8.4 wrong fpmstatus output

[PLTytus]

Description

fpmstatus seems to return wrong values, sample

pool:                 www
process manager:      dynamic
start time:           25/Nov/2024:13:00:38 +0000
start since:          5057
accepted conn:        1
listen queue:         0
max listen queue:     0
listen queue len:     0
idle processes:       0 
active processes:     1
total processes:      1
max active processes: 11
max children reached: 0
slow requests:        0
memory peak:          81326080

accepted conn not incresing, even decreasing, e.g. shows 3 after refreshing it shows 1 again
idle processes, active processes, idle processes: in this example there 15 running fpm processes in total

PHP Version

8.4.1

Operating System

No response

[devnexen]

We might need a bit more to understand if the issue is relevant, i.e. configuration, how the logs look ...

[PLTytus]

This is in /usr/local/etc/php-fpm.d/www.conf on php:8.4.1-fpm-alpine image

[www]
user = www-data
group = www-data

pm = dynamic
pm.max_children = 200
pm.start_servers = 10
pm.min_spare_servers = 10
pm.max_spare_servers = 20
pm.max_requests = 200

pm.status_listen = 127.0.0.1:9001
pm.status_path = /fpmstatus

No errors in logs.

It kind of behaves like processes are overriding current stats: https://github.com/user-attachments/assets/61aab54b-2d25-45c7-b0d7-7562b8aaef2b

There is no such issue on PHP 8.3

[lucasnetau]

Possibly this PR #14153

php-src/sapi/fpm/fpm/fpm_request.c

Line 204 in ba6c005

fpm_scoreboard_update_commit(0, 0, 0, 0, 0, 0, 0, proc->memory, FPM_SCOREBOARD_ACTION_SET, NULL);

This is calling FPM_SCOREBOARD_ACTION_SET at the end of the request with all stats set to 0, the unmodified stats should be set as -1

so either don't set the values

--- fpm_scoreboard_update_commit(0, 0, 0, 0, 0, 0, 0, proc->memory, FPM_SCOREBOARD_ACTION_SET, NULL);
+++ fpm_scoreboard_update_commit(-1, -1, -1, -1, -1, -1, -1, proc->memory, FPM_SCOREBOARD_ACTION_SET, NULL);

or INC vs SET

--- fpm_scoreboard_update_commit(0, 0, 0, 0, 0, 0, 0, proc->memory, FPM_SCOREBOARD_ACTION_SET, NULL);
+++ fpm_scoreboard_update_commit(0, 0, 0, 0, 0, 0, 0, proc->memory, FPM_SCOREBOARD_ACTION_INC, NULL);

[PLTytus]

Looking at fpm_scoreboard_update_commit definition, both @lucasnetau suggested solutions should resolve the issue.

php-src/sapi/fpm/fpm/fpm_scoreboard.c

Lines 100 to 177 in afa08b5

	void fpm_scoreboard_update_commit(
	int idle, int active, int lq, int lq_len, int requests, int max_children_reached,
	int slow_rq, size_t memory_peak, int action, struct fpm_scoreboard_s *scoreboard) /* {{{ */
	{
	scoreboard = fpm_scoreboard_get_for_update(scoreboard);
	if (!scoreboard) {
	return;
	}
	if (action == FPM_SCOREBOARD_ACTION_SET) {
	if (idle >= 0) {
	scoreboard->idle = idle;
	}
	if (active >= 0) {
	scoreboard->active = active;
	}
	if (lq >= 0) {
	scoreboard->lq = lq;
	}
	if (lq_len >= 0) {
	scoreboard->lq_len = lq_len;
	}
	#if HAVE_FPM_LQ /* prevent unnecessary test */
	if (scoreboard->lq > scoreboard->lq_max) {
	scoreboard->lq_max = scoreboard->lq;
	}
	#endif
	if (requests >= 0) {
	scoreboard->requests = requests;
	}
	if (max_children_reached >= 0) {
	scoreboard->max_children_reached = max_children_reached;
	}
	if (slow_rq > 0) {
	scoreboard->slow_rq = slow_rq;
	}
	} else {
	if (scoreboard->idle + idle > 0) {
	scoreboard->idle += idle;
	} else {
	scoreboard->idle = 0;
	}
	if (scoreboard->active + active > 0) {
	scoreboard->active += active;
	} else {
	scoreboard->active = 0;
	}
	if (scoreboard->requests + requests > 0) {
	scoreboard->requests += requests;
	} else {
	scoreboard->requests = 0;
	}
	if (scoreboard->max_children_reached + max_children_reached > 0) {
	scoreboard->max_children_reached += max_children_reached;
	} else {
	scoreboard->max_children_reached = 0;
	}
	if (scoreboard->slow_rq + slow_rq > 0) {
	scoreboard->slow_rq += slow_rq;
	} else {
	scoreboard->slow_rq = 0;
	}
	}
	if (scoreboard->active > scoreboard->active_max) {
	scoreboard->active_max = scoreboard->active;
	}
	if (scoreboard->memory_peak < memory_peak) {
	scoreboard->memory_peak = memory_peak;
	}
	fpm_unlock(scoreboard->lock);
	}