Question
What is the difference between access_log, access_log.processed and access_log_processed.1.gz?
Answer
Plesk uses access log files for the statistics calculation. The log files are modified by internal utilities during this process for statistics calculation purposes.
1. The access_log files:
This is the log file using to keep current visits. It contains current actual state of a program (Apache in the case of access_log) that writes the status and results of its work into such log files. access_log is used to calculate statistics.
2. The access_log.processed files:
During the statistics calculation original access_log files are analyzed by internal utilities. The extension .processed indicates that this log file has been already analyzed by statistics utilities.
3. The access_log_processed.[0-9].gz files:
This means that the file is compressed into gunzip archive depending on the Log rotation settings in order to save disk space. Log rotation settings could be changed on Service Plan level at Home > Service Plans > Default domain > Logs & Statistics tab.
For more details regarding log files refer to the Plesk Documentation.