How It Works: Online Index Rebuild - Can Cause Increased Fragmentation
First published on MSDN on Sep 05, 2012 SQL Server Books Online alludes to the fragmentation possibility but does not fully explain that the Online Index rebuilding may increase fragmentation when it is allowed to run with MAX DOP > 1 and ALLOW_PAGE_LOCKS = OFF directives.Effectively troubleshoot latency in SQL Server Transactional replication: Part 1
Are you struggling with latency issues in SQL Server Transactional replication? This article provides clear, step-by-step instructions to effectively troubleshoot and resolve these challenges. Dive into proven techniques and best practices that will help you enhance your SQL Server's performance and ensure seamless data replication. Don't let latency slow you down—master the art of SQL Server troubleshooting today! I hope you find this teaser engaging! If you need any adjustments or additional content, feel free to let me know. Thanks to Collin Benkler, Senior Escalation Engineer in Microsoft for SQL Server for his valuable feedbacks.
How to troubleshoot “SQL Server is terminating because of fatal exception c06d007e”
Case 1, with Dump generated Issue definition: ======== Customer have SQL 2008/2012/2014 running on the same server, and then applied the SP4 for SQL Server 2012 in Windows update. But after this customer saw some issue from application side, then you rollback the update. And then Customer applied the SP3 for SQL Server 2012, but after that the SQL Server service can’t startup with following message and dump generated. Customer also tried to repair SQL Server many times, it doesn’t work. 2018-02-22 18:31:43.52 Server Error: 17311, Severity: 16, State: 1. 2018-02-22 18:31:43.52 Server SQL Server is terminating because of fatal exception c06d007e. This error may be caused by an unhandled Win32 or C++ exception, or by an access violation encountered during exception handling. Check the SQL error log for any related stack dumps or messages. This exception forces SQL Server to shutdown. To recover from this error, restart the server (unless SQLAgent is configured to auto restart). 2018-02-22 18:31:43.53 Server Using 'dbghelp.dll' version '4.0.5' 2018-02-22 18:31:43.53 Server **Dump thread - spid = 0, EC = 0x0000000000000000 2018-02-22 18:31:43.53 Server ***Stack Dump being sent to E:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\LOG\SQLDump0094.txt 2018-02-22 18:31:43.53 Server * ******************************************************************************* 2018-02-22 18:31:43.53 Server * 2018-02-22 18:31:43.53 Server * BEGIN STACK DUMP: 2018-02-22 18:31:43.53 Server * 02/22/18 18:31:43 spid 11352 2018-02-22 18:31:43.53 Server * 2018-02-22 18:31:43.53 Server * ex_handle_except encountered exception C06D007E - Server terminating Issue analysis and troubleshooting thinking ======== In the live meeting with customer, we first checking the setup log. And we saw that the SP4 has been applied, but after a while there is another setup folder generated reporting the failed error message: Exception type: Microsoft.SqlServer.Chainer.Infrastructure.ChainerInvalidOperationException Message: The NT service 'SQLSERVERAGENT' could not be started. HResult : 0x84b20001 FacilityCode : 1202 (4b2) ErrorCode : 1 (0001) Data: HelpLink.EvtType = 0xAE7B8BF3@0xF762992B@1202@1 DisableWatson = true Stack: at Microsoft.SqlServer.Configuration.SetupExtension.RunPatchAllInstanceAction.RestoreServiceStates() at Microsoft.SqlServer.Configuration.SetupExtension.RunPatchAllInstanceAction.ExecuteAction(String actionId) at Microsoft.SqlServer.Chainer.Infrastructure.Action.Execute(String actionId, TextWriter errorStream) at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionHelper(TextWriter statusStream, ISequencedAction actionToRun, ServiceContainer context) Then we get the dump file from customer and performed a detailed analysis . This callstack seems that we have issue while Initialize Server Components(InitServerComponents), and then we get the detailed component name “SqlServerSpatial110.dll” # Child-SP RetAddr Call Site 00 00000000`01bf9cf8 000007fe`fd3810ac ntdll!ZwWaitForSingleObject+0xa 01 00000000`01bf9d00 00000000`ff6af3ee KERNELBASE!WaitForSingleObjectEx+0x79 02 00000000`01bf9da0 00000000`ff6af874 sqlservr!CDmpDump::DumpInternal+0x20e 03 00000000`01bf9e40 00000000`ff6af919 sqlservr!CDmpDump::DumpFilter+0x64 04 00000000`01bf9f10 00000000`74d712e3 sqlservr!