Monitor Apache Server

Overview

Apache Server’s monitoring involves monitoring of the following elements:

• Apache Access Logs
• Apache Error Logs
• Apache Server Health

note

The configurations given below apply only to the Apache server running on an instance.

Pre-requisites

1. Ensure Apache access logs are in format expected by sfAgent parser.

   Edit configuration file , conf file can be /etc/apache2/apache2.conf, /etc/apache2/sites-enabled/000-default.conf, /etc/apache2/conf-enabled/other-vhosts-access-log.conf and set log format as follows:

   LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %D" combined  
   
   CustomLog "logs/access_log" combined  

   After configuring log format, the expected log entry would be:

   45.112.52.50 - - [28/Jun/2020:23:34:10 -0700] "GET / HTTP/1.1" 302 242 "-" "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.106 Safari/537.36" 271  

   Apache configuration file can be found in these paths:

   • Ubuntu: /etc/apache2/mods-enabled/status.conf 
   • Centos: /etc/httpd/conf/httpd.conf

2. Check if Apache status module is enabled

   This is required to monitor Apache server health.

   Apache web server exposes metrics through its status module, mod_status. If apache server is running and mod_status is enabled, apache server’s status page should be available at http://127.0.0.1/server-status.

   Alternatively, you can check is mod_status is enabled by running the following commands:

   Ubuntu(or Debian based systems):

   sudo apache2ctl -M | grep status_module  

   Centos/RHEL/Fedora

   sudo httpd -M | grep status_module  

   if output of above command is status_module , then apache status module is enabled. If mod_status is not enabled , follow next step to enable it.

3. Enable Apache status module

   In order to enable mod_status ,  edit the status module’s configuration file (on Debian platforms), or your main Apache configuration file (all other Unix-like platforms). 

   Debian users can find the status module’s configuration file in /etc/apache2/mods-enabled/status.conf 

   Users of other platforms (such as Red Hat–based systems) will find their main configuration file in /etc/apache2/apache2.conf, /etc/httpd/conf/httpd.conf, or /etc/apache2/httpd.conf. 

    In the main configuration file, allow access from local or from a specific ip address as shown below:  

      <Location /server-status>  
          SetHandler server-status  
          Require local  
    #     Require all granted  
          Require ip x.x.x.x  
      </Location>  

   Check your configuration file for errors with the following command:

   apachectl configtest   

   Perform a graceful restart to apply the changes without interrupting live connections:

   (apachectl -k graceful or service apache2 graceful)  

   After enabling mod_status and restarting Apache, status page is accessible at http://localhost/server-status  or http://ipaddress/server-status.

Configuration

sfAgent section provides steps to install and automatically generate plugin configurations. User can also manually add the configuration shown below to config.yaml under /opt/sfagent/ directory

key: <profile key> 
generate_name: true 
tags: 
  Name: <unique instance name or will be generated from IP> 
  appName: <add application name> 
  projectName: <add project name> 
 metrics: 
  plugins: 
    - name: apache 
      enabled: true 
      interval: 300 
      config: 
        port: <apache port number>
        secure: false ## while using secured connection set secure flag to true
        location: server-status 
 logging: 
  plugins: 
    - name: apache-access 
      enabled: true 
      config: 
        geo_info: true  
        log_path: /var/log/apache2/access.log, var/log/apache2/access_log
        ua_parser: false 
     - name: apache-error 
      enabled: true 
      config: 
        log_level: 
          - notice 
          - warning 
          - error 
        log_path: /var/log/apache2/error.log, /var/log/httpd/error_log

Viewing data and dashboards

Data generated by plugin can be viewed in browse data page inside the respective application under plugin=apache and documentType=apache. Logger data is available inside plugin=apache-access with documentType=apacheAccess and plugin=apache-error with documentType=apacheError.

Dashboard for this data can be instantiated by Importing dashboard template Apache_Server and Apache_Access to the application dashboard.