First I am assuming you are using the Red Hat distributed version. Is upgrading to Apache httpd 2.4 from the Red Hat Software Collection an option?
I can think of several options to detect and automate the restart as a remediation. One would be to script a memory watcher using the free command and automatically executing the restart steps you do manually. The run the script out of cron every 5 minutes. For a fix you might want to peruse the release note for Apache versions of 2.2 after 2.2.15, and the mods, for memory leak fixes and see if Red Hat has backported them into their version. If you find one that wasn’t backported time to nudge Res Hat. Maybe someone on this list more in tune with the releases can point you at one or two of these. Or just build a newer version of Apache 2.2 from source Darryl Baker NIT - CI -DAPS X76674 From: Michele Mase' [mailto:michele.m...@gmail.com] Sent: January 24, 2017 12:10 PM To: Httpd Users List <users@httpd.apache.org> Subject: [users@httpd] Unable to fork new process All, I've a apache web server with 600 web sites as reverse proxy. The average of req. is more than 100 req/sec during all the day. The apache is a 2.2.15 release 56.el6_8.3 (RedHat 6.x system up to date) + mod_ssl. Every 10 days, the system has problems, and in the error log i found dozen of: [error] (12)Cannot allocate memory: fork: Unable to fork new process The temporary solution for me is the following: after an alert mail from the system monitoring server, I must restart the httpd using: service httpd stop; killall httpd.worker; killall -9 httpd.worker; service httpd start Adding more ram to the system does not help. Any suggestion? Best regards apachectl -l Compiled in modules: core.c worker.c http_core.c mod_so.c apachectl -M Loaded Modules: core_module (static) mpm_worker_module (static) http_module (static) so_module (static) log_post_module (shared) evasive20_module (shared) auth_basic_module (shared) auth_digest_module (shared) authn_file_module (shared) authn_alias_module (shared) authn_anon_module (shared) authn_dbm_module (shared) authn_default_module (shared) authz_host_module (shared) authz_user_module (shared) authz_owner_module (shared) authz_groupfile_module (shared) authz_dbm_module (shared) authz_default_module (shared) ldap_module (shared) authnz_ldap_module (shared) include_module (shared) log_config_module (shared) logio_module (shared) env_module (shared) ext_filter_module (shared) mime_magic_module (shared) expires_module (shared) deflate_module (shared) headers_module (shared) usertrack_module (shared) setenvif_module (shared) mime_module (shared) dav_module (shared) status_module (shared) autoindex_module (shared) info_module (shared) dav_fs_module (shared) vhost_alias_module (shared) negotiation_module (shared) dir_module (shared) actions_module (shared) speling_module (shared) userdir_module (shared) alias_module (shared) substitute_module (shared) rewrite_module (shared) proxy_module (shared) proxy_balancer_module (shared) proxy_ftp_module (shared) proxy_http_module (shared) proxy_ajp_module (shared) proxy_connect_module (shared) cache_module (shared) suexec_module (shared) disk_cache_module (shared) cgi_module (shared) version_module (shared) unique_id_module (shared) ssl_module (shared) reqtimeout_module (shared) Syntax OK
