How can I kill MySQL queries or sleeping connections every 60 seconds in Windows?

Question

I want to check my MySQL server every minute and kill queries that have run longer than 150 seconds. The main reason I want to do this is because I don't want queries from certain people to lock up the DB for everyone else. I know this is not the ultimate solution to the problem, but at least it's a fallback in case something goes wrong with a query. I don't have a slave DB (this is just an at-home project).

I'd like to schedule a script to run that does this for me. I'm unfamiliar with Perl or Ruby and I need it done on my Windows 2008 Server box. I've looked into creating a simple cmd line script, but that doesn't seem to be possible. I know currently I can do something like this but I have to do it manually:

mysqladmin processlist
mysqladmin kill

Anyone have any ideas or examples on how I could do this?

Answer 1

If you have Wscript installed - I think it should be - you can try this. Save as "somethingorother.vbs" and execute every now and then. Or you can use the provided loop. Both loop and kill-for-real options are commented; test the script before uncommenting on a production server.

I assume that 'mysqladmin processlist' outputs something like this (taken from my XP):

+----+------+----------------+----+---------+------+-------+------------------+
| Id | User | Host           | db | Command | Time | State | Info             |
+----+------+----------------+----+---------+------+-------+------------------+
| 21 | root | localhost:1648 |    | Query   | 0    |       | show processlist |
+----+------+----------------+----+---------+------+-------+------------------+

So we have to eliminate rows containing "----" and rows containing "Id | User", and what remains is

| 21 | root | localhost:1648 |    | Query   | 0    |       | show processlist |

which we can split by pipe signs '|', getting nine fields from 0 to 8:

0   1     2          3          4      5        6      7           8
 | 21 | root | localhost:1648 |    | Query   | 0    |       | show processlist |

Field #1 is Id, and field #6 yields the run time.

Option Explicit

Dim objShell, objWshScriptExec, objStdOut, strLine
Dim id, fields, rt, Killer, KillRun

' While True
'     WScript.Sleep 150000

Set objShell = CreateObject("WScript.Shell")
Set objWshScriptExec = objShell.Exec("mysqladmin processlist")
Set objStdOut = objWshScriptExec.StdOut

While Not objStdOut.AtEndOfStream
   strLine = objStdOut.ReadLine
   If (InStr(strLine, "----") = 0 and InStr(strLine, "| Id | User |") = 0) Then
       fields = Split(strLine, "|")
       id = trim(fields(1))
       rt = trim(fields(6))
       If rt > 150 Then
           ' Set Killer = CreateObject("WScript.Shell")
           ' Set KillRun = objShell.Exec("mysqladmin kill " & id)
           echo 
       End If
   End If
Wend

' Wend

Answer 2

Here is the final script I ended up using. Thanks to Iserni with his initial answer that helped me get to this point!

I ended up launching this from a .bat file where csript.exe is call because I can output messages to the command line console (rather than a message box). If you want to output to a text file, you can add that as well, just make sure you launch the .bat file with full Administrator UAC access. Here is what the .bat file contains:

C:\Windows\System32\cscript.exe "C:\Program Files\MySQL\MySQL Server 5.6\bin\kill-slow-queries.vbs"

And here is what is inside of the .vbs file:

    Option Explicit

    Dim objShell, objWshScriptExec, objStdOut, strLine, fields
    Dim id, rt, Killer, KillRun

     While True
         WScript.Sleep 10000

    Set objShell = CreateObject("WScript.Shell")
    Set objWshScriptExec = objShell.Exec("C:\Program Files\MySQL\MySQL Server 5.6\bin\mysqladmin processlist -u root -pMYPASSWORD")
    Set objStdOut = objWshScriptExec.StdOut

On Error Resume Next
    While Not objStdOut.AtEndOfStream
       strLine = objStdOut.ReadLine
       If InStr(strLine, "| 1") > 0 or InStr(strLine, "| 2") > 0 or InStr(strLine, "| 3") > 0 or InStr(strLine, "| 4") > 0 or InStr(strLine, "| 5") > 0 or InStr(strLine, "| 6") > 0 or InStr(strLine, "| 7") > 0 or InStr(strLine, "| 8") > 0  or InStr(strLine, "| 9") > 0 Then
           fields = Split(strLine, "|") 
           id = trim(fields(1))
           rt = trim(fields(6))
           If rt = "" Then 
              rt = 0
           End If
           WScript.Echo "ID: " + id + " Time: " + rt
           If rt > 80 Then
                Set Killer = CreateObject("WScript.Shell")
                Set KillRun = objShell.Exec("C:\Program Files\MySQL\MySQL Server 5.6\bin\mysqladmin kill " + id + " -u root -pMYPASSWORD")
               WScript.Echo "Killed ID: " + id
           End If
       End If

     Wend

      WScript.Echo ""
      WScript.Echo ""

    Wend

The reason I have an If statement that checks for each Integer is because it guarantees and exact match to an ID number of a process. Anything other than those nine options will fail, and you never know what the process list could contain there, so better safe than sorry.