MINOR: peers: Add a message for heartbeat.
This patch implements peer heartbeat feature to prevent any haproxy peer
from reconnecting too often, consuming sockets for nothing.
To do so, we add PEER_MSG_CTRL_HEARTBEAT new message to PEER_MSG_CLASS_CONTROL peers
control class of messages. A ->heartbeat field is added to peer structs
to store the heatbeat timeout value which is handled by the same function as for ->reconnect
to control the session timeouts. A 2-bytes heartbeat message is sent every 3s when
no updates have to be sent. This way, the peer which receives such a message is sure
the remote peer is still alive. So, it resets the ->reconnect peer session
timeout to its initial value (5s). This prevents any reconnection to an
already connected alive peer.
diff --git a/include/types/peers.h b/include/types/peers.h
index 5200d56..6bc99c2 100644
--- a/include/types/peers.h
+++ b/include/types/peers.h
@@ -62,6 +62,7 @@
unsigned int flags; /* peer session flags */
unsigned int statuscode; /* current/last session status code */
unsigned int reconnect; /* next connect timer */
+ unsigned int heartbeat; /* next heartbeat timer */
unsigned int confirm; /* confirm message counter */
struct appctx *appctx; /* the appctx running it */
struct shared_table *remote_table;