Log Filename
The pCDN server creates several log files:
- server.log -- contains debugging info, access logs, and route info (gathered by ping and traceroute packets)
- squid_access.log -- contains squid-like downloading logs
Upon a pCDN server is launched, a new server.log is created. We avoid name conflicts by suffixing an integer to the filenames, e.g., server.log.3. The squid_access files support log rotations: squid_access.log is the current log file, squid_access.log.1 (the most recent) through squid_access.log.6 (the least recent) are historical logs. The pCDN server, by default, keeps 7 historical log files and creates a new log file every 24-hr.
Stats Log Format
In pCDN, several measurements are taken and logged for further analysis. We list all stat log format in the following, where time durations (e.g., session time) are in msecs and data amounts (e.g., total transer size) are in bytes.
The general log format is date_and_time | received_timestamp | stats_type | stats_message, where the stats_message contains type-dependent fields.
Four types of statistic messages are supported:
- Session Info: data transfer counters, media | media_length | receiver | sender | time | transfer_size | ctrl_msg_# | session_time | total_transfer_size
- Host Info: hop distance and round-trip time from a receiver to all its potential senders, media | receiver | sender | hop_ip | hop_dist | rtt
- Path Info: hop distance and round-trip time for all intermediate routers between a receiver and its potential senders", media | receiver | sender | hop_ip | hop_dist | rtt
