[OPTIM] http: set MSG_MORE on response when a pipelined request is pending

Many times we see a lot of short responses in HTTP (typically 304 on a
reload). It is a waste of network bandwidth to send that many small packets
when we know we can merge them. When we know that another HTTP request is
following a response, we set BF_EXPECT_MORE on the response buffer, which
will turn MSG_MORE on exactly once. That way, multiple short responses can
leave pipelined if their corresponding requests were also pipelined.
This commit is contained in:
Willy Tarreau 2010-01-03 11:37:54 +01:00
parent d38b53b896
commit face839296
3 changed files with 15 additions and 3 deletions

View File

@ -112,6 +112,7 @@
#define BF_AUTO_CONNECT 0x800000 /* consumer may attempt to establish a new connection */
#define BF_DONT_READ 0x1000000 /* disable reading for now */
#define BF_EXPECT_MORE 0x2000000 /* more data expected to be sent very soon (one-shoot) */
/* Use these masks to clear the flags before going back to lower layers */
#define BF_CLEAR_READ (~(BF_READ_NULL|BF_READ_PARTIAL|BF_READ_ERROR|BF_READ_ATTACHED))

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@ -3497,6 +3497,13 @@ int http_request_forward_body(struct session *s, struct buffer *req, int an_bit)
if (s->be->options2 & PR_O2_INDEPSTR)
s->req->cons->flags |= SI_FL_INDEP_STR;
/* if the request buffer is not empty, it means we're
* about to process another request, so send pending
* data with MSG_MORE to merge TCP packets when possible.
*/
if (s->req->l)
s->rep->flags |= BF_EXPECT_MORE;
/* make ->lr point to the first non-forwarded byte */
s->req->lr = s->req->w + s->req->send_max;
if (s->req->lr >= s->req->data + s->req->size)

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@ -608,16 +608,20 @@ static int stream_sock_write_loop(struct stream_interface *si, struct buffer *b)
* tests.
*/
if (MSG_NOSIGNAL) {
if (MSG_NOSIGNAL && MSG_MORE) {
unsigned int send_flag = MSG_DONTWAIT | MSG_NOSIGNAL;
if (MSG_MORE &&
((b->to_forward && b->to_forward != BUF_INFINITE_FORWARD) ||
if (((b->to_forward && b->to_forward != BUF_INFINITE_FORWARD) ||
((b->flags & (BF_SHUTW|BF_SHUTW_NOW|BF_HIJACK)) == BF_SHUTW_NOW && (max == b->send_max)) ||
(max != b->l && max != b->send_max))
&& (fdtab[si->fd].flags & FD_FL_TCP)) {
send_flag |= MSG_MORE;
}
else if (b->flags & BF_EXPECT_MORE) {
/* it was forced on the buffer, this flag is one-shoot */
b->flags &= ~BF_EXPECT_MORE;
send_flag |= MSG_MORE;
}
ret = send(si->fd, b->w, max, send_flag);
} else {