`CDmpDump::Dump'::`1'::filt$0+0x19 05 00000000`01bf9f40 00000000`7769bf9d msvcr100!__C_specific_handler+0x97 06 00000000`01bf9fb0 00000000`776704ca ntdll!RtlpExecuteHandlerForException+0xd 07 00000000`01bf9fe0 00000000`77673c1f ntdll!RtlDispatchException+0x45a 08 00000000`01bfa6c0 000007fe`fd39a06d ntdll!RtlRaiseException+0x22f 09 00000000`01bfb070 00000000`ff6af8ec KERNELBASE!RaiseException+0x39 0a 00000000`01bfb140 000007fe`cd6bd4c4 sqlservr!CDmpDump::Dump+0x4c 0b 00000000`01bfb180 000007fe`cd6bdf06 sqllang!SQLDumperLibraryInvoke+0x2e4 0c 00000000`01bfb420 000007fe`cd684b6b sqllang!CImageHelper::DoMiniDump+0x426 0d 00000000`01bfb610 000007fe`cd683f6a sqllang!stackTrace+0xbdb 0e 00000000`01bfd050 000007fe`e0312a75 sqllang!stackTraceCallBack+0xca 0f 00000000`01bfd090 00000000`775abc20 sqldk!ex_handle_except+0x125 10 00000000`01bfd2e0 00000000`776a9035 kernel32!UnhandledExceptionFilter+0x160 11 00000000`01bfd3c0 00000000`77687398 ntdll!RtlUserThreadStart$filt$0+0x45 12 00000000`01bfd3f0 00000000`7769bf9d ntdll!__C_specific_handler+0x8c 13 00000000`01bfd460 00000000`776704ca ntdll!RtlpExecuteHandlerForException+0xd 14 00000000`01bfd490 00000000`77673c1f ntdll!RtlDispatchException+0x45a 15 00000000`01bfdb70 000007fe`fd39a06d ntdll!RtlRaiseException+0x22f 16 00000000`01bfe520 000007fe`ccb7bc0b KERNELBASE!RaiseException+0x39 17 00000000`01bfe5f0 000007fe`cdb8e40f sqllang!__delayLoadHelper2+0x199 18 00000000`01bfe6a0 000007fe`cdb49a75 sqllang!_tailMerge_SqlServerSpatial110_dll+0x3f 19 (Inline Function) --------`-------- sqllang!InitializeSpatialNativeImpl+0x26 1a 00000000`01bfe710 00000000`ff69af2a sqllang!SQLLangInitComponents+0x275 1b 00000000`01bfe770 00000000`ff69c094 sqlservr!InitServerComponents+0x8a 1c 00000000`01bfe7d0 00000000`ff693c48 sqlservr!sqlservr_main+0x3b4 1d 00000000`01bfea20 000007fe`fe32a82d sqlservr!sqlservr_main_thread+0x178 1e 00000000`01bffd30 00000000`775259cd sechost!ScSvcctrlThreadA+0x25 1f 00000000`01bffd60 00000000`7768383d kernel32!BaseThreadInitThunk+0xd 20 00000000`01bffd90 00000000`00000000 ntdll!RtlUserThreadStart+0x1d Looked at the DLL being loaded szDll : 0x7fecdeef9c0 : "SqlServerSpatial110.dll" [Type: char *] Then we checked the SqlServerSpatial110.dll both in C:\Windows\System32 and C:\Windows\SystemWOW64. System32 WOW64: And then we checked this SqlServerSpatial110.dll properties in another working server as below. Then we got the root cause that the current server SqlServerSpatial110.dll original filename is SqlServerSpatial120.dll(it is SQL 2014). But in this case, somehow is has been changed, but we don’t know why, we only get to the result. Then we tried to copy the correct one from another server to current server(system32 and systemWOW64 respectively). But this doesn’t work. After we restart the SQL Server it failed again, with same error. Then we come up with another solution, we can rename the current SqlServerSpatial110.dll to SqlServerSpatial110.dll.old and then launch the repair again. This worked. After repairing, we can see the new SqlServerSpatial110.dll has been created automatically with correct SP3 version(same with the current SQL Server version) Root cause: ======== Somehow, SqlServerSpatial110.dll has been changed. Resolution: ======== Rename the SqlServerSpatial110.dll under C:\Windows\System32 and C:\Windows\SystemWOW64 Launch the repair for SQL Server 2012. This resolved this issue successfully. Case 2, there is no dump generated Issue definition: ======== After you patch the SQL Server 2016, 9 instances failed to start due to the following error. 