Assume if i have a connection(Application intent readonly) starts with reading, writing and again reading data for a report. how it will works in SQL 2014 Always availability on?
View 3 RepliesWe have a reporting database which is refreshed daily from prod backup and later creating new tables/views/indexes as part of the refresh job. Is there a better approach we can implement in sql 2012/2014 for this scenario since we are planning to migrate to sql2014.
View 5 Replies View RelatedI have 3 servers taking part in an AlwaysOn AG.
I want to grant a user READ access to only one replica, and certainly not to the principle.
How do I go about doing this?
We are not able to failover the AG to secondary replica. The process gets timed out and AG goes to resolving mode. Had to reboot the box in order to switch the AG back to primary node. We even rebuilt the whole AG from scratch but the issue remains.
Failed to bring availability group 'xxxx' online. The operation timed out. Verify that the local Windows Server Failover Clustering (WSFC) node is online. Then verify that the availability group resource exists in the WSFC cluster. If the problem persists, you might need to drop the availability group and create it again. [SQLSTATE 42000] (Error 41131). The step failed.
Not much information is available in the logs.
Version : sql server 2014 sp1
I am working on adding DBs to the AG but for some reason I am getting this error.
"Joining DB on secondary replica resulted in error"
Msg: The remote copy of the database is not recovered far enough to enable DB mirroring or to join AG. Missing log records have to be applied to the remote DB by restoring the current log backups" Which I did. I took the log backup of DB1, restored it on DB2 with no recovery, but still I am getting the same error.
We have 2 switch between primary and secondary this morning.
after that one database in secondary went to "initializing / recovery pending".
How can i exit from this situation ?
Having an annoying AG/AO problem with the read only routing side of it.
Let me give some specifics first:
2 SQL Server Instances, Not Clustered.
Availability Group is named 'Ireland'
There is a primary Replica and a Secondary Replica, named:
'IrelandPrimary' and 'IrelandSecondary'
There is a listener configured with the name 'ListenIreland' on Port 14330 (the two 3's are correct)
Read Only Routing URLS are configured as follows:
IrelandPrimary tcp://Ireland.dom.local:49891ALL
IrelandSecondary tcp://Ireland.dom.local:49841ALL
So now my problem:
When I try to connect using the ApplicationIntent=Readonly; or even using -K ReadONLY in sqlcmd I get the error telling me that my connection was actively refused.
This is connecting to the Listener, not the instance itself - that works fine. I'm at a bit of a loss now.
To explain what I am trying to achieve is a for a connection to be redirected to the secondary replica when its set for read-intent.
I've just noticed that it only fails when I specify ApplicationIntent=ReadOnly; If I omit the Intent It connects to the read-write database instead.
We have always on setup in our environment with read only replica. The primary database has 2 schema one is a dbo and other xyz. We have some store procs created in dbo schema and xyz schema. These store procs are being used by SSRS reports to retrieve the data (select only) no data changes will be made.
when we run the store proc from the read only server the storeprocs in the dbo schema run fine but xyz schema are failing with the message saying failed to update the database as this is a read only...
I have a 2 node cluster with 2 standalone 2k14 instances having alwayson setup. As per client requirement we have created a client access point with a cname alias in dns to connect to secondary replica. Now, everytime whenerver the roles switch over one has to manually move this resource from the previous secondary node to the new secondary node. This is tedious, and should not be done manually either, so I am looking for a way to automate it so that as soon as the role switches over, the resource group after some time should also switch over to the current secondary.
Env details
xa (current primary)
y2a (secondary)
client access point (resource group): aglreadtest
I was hoping for some information regarding table triggers. We have databases that are part of an AlwaysOn availability group on SQL Server 2012. Some of the tables have table triggers defined. There are both types of triggers, INSTEAD OF and AFTER INSERT, etc.
From my understanding of how secondary read-only replicas work, I am assuming that these triggers have no impact at all when the database is a read-only secondary replica and they only fire when the database is the primary read-write database.
However, after doing a search on the internet, I have not been able to find a definitive source of information.
