503 service unavailable

hi all need help
the site works. but sometimes gives 503
I changed the version of php 7.0, 7.1, 7.3 but the result is 0
server information - Cpu 8 core / Ram 16g | Nginx+apache

/domlogs/ Log

[Wed Aug 14 13:04:38.722449 2019] [proxy_fcgi:error] [pid 11474:tid 140512740669184] [client 31.13.115.14:36860] AH01067: Failed to read FastCGI header
[Wed Aug 14 13:04:38.722485 2019] [proxy_fcgi:error] [pid 11474:tid 140512740669184] (104)Connection reset by peer: [client 31.13.115.14:36860] AH01075: Error dispatching request to :
[Wed Aug 14 13:07:59.501245 2019] [proxy_fcgi:error] [pid 11473:tid 140512757454592] [client 95.140.193.250:37378] AH01071: Got error 'PHP message: PHP Parse error:  syntax error, unexpected end of file in /home/anews/public_html/storage/framework/views/2a5121335225dc02fc2e6148ec7b9c35ef605ff3.php on line 136\n', referer: http://www.google.co.uk/url?sa=t&source=web&cd=1
[Wed Aug 14 13:11:45.071498 2019] [proxy_fcgi:error] [pid 11581:tid 140512866559744] [client 37.186.85.46:37826] AH01067: Failed to read FastCGI header, referer: http://m.facebook.com
[Wed Aug 14 13:11:45.071544 2019] [proxy_fcgi:error] [pid 11581:tid 140512866559744] (104)Connection reset by peer: [client 37.186.85.46:37826] AH01075: Error dispatching request to : , referer: http://m.facebook.com

/php-fpm/ log

[14-Aug-2019 13:05:13] WARNING: [pool anews] server reached max_children setting (4), consider raising it
[14-Aug-2019 13:07:59] WARNING: [pool anews] child 15979 said into stderr: "NOTICE: PHP message: PHP Parse error:  syntax error, unexpected end of file in /home/anews/public_html/storage/framework/views/2a5121335225dc02fc2e6148ec7b9c35ef605ff3.php on line 136"
[14-Aug-2019 13:11:45] WARNING: [pool anews] child 15979 exited on signal 7 (SIGBUS) after 393.638345 seconds from start
[14-Aug-2019 13:11:45] NOTICE: [pool anews] child 17770 started

Perhaps this is your prpblem and the solution...

 server reached max_children setting (4), consider raising it

max_children 4 to 32
I don’t understand what’s wrong,

[15-Aug-2019 09:23:35] WARNING: [pool anews] child 13558 exited on signal 7 (SIGBUS) after 13.433788 seconds from start
[15-Aug-2019 09:23:35] NOTICE: [pool anews] child 13598 started
[15-Aug-2019 09:37:55] WARNING: [pool anews] child 14518 exited on signal 7 (SIGBUS) after 2.480640 seconds from start

[Thu Aug 15 09:37:55.458830 2019] [proxy_fcgi:error] [pid 25532:tid 139911260739328] [client 95.140.193.250:57026] AH01067: Failed to read FastCGI header, referer: http://www.google.co.uk/url?sa=t&source=web&cd=1
[Thu Aug 15 09:37:55.458852 2019] [proxy_fcgi:error] [pid 25532:tid 139911260739328] (104)Connection reset by peer: [client 95.140.193.250:57026] AH01075: Error dispatching request to : , referer: http://www.google.co.uk/url?sa=t&source=web&cd=1
[Thu Aug 15 09:37:55.458983 2019] [proxy_fcgi:error] [pid 25532:tid 139911277524736] [client 95.140.193.250:57032] AH01067: Failed to read FastCGI header, referer: http://www.google.co.uk/url?sa=t&source=web&cd=1

Perhaps try this solution...
https://serverpilot.io/docs/error-failed-to-read-fastcgi-header