255 lines
8.8 KiB
Diff
255 lines
8.8 KiB
Diff
What we do now:
|
|
We use a static record size of 4K. This gives a good balance of latency and
|
|
throughput.
|
|
|
|
Optimize latency:
|
|
By initialy sending small (1 TCP segment) sized records, we are able to avoid
|
|
HoL blocking of the first byte. This means TTFB is sometime lower by a whole
|
|
RTT.
|
|
|
|
Optimizing throughput:
|
|
By sending increasingly larger records later in the connection, when HoL is not
|
|
a problem, we reduce the overhead of TLS record (29 bytes per record with
|
|
GCM/CHACHA-POLY).
|
|
|
|
Logic:
|
|
Start each connection with small records (1369 byte default, change with
|
|
ssl_dyn_rec_size_lo). After a given number of records (40, change with
|
|
ssl_dyn_rec_threshold) start sending larger records (4229, ssl_dyn_rec_size_hi).
|
|
Eventually after the same number of records, start sending the largest records
|
|
(ssl_buffer_size).
|
|
In case the connection idles for a given amount of time (1s,
|
|
ssl_dyn_rec_timeout), the process repeats itself (i.e. begin sending small
|
|
records again).
|
|
|
|
|
|
diff --color -uNr a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
|
|
--- a/src/event/ngx_event_openssl.c 2023-06-13 23:08:10.000000000 +0800
|
|
+++ b/src/event/ngx_event_openssl.c 2023-06-14 15:43:05.834243714 +0800
|
|
@@ -1674,6 +1674,7 @@
|
|
|
|
sc->buffer = ((flags & NGX_SSL_BUFFER) != 0);
|
|
sc->buffer_size = ssl->buffer_size;
|
|
+ sc->dyn_rec = ssl->dyn_rec;
|
|
|
|
sc->session_ctx = ssl->ctx;
|
|
|
|
@@ -2645,6 +2646,41 @@
|
|
|
|
for ( ;; ) {
|
|
|
|
+ /* Dynamic record resizing:
|
|
+ We want the initial records to fit into one TCP segment
|
|
+ so we don't get TCP HoL blocking due to TCP Slow Start.
|
|
+ A connection always starts with small records, but after
|
|
+ a given amount of records sent, we make the records larger
|
|
+ to reduce header overhead.
|
|
+ After a connection has idled for a given timeout, begin
|
|
+ the process from the start. The actual parameters are
|
|
+ configurable. If dyn_rec_timeout is 0, we assume dyn_rec is off. */
|
|
+
|
|
+ if (c->ssl->dyn_rec.timeout > 0 ) {
|
|
+
|
|
+ if (ngx_current_msec - c->ssl->dyn_rec_last_write >
|
|
+ c->ssl->dyn_rec.timeout)
|
|
+ {
|
|
+ buf->end = buf->start + c->ssl->dyn_rec.size_lo;
|
|
+ c->ssl->dyn_rec_records_sent = 0;
|
|
+
|
|
+ } else {
|
|
+ if (c->ssl->dyn_rec_records_sent >
|
|
+ c->ssl->dyn_rec.threshold * 2)
|
|
+ {
|
|
+ buf->end = buf->start + c->ssl->buffer_size;
|
|
+
|
|
+ } else if (c->ssl->dyn_rec_records_sent >
|
|
+ c->ssl->dyn_rec.threshold)
|
|
+ {
|
|
+ buf->end = buf->start + c->ssl->dyn_rec.size_hi;
|
|
+
|
|
+ } else {
|
|
+ buf->end = buf->start + c->ssl->dyn_rec.size_lo;
|
|
+ }
|
|
+ }
|
|
+ }
|
|
+
|
|
while (in && buf->last < buf->end && send < limit) {
|
