Log File

A log file is a text file that records when things occur. Sometimes log files are a garbage dump of sort, just outputting data as it occurs.

Some log files can be analyzed relatively easily (e..g, web server logs). However, more commonly extensive skill is required to perform data analysis using log files, and this preparation is often best done using specialist tools (e.g., Perl).

Example of a log file

2022-03-18 10:57:19,718 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,734 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:57:19,734 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,735 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,735 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:57:19,735 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,735 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,736 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:57:19,736 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,736 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:57:19,737 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:58:39,845 [31544-SubscriptionTimeoutAvoider] QQyu INFO - Subscription response - Client 2510d781-6434-4f63-afec-ff51e4b3a59f ChangeID 8:
2022-03-18 10:58:39,845 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,846 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,846 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:58:39,846 [31544-Main] QQcq INFO - ResetAutoRecovery
2022-03-18 10:58:39,846 [31544-Main] QQcq INFO - Not auto-recovering because nothing has changed since last time.
2022-03-18 10:58:39,878 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,879 [31544-Main] QQrq INFO - Request Subscribe: {"Request":"Subscribe","SubscriptionUpdateID":116,"LastChangeID":8,"To":[[false,8,{"Request":"GetTableFormatsCss","GetAllFormats":false}],[false,8,{"Request":"TablesTab_SelectionHasRules","SelectedGuids":["1f2263b9-07db-44d8-a46e-ee5132a47911"]}],[false,8,{"Request":"GetSuggestions","ClientGuiCon...
2022-03-18 10:58:39,880 [31544-94] QQam0 INFO - Converted json subscription for last_change_id = 8. found 0 immediate responses
2022-03-18 10:58:39,880 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,880 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 10:58:39,881 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,881 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 10:58:39,881 [31544-Main] QQam0 INFO - RequestsIdle
2022-03-18 11:00:39,892 [31544-SubscriptionTimeoutAvoider] QQyu INFO - Subscription response - Client 2510d781-6434-4f63-afec-ff51e4b3a59f ChangeID 8:
2022-03-18 11:00:39,895 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 11:00:39,896 [31544-Main] QQam0 INFO - UpdateChangeID because Default
2022-03-18 11:00:39,899 [31544-Main] QQam0 INFO - RequestsIdle