DBRaven
Relationship · Vulnerable To
Source: Workload·Target: Failure Mode

Summary

Time-series metric workloads generate write throughput that can saturate disk I/O: 100,000-1,000,000 data points per second produce continuous sequential write load that exceeds spinning disk capacity and requires NVMe or storage-optimized instances to sustain.

Evidence

  • ·Prometheus remote write at 1M samples/second generates 500MB-2GB/s of WAL and index writes
  • ·InfluxDB 2.0 documentation requires NVMe SSDs for ingestion above 100K points/second
  • ·TimescaleDB chunk compression at the end of a chunk's lifecycle generates significant I/O spikes
  • ·{'Spinning disk throughput ceiling': '~150-200MB/s sequential, 100-200 IOPS random: insufficient for 500K points/second'}
  • ·AWS io1/io2 volumes are recommended for time-series databases exceeding 50K writes/second

Operational Context

  • ·Monitor disk write latency (iostat await): sustained >10ms write latency indicates I/O saturation
  • ·Use WAL and data on separate volumes to prevent WAL writes from competing with data reads
  • ·Enable compression at the storage engine level: ClickHouse achieves 10:1 compression on metric data

Tradeoffs

  • ·NVMe SSDs are 10-20x more expensive than spinning disks per GB but required for high-throughput time-series
  • ·Write batching (accumulate 1000+ points before writing) amortizes I/O overhead : increases latency from ms to seconds
  • ·Column-oriented storage (ClickHouse, TimescaleDB compression) reduces I/O dramatically but requires columnar query patterns

Evidence grounding

Grounded, 5 supporting items

Disk I/O saturation from time-series write throughput is documented in Prometheus, InfluxDB, and TimescaleDB operational guides and production post-mortems.

time_series_metrics vulnerable to disk_io_saturation: DBRaven