I would like to setup replica for one of the databases for reporting. The current environment is a 2 node cluster(active/passive). I would like to add a 3rd node that can server as a secondary replica. The secondary replica will be on asynchronous commit mode.
The database that needs to have alwayson setup has column level encryption enabled.
Other Questions,
* Do I need to backup and restore the service master key on secondary server in order to have the column level encryption to work on secondary server?
* What would be preferred Quorum settings?
* What is the setting for 'readable secondary' for primary and replica db?
* What should be the setting for 'Connections in Primary Role' for primary and replica db?
* We are trying to setup without a Listner. Do I need to setup AG Listener? Can the application exclusively use the [secondary instance name].[replica DB name] without a listener?
What happens when an automatic failover occurs, in a two server AlwaysOn Availability Group configuration, where the secondary replica is configured as read-only?
Will it only allow read-only connections, or will it become read-write and can accept INSERT, UPDATES and DELETES when assigned the new role as Primary?
Is it correct that adding a third server/node, that just acts as passive and should be used for automatic failover, to support true HADR, would NOT need another license .. and that licenses would only be required for the previous Primary and Secondary (Read-Only) replicas?
We have a 2 node clustered instance(SQL 2014) with 26 databases and we would like to enable alwayson for one of the databases for reporting (only one secondary and do not need high availability setup). I'm thinking if the reporting application/queries can explicitly connect to the secondary database(Instance namedatabase name) without using a listener and setup the secondary in asynchronous commit mode. Read about the REDO thread blocking due to reporting workload. How does this affect if I implement the secondary in this way.
View 3 Replies View RelatedBackground information: SQL 2014 Ent. highly volatile OLTP environment. We generate 10 - 12 GB compressed transaction log backup files every 15 minutes.
Currently - we have two-node A/P cluster residing on flash array. Need to leverage AlwaysOn to offload processing. Replica server with have Flash storage. Replica node has same CPU and memory footprint. 10GB connection between nodes. Anyone generating such large transaction log for 15/30 minute time period?
We had a big issue today during maintenance work in our SQL environment.
So our environment:
- 2x SQL Server 2014 Enterprise on Windows Server 2012 R2 (SRV1 and SRV2)
-- Both Hyper-V VMs on different Hosts
-- Both configured to an Windows Failover Cluster and AlwaysOn Availability Group (AG1)
-- AG Listener: AG1_lis
-- No shared storage (each Hyper-V Host has its own local storage)
-- Asynchronous Mode
-- SRV1 is primary, SRV2 is secondary SQL node
What happened?
- Shutting down Windows on SRV2 due hardware maintenance
- Cluster goes offline, AG1 goes offline
-- Error message: "Stopped listening on virtual network name 'AG1_lis'."
-- Error message: "The availability group database "DatabaseXY" is changing roles from "PRIMARY" to "RESOLVING" because the mirroring session or availability group failed over due to role synchronization."
Results?
- AG1_lis wasn't available for our applications and they stopped working properly because database connection was lost!
I think, I HOPE, this is not the normale behaviour when one node is shutting down (especially the secondary node!)
Recently I have faced one DBA interview, below is the question they asked me.
" Does AlwaysON secondary replica support Full backup, if it is not why"?
I know AlwaysON secondary replicas support only copy_only and tlog backups, why they wont support full backup?
I have been creating databases in SQL 2008 with a primary filegroup for the system objects and a secondary, marked Default, for the data.
We are preparing a migration to SQL 2014, and the administrator is complaining he won't adopt this structure on the new servers because 'there is no benefit' and 'a backup cannot be restored (!?)'.
I read , When sql server Database having multiple data files within single filegroup then sql server writes data in multiple proportional file algorithm where the amount of data written to a file is proportionate to the amount of free space in that file, compared to other files in the filegroup.
so if there is no filegroups created and multiple secondary files are attached in databse , is there same way data stored and writes data in multiple files by the same algorithm or any different way.
I have 2 SQL Server replicas configured on SQL Server 2012 AlwaysOn. e.g. SQL1 & SQL2.