|
if (in->buf->last_buf || in->buf->flush) {
|
|
flush = 1;
|
|
@@ -2784,6 +2820,9 @@
|
|
|
|
if (n > 0) {
|
|
|
|
+ c->ssl->dyn_rec_records_sent++;
|
|
+ c->ssl->dyn_rec_last_write = ngx_current_msec;
|
|
+
|
|
if (c->ssl->saved_read_handler) {
|
|
|
|
c->read->handler = c->ssl->saved_read_handler;
|
|
diff --color -uNr a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
|
|
--- a/src/event/ngx_event_openssl.h 2023-06-13 23:08:10.000000000 +0800
|
|
+++ b/src/event/ngx_event_openssl.h 2023-06-14 15:43:05.834243714 +0800
|
|
@@ -86,10 +86,19 @@
|
|
typedef struct ngx_ssl_ocsp_s ngx_ssl_ocsp_t;
|
|
|
|
|
|
+typedef struct {
|
|
+ ngx_msec_t timeout;
|
|
+ ngx_uint_t threshold;
|
|
+ size_t size_lo;
|
|
+ size_t size_hi;
|
|
+} ngx_ssl_dyn_rec_t;
|
|
+
|
|
+
|
|
struct ngx_ssl_s {
|
|
SSL_CTX *ctx;
|
|
ngx_log_t *log;
|
|
size_t buffer_size;
|
|
+ ngx_ssl_dyn_rec_t dyn_rec;
|
|
};
|
|
|
|
|
|
@@ -128,6 +137,10 @@
|
|
unsigned in_ocsp:1;
|
|
unsigned early_preread:1;
|
|
unsigned write_blocked:1;
|
|
+
|
|
+ ngx_ssl_dyn_rec_t dyn_rec;
|
|
+ ngx_msec_t dyn_rec_last_write;
|
|
+ ngx_uint_t dyn_rec_records_sent;
|
|
};
|
|
|
|
|
|
@@ -137,7 +150,7 @@
|
|
#define NGX_SSL_DFLT_BUILTIN_SCACHE -5
|
|
|
|
|
|
-#define NGX_SSL_MAX_SESSION_SIZE 4096
|
|
+#define NGX_SSL_MAX_SESSION_SIZE 16384
|
|
|
|
typedef struct ngx_ssl_sess_id_s ngx_ssl_sess_id_t;
|
|
|
|
diff --color -uNr a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
|
|
--- a/src/http/modules/ngx_http_ssl_module.c 2023-06-13 23:08:10.000000000 +0800
|
|
+++ b/src/http/modules/ngx_http_ssl_module.c 2023-06-14 15:43:05.834243714 +0800
|
|
@@ -290,6 +290,41 @@
|
|
offsetof(ngx_http_ssl_srv_conf_t, reject_handshake),
|
|
NULL },
|
|
|
|
+ { ngx_string("ssl_dyn_rec_enable"),
|
|
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
|
|
+ ngx_conf_set_flag_slot,
|
|
+ NGX_HTTP_SRV_CONF_OFFSET,
|
|
+ offsetof(ngx_http_ssl_srv_conf_t, dyn_rec_enable),
|
|
+ NULL },
|
|
+
|
|
+ { ngx_string("ssl_dyn_rec_timeout"),
|
|
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
|
|
+ ngx_conf_set_msec_slot,
|
|
+ NGX_HTTP_SRV_CONF_OFFSET,
|
|
+ offsetof(ngx_http_ssl_srv_conf_t, dyn_rec_timeout),
|
|
+ NULL },
|
|
+
|
|
+ { ngx_string("ssl_dyn_rec_size_lo"),
|
|
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
|
|
+ ngx_conf_set_size_slot,
|
|
+ NGX_HTTP_SRV_CONF_OFFSET,
|
|
+ offsetof(ngx_http_ssl_srv_conf_t, dyn_rec_size_lo),
|
|
+ NULL },
|
|
+
|
|
+ { ngx_string("ssl_dyn_rec_size_hi"),
|
|
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
|
|
+ ngx_conf_set_size_slot,
|
|
+ NGX_HTTP_SRV_CONF_OFFSET,
|
|
+ offsetof(ngx_http_ssl_srv_conf_t, dyn_rec_size_hi),
|
|
+ NULL },
|
|
+
|
|
+ { ngx_string("ssl_dyn_rec_threshold"),
|
|
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
|
|
+ ngx_conf_set_num_slot,
|
