bpf-developer-tutorial/40-mysql/dispatch_command.bt

#!/usr/bin/env bpftrace


// Trace the dispatch_command function in MySQL
uprobe:/usr/sbin/mysqld:dispatch_command
{
    // Store the start time of the command execution in the map
    @start_times[tid] = nsecs;
    
    // Print the process ID and command string
    printf("MySQL command executed by PID %d: ", pid);
    
    // The third argument to dispatch_command is the SQL query string
    printf("%s\n", str(arg3));
}

uretprobe:/usr/sbin/mysqld:dispatch_command
{
    // Retrieve the start time from the map
    $start = @start_times[tid];
    
    // Calculate the latency in milliseconds
    $delta = (nsecs - $start) / 1000000;
    
    // Print the latency
    printf("Latency: %u ms\n", $delta);
    
    // Delete the entry from the map to avoid memory leaks
    delete(@start_times[tid]);
}