I have configured backup job on both SQL Server with the following statement. and the job occurs every 10 minutes.
•declare @DBNAME sysname,@sqlstr varchar(500)
set @DBNAME = 'dba'
IF (sys.fn_hadr_backup_is_preferred_replica(@DBNAME)=0)
BEGIN
--Select 'This is not the preferred replica, exiting with success';
[Code] ...
I turned off SQL2 for Windows maintenance. So there is only SQL1 is online. Afterwards. I checked the backup folder and didn't see any new backup files was created after SQL2 was offline. I rerun the job. It still doesn't backup database on the Primary Replica. Then I searched on SQL Server Book online. It says
Prefer Secondary
Specifies that backups should occur on a secondary replica except when the primary replica is the only replica online. In that case, the backup should occur on the primary replica. This is the default option.
According to what it says, it should backup on the Primary Replica.
What is the best approach for a read only copy of a database that is ~ 1TB. The primary database is fed nightly with an ETL process. We are currently trying to duplicate the ETL to read only server but that process is not going well. So we are looking at other options to let SQL make the copy.
The primary database is on a Win12R2 with SQL 12 or 14, a 2 node A/P failover cluster.
The read only copy will be on a Win12R2 with SQL 12 or 14. It is not a requirement to fail over to the read only copy if the primary should go down.
What would best the approach to accomplish the end result?
we are about to start a logshipping with the secondary server in read only mode.
I just wanted to know the disadvantages of using a read only on the secondary server.
I mean whether the transactional logs will be restored periodically or it won't be restored till users are connected on the secondary server.
I am curious what other people have done to implement read-only routing for a large number of procedures.
Basically figuring out when to call procedures that are read-only with read-only intent.
We have a user application that passes an encrypted string to a web service that directs it to our SQL Servers.
I've been tasked with finding a way to make this happen without changing the application.
The only thing I have been able to come up with is writing something (which I did) that will identify whether something is read-only or not and storing a big list.
Then having the web service look up the given procedure and adding the intent where needed.
We installed SP1 for SQL Server 2014 this past weekend and got this error message in the logs. I found that if you set the db to read-write, it updates the system objects, even after SP1 has completed. Then you can set it back to read-only. I'm just posting this so other people can find it on the internet, as I wasn't able to find it specifically.
Error Log Entry:System objects could not be updated in database 'x' because it is read-only.
Problem: After installing SP1 for SQL Server 2014 you will find this message in the error logs saying read-only databases could not be updated.
Solution: Simply set the db to read-write and the system objects will get updated, long after SP1 was installed.
ALTER DATABASE [x] SET READ_WRITE WITH NO_WAIT
Then set it back to read-only:
ALTER DATABASE [x] SET READ_ONLY WITH NO_WAIT
You should then see these log entries:
System objects could not be updated in database 'x' because it is read-only.
Setting database option READ_WRITE to ON for database 'x'.
Starting up database 'x'.
CHECKDB for database 'x' finished without errors on 2015-07-25 01:02:28.143 (local time). This is an informational message only; no user action is required.
Synchronize Database 'x' (129) with Resource Database.
Setting database option READ_ONLY to ON for database 'x'.
Starting up database 'x'.
CHECKDB for database 'x' finished without errors on 2015-07-25 01:02:29.888 (local time). This is an informational message only; no user action is required.
I am setting up extended events more or less just fine, however I am a bit confused as to how to read and load them into a table for querying. In particular the offset part - is there a way to load just a given dates worth in?
I've got the files configured to be 20MB before rolling over, the XE is running all the time.
So if i load in the full file now, say that covers 2.5 days worth, when I load it again tomorrow to get the updated data I'm also reloading today, which is a waste?
I presume I am going about this wrong, but lack an example that really goes into detail of practicalities of loading this data.
How you would calculate the average read/write latency experienced by a SQL Server instance during a specific time window in order to monitor this for multiple instances. From this MSDN blog, I know that you have to take multiple samples and do some calculations to get the correct latency.
