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L · Leader Notice

Structurerefresh

Not a response to a request — a notice the server pushes on its own (cluster only). When a node detects that the Raft leader has changed, it sends the new leader's client address once to every client connected to it.

How It Differs from M

M · MovedL · Leader Notice
NatureA response to a requestA server-initiated notice (unrelated to any request)
Meaning"This request can't be handled here""The leader has changed" (informational)
ConnectionClose it and reconnect to the new leaderKeep it — update the hint only
This nodeDefinitely not the leaderMay well be the new leader itself

Do not close the connection on L. The node that sent the notice is often the new leader itself, and there may still be requests in flight on that connection.

Why It Exists

Without this notice, a client only learns the leader changed by throwing a request at it and getting bounced with M. L removes that round trip, so the very first request after a failover goes straight to the new leader.

An older client that doesn't know this op can safely ignore it — only performance returns to the pre-notice level (request → M → retry).

Byte notation: op is an ASCII character, and addr is UTF-8 text (variable-length, shown as N in the structure). The trailing \n is 0A.

Flow

Client
Connected node
New leader
an election changes the leader
L · leader notice (new leader address)
updates the leader hint only — connection stays open
the next request goes straight to the new leader
A · acquired (token)
requestresponse

Single-server mode has no notion of a leader, so this notice is never sent. See Protocol (Cluster) for cluster behavior overall.