mir/bind
2
0
Fork 0
mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-30 05:57:52 +00:00
Code Issues Releases Wiki Activity

DoH: Track the amount of in flight outgoing data

Browse Source 
Previously we would limit the amount of incoming data to process based
solely on the presence of not completed send requests. That worked,
however, it was found to severely degrade performance in certain
cases, as was revealed during extended testing.

Now we switch to keeping track of how much data is in flight (or ready
to be in flight) and limit the amount of processed incoming data when
the amount of in flight data surpasses the given threshold, similarly
to like we do in other transports.

(cherry picked from commit 05e8a508188116e8e367aaf5e68575c8cebb4207)
This commit is contained in:
Artem Boldariev 2025-02-13 14:53:18 +02:00
parent 5f6080a959
commit 96e8ea1245
1 changed files with 23 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
lib/isc/netmgr/http.c
View File

@ -188,6 +188,8 @@ struct isc_nm_http_session {
isc__nm_http_pending_callbacks_t pending_write_callbacks;
isc_buffer_t *pending_write_data;
size_t data_in_flight;
/*
* The statistical values below are for usage on server-side
* only. They are meant to detect clients that are taking too many
@ -1054,6 +1056,19 @@ client_submit_request(isc_nm_http_session_t *session, http_cstream_t *stream) {
return ISC_R_SUCCESS;
}
static inline size_t
http_in_flight_data_size(isc_nm_http_session_t *session) {
size_t in_flight = 0;
if (session->pending_write_data != NULL) {
in_flight += isc_buffer_usedlength(session->pending_write_data);
}
in_flight += session->data_in_flight;
return in_flight;
}
static ssize_t
http_process_input_data(isc_nm_http_session_t *session,
isc_buffer_t *input_data) {
@ -1105,13 +1120,14 @@ http_process_input_data(isc_nm_http_session_t *session,
(session->received - session->processed);
/*
* If there are non completed send requests in flight -let's
* not process any incoming data, as it could lead to piling
* up too much send data in send buffers. With many clients
* If there is too much outgoing data in flight - let's not
* process any incoming data, as it could lead to piling up
* too much send data in send buffers. With many clients
* connected it can lead to excessive memory consumption on
* the server instance.
*/
if (session->sending > 0) {
const size_t in_flight = http_in_flight_data_size(session);
if (in_flight >= ISC_NETMGR_TCP_SENDBUF_SIZE) {
break;
}
@ -1320,6 +1336,8 @@ http_writecb(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
isc_nmhandle_detach(&req->httphandle);
}
session->data_in_flight -=
isc_buffer_usedlength(req->pending_write_data);
isc_buffer_free(&req->pending_write_data);
session->processed += req->submitted;
isc_mem_put(session->mctx, req, sizeof(*req));
@ -1509,6 +1527,7 @@ http_send_outgoing(isc_nm_http_session_t *session, isc_nmhandle_t *httphandle,
session->sending++;
isc_buffer_usedregion(send->pending_write_data, &send_data);
session->data_in_flight += send_data.length;
isc_nm_send(transphandle, &send_data, http_writecb, send);
return true;