redis: no valid results to aggregate for max operation

Error message

redis: no valid results to aggregate for max operation

What it means

routing.ErrMaxAggregation is returned by AggMaxAggregator.Result() when no shard contributed a valid integer result (aggregator.go:459-462). The max aggregator only has a value once at least one Add produced an int64; if every shard errored or none were added, hasVal is false and Result fails.

Source

Thrown at internal/routing/aggregator.go:16

package routing

import (
	"errors"
	"fmt"
	"math"
	"sync"

	"sync/atomic"

	"github.com/redis/go-redis/v9/internal/util"
	uberAtomic "go.uber.org/atomic"
)

var (
	ErrMaxAggregation = errors.New("redis: no valid results to aggregate for max operation")
	ErrMinAggregation = errors.New("redis: no valid results to aggregate for min operation")
	ErrAndAggregation = errors.New("redis: no valid results to aggregate for logical AND operation")
	ErrOrAggregation  = errors.New("redis: no valid results to aggregate for logical OR operation")
)

// ResponseAggregator defines the interface for aggregating responses from multiple shards.
type ResponseAggregator interface {
	// Add processes a single shard response.
	Add(result interface{}, err error) error

	// AddWithKey processes a single shard response for a specific key (used by keyed aggregators).
	AddWithKey(key string, result interface{}, err error) error

	BatchAdd(map[string]AggregatorResErr) error

	BatchSlice([]AggregatorResErr) error

	// Result returns the final aggregated result and any error.

View on GitHub (pinned to 36d97525cd)

Solutions

Check cluster health — one or more shards may be down (inspect the underlying shard errors).
Ensure the aggregated command actually returns numeric values on every shard.
Verify the command's response policy mapping (agg_max) is correct for the data shape.

Example fix

// before
res, err := clusterClient.SomeMaxAggCmd(ctx)
// after — handle empty/aggregation failure explicitly
res, err := clusterClient.SomeMaxAggCmd(ctx)
if errors.Is(err, routing.ErrMaxAggregation) {
    // no shard had a valid value; degrade gracefully
    return 0, nil
}

Defensive patterns

Strategy: try-catch

Validate before calling

// No app-level pre-check; ensure cluster is healthy and the command maps to agg_max correctly.

Try / catch

res, err := clusterClient.SomeMaxAggCmd(ctx)
if errors.Is(err, routing.ErrMaxAggregation) {
    // no shard contributed a valid value
    return 0, nil
}

Prevention

Monitor cluster node health; a downed shard fans out as errors.
Verify response policy agg_max matches a numeric-returning command.
Handle the empty-aggregation case explicitly in callers.

When it happens

Trigger: A ClusterClient running a multi-shard command whose response policy is RespAggMax (e.g. a max-aggregating custom/aggregate command) where all shards returned errors or no shard returned a usable integer.

Common situations: Cluster node failures during a fan-out, keys missing on all shards, or a command returning non-numeric results fed into a max aggregator.

Related errors

AI-assisted analysis of go-redis/redis@36d97525cd (2026-08-06). Data as JSON: /data/errors/d82c9b85925afe9e.json. Report an issue: GitHub.