Environment

• YugabyteDB Version: - v2024.2.3.2 and later

Issue

After upgrading YugabyteDB to version v2024.2.3.2 or later (e.g., v2024.2.6.0), user may observed the xCluster replication lag metric displays a constant value of 1 µs even when the system is idle. Previously, this metric would display 0 µs when there was no lag.

Cause

Starting from YugabyteDB v2024.2.3.2, the internal metric
async_replication_sent_lag_micros was intentionally changed to default to 1 µs instead of 0 µs.

Resolution

The default value for the internal metric async_replication_sent_lag_micros was updated from 0 to 1 microsecond. This change was implemented to allow YugabyteDB to distinguish between two distinct between no data to replicate and zero lag.

This behavior is expected and does not indicate a performance issue or a problem with replication. No corrective action is required.

Reference: SUPPORT-834