fdaa55a918
- Major version jump from v2.0 to v2.1 - Update haproxy download URL and hash - Add new patches (see https://www.haproxy.org/bugs/bugs-2.1.2.html) - Stop building LUA 5.3 in the haproxy build-process and use liblua5.3 as a dependency instead Signed-off-by: Christian Lachner <gladiac@gmail.com>
79 lines
3.5 KiB
Diff
79 lines
3.5 KiB
Diff
commit eb134e46e41b06f6022f1c9a481205a8180515bd
|
|
Author: Willy Tarreau <w@1wt.eu>
|
|
Date: Tue Jan 14 11:42:59 2020 +0100
|
|
|
|
BUG/MEDIUM: mux-h2: don't stop sending when crossing a buffer boundary
|
|
|
|
In version 2.0, after commit 9c218e7521 ("MAJOR: mux-h2: switch to next
|
|
mux buffer on buffer full condition."), the H2 mux started to use a ring
|
|
buffer for the output data in order to reduce competition between streams.
|
|
However, one corner case was suboptimally covered: when crossing a buffer
|
|
boundary, we have to shrink the outgoing frame size to the one left in
|
|
the output buffer, but this shorter size is later used as a signal of
|
|
incomplete send due to a buffer full condition (which used to be true when
|
|
using a single buffer). As a result, function h2s_frt_make_resp_data()
|
|
used to return less than requested, which in turn would cause h2_snd_buf()
|
|
to stop sending and leave some unsent data in the buffer, and si_cs_send()
|
|
to subscribe for sending more later.
|
|
|
|
But it goes a bit further than this, because subscribing to send again
|
|
causes the mux's send_list not to be empty anymore, hence extra streams
|
|
can be denied the access to the mux till the first stream is woken again.
|
|
This causes a nasty wakeup-sleep dance between streams that makes it
|
|
totally impractical to try to remove the sending list. A test showed
|
|
that it was possible to observe 3 million h2_snd_buf() giveups for only
|
|
100k requests when using 100 concurrent streams on 20kB objects.
|
|
|
|
It doesn't seem likely that a stream could get blocked and time out due
|
|
to this bug, though it's not possible either to demonstrate the opposite.
|
|
One risk is that incompletely sent streams do not have any blocking flags
|
|
so they may not be identified as blocked. However on first scan of the
|
|
send_list they meet all conditions for a wakeup.
|
|
|
|
This patch simply allows to continue on a new frame after a partial
|
|
frame. with only this change, the number of failed h2_snd_buf() was
|
|
divided by 800 (4% of calls). And by slightly increasing the H2C_MBUF_CNT
|
|
size, it can go down to zero.
|
|
|
|
This fix must be backported to 2.1 and 2.0.
|
|
|
|
(cherry picked from commit c7ce4e3e7fb2d7f9f037b4df318df7d6e23e8f7a)
|
|
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
|
|
|
|
diff --git a/src/mux_h2.c b/src/mux_h2.c
|
|
index d46a316ac..8a82f60fd 100644
|
|
--- a/src/mux_h2.c
|
|
+++ b/src/mux_h2.c
|
|
@@ -5157,6 +5157,7 @@ static size_t h2s_frt_make_resp_data(struct h2s *h2s, struct buffer *buf, size_t
|
|
struct htx_blk *blk;
|
|
enum htx_blk_type type;
|
|
int idx;
|
|
+ int trunc_out; /* non-zero if truncated on out buf */
|
|
|
|
TRACE_ENTER(H2_EV_TX_FRAME|H2_EV_TX_DATA, h2c->conn, h2s);
|
|
|
|
@@ -5183,6 +5184,7 @@ static size_t h2s_frt_make_resp_data(struct h2s *h2s, struct buffer *buf, size_t
|
|
type = htx_get_blk_type(blk); // DATA or EOM
|
|
bsize = htx_get_blksz(blk);
|
|
fsize = bsize;
|
|
+ trunc_out = 0;
|
|
|
|
if (type == HTX_BLK_EOM) {
|
|
if (h2s->flags & H2_SF_ES_SENT) {
|
|
@@ -5345,6 +5347,7 @@ static size_t h2s_frt_make_resp_data(struct h2s *h2s, struct buffer *buf, size_t
|
|
b_data(mbuf) <= MAX_DATA_REALIGN)
|
|
goto realign_again;
|
|
fsize = outbuf.size - 9;
|
|
+ trunc_out = 1;
|
|
|
|
if (fsize <= 0) {
|
|
/* no need to send an empty frame here */
|
|
@@ -5402,6 +5405,8 @@ static size_t h2s_frt_make_resp_data(struct h2s *h2s, struct buffer *buf, size_t
|
|
} else {
|
|
/* we've truncated this block */
|
|
htx_cut_data_blk(htx, blk, fsize);
|
|
+ if (trunc_out)
|
|
+ goto new_frame;
|
|
}
|
|
|
|
if (es_now) {
|