[URL] ...
However, the SQLServer:Resource Pool Stats object tracks these numbers per resource pool and we want to get one number for the whole server. Since there can be a different base value for each resource pool, you can't simply sum the numerator values together. Here's some sample data from a server that illustrates the problem.
object_name counter_name instance_name cntr_value cntr_type
SQLServer:Resource Pool Stats Avg Disk Read IO (ms) default 307318919 1073874176
SQLServer:Resource Pool Stats Avg Disk Read IO (ms) Base default 25546724 1073939712
SQLServer:Resource Pool Stats Avg Disk Read IO (ms) internal 2045730 1073874176
SQLServer:Resource Pool Stats Avg Disk Read IO (ms) Base internal 208270 1073939712
I'm thinking I would need to do some sort of weighted average, but I'm not sure if that will result in the correct value. Here's the formula I am thinking about using currently before doing the calculation over time
((default * default[base]) + (internal * internal[base]))/(default[base] + internal[base])
Then to do the calculation over time, I'd use the changes in the calculated numerator and denominator to get the average.
Does this sound like to correct way to get this value? Is there a good way to verify?
in my secondary server the database which is in restoring state , when i checked in always on dash board "This secondary database is not joined to the availability group" ,
View 3 Replies View RelatedMSDN states the following on: Readable Secondary Replicas (AlwaysOn Availability Groups) for SQL Server 2014:
Limitations and Restrictions:
Change tracking and change data capture are not supported on secondary databases that belong to a readable secondary replica:
Change tracking is explicitly disabled on secondary databases.
Change data capture can be enabled on a secondary database, but this is not supported.
This confuses me: You can not track the changes. However you can enable CDC?
The scenario I am trying to achieve is to use SSIS CDC components on an asynchronous secondary replica. Is this possible? If not what would be other viable approaches?
SQL is generating dump every 1 min with error
EXCEPTION_ACCESS_VIOLATION reading address 0000000000000020 at
Server is running SP2 CU2.
Environment:-
Windows 2012 R2,
SQL 2012 (Primary Replica)
SQL 2012 (Seondary Replica)
SQL 2012 (Secondary Replica over WAN site)
There are database replicating on three SQL servers. WAN line is having performance issue because of limited bandwidth I have to remove SQL secondary replica over WAN site temporarily and add it again later when the WAN line is upgraded with between bandwidth What is the best practice to remove secondary replica and replicating database and add later from SQL management studio without interruptions on databases?
I have an AlwaysOn Availability group configured between 2 nodes (Synchronous)
Automatic failover was working fine until recently
I can failover between the nodes manually but automatic failover doesn't seem to be working. In my earlier test, I would shut down the SQL Service on the primary and within seconds, the secondary replica would take over. Recently I have performed the same test and the secondary replica enters the resolving state and the DB in unavailable.
I have tried everything here: [URL] ....
The only change I made was changing the availability mode from Synchronous to Asynchronous - Could that be the cause?
Looking for info on ole/requirement of primary and secondary replica under SQL Server 2012 AlwaysOn.
View 4 Replies View RelatedAs per our client requirement we want to set synchronization time from primary replica to secondary replica after 20 minutes. Is it possible in MSSQL AlwaysOn Availability Groups in SQL Server 2012?
View 6 Replies View RelatedI was working on a job to send me info each morning about database file free space and was noticing some odd things when looking at the log file VLFs for one of my databases in an AlwaysOn availability group.When I run DBCC LOGINFO on the secondary replica for this database, I get what I expect and most VLFs have a status of 0 (indicating the VLFs are reusable or unused). When I run DBCC LOGINFO on the primary replica, all of the VLFs have a status of 2 (active or recoverable).
Since log backups on the secondary replica in AlwaysOn still truncate the log in the primary replica, I would expect that the VLFs in the primary replica would also be mostly in a reusable or unused state. My log file sizes are the same size on each server and my backups are completing successfully. what might be causing the VLFs on the primary replica to have a status of 2 in DBCC LOGINFO when taking log backups from the secondary replica?