v.24.2New Feature

Implemented system.dns_cache table for DNS debugging in ClickHouse

Official CH changelog text
Implemented system.dns_cache table, which can be useful for debugging DNS issues. New server setting dns_cache_max_size. #60257 (Kirill Nikiforov).
Introduced the system.dns_cache table to monitor and debug DNS resolution within ClickHouse, along with a new server setting dns_cache_max_size to control the DNS cache size.

Why it matters

This feature addresses the need for better visibility and control over DNS caching in ClickHouse. By exposing DNS cache details in system.dns_cache, users can diagnose and troubleshoot DNS-related issues more effectively. The dns_cache_max_size setting allows tuning the maximum size of the DNS cache, optimizing performance and resource usage.

How to use it

Users can query the system.dns_cache table to inspect cached DNS entries for debugging purposes. To adjust the size of the DNS cache, set the dns_cache_max_size parameter in the server configuration file or pass it as a startup option.

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