2020-02-22 18:43:17.14 Server Error: 17311, Severity: 16, State: 1. 2020-02-22 18:43:17.14 Server SQL Server is terminating because of fatal exception c06d007e. This error may be caused by an unhandled Win32 or C++ exception, or by an access violation encountered during exception handling. Check the SQL error log for any related stack dumps or messages. This exception forces SQL Server to shutdown. To recover from this error, restart the server (unless SQLAgent is configured to auto restart). 2020-02-22 18:43:17.14 Server Using 'dbghelp.dll' version '4.0.5' 2020-02-22 18:43:17.14 Server **Dump thread - spid = 0, EC = 0x0000000000000000 2020-02-22 18:43:17.14 Server * ******************************************************************************* 2020-02-22 18:43:17.14 Server * 2020-02-22 18:43:17.14 Server * BEGIN STACK DUMP: 2020-02-22 18:43:17.14 Server * 02/22/20 18:43:17 spid 8832 2020-02-22 18:43:17.14 Server * 2020-02-22 18:43:17.14 Server * ex_handle_except encountered exception C06D007E - Server terminating 2020-02-22 18:43:17.22 Server Stack Signature for the dump is 0x00000001A124A749 2020-02-22 18:43:17.22 Server Unable to create dump because SQLDUMPER library is not available. 2020-02-22 18:43:17.22 Server SQL Server shutdown has been initiated Issue analysis: ======== Based on the log, this issue should happened when loading some DLL. But as there no dump generated due to Unable to create dump because SQLDUMPER library is not available(from the following analysis, we can also see that dbgheko.dll not loaded yet). So we captured a process monitor, and then analyze the process monitor log. From the process monitor log, we can’t get the callstack which can help us to identify the DLL. So we are not able to find the DLL from the callstack, but we can compare the DLL which has already been loaded with a working server, and find out all the non-loaded DLL, and maybe we can find more clue. Compared the working server loaded DLL and this problematic server. All the yellow-mark DLL are non-loaded DLL in the problematic SQL. Working Server: <<<<<<<<<<<<<<< SQLNCLIRDAR11.RLL 0x18261ee0000 0x38000 c:\Program Files\Microsoft SQL Server\140\Shared\1033\SQLNCLIRDAR11.RLL Microsoft Corporation 2011.0110.5069.066 ((SQL11_OLEDB_AAD).160321-0812 ) 3/21/2016 11:56:15 PM instapi140.dll 0x7ffc21c80000 0x13000 c:\Program Files\Microsoft SQL Server\140\Shared\instapi140.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:36:59 AM sqlnclirda11.dll 0x59e10000 0x359000 c:\Program Files\Microsoft SQL Server\140\Shared\sqlnclirda11.dll Microsoft Corporation 2011.0110.5069.066 ((SQL11_OLEDB_AAD).160321-0812 ) 3/21/2016 11:57:40 PM BatchParser.dll 0x7ffbf7990000 0x2c000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\BatchParser.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:36:47 AM dbghelp.dll 0x59c70000 0x196000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\dbghelp.dll Microsoft Corporation 6.12.0002.633 (debuggers(dbg).100201-1211) 2/2/2010 4:15:44 AM ftimport.dll 0x60000000 0x25000 c:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\ftimport.dll Microsoft Corporation 12.0.7031.9999 11/1/2006 12:27:20 PM hkcompile.dll 0x7ffbf86f0000 0x162000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\hkcompile.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:47:36 AM hkengine.dll 0x7ffbf7fe0000 0x70b000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\hkengine.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:51:33 AM hkruntime.dll 0x7ffbf8860000 0x2d1000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\hkruntime.