Posted by blakhani on May 21, 2015
One of my colleague in office sent an email to find the cause of the error. He wanted to configure Log-Shipping with secondary on Standby mode. Rather than “reply to all”, I generally ping the person directly to tell the possible reason of error. Here is what we discussed (let’s assume that his name is Manoj – M)
B: Hi Manoj
B: Saw you email to DL about log shipping problem.
M: Oh yeah. Thanks for reaching out.
B: No problem.
B: Are you restoring database from lower version to higher version of SQL?
M: No, both are 2008.
B: That’s doesn’t sound right. Can you please run Select @@version command in Management Studio on both the server and share the output?
M: Sure. Give me a minute to connect and run the query.
<1 min pause>
M: There you go
Microsoft SQL Server 2008 (SP1) – 10.0.2573.0 (X64)
Feb 4 2011 11:27:06
Copyright (c) 1988-2008 Microsoft Corporation
Developer Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1)
Microsoft SQL Server 2008 R2 (RTM) – 10.50.1600.1 (X64)
Apr 2 2010 15:48:46
Copyright (c) Microsoft Corporation
Enterprise Edition (64-bit) on Windows NT 6.0 (Build 6002: Service Pack 2)
B: Okay. that is the problem. You are taking backup from SQL 2008 and restoring on SQL 2008 R2 in standby mode.
M: Both are not 2008?
B: No, destination is 2008 “R2” which is the next release after 2008.
M: Oh.. I thought its like a service pack on top of SQL 2008.
B: Unfortunately, its not a service pack. It’s fresh release having some enhancements.
M: Okay. So error message is correct.
B: Yeah. If you want to use secondary for reporting then you have to use standby mode. This can only be done on destination which has same version of SQL. Or you need to upgrade current primary server.
M: Hmm.. I got it now. Let me check with my DBA team and management to decide the next action.
B: Sure Manoj. Is there any other clarification you might need?
M: No Balmukund. I am good at this point. You have been very helpful. Appreciate it.
B: My pleasure. Bye for now.
In summary, Here is what you would get in SSMS if we try to restore a backup from lower version of SQL to higher version of SQL in standby mode.
TITLE: Microsoft SQL Server Management Studio
SQL Server Management Studio restore database ‘DabbaWala’
Restore failed for Server ‘Destination’. (SqlManagerUI)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=12.0.2000.8+((SQL14_RTM).140220-1752)&EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&EvtID=Restore+Server&LinkId=20476
System.Data.SqlClient.SqlError: This backup cannot be restored using WITH STANDBY because a database upgrade is needed. Reissue the RESTORE without WITH STANDBY. (Microsoft.SqlServer.Smo)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=12.0.2000.8+((SQL14_RTM).140220-1752)&LinkId=20476
The error is raised because during restore from lower to higher version the database version needs an upgrade to match with system table (or any other) change in higher version. Here is the query to see the version I am talking about.
Select name, version from sys.sysdatabases
This version upgrade is part of recovery process and we can’t pause recovery in middle and view the database state (that’s what is done in standby mode). So, the only way to restore that would be to use “with recovery” or “with norecovery” option.
Hope this helps!
Author: SQL Server 2012 AlwaysOn – Paperback, Kindle
Posted in Error, Logshipping, Restore, SQL Server | Tagged: error, sql server, This backup cannot be restored using WITH STANDBY because a database upgrade is needed | 2 Comments »
Posted by blakhani on May 19, 2015
My job revolves around troubleshooting and fixing the broken thing. Here is one of the situation which I ran into recently and was unable to find solution on internet. It my responsibility to provide self-assist option to the SQL community so that they can find the problem and fix by themselves.
I was trying to install SQL Server 2012 on a 2 nodes Windows cluster. When I tried installing it, it failed with error in subject line. At this first look it sounds like some COM+ error but as always, setup logs are my first place to find the errors. Here is the MSDN link which explains the various files created by setup
https://msdn.microsoft.com/en-us/library/ms143702(v=sql.110).aspx (View and Read SQL Server Setup Log Files)
The information which I saw in setup logs was pretty interesting. In particular, I looked into Detail.txt file which is the parent file of all MSI logs. (I have removed date and time for better reading)
Error: Action "Microsoft.SqlServer.Configuration.SetupExtension.ValidateFeatureSettingsAction" threw an exception during execution.
