Data collected by Mod_jk module

The Apache mod_jk module forwards requests from the Apache web server to a Servlet container, such as Tomcat.

Additional mod_jk directives can also manage load balancing. Discovery populates the CMDB when it detects an Apache Server. When the Apache Web Server process is detected, if the mod_jk module is running on the web server as a load balancer, the related information populates to the CMDB.

  • The MID Server user account to explore the target server must have access to the httpd.conf configuration file in the /etc/httpd/conf/ folder.
  • Discovery uses secure shell (SSH) commands to identify the following associated elements:
    • Apache Get Configuration
    • Apache Version
    • Apache Get JK Module
  • The following probes require execute privileges to run commands:
    Table 1. Probes that require execute privileges
    Probe Command
    Apache – Get Configuration echo, sed, httpd, cut, grep, egrep (within the Borne shell script)
    Apache – Version httpd
    Apache – Get JK Module echo, sed, httpd, cut, grep, egrep (within the Borne shell script)

Probes and sensors

Discovery uses the Unix - Active Processes probe to identify an Apache server that contains the mod_jk module:

  1. The Unix - Active Processes probe detects a running process that matches one of the following criteria:
    • The name of the process is httpd.
    • The name of the process is apache.
  2. If there is a match on one of these criteria, a record is created in the Web Server table [cmdb_ci_web_server] if one does not already exist for that running process. The following probes are also triggered:
    • Apache – Version: the sensor of this probe populates the Apache version information in the Web Server record.
    • Apache – Get Configuration: this probe contains a Bourne shell script and an argument that determines the path of the Apache configuration file. The sensor of this probe populates some additional information in the Web Server record.
  3. The sensor processing of Apache – Get configuration probe results triggers the following probes if the mod_jk module is running on the web server:
    • Apache – JK Module: if the mod_jk module is running as a load balancer on the server, the sensor of this probe populates the information in the Load Balancer Service [cmdb_ci_lb_service], Load Balancer Pool [cmdb_ci_lb_pool] and Load Balancer Pool Member [cmdb_ci_lb_pool_member] tables.

Data Collected

For the mod_jk module with no load balancer, the following data is collected by default:
Table 2. Default Data Collected by Discovery
Table Name Field and Label Name Probe
cmdb_ci_web_server Name [name] Apache – Get Configuration
cmdb_ci_web_server Version [version] Apache – Version
cmdb_ci_web_server Description [short_description] Apache – Version
If the mod_jk module is enabled for load balancing, Discovery connects the following data:
Table 3. Data Collected by Discovery When the mod_jk Module is Identified as a Load Balancer
Table Name Field and Label Name Probe
cmdb_ci_lb_appl Name [name] Apache – Apache - Get JK Module
cmdb_ci_lb_appl IP Address [ip_address] Apache – Apache - Get JK Module
cmdb_ci_lb_appl Last Discovered [last_discovered] Apache – Apache - Get JK Module
cmdb_ci_lb_pool_member Name [name] Apache – Apache - Get JK Module
cmdb_ci_lb_pool_member Last Discovered [last_discovered] Apache – Apache - Get JK Module
cmdb_ci_lb_pool_member IP Address [ip_address] Apache – Apache - Get JK Module
cmdb_ci_lb_pool_member Load Balancer [load_balancer] Apache – Apache - Get JK Module
cmdb_ci_lb_pool_member Port [port] Apache – Apache - Get JK Module
cmdb_ci_lb_service Input URL [Input_url] Apache – Apache - Get JK Module
cmdb_ci_lb_service Last Discovered [last_discovered] Apache – Apache - Get JK Module
cmdb_ci_lb_service IP Address [ip_address] Apache – Apache - Get JK Module
cmdb_ci_lb_service Name [name] Apache – Apache - Get JK Module
cmdb_ci_lb_service Load Balancer [load_balancer] Apache – Apache - Get JK Module
cmdb_ci_lb_service Port [port] Apache – Apache - Get JK Module
cmdb_ci_lb_pool Last Discovered [last_discovered] Apache – Apache - Get JK Module
cmdb_ci_lb_pool Load balancing Method [load_balancing_method] Apache – Apache - Get JK Module
cmdb_ci_lb_pool Load Balancer [load_balancer] Apache – Apache - Get JK Module
cmdb_ci_lb_pool Name [name] Apache – Apache - Get JK Module

Relationships

In addition to data population, the following relationships are created in the CI Relationship [cmdb_rel_ci] table:
  • The records in the cmdb_ci_lb_appl table run on the cmdb_ci_web_server table records.
  • The records in the cmdb_ci_lb_service table use the cmdb_ci_lb_pool table records.
  • The records in the cmdb_ci_pool table are used by the cmdb_ci_service table record.
  • The records in the cmdb_ci_pool table are members of the cmdb_ci_pool_member table.
  • The records in the cmdb_ci_pool_member table are members of the cmdb_ci_pool table.