MEDIUM: h2: prepare a graceful shutdown when the frontend is stopped
During a reload operation, instead of keeping the H2 connections opened
forever causing confusion during configuration changes, let's send a
graceful shutdown so that the client knows that it would better open a
new connection for future requests. We can't really catch the signal
from H2, but we can advertise this graceful shutdown upon the next I/O
event (eg: a WINDOW_UPDATE from the client or a new request). One of
the visible effect is that the old process quits much faster.
This patch should be backported to 1.8 since it is affected by this
problem.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 71660f8..c6e15ec 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -2250,6 +2250,7 @@
static int h2_wake(struct connection *conn)
{
struct h2c *h2c = conn->mux_ctx;
+ struct session *sess = conn->owner;
if (h2c->dbuf->i && !(h2c->flags & H2_CF_DEM_BLOCK_ANY)) {
h2_process_demux(h2c);
@@ -2261,6 +2262,18 @@
h2c->flags &= ~H2_CF_DEM_DFULL;
}
+ if (sess && unlikely(sess->fe->state == PR_STSTOPPED)) {
+ /* frontend is stopping, reload likely in progress, let's try
+ * to announce a graceful shutdown if not yet done. We don't
+ * care if it fails, it will be tried again later.
+ */
+ if (!(h2c->flags & (H2_CF_GOAWAY_SENT|H2_CF_GOAWAY_FAILED))) {
+ if (h2c->last_sid < 0)
+ h2c->last_sid = (1U << 31) - 1;
+ h2c_send_goaway_error(h2c, NULL);
+ }
+ }
+
/*
* If we received early data, try to wake any stream, just in case
* at least one of them was waiting for the handshake