IBM HTTP Server V5.3 for z/OS: Part 5: Advanced configuration
Various capabilities in IBM® HTTP Server V5.3 for z/OS® are available in IBM HTTP Server, but implemented differently. Learn about key differences in the advanced configuration of the two web servers.
The part and chapters correspond to the part and chapters in publication number SC34-4826-09 of the z/OS HTTP Server Planning, Install, and Using guide for IBM HTTP Server V5.3 for z/OS.
- Use the mod_expires module to set browser cache headers. Read the mod_expires module topic in the Apache HTTP Server documentation for further information.
- Use the mod_cache module and the CacheEnable directive to cache local files. Read the mod_cache module topic in the Apache HTTP Server documentation for further information.
IBM HTTP Server has three main types of logs:
- Error logs
- Have a fixed format. Configure them by using the ErrorLog directive.
- Access logs
- Have custom formats. IBM HTTP Server updates them on a per-request basis. Configure them by using the LogFormat and CustomLog directives. Read the Apache HTTP Server documentation for information about custom log formats.
- Module-specific diagnostic logs
- Have logs for particular modules. Examples include the rewriting log file for the mod_rewrite module and the script error log file for the mod_cgi module. Read the log files topic in the Apache HTTP Server documentation for further information.
You can pipe access and error logs to an external program for rotation or maintenance. IBM HTTP Server includes a piped logger that does simple time based and size based rotation. IBM HTTP Server does not manage the rotated log files. You must manage these logs external to the server or through the custom pipe logger. Read the topic in the Apache HTTP server documentation about the Rotatelogs program for more information.
Filters for the access log
IBM HTTP Server uses conditional logging for the access log instead of filters. Read about conditional logging in the log files topic in the Apache HTTP Server documentation.
Reports for logs
IBM HTTP Server by default produces logs in the Apache HTTP Server standard formats. Various tools can use these logs to generate reports.
System Management Facility record types
- Record aggregate server statistics periodically by using the mod_mpmstats module and setting the SMFReportInterval directive to a non-zero value.
- Record access log like data by using the mod_smf module and setting the SMFRecord directive to on. You can set the SMFRecord directive in any scope of the Location directive or the Directory directive in the httpd.conf file.
The HTCounter and other CGI programs
IBM HTTP Server does not include an HTCounter program or any other CGI program.
You can use server-side includes with IBM HTTP Server. Implement server-side includes by using the mod_include module.
Server-side image maps
You can use server-side image maps with IBM HTTP Server. However, the technology is deprecated. Implement server-side image maps by using the mod_imagemap module.
Modes of operation
IBM HTTP Server has one mode of operation, which is a multithreaded, multiprocess server. The IBM HTTP Server parent process starts servers dynamically in response to thread utilization instead of using Workload Management (WLM).
Server activity monitor
You can implement a web-accessible monitoring interface or periodically collect server statistics in an error log.
To implement the web-accessible monitoring interface, use the mod_status module.
To periodically collect server statistics, use the mod_mpmstats module. The module generates messages in the error logs. The messages contain the statistics.
Simple Network Management Protocol (SNMP)
IBM HTTP Server does not include an SNMP subagent or provide any SNMP data.
z/OS operator console modify command for System Management Facilities
You cannot use the z/OS operator console modify command to manage your System Management Facilities (SMF). Instead, use IBM HTTP Server directives. The SMFReportInterval directive controls how often aggregate server statistics are recorded in SMF. The SMFRecord directive controls which URL patterns record access-log like details in SMF.
You can create your own SMF custom module to manage SMF. Use the sample SMF custom module as a guide.
SMF record formats
Use the mod_mpmstats module to record type 103 subtype 13 records. Read the topic about configuring the server for SMF recording.
Use the mod_smf module to record type 103 subtype 14 records. Read the topic about the mod_smf module.
Website ratings with Platform for Internet Content Selection (PICS)
Platform for Internet Content Selection (PICS) is not supported in IBM HTTP Server.
Lightweight Directory Access Protocol (LDAP) information retrieval
Use the mod_ldap module and the mod_authnz_ldap module to do LDAP authentication and authorization.
Your server as a proxy
You can use IBM HTTP Server as a forward proxy or as a reverse proxy. To implement a proxy, use the mod_proxy module.
To configure IBM HTTP Server as a forward proxy, generally use the <Proxy> container and the ProxyRequests directive. As a forward proxy, IBM HTTP Server supports Secure Sockets Layer (SSL) tunneling for SSL clients. Use the mod_proxy_connect module to do SSL tunneling.
IBM HTTP Server can be a reverse proxy to HTTPS, HTTP, and FTP origin servers. However, reverse proxy support to FTP origin servers is deprecated. To configure IBM HTTP Server as a reverse proxy, use directives that begin with ProxyPass. Additionally, set the SSLProxyEngine directive to on to use IBM HTTP Server as a reverse proxy to an HTTPS origin server.
Proxy capability is turned off by default.
When you use IBM HTTP Server as a web server, the Apache HTTP Server caching capability and the Fast Response Cache Accelerator capability are supported. However, when you use IBM HTTP Server as a proxy, the Apache HTTP Server caching capability is supported, but the Fast Response Cache Accelerator capability is not.
Multiple IP addresses or virtual hosts for your server
The documentation on Apache virtual hosts provides comprehensive documentation for IP and name-based virtual hosts.