How to increase log levels?

1. Oracle HTTP Server:
1. Backup and then edit ORACLE_HOME/Apache/Apache/conf/httpd.conf on Apps Tier.
Change
LogLevel warn
to
LogLevel debug

If HTTP Server is SSL enabled, backup and edit ORACLE_HOME/Apache/Apache/conf/ssl.conf
Change
SSLLogLevel warn
to
SSLLogLevel debug

2. Attempt to start HTTP Server again and review the newly created output (or pass this output to Oracle Support)