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:52:55 AM MSFTE.DLL 0x49980000 0x3ae000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\MSFTE.DLL Microsoft Corporation 12.0.6828.0 8/28/2006 7:15:55 PM opends60.dll 0x7ffbf8cb0000 0x9000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\opends60.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:36:08 AM qds.dll 0x7ffbf8b80000 0x12e000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\qds.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:38:39 AM sqlevn70.rll 0x17cc64a0000 0x310000 c:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\Resources\1033\sqlevn70.rll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:36:13 AM xplog70.RLL 0x183ea3d0000 0x4000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\Resources\1033\xplog70.RLL Microsoft Corporation 2017.0140.1000.169 ((SQLServer).170822-2340) 8/23/2017 7:50:34 AM xpstar.rll 0x183e93a0000 0xd000 c:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\Resources\1033\xpstar.rll Microsoft Corporation 2017.0140.1000.169 ((SQLServer).170822-2340) 8/23/2017 7:50:29 AM secforwarder.dll 0x7ffbf8b40000 0xa000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\secforwarder.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:45:38 AM SqlAccess.dll 0x7ffbf7f60000 0x75000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\SqlAccess.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:37:39 AM sqldk.dll 0x7ffbf8cc0000 0x4fc000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqldk.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:35:28 AM sqllang.dll 0x7ffbf9af0000 0x2782000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqllang.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:44:02 AM sqlmin.dll 0x7ffbfc280000 0x31fe000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqlmin.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:38:05 AM SQLOS.dll 0x7ffbff480000 0x7000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\SQLOS.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:45:34 AM SQLSCM.dll 0x7ffbf7e30000 0x13000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\SQLSCM.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:40:48 AM sqlservr.exe 0x7ff7869e0000 0x7f000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqlservr.exe Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:35:24 AM sqlTsEs.dll 0x7ffbf91c0000 0x92f000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqlTsEs.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 9:35:33 AM svl.dll 0x7ffbf8b50000 0x2e000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\svl.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:57:13 AM xplog70.dll 0x7ffc2ea50000 0x14000 c:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\xplog70.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:55:14 AM xpsqlbot.dll 0x7ffbf7cd0000 0x8000 C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\xpsqlbot.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:38:05 AM xpstar.dll 0x7ffbf7c60000 0x6e000 c:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\xpstar.dll Microsoft Corporation 2017.0140.3238.01 ((SQLServer2017-CU14).190913-2228) 9/14/2019 6:47:53 AM Non_working Server <<<<<<<<<<<<<<< HKRUNTIME.DLL 0x7fffea270000 0x2d0000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\HKRUNTIME.DLL 1/1/1970 8:00:00 AM OPENDS60.DLL 0x7ffffe550000 0x9000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\OPENDS60.DLL 1/1/1970 8:00:00 AM QDS.DLL 0x7fffeac80000 0xdc000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\QDS.DLL 1/1/1970 8:00:00 AM SQLEVN70.RLL 0x7fffe5180000 0x2f0000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\RESOURCES\1033\SQLEVN70.RLL 1/1/1970 8:00:00 AM SQLBOOT.DLL 0x7fffeb230000 0x2e000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLBOOT.DLL 1/1/1970 8:00:00 AM SQLDK.DLL 0x7fffe97b0000 0x4c8000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLDK.DLL 1/1/1970 8:00:00 AM SQLLANG.DLL 