|
+ NGX_HTTP_SRV_CONF_OFFSET,
|
|
+ offsetof(ngx_http_ssl_srv_conf_t, dyn_rec_threshold),
|
|
+ NULL },
|
|
+
|
|
ngx_null_command
|
|
};
|
|
|
|
@@ -629,6 +664,11 @@
|
|
sscf->ocsp_cache_zone = NGX_CONF_UNSET_PTR;
|
|
sscf->stapling = NGX_CONF_UNSET;
|
|
sscf->stapling_verify = NGX_CONF_UNSET;
|
|
+ sscf->dyn_rec_enable = NGX_CONF_UNSET;
|
|
+ sscf->dyn_rec_timeout = NGX_CONF_UNSET_MSEC;
|
|
+ sscf->dyn_rec_size_lo = NGX_CONF_UNSET_SIZE;
|
|
+ sscf->dyn_rec_size_hi = NGX_CONF_UNSET_SIZE;
|
|
+ sscf->dyn_rec_threshold = NGX_CONF_UNSET_UINT;
|
|
|
|
return sscf;
|
|
}
|
|
@@ -694,6 +734,20 @@
|
|
ngx_conf_merge_str_value(conf->stapling_responder,
|
|
prev->stapling_responder, "");
|
|
|
|
+ ngx_conf_merge_value(conf->dyn_rec_enable, prev->dyn_rec_enable, 0);
|
|
+ ngx_conf_merge_msec_value(conf->dyn_rec_timeout, prev->dyn_rec_timeout,
|
|
+ 1000);
|
|
+ /* Default sizes for the dynamic record sizes are defined to fit maximal
|
|
+ TLS + IPv6 overhead in a single TCP segment for lo and 3 segments for hi:
|
|
+ 1369 = 1500 - 40 (IP) - 20 (TCP) - 10 (Time) - 61 (Max TLS overhead) */
|
|
+ ngx_conf_merge_size_value(conf->dyn_rec_size_lo, prev->dyn_rec_size_lo,
|
|
+ 1369);
|
|
+ /* 4229 = (1500 - 40 - 20 - 10) * 3 - 61 */
|
|
+ ngx_conf_merge_size_value(conf->dyn_rec_size_hi, prev->dyn_rec_size_hi,
|
|
+ 4229);
|
|
+ ngx_conf_merge_uint_value(conf->dyn_rec_threshold, prev->dyn_rec_threshold,
|
|
+ 40);
|
|
+
|
|
conf->ssl.log = cf->log;
|
|
|
|
if (conf->certificates) {
|
|
@@ -890,6 +944,28 @@
|
|
return NGX_CONF_ERROR;
|
|
}
|
|
|
|
+ if (conf->dyn_rec_enable) {
|
|
+ conf->ssl.dyn_rec.timeout = conf->dyn_rec_timeout;
|
|
+ conf->ssl.dyn_rec.threshold = conf->dyn_rec_threshold;
|
|
+
|
|
+ if (conf->buffer_size > conf->dyn_rec_size_lo) {
|
|
+ conf->ssl.dyn_rec.size_lo = conf->dyn_rec_size_lo;
|
|
+
|
|
+ } else {
|
|
+ conf->ssl.dyn_rec.size_lo = conf->buffer_size;
|
|
+ }
|
|
+
|
|
+ if (conf->buffer_size > conf->dyn_rec_size_hi) {
|
|
+ conf->ssl.dyn_rec.size_hi = conf->dyn_rec_size_hi;
|
|
+
|
|
+ } else {
|
|
+ conf->ssl.dyn_rec.size_hi = conf->buffer_size;
|
|
+ }
|
|
+
|
|
+ } else {
|
|
+ conf->ssl.dyn_rec.timeout = 0;
|
|
+ }
|
|
+
|
|
return NGX_CONF_OK;
|
|
}
|
|
|
|
diff --color -uNr a/src/http/modules/ngx_http_ssl_module.h b/src/http/modules/ngx_http_ssl_module.h
|
|
--- a/src/http/modules/ngx_http_ssl_module.h 2023-06-13 23:08:10.000000000 +0800
|
|
+++ b/src/http/modules/ngx_http_ssl_module.h 2023-06-14 15:43:38.264102815 +0800
|
|
@@ -62,6 +62,12 @@
|
|
ngx_flag_t stapling_verify;
|
|
ngx_str_t stapling_file;
|
|
ngx_str_t stapling_responder;
|
|
+
|
|
+ ngx_flag_t dyn_rec_enable;
|
|
+ ngx_msec_t dyn_rec_timeout;
|
|
+ size_t dyn_rec_size_lo;
|
|
+ size_t dyn_rec_size_hi;
|
|
+ ngx_uint_t dyn_rec_threshold;
|
|
} ngx_http_ssl_srv_conf_t;
|
|
|
|
|