ClickHouse community and development team participated in FOSDEM 2026 in Brussels, hosting a community dinner and delivering technical presentations across multiple developer tracks. Presentations covered a range of engineering topics, including building geospatial analytical applications with Leaflet and ClickHouse, as well as integrating LLVM XRay to dynamically hot-patch production logging without redeployments. Additional ClickHouse sessions addressed the engineering challenges of integrating Rust libraries into large C++ codebases, optimizing low-level memcpy routines, and implementing specialized inverted indexes for large-scale text processing. Contributed community sessions detailed workflows for upstream patches in MariaDB and Postgres, alongside WebShield, an open-source Python daemon that streams web accelerator access logs into ClickHouse for bot analysis.

## Context

The ClickHouse engineering team and community members presented multiple talks and organized community gatherings at FOSDEM 2026 in Brussels.

## Approach / What changed

Speakers delivered presentations covering dynamic runtime instrumentation using LLVM XRay, inverted indexes for text processing, C++ and Rust code integration, low-level memcpy optimization, open-source database contribution workflows, and log-based bot detection.

## Takeaways

- ClickHouse integrated LLVM XRay to hot-patch running production binaries via SQL queries, allowing engineers to dynamically inject logging, profiling, and delays with near-zero runtime overhead and a 4–7% binary size increase.
- Processing large-scale text data and log search in column-oriented OLAP databases requires the implementation of specialized inverted indexes.
- WebShield uses Tempesta FW access logs routed to ClickHouse to analyze traffic patterns and compute fingerprints for identifying and blocking automated bots.

**Tags:** [Observability](https://yomu.fyi/topic/observability), [Open Source](https://yomu.fyi/topic/open-source), [Performance](https://yomu.fyi/topic/performance), [Rust](https://yomu.fyi/topic/rust), [Search](https://yomu.fyi/topic/search)

- Source: [Clickhouse](https://clickhouse.com/blog/clickhouse-at-fosdem-2026)
- Source URL: https://clickhouse.com/blog/clickhouse-at-fosdem-2026
- Ingested by Yomu: 2026-08-28T01:23:59.789Z

[Read original post](https://clickhouse.com/blog/clickhouse-at-fosdem-2026)