0x7fffddf90000 0x25c7000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLLANG.DLL 1/1/1970 8:00:00 AM SQLMIN.DLL 0x7fffe0560000 0x24fa000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLMIN.DLL 1/1/1970 8:00:00 AM SQLOS.DLL 0x7fffff390000 0x7000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLOS.DLL 1/1/1970 8:00:00 AM SQLSERVR.EXE 0x7ff7c29d0000 0x68000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLSERVR.EXE 1/1/1970 8:00:00 AM SQLTSES.DLL 0x7fffe5470000 0x88b000 \Device\CSVVolume137\MSSQL13.KCOM1S130EDAM01\MSSQL\BINN\SQLTSES.DLL 1/1/1970 8:00:00 AM We can see HKRUNTIME already loaded in our problematic SQL, so the next most possible DLL should be the HKEngine.dll HKCompile.dll. Then check them in your environment, they do have some problem in those DLLs, for example the size/the modified date. Then we rename those DLL, for example HKEngine.dll.Old, and then run repair SQL Server, and after that we confirmed 1 instance start successfully. Solution: ======== HKEngine.dll HKCompile.dll has some problem when SQL Server trying to load them. So rename them and then run SQL Repair, and new DLL will be generated, then SQL Server start successfully.Recommendations for Index Maintenance with AlwaysOn Availability Groups
First published on MSDN on Mar 03, 2015 SYMPTOMSConsider the following scenarioThe database is part of AlwaysOn Availability GroupsYou run long and log-intensive transactions like Index maintenance/rebuildsYou observe one or more of the following symptoms:Poor performing DML operations in availability databases on the primary replica if synchronous secondary replicas are present.
TSQL Scripts for Troubleshooting Common Issues with SQL Server
This blog provides TSQL samples for troubleshooting common SQL Server issues as listed below. You can modify the parameters (i.e. database name, table name, keyword name, duration, etc.) based on customized environment settings and requirements. (Test these scripts before implementing in PROD environment. Please be aware of all potential risks for implementing the script in your PROD environment.) 1. Performance Troubleshooting(blocking, high CPU, memory, idle, query execution) 2. Deadlock and Database Object ID mapping 3. HA (Clustered SQL Server) 4. Backup & Transaction Log Related Issue 5. Query Store (QDS) 6. Database Encryption (TDE) 7. Tool (Profiler trace and X-event) Performance Troubleshooting ========================= (blocking, high CPU, memory, idle, query execution) 1.List all active sessions and its queries that contain your target table name or specific TSQL structure (input your target key word) SELECT sqltext.TEXT, req.session_id, req.status, req.command, req.cpu_time,req.database_id, req.total_elapsed_time FROM sys.dm_exec_requests req CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS sqltext where sqltext.text like '%Your Target Key Word%' 2.List all sleeping user sessions that have been idle for over 15 minutes with detailed queries (You can customize the session’s status and idle time) SELECT CURRENT_TIMESTAMP as currenttime, datediff(minute,last_batch,GETDATE()) as 'idletime_in_minute' ,sp.status,sp.spid,sp.login_time,sp.program_name,sp.hostprocess,sp.loginame,text FROM sys.sysprocesses sp CROSS APPLY sys.dm_exec_sql_text(sp.sql_handle) AS QT where sp.status = 'sleeping' and datediff(minute,last_batch,GETDATE()) >15 and spid>50 3.List top 10 high CPU queries that currently running in this SQL instance SELECT s.session_id,r.status,r.blocking_session_id 'Blk by',r.wait_type,wait_resource,r.wait_time / (1000 * 60) 'Wait M',r.cpu_time,r.logical_reads,r.reads,r.writes,r.total_elapsed_time / (1000 * 60) 'Elaps M',Substring(st.TEXT,(r.statement_start_offset / 2) + 1, ((CASE r.statement_end_offset WHEN -1 THEN Datalength(st.TEXT) ELSE r.statement_end_offset END - r.statement_start_offset) / 2) + 1) AS