web server no response

[sunix]

I can't open webpages but the apache is running which is showed in SSH windows. It would be ok after manually restart
This thing happens everyday recently,
Anyone here has such experiences? And how to fix it?

[sunix]

Code: Select all

[Wed Dec 02 15:12:33.146349 2015] [core:error] [pid 14797] AH00046: child process 24537 still did not exit, sending a SIGKILL
[Wed Dec 02 15:12:33.147660 2015] [core:error] [pid 14797] AH00046: child process 24791 still did not exit, sending a SIGKILL
[Wed Dec 02 15:12:33.148833 2015] [core:error] [pid 14797] AH00046: child process 25277 still did not exit, sending a SIGKILL
[Wed Dec 02 15:12:33.149795 2015] [core:error] [pid 14797] AH00046: child process 27515 still did not exit, sending a SIGKILL
[Wed Dec 02 15:12:33.150903 2015] [core:error] [pid 14797] AH00046: child process 6535 still did not exit, sending a SIGKILL
[Wed Dec 02 15:12:34.154143 2015] [mpm_prefork:notice] [pid 14797] AH00169: caught SIGTERM, shutting down
[Wed Dec 02 15:12:34.845052 2015] [suexec:notice] [pid 30814] AH01232: suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec)
[Wed Dec 02 15:12:34.872049 2015] [:notice] [pid 30815] mod_ruid2/0.9.8 enabled
[Wed Dec 02 15:12:34.874121 2015] [mpm_prefork:notice] [pid 30815] AH00163: Apache/2.4.7 (Ubuntu) mod_fcgid/2.3.9 PHP/5.5.9-1ubuntu4.14 OpenSSL/1.0.1f configured -- resuming normal operations
[Wed Dec 02 15:12:34.874143 2015] [core:notice] [pid 30815] AH00094: Command line: '/usr/sbin/apache2'

part of error logs posted,hope it will help

also there are some strange lines like \xe4\x6\ with the domain log

[Tue Dec 01 20:56:53.439928 2015] [:error] [pid 24533] [client 107.155.120.128:33321] WordPress\xe6\x95\xb0\xe6\x8d\xae\xe5\xba\x93\xe6\x9f\xa5\xe8\xaf\xa2SELECT t.*, tt.*, tr.object_id FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN wp_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ('category', 'post_tag', 'post_format') AND tr.object_id IN (197, 207, 210, 213, 220) ORDER BY t.name ASC\xe6\x97\xb6\xe5\x8f\x91\xe7\x94\x9fGot error -1 from storage engine\xe9\x94\x99\xe8\xaf\xaf\xef\xbc\x8c\xe8\xbf\x99\xe6\x98\xaf\xe7\x94\xb1require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/twentyeleven/archive.php'), get_sidebar, locate_template, load_template, require_once('/themes/twentyeleven/sidebar.php'), dynamic_sidebar