Microsoft.SqlServer.Setup.Chainer.Workflow.ActionExecutionException: Element not found. (Exception from HRESULT: 0x80070490) —> System.Runtime.InteropServices.COMException (0x80070490): Element not found. (Exception from HRESULT: 0x80070490)
at Microsoft.SqlServer.Configuration.ClusterConfiguration.ClusterDiskPublicConfigObject.IsPathOnSharedDisk(String path)
at Microsoft.SqlServer.Configuration.SetupExtension.SlpInputSettings.ValidateNotOnSharedDisk(ValidationState vs, String directoryName, String bindingKey, String errorMessage)
at Microsoft.SqlServer.Configuration.SetupExtension.SlpInputSettings.Validate_InstallSharedDir(ValidationState vs)
at Microsoft.SqlServer.Configuration.SetupExtension.ValidateFeatureSettingsAction.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)
The stack goes from bottom to Top. If we read the function calls made, anyone can conclude that there is something happening with cluster disks. That’s a good hint. So, I went back to failover cluster manager and looked into Disks under “Storage”. There was a disk which was in failed state. I was not able to bring this online and that’s THE problem! SQL Setup would enumerate the disks to find eligible disks which can be used and it’s not able to find details about that disk. Here was the error when I attempted to bring it online.
The resource ‘Cluster Disk 1’ did not come online.
The desired state change for ‘Cluster Disk 1’ did not occur before the timeout expired.
I realized that I have played with iSCSI and messed up the disk which was presented.
Solution: Delete the disks which are not able to come online under “Storage > Disks” or “Available Storage” in failover cluster manager interface.
Hope this helps.
Author: SQL Server 2012 AlwaysOn – Paperback, Kindle
Posted in Cluster, Installation, Setup, SQL Server 2012, SQL Server 2014 | Tagged: 0x80070490, Cluster, Element not found, setup, sql server | 3 Comments »
Posted by blakhani on April 14, 2015
This is one of the common question asked. This blog has list of resources which can be useful in getting answer. First lets look at books online.
Prerequisites, Restrictions, and Recommendations for AlwaysOn Availability Groups (SQL Server)
Maximum number of availability groups and availability databases per computer: The actual number of databases and availability groups you can put on a computer (VM or physical) depends on the hardware and workload, but there is no enforced limit. Microsoft has extensively tested with 10 AGs and 100 DBs per physical machine. Signs of overloaded systems can include, but are not limited to, worker thread exhaustion, slow response times for AlwaysOn system views and DMVs, and/or stalled dispatcher system dumps. Please make sure to thoroughly test your environment with a production-like workload to ensure it can handle peak workload capacity within your application SLAs. When considering SLAs be sure to consider load under failure conditions as well as expected response times.
In general, the more databases that are replicated and the more secondary replicas that exist – the more worker threads and more memory that will be consumed just to have the AlwaysOn infrastructure. As the text above indicates, there is no enforced limit, but the more you have the more worker threads and memory will be needed. If there are insufficient worker threads you will probably see error messages in the SQL Error log similar to:
“The thread pool for AlwaysOn Availability Groups was unable to start a new worker thread because there are not enough available worker threads. This may degrade AlwaysOn Availability Groups performance. Use the "max worker threads" configuration option to increase number of allowable threads.”
If starved for memory, you could see many different error messages – that may or may not look like they relate to AlwaysOn. One possible message could be:
“Could not start the AlwaysOn Availability Groups transport manager. This failure probably occurred because a low memory condition existed when the message dispatcher started up. If so, other internal tasks might also have experienced errors. Check the SQL Server error log and the Windows error log for additional error messages. If a low memory condition exists, investigate and correct its cause.”
Here are other blogs which explain the number of threads in worker pool to support availability group.
AlwaysOn – HADRON Learning Series: Worker Pool Usage for HADRON enabled databases
Monitoring SQL Server 2012 AlwaysOn Availability Groups Worker Thread Consumption
Hope this helps.
Posted in AlwaysOn, SQL Server 2012, SQL Server 2014 | Tagged: AG, AlwaysOn, Availability Group, sql server | Leave a Comment »