statement_text, Coalesce(Quotename(Db_name(st.dbid)) + N'.' + Quotename(Object_schema_name(st.objectid, st.dbid)) + N'.' + Quotename(Object_name(st.objectid, st.dbid)), '') AS command_text,r.command,s.login_name, s.host_name,s.program_name,s.last_request_end_time,s.login_time, r.open_transaction_count FROM sys.dm_exec_sessions AS s JOIN sys.dm_exec_requests AS r ON r.session_id = s.session_id CROSS APPLY sys.Dm_exec_sql_text(r.sql_handle) AS st WHERE r.session_id != @@SPID ORDER BY r.cpu_time desc 4. List top 10 high memory usage queries that currently running in this SQL instance SELECT mg.session_id,mg.granted_memory_kb,mg.requested_memory_kb,mg.ideal_memory_kb,mg.request_time,mg.grant_time,mg.query_cost,mg.dop,st.[TEXT],qp.query_plan FROM sys.dm_exec_query_memory_grants AS mg CROSS APPLY sys.dm_exec_sql_text(mg.plan_handle) AS st CROSS APPLY sys.dm_exec_query_plan(mg.plan_handle) AS qp ORDER BY mg.required_memory_kb DESC 5. List detailed memory usage for each memory clerk DBCC MEMORYSTATUS 6. List memory usage for plan cache and its maximum size based on current setting. By removing the WHERE condition, you will get a full list for all memory cache clerks’ information select name, type, buckets_count from sys.dm_os_memory_cache_hash_tables where name IN ( 'SQL Plans' , 'Object Plans' , 'Bound Trees' ,'Extended Stored Procedures') select name, type, pages_kb, entries_count from sys.dm_os_memory_cache_counters where name IN ( 'SQL Plans' , 'Object Plans' , 'Bound Trees' ,'Extended Stored Procedures') 7. List progressive (on-going) execution plan for a specific session (Starting with SQL 2016) For SQL 2016 and 2017, please first run below TSQL in the query session of which the execution plan you wish to extract later set statistics profile on Run below query to extract the on-going execution plan for your target session (input the SPID in the bracket) SELECT * FROM sys.dm_exec_query_statistics_xml(59); 8.List all block header queries that currently detected in this SQL instance declare @blocker varchar(100),@sql varchar(100) print convert(varchar(20), getdate(),120) select distinct blocked into #blocker from sysprocesses where blocked <> 0 DECLARE blocker CURSOR FOR select spid from sysprocesses where spid in (select * from #blocker) and blocked = 0 OPEN blocker FETCH NEXT FROM blocker INTO @blocker WHILE @@FETCH_STATUS = 0 BEGIN set @sql='DBCC inputbuffer(' + @blocker + ')' execute (@sql) set @sql= 'select * from sysprocesses where spid=' + @blocker execute (@sql) FETCH NEXT FROM blocker INTO @blocker END CLOSE blocker DEALLOCATE blocker drop table #blocker 9.Kill all sleeping sessions that has been idle over 1 hour (You can customize the idle duration) DECLARE user_spid INT DECLARE CurSPID CURSOR FAST_FORWARD FOR SELECT SPID FROM master.dbo.sysprocesses (NOLOCK) WHERE spid>50 AND status='sleeping' -- only sleeping threads AND DATEDIFF(HOUR,last_batch,GETDATE())>=1 -- thread sleeping for 1 hours AND spid<>@@spid -- ignore current spid OPEN CurSPID FETCH NEXT FROM CurSPID INTO user_spid WHILE (@@FETCH_STATUS=0) BEGIN PRINT 'Killing '+CONVERT(VARCHAR,@user_spid) EXEC('KILL '+@user_spid) FETCH NEXT FROM CurSPID INTO user_spid END CLOSE CurSPID DEALLOCATE CurSPID GO 10.Kill all block headers. This script will continuously scan every 5 seconds for all block header sessions and kill all block headers Use master go while 1=1 Begin declare @blocker varchar(100),@sql varchar(100) print convert(varchar(20), getdate(),120) select distinct blocked into #blocker from sysprocesses where blocked <> 0 DECLARE blocker CURSOR FOR select spid from sysprocesses where spid in (select * from #blocker) and status='sleeping' OPEN blocker FETCH NEXT FROM blocker INTO @blocker WHILE @@FETCH_STATUS = 0 BEGIN set @sql='DBCC inputbuffer(' + @blocker + ')' execute (@sql) set @sql= 'kill ' + @blocker execute (@sql) FETCH NEXT FROM blocker INTO @blocker END CLOSE blocker DEALLOCATE blocker drop table #blocker waitfor delay '0:0:05' End Deadlock and Database Object ID mapping =================================== Below are 3 examples to map the issued object based on the ID to its source database, index or schema. 