【File Detection】 monitors the 【last modification time and usage】 of specified files to prevent potential issues that could significantly impact system performance.


Core Functions of File Detection
Using the last modification time of files to check if the application system is operating normally and to evaluate the functionality of system programs.
Additionally, file usage is an important indicator of the normalcy of the application system or file records.

Impact on System Performance
Improper application system control can significantly impact server performance and may cause application issues.
Therefore, file detection serves as an auxiliary monitoring function at the application system level, crucial for maintaining system stability.

System Specifications
➢ Detection Purpose: Regularly check file update times and usage to confirm whether the application is running.
➢ Monitoring Target: Specific file names.
➢ Alarm Conditions: Set the maximum allowable delay time in seconds and file usage upper and lower limits.
➢ Real-Time Information, Information Collection, and Emergency Response: Including real-time data, alert issuance and resolution times, and abnormal notifications with execution of predefined programs.

Alarm Threshold Settings
➢ File last modification time exceeds the set maximum delay.
➢ File usage is below or above the set threshold.


Practical Application Case Analysis
Example 1
Take the transaction log or record file of Microsoft SQL Server as an example.
➢ Transaction Log: The ERRORLOG file located at 【C:\Program Files\Microsoft SQL Server\MSSQL12.MSSQLSERVER\MSSQL\Log\ERRORLOG】 records all database transaction details. Monitoring the modification time of this file helps determine whether the database is functioning normally.

➢ Data File: Such as the TmpDB.mdf file located at 【F:\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\DATA\WEB\TmpDB.mdf】, which is a primary database data file storing actual data. Monitoring changes in file usage can help identify abnormal growth or reduction in the database size.

➢ Log File: Similarly, the TmpDB_log.ldf file located in the 【F:\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\DATA\WEB】 directory records database operation logs. By monitoring its modification time and size, we can determine if the database is operating normally.

Example 2
To detect the survival of an application, if the program is self-developed, its operation cycle can be divided into multiple stages, focusing on file output in the intermediate stage for monitoring.
When the application reaches its set intermediate stage, it will automatically generate or update a specific file. This action serves as a "sign of life" indicating the program is operating as expected.
By real-time monitoring the last modification time of this file, we can determine if the application is still "alive" and running. If there is no file modification within the expected time, it may indicate that the program has stopped running or encountered an issue.