OS4X logging

Logging mechanisms

Different technologies are used for deep system logging situations. These are differented in the following topics.

OS4Xapi logging

The communication between the web interface (and the native administrative application) and the PHP backend is logged in the OS4Xapi logfile. The following parameters are configurable:

• absolute position of the logfile ("Configuration" -> "Logging" -> "Absolute path to logfile of OS4X API")
• OS4Xapi loglevel ("Configuration" -> "Logging" -> "OS4X API loglevel")

The default position of the logfile is:

/opt/os4x/tmp/os4xapi.log

The logfile writer creates up to 6 files with a maximum filesize of 10MB, the actually used logfile is the configured one. Older logfiles have number suffixes like:

os4xapi.log.1
os4xapi.log.2
os4xapi.log.3
os4xapi.log.4

Daemon logging

When external communication is being involved for logging, the OS4X debug daemon collects all information of all running programs and saves them into a ring buffer. This means, that older log entries are eliminated by newer log entries, the more activity is being logged, the less is the timeframe for the actual memory content. In order to analyze special situations, it may be interesting to collect all information.

The position where the OS4X debug daemon writes its logfiles is dependant on the OS4X's configured temporary directory. Configuration options for the daemons are:

• Temporary directory ("Configuration" -> "Directories" -> "Temporary directory")
• Enable continuous write of OS4X debug daemon output? ("Configuration" -> "Logging" -> "Enable continuous write of OS4X debug daemon output?")
• debug daemon log script ("Configuration" -> "Events" -> "debug daemon log script")

The temporary output is the directory where the logfiles are written in. The filename schema is:

os4x-logfile-<datestamp>-<timestamp>.log

Example:

/opt/os4x/tmp/os4x-logfile-20130604-165815.log

Every time the debug daemon writes a debug dump file, the optionally configured debug daemon log script is being executed. The single parameter is the absolute path of the logfile itself. OS4X debug daemon logfiles can be compressed quite good (about 90% shrinking factor with gzip).

A dedicated documentation about how to handle the OS4X debug daemon is available here.

Database performance logging

If you suspect a database environment to be slow, an environment variable lets you control where to log all database statement performance information: Database performance benchmarking