From b384f982b98e6e3458766ab3ea909f552cc59254 Mon Sep 17 00:00:00 2001
From: yunwei37 <1067852565@qq.com>
Date: Mon, 2 Sep 2024 06:40:19 +0000
Subject: [PATCH] =?UTF-8?q?Deploying=20to=20gh-pages=20from=20@=20eunomia-?=
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---
 40-mysql/dispatch_command.bt | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 40-mysql/dispatch_command.bt

diff --git a/40-mysql/dispatch_command.bt b/40-mysql/dispatch_command.bt
new file mode 100644
index 0000000..e42e378
--- /dev/null
+++ b/40-mysql/dispatch_command.bt
@@ -0,0 +1,30 @@
+#!/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]);
+}