This is the PPT deck that I had used for my session at SQL Saturday 116 at Bangalore "Demsytifying SQL Server Memory Dumps". This session will help you understand when memory dumps are generated in SQL Server, what information can be gathered without analyzing the dump and how much can be done by just using public symbols.
1. Demystifying SQL Server Memory Dumps
Amit Banerjee
Microsoft Corporation
Blog: www.troubleshootingsql.com
Twitter: @banerjeeamit
Facebook: www.facebook.com/TroubleshootingSQL
2. Agenda
When does it happen?
How can I be notified?
Where are the files?
What can I do?
Who was responsible?
WHY did it happen?
3. WHEN does it happen
Non-yielding scheduler
Non-yielding resource monitor
Non-yielding IOCP listener
Deadlocked Schedulers
Exceptions/Assertions
Database Corruption
Latch Timeout
Other conditions
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4. HOW can I be notified
Alerts on EventIDs
Use custom FileWatcher
task on your LOG folders*
Monitor SQL Errorlogs for
dump generation messages
5. WHERE are the files
• Default location is LOG folder
Path
• Symptom dump text file
SQLDumpXXXX.txt
• Relevant SQL Errorlog snippet
SQLDumpXXXX.log
• THE mini-dump file
SQLDumpXXXX.mdmp
6.
7. WHAT can I do Why this
Kolaveri di?
Finally
lets
Look at analyze
.txt and the dump
.log files
Inspect
Windows
Event logs
Check
SQL
Errorlogs
8. WHO was responsible
spid148 Time out occurred while waiting for buffer latch —
type 4, bp 0000000832FE1200, page 3:11234374, stat
0x7c20009, database id: 120, allocation unit id:
72057599731367936, task 0x0000000003C4F2E8 : 0, waittime
300, flags 0x1a, owning task 0x0000000003C129B8.
Continuing to wait.
spid148 **Dump thread – spid = 148, PSS =
0x000000044DC17BD0, EC = 0x000000044DC17BE0
spid148 ***Stack Dump being sent to D:Microsoft SQL
ServerMSSQL.1MSSQLLOGSQLDump0001.txt
spid148 * Latch timeout
spid148 * Input Buffer 84 bytes -
spid148 * DBCC CHECKDB WITH ALL_ERRORMSGS
External dump process returned no errors.
9. WHY
Demo !!!
Time to wake up!
It’s time to play with the debugger!
I have some fancy stuff to show you!
Can you even read this?
You have good eyesight!!!
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10. Resources
Whitepaper: How To Diagnose and Correct Errors
17883, 17884, 17887 and 17888
Use the Microsoft Symbol Server to obtain debug symbol
files: http://support.microsoft.com/kb/311503
Debugging walkthroughs:
http://troubleshootingsql.com/category/debugging/
WinDBG: http://msdn.microsoft.com/en-
us/windows/hardware/gg463009.aspx