1. Key type wait resource waitresource=KEY: 6:12345678990 (987654321a9b) database_id = 6 hobt_id = 12345678990 hash value = (987654321a9b) We can use below TSQL to check the database name based on DATABASE ID select db_name(6) Use below TSQL to check the schema, object, and index details related to this key USE DatabaseName GO SELECT sc.name as schema_name, so.name as object_name, si.name as index_name FROM sys.partitions AS p JOIN sys.objects as so on p.object_id=so.object_id JOIN sys.indexes as si on p.index_id=si.index_id and p.object_id=si.object_id JOIN sys.schemas AS sc on so.schema_id=sc.schema_id WHERE hobt_id = 12345678990 2. Object Wait resource type waitresource=OBJECT: 6:1234567890:4 database_id = 6 Object ID = 1234567890 We can use below TSQL to check the specific object name based on the waitresource details select OBJECT_NAME(1234567890,6) 3. Page Wait Resource Type waitresource=“PAGE: 6:3:70133 ” = Database_Id : FileId : PageNumber database_id=6 data_file_id = 3 page_number = 70133 HA (Clustered SQL Server) =================== List the latest error encountered by local AG replica for connection timeout select r.replica_server_name, r.endpoint_url, rs.connected_state_desc, rs.last_connect_error_description, rs.last_connect_error_number, rs.last_connect_error_timestamp from sys.dm_hadr_availability_replica_states rs join sys.availability_replicas r on rs.replica_id=r.replica_id where rs.is_local=1 List the current redo rate, redo queue size, log send rate, log send queue size for current AG replica SELECT CURRENT_TIMESTAMP as currenttime,drs.last_commit_time,ar.replica_server_name, adc.database_name, ag.name AS ag_name, drs.is_local, drs.is_primary_replica, drs.log_send_queue_size, drs.log_send_rate, drs.redo_queue_size, drs.redo_rate FROM sys.dm_hadr_database_replica_states AS drs INNER JOIN sys.availability_databases_cluster AS adc ON drs.group_id = adc.group_id AND drs.group_database_id = adc.group_database_id INNER JOIN sys.availability_groups AS ag ON ag.group_id = drs.group_id INNER JOIN sys.availability_replicas AS ar ON drs.group_id = ar.group_id AND drs.replica_id = ar.replica_id Restart endpoint Check SQL AG endpoint name SELECT * FROM sys.endpoints Restart AG endpoint on this local replica ALTER ENDPOINT <Your AG Endpoint Name> STATE=STOPPED ALTER ENDPOINT <Your AG Endpoint Name> STATE=STARTED Backup & Transaction Log Related Issue ================================ List all backup history and backup file details for the past 7 days (You can modify the date) SELECT CONVERT(CHAR(100), SERVERPROPERTY('Servername')) AS Server, msdb.dbo.backupset.database_name, msdb.dbo.backupset.backup_start_date, msdb.dbo.backupset.backup_finish_date, msdb.dbo.backupset.expiration_date, CASE msdb..backupset.type WHEN 'D' THEN 'Database' WHEN 'L' THEN 'Log' END AS backup_type, msdb.dbo.backupset.backup_size, msdb.dbo.backupmediafamily.logical_device_name, msdb.dbo.backupmediafamily.physical_device_name, msdb.dbo.backupset.name AS backupset_name, msdb.dbo.backupset.description FROM msdb.dbo.backupmediafamily INNER JOIN msdb.dbo.backupset ON msdb.dbo.backupmediafamily.media_set_id = msdb.dbo.backupset.media_set_id WHERE (CONVERT(datetime, msdb.dbo.backupset.backup_start_date, 102) >= GETDATE() - 7) ORDER BY msdb.dbo.backupset.database_name, msdb.dbo.backupset.backup_finish_date List all databases’ data and log file path and logical name USE master; SELECT name 'Logical Name', physical_name 'File Location' FROM sys.master_files; List each database’ transaction log size usage and space DBCC SQLPERF(LOGSPACE) List VLF size and counts for all databases as well as detailed size for your target database select * from