Simple way to find errors in SQL Server error log
By: Greg Robidoux | Updated: 2018-07-05 | Comments (4) | Related: More > Error Logs
When managing SQL Server there are so many different places to look for data. These include the error logs, system event logs, profiler data, performance counter data, etc. Once you have collected the data you then need to parse through and interpret the data you collected. One of these areas where errors and other informational data is stored is the SQL Server error log. The problem with the error log file is that there is so much data collected it is sometimes hard to determine where the real errors lie. By default all backups and integrity checks are logged in the error log. In addition, if you are auditing logins these messages are also stored in the error log, so this further compounds the problem. It is great to have all of this data, but trying to find your problems can become quite a chore. So how can you find the errors much easier?
With SQL Server 2005 and later Microsoft has made this a bit easier to set filters, but this is still pretty cumbersome and does not really provide you all of the data you need. The best approach as with many things is to build your own data parser to find exactly what you need.
Here is a simple view of the Error Log as it normally displays:
Here is a simple view of the Error Log after the errors have been parsed out:
As you can see this new version is much easier to read and also only shows you the errors instead of all that additional informational data that is stored in the error logs. In addition, it shows you all of the error lines at the particular time the error occurred for the same source, so you do not need to go back to the error log to get the additional error lines.
Option 1 - Find SQL Server Errors with sp_readerrorlog
This tip was first written in 2007 and after reviewing the tip to see if it was still relevant, I thought of a much simpler way of doing this using just T-SQL.
Here is the script. The only thing you need to change is the error log number you want to pass to sp_readerrorlog (see the comment in the code). This will produce the output as shown in the above image.
DROP TABLE IF EXISTS #errorLog; -- this is new syntax in SQL 2016 and later CREATE TABLE #errorLog (LogDate DATETIME, ProcessInfo VARCHAR(64), [Text] VARCHAR(MAX)); INSERT INTO #errorLog EXEC sp_readerrorlog 6 -- specify the log number or use nothing for active error log SELECT * FROM #errorLog a WHERE EXISTS (SELECT * FROM #errorLog b WHERE [Text] like 'Error:%' AND a.LogDate = b.LogDate AND a.ProcessInfo = b.ProcessInfo)
To figure out the error log number to use, you can look at the error logs in SSMS as shown below. The current log does not have a number, where each of the archives has a number associated with the archive, so for the above code either use one of these numbers to read that log or use no number to read the current error log.
If you want to read through all error logs, take a look at this tip Search multiple SQL Server Error Logs at the same time. You can combine the above with the code in that tip to search for all errors.
Option 2 - Find SQL Server Errors with VBScript
This was the original way of doing this. This code still works and works with SQL 2000 through SQL 2017, but I would suggest using the T-SQL approach above.
Below is a VBScript that allows you to parse out the error messages. It is not the most elegant piece of code, but it does work.
The script takes two arguments:
- logType - 2000 (SQL 2000) or 2005+ (SQL 2005 or later)
- fileName - name and path of the file that you want to parse
This could be called from a command line such as the following.
ParseLog.vbs "2005+" "C:\Program Files\Microsoft SQL Server\MSSQL14.SQL2017\MSSQL\Log\ERRORLOG.2"
Before you can use this, you need to save the following code into a new file called ParseLog.vbs. Once you have done this you are ready to roll. This code will read the file that you specify and will create a secondary file using the same name and appending a ".txt" at the end of the file name, so you can easliy open it with a text editor.
Const FOR_READING = 1 Const FOR_WRITING = 2 logType = Wscript.Arguments(0) strFileName = Wscript.Arguments(1) strNewFileName = Wscript.Arguments(1) & ".txt" strCheckForString0 = UCase("error:") SET objFS = CreateObject("Scripting.FileSystemObject") IF NOT objFS.FileExists(strFileName) THEN MsgBox Wscript.Arguments(1) & " is not a legitimate file name." Wscript.Quit 1 END IF SELECT CASE logType CASE "2000" SET objTS = objFS.OpenTextFile(strFileName, FOR_READING) CASE "2005+" SET objTS = objFS.OpenTextFile(strFileName, 1, , true) CASE ELSE Wscript.Quit 1 END SELECT strContents = objTS.ReadAll objTS.CLOSE arrLines = Split(strContents, vbNewLine) SET objTS = objFS.CreateTextFile(strNewFileName, FOR_WRITING) errorFound = False counter = 1 errorTime = "" Dim ErrorArray(20) FOR Each strLine IN arrLines IF errorTime <> LEFT(strLine,22) THEN IF errorFound THEN i = 1 Do Until i = counter + 1 objTS.WriteLine ErrorArray(i) i = i + 1 Loop objTS.WriteLine END IF errorTime = LEFT(strLine,22) counter = 1 errorFound = False Erase ErrorArray ErrorArray(counter) = strLine ELSE counter = counter + 1 ErrorArray(counter) = strLine END IF IF instr(UCase(strLine), strCheckForString0) THEN errorFound = True END IF Next
- That's all there is to it. Hopefully you will find this to be useful.
- This has been tested with SQL 2000 thru SQL 2017
- See if you can make this more robust enter your feedback in the comments section below.
|8/15/2007||Another way to parse
the sql errorlog is using the
Microsoft LogParser application.
Here is my sample to find the message "Starting up database 'master'" in all sql 2005 errorlog.
I'm sure you will love the sql syntax to write your query request. A very powerful tool that can parse multiple file (you can see the ERRORLOG.*)
Logparser.exe "select top 10 substr(text,0,22) as Date, substr(text,23,9) as Source, substr(text,32) as Message from \\porphyra\d$\bases\MSSQL$ABO_TEST\LOG\ERRORLOG.* where Message like '%Starting up database \'master\'.%'" -i:textline
Last Updated: 2018-07-05
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