YugabyteDB ERROR 40001 Restart read required signals clock skew

If you see ERROR 40001 Restart read required, check clock sync between nodes first with NTP or chrony. Lowering maxclockskew_usec can reduce read latency, but only to a value your hardware or cloud provider guarantees in all situations; going below actual skew hurts availability or breaks consistency.

Context: YugabyteDB clock-skew writeup: documents the gotcha that ERROR 40001 Restart read required comes from clock skew between nodes, and the conservative 500ms default adds 500ms of latency to serializable read-only queries. Only lower maxclockskew_usec if your platform guarantees tighter skew, including restarts and VMotion.

Source: YugabyteDB clock-skew writeup: documents the gotcha that ERROR 40001 Restart read required comes from clock skew between nodes, and the conservative 500ms default adds 500ms of latency to serializable read-only queries. Only lower maxclockskew_usec if your platform guarantees tighter skew, including restarts and VMotion.

Verified resolution: If you see ERROR 40001 Restart read required, check clock sync between nodes first with NTP or chrony. Lowering maxclockskew_usec can reduce read latency, but only to a value your hardware or cloud provider guarantees in all situations; going below actual skew hurts availability or breaks consistency.

Source URL: https://Dev.to/yugabyte/observing-clock-skew-error-40001-restart-read-required-580j