go-redis/redis · error

redis: can't peek push notification name, next reply is not

Error message

redis: can't peek push notification name, next reply is not a push notification

What it means

Error "redis: can't peek push notification name, next reply is not a push notification" thrown in go-redis/redis.

Source

Thrown at internal/proto/reader.go:138

//
// To identify the name the method may block reading more bytes from the
// underlying connection, but only ever waits for one byte beyond the valid
// frame prefix it has already seen. That byte is guaranteed to arrive: an
// incomplete prefix means the server is still committed to sending the rest
// of the frame. Demanding any fixed amount instead can deadlock — a complete
// frame such as a subscribe confirmation for a short channel name can be
// smaller than the fixed window, and once it is buffered the server has
// nothing more to send (issue #3935). Blocking for in-flight bytes is
// preferred to a truncated peek, which would silently misidentify the
// notification and cause the caller's ReadReply to consume (and drop) the
// frame; see issue #3839.
func (r *Reader) PeekPushNotificationName() (string, error) {
	c, err := r.rd.Peek(1)
	if err != nil {
		return "", err
	}
	if c[0] != RespPush {
		return "", fmt.Errorf("redis: can't peek push notification name, next reply is not a push notification")
	}

	const maxPushHeaderPeek = 4096

	for {
		// Parse from what is already buffered; this never blocks.
		avail := r.rd.Buffered()
		if avail > maxPushHeaderPeek {
			avail = maxPushHeaderPeek
		}
		buf, peekErr := r.rd.Peek(avail)
		if peekErr != nil {
			return "", peekErr
		}
		name, complete, parseErr := parsePushNotificationName(buf)
		if parseErr != nil {
			return "", parseErr
		}

View on GitHub (pinned to 36d97525cd)

Solutions

  1. Only call the push-name peek when a push notification frame (RESP3 '>') is actually next
  2. Use the standard read path for non-push replies

When it happens

Trigger: Thrown at internal/proto/reader.go:138 when the library encounters an invalid state.

Common situations: Branch on the frame type byte before invoking push-specific parsing.

AI-assisted analysis of go-redis/redis@36d97525cd (2026-08-06). Data as JSON: /data/errors/ab564cb8b4f97ada.json. Report an issue: GitHub.