A production field guide for running Vitess on sharded MySQL: topology design, VSchema & routing, online DDL coordination, and observability.

A linter for Vitess VSchema JSON. Runs 30 rules over your keyspaces, vindexes, sequences and routing rules — optionally cross-checked against your CREATE TABLE DDL — and reports each problem with a stable rule ID, exact line number and fix hint. Pretty, JSON, GitHub-annotation and SARIF output. Ships as a composite GitHub Action.

Simulate a Vitess vindex over a shard layout and see the skew, hot shards and scatter-gather risk before you commit to a shard key. Faithful hash/xxhash/numeric/binary/reverse_bits implementations, Gini and entropy metrics, heavy-hitter detection, query-fanout estimation, and side-by-side candidate ranking.

Monitors Vitess shard health and alerts when live topology drifts from a declared desired topology. Validates that shard key ranges tile the key space, tracks replication lag, throttler state, scatter-query ratio and reparent flapping. Ships a self-contained web dashboard, a Prometheus /metrics endpoint, and a CI-friendly CLI.