sys.dm_db_log_info(5); /*input here your DB ID to get detailed size for existing VLFs on this database*/ SELECT [name], s.database_id, COUNT(l.database_id) AS 'VLF Count', SUM(vlf_size_mb) AS 'VLF Size (MB)', SUM(CAST(vlf_active AS INT)) AS 'Active VLF', SUM(vlf_active*vlf_size_mb) AS 'Active VLF Size (MB)', COUNT(l.database_id)-SUM(CAST(vlf_active AS INT)) AS 'In-active VLF', SUM(vlf_size_mb)-SUM(vlf_active*vlf_size_mb) AS 'In-active VLF Size (MB)' FROM sys.databases s CROSS APPLY sys.dm_db_log_info(s.database_id) l GROUP BY [name], s.database_id ORDER BY 'VLF Count' DESC GO For the purpose of shrinking transaction log file, check the log_reuse_wait_desc type for all database select name,database_id,log_reuse_wait, log_reuse_wait_desc from sys.databases Please refer this link for how to fix each of the log_reuse_wait_desc type when it is not “NOTHING” https://docs.microsoft.com/en-us/sql/relational-databases/system-catalog-views/sys-databases-transact-sql?view=sql-server-ver15 Database Corruption Issue Force repair of database with REPAIR_ALLOW_DATA_LOSS option (data loss expected and sometimes can cause more damage. Please refrain from using this method unless as for a last resort. More details for fixing database corruption, please refer this link https://docs.microsoft.com/en-us/sql/t-sql/database-console-commands/dbcc-checkdb-transact-sql?view=sql-server-ver15) Alter database YourDBName set single_user with rollback immediate; DBCC CHECKDB('YourDBName', REPAIR_ALLOW_DATA_LOSS); Alter database YourDBName set multi_user with rollback immediate; Query Store (QDS) ================= 1.List a database’s query store status select * from sys.database_query_store_options 2. List all databases that have query store configured select name as 'DATABASE NAME', CASE is_query_store_on when 1 then 'ENABLED' else 'OTHER' END AS 'QUERY STORE STATE' from sys.databases where is_query_store_on = 1 order by 1 ; Database Encryption (TDE) ====================== Check if the DMK exist in master database USE master GO SELECT * FROM sys.symmetric_keys WHERE name = '##MS_DatabaseMasterKey##' Check if the certificate is created in master database. A certificate is equivalent to an asymmetric key USE master GO select * from sys.certificates Check if the database is encrypted/progress (encryption_state = 3 encrypted; =2 in progress) USE master GO SELECT db_name(database_id) [TDE Encrypted DB Name], c.name as CertName, encryptor_thumbprint , dek.* FROM sys.dm_database_encryption_keys dek INNER JOIN sys.certificates c on dek.encryptor_thumbprint = c.thumbprint Check if the DMK in the master database is now encrypted by the SMK (is_master_key_encrypted_by_server = 1) select is_master_key_encrypted_by_server, * from sys.databases where database_id = db_id(N'master') Tool (Profiler trace and X-event) ======================= Import SQL Profiler trace into SQL Server database tables USE DatabaseName GO select * into Sample from fn_trace_gettable('c:\trace\YourFolderToStoreTheTrace\YourTraceFile.trc',default) where eventclass in (10, 12) For event class ID, check the list in this link https://docs.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sp-trace-setevent-transact-sql?view=sql-server-ver15 Use XELoader to process X-event and import the data into SQL database table for data analysis purpose. XELoader can be downloaded from this opensource link https://github.com/suresh-kandoth/XELoader Use CMD script to load the X-event files into SQL Server database Sample script: C:\XELoader\6.2>XELoader.exe -D"C:\Users\yixin\Desktop\xeloader\xevent" -SYourServerName\InstanceName -dYourDBName Use TSQL query to check aggregated data result Sample TSQL: SELECT sum(c_duration) as SUM_DURAION,sum(c_signal_duration) as SUM_SIGNAL_DURATION,c_wait_type from [xel].[wait_info] group by c_wait_type order by SUM_DURAION desc DISCLAIMER : THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
