vitessio/vitess · error

GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed:

Error message

GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed: %w

What it means

When the Vtctld.GetSchema RPC for a specific tablet fails, vtadmin wraps the error with cluster ID, keyspace, and tablet alias and records it. Because the fan-out aggregates per-tablet errors, the overall GetSchema can partially succeed — the error names exactly which tablet's schema query failed.

Source

Thrown at go/vt/vtadmin/cluster/cluster.go:1703

			req.TableSizesOnly = sizesOnly
			req.TabletAlias = tablet.Tablet.Alias

			AnnotateSpan(c, span)
			annotateGetSchemaRequest(req, span)
			span.Annotate("keyspace", keyspace)
			span.Annotate("shard", tablet.Tablet.Shard)

			if err := c.schemaReadPool.Acquire(ctx); err != nil {
				err = fmt.Errorf("GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed to acquire schemaReadPool: %w", c.ID, keyspace, tablet.Tablet.Alias, err)
				rec.RecordError(err)
				return
			}

			resp, err := c.Vtctld.GetSchema(ctx, req)
			c.schemaReadPool.Release()

			if err != nil {
				err = fmt.Errorf("GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed: %w", c.ID, keyspace, tablet.Tablet.Alias, err)
				rec.RecordError(err)

				return
			}

			if resp == nil || resp.Schema == nil {
				return
			}

			m.Lock()
			defer m.Unlock()

			if !sizesOnly {
				schema.TableDefinitions = resp.Schema.TableDefinitions
			}

			if !opts.TableSizeOptions.AggregateSizes {
				return

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Read the recorded error to identify the failing tablet alias and wrapped cause
2. Check tablet health (vtctld GetTablets / tablet status page) and mysqld connectivity on that host
3. Retry GetSchema — healthy tablets' results are kept, only failed tablets need re-querying
4. Prefer querying a healthy replica/primary rather than a tablet in a transient state

// Go: filter to healthy tablets before requesting schema
healthy := filterTablets(tablets, func(t *vtadminpb.Tablet) bool {
	return t.Tablet.Type != topodatapb.TabletType_UNKNOWN && t.State == vtadminpb.Tablet_SERVING
})

schema, err := c.GetSchema(ctx, req)
if err != nil {
	// error names the failing tablet alias
	var alias string
	if _, scanErr := fmt.Sscanf(err.Error(), "GetSchema(cluster = %*s keyspace = %*s tablet = %s", &alias); scanErr == nil {
		// check/restart that tablet, then retry
	}
	return err
}

When it happens

Trigger: Vtctld.GetSchema RPC failure for one tablet: tablet down/restarting, mysqld unreachable from the tablet, vtctld timeout, or per-tablet ctx cancellation during the fan-out.

Common situations: A replica tablet being resynced/reparented during schema fetch; mysqld socket issues on one host; vtctld under load timing out on slow tablets; tablet drained or decommissioned mid-request.

Related errors

• ReloadSchemas(cluster = %s) failed: %w
• invalid key:value pair
• Error setting tablet to read-only: %w
• Error setting tablet to read-write: %w
• GetKeyspaces(cluster = %s) failed: %w

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/a3b3678653187652. Report an issue: GitHub.