Infrastructure

ClickHouse rewrites WAL-G PostgreSQL backups in Rust as WAL-RUS

2026-06-28 digest discussion

  • Category: Infrastructure
  • Status: discussion
  • Sources: ClickHouse blog, repository, HN discussion
  • Summary: ClickHouse published WAL-RUS on 2026-06-25, a Rust port of the Go-based WAL-G PostgreSQL backup and write-ahead-log archival tool, built to bound memory use on no-overcommit hosts through streaming I/O without full-segment buffering. ClickHouse's own benchmark reports WAL-RUS held virtual memory under 1 GB where WAL-G reached about 2.8 GB, a reduction above 70 percent, while both kept minimal WAL backlog under four concurrent workers. It reuses the existing WALG_ configuration variables, reads and writes WAL-G-compatible archives, and supports file, S3, and GCS backends with zstd, brotli, lz4, lzma, and gzip compression.
  • Why it matters: Memory-bounded WAL archival matters for dense Postgres fleets where WAL-G's per-segment buffering can exhaust constrained hosts, and archive compatibility lets operators adopt it incrementally.
  • Follow-up: Watch for a tagged release, an explicit license declaration (the repository currently carries an unrecognized license file), and independent benchmarks outside ClickHouse Cloud.

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