Nginx php-fpm 502 报错：设置参数调大后依然没解决

相关报错：

Nginx Error Log

recv() failed (104: Connection reset by peer) while reading response header from upstream

PHP FPM Error Log

449 [04-Jan-2019 10:52:30] WARNING: [pool www] child 25054 exited on signal 11 (SIGSEGV - core dumped) after 47484.155316 seconds from start 450 [04-Jan-2019 10:52:30] NOTICE: [pool www] child 1310 started 451 [04-Jan-2019 11:23:24] WARNING: [pool www] child 25033 exited on signal 11 (SIGSEGV - core dumped) after 49338.447068 seconds from start 452 [04-Jan-2019 11:23:24] NOTICE: [pool www] child 1857 started 453 [04-Jan-2019 11:46:21] WARNING: [pool www] child 25052 exited on signal 11 (SIGSEGV - core dumped) after 50715.557187 seconds from start 454 [04-Jan-2019 11:46:21] NOTICE: [pool www] child 2263 started 455 [04-Jan-2019 11:54:20] WARNING: [pool www] child 25038 exited with code 1 after 51193.974856 seconds from start 456 [04-Jan-2019 11:54:20] NOTICE: [pool www] child 2378 started 457 [04-Jan-2019 12:23:16] WARNING: [pool www] child 1005 exited on signal 11 (SIGSEGV - core dumped) after 6101.226650 seconds from start

当前 PHP-FPM 参数配置：

115 ; The number of child processes created on startup. 116 ; Note: Used only when pm is set to 'dynamic' 117 ; Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2 118 pm.start_servers = 40 119 120 ; The desired minimum number of idle server processes. 121 ; Note: Used only when pm is set to 'dynamic' 122 ; Note: Mandatory when pm is set to 'dynamic' 123 pm.min_spare_servers = 20 124 125 ; The desired maximum number of idle server processes. 126 ; Note: Used only when pm is set to 'dynamic' 127 ; Note: Mandatory when pm is set to 'dynamic' 128 pm.max_spare_servers = 60 129 130 ; The number of seconds after which an idle process will be killed. 131 ; Note: Used only when pm is set to 'ondemand' 132 ; Default Value: 10s 133 ; pm.process_idle_timeout = 10s; 134 135 ; The number of requests each child process should execute before respawning. 136 ; This can be useful to work around memory leaks in 3rd party libraries. For 137 ; endless request processing specify '0'. Equivalent to PHP_FCGI_MAX_REQUESTS. 138 ; Default Value: 0 139 ; pm.max_requests = 0

现在问题是参数调高了也没解决问题：之前看说可能是因为 PHP 执行太慢，但我单独测试过，每个接口单独执行都不会超过 100毫秒 所以想问下问题可能出在哪？

服务器是腾讯云免费的：1 核 1 GB 5 Mbps