SQL 2012 :: DR Replication Type For Failover And Recover
Jun 26, 2015
what type of replication is best and easiest to startup on the DR site in event of a failover for an SQL server with very high transaction occurring on the database.I normally handle Oracle database and we use SAN to SAN replication to the DR site, all w have to do is mount the replicated disks at the DR site and Startup the database.How do i achieve this on SQL database including having the using logging details work at the DR site.
-- RESULT: Server: Msg 14101, Level 11, State 1, Procedure sp_MSaddpub_snapshot, Line 73 The publication 'publication_name' already has a Snapshot Agent defined.
Recently i got task from Senior DBA, as : Recover a database without LOG file Currently Data File is available.
Log file is also available, but shows size as 0 KB. Means Log file is corrupted.
Currently existing DB is shown as Offline Mode in SSMS.
So i got below link:
[URL]
When i tried 1st/2nd solution from above link, i got below message:The log cannot be rebuilt because there were open transactions/users when the database was shutdown, no checkpoint occurred to the database, or the database was read-only. This error could occur if the transaction log file was manually deleted or lost due to a hardware or environment failure.
To try that 3rd solution, I had to DELETE/Remove existing DB from SSMS, so i can create New DB with same name.
When i tried to delete Log file from Command Prompt, using below command, Windows replied that File is corrupted, so it cannot be deleted.
DEL /F /Q /A C:Program FilesMicrosoft SQL ServerMSSQL11.SQLEXPRESS2012MSSQLDATAMyDB.ldf
Meanwhile my Senior DBA brought DB in Recovery Pending mode.
So if i want to go for 3rd solution,then i need to DELETE file, But Windows is not allowing me.
Dear All, we have one production server and continuously getting the data from application. we have replication server with transactional replication for the main database.
so, for taking the data, we are using prod server, and for fetching the data, we are using replication server.
now what i'm expecting from you is, if something happend to the main server, there is no cluster except backup. what is the best plan for this? and one more thing, if replication server fails, then the application will not fetch the data then what is the plan for this?
please give me a good plan for this kind of strategy.
I run MSDE on a Windows XP Server and my database was marked as "suspect" by Enterprise Manager and its icon become gray. I detach that database and try to re-attach it but there is an error as the following:
After that, I uninstall the MSDE and re-install new MSDE SP4 and try to re-attach the database file again and there is still an error. Is there anyway i can recover the data from that database?
Hi All,I would like to set up transactional replication with failover cluster.Did anybody tried this? Does it work together? Is there anything Ishould be coutios when I set up these together? or Is there anyglitches?If somebody helps me I will really appreciate itThanks
I'm trying setup a proof of concept for a client but I€™m having issues with mirroring and replication.
With the help of http://technet.microsoft.com/en-us/library/ms151799.aspx I€™ve done the following..
The setup is as follows, I have several instances of SQL Server
A+B are mirrored with each other, with A being the principle and B the mirror
C is the distributor
E is subscribes to A, with parameters for PublicationFailoverPartner set to B
The mirroring between A+B works fine, I can manually fail each and the databases keep in step.
Without testing the mirroring failover, the replication between A+C+E also works.
However when I test the mirror to failover between A+B no transactions are replicated though to E. The publication moves from A to B in the Server Management Studio.
The logs state that the log reader agent can not gain access to A, however nothing is recorded regarding any attempts to contact B. In the replication monitor the error message
"The concurrent snapshot for publication ABCXYZ is not available because it has not been fully generated of the Log Reader Agent is not running to activate it. If generation of the concurrent snapshot was interrupted, the Spapshot Agent for the publica..." (cut off).
"the process could not execute 'sp_replcmds' on 'A'
I have checked that the SQL Server Agents are running on all agents,
I have checked that that server B is set at the PublisherFailoverPartner on server C agent configuration; I'm now at a lost as to what is wrong,
If I have multiple servers in my AG group and set two of the secondaries to synchronous with auto failover, how do I control which one one of the two secondaries will become primary if the original primary goes down?We need to maintain HA even during patching so need a first choice auto failover and a second choice auto failover.
I have virtualbox installed on my notebook. For testing purpose, is it possible to setup SQL Server Fail-Over cluster using virtual box? I don't have a shared storage. How can I simulate that?
if for any reason AG fails over to async node, how replication behaves? As data will not be in sync with previous primary replica, how replication will work? I think that we have to reset replication from scratch as there's a high chance subscribers might be more updated than current primary replica as failover to this node causes data loss. How to keep replication in sync without resetting up? Can we achieve this?
Data synchronization and manual failover works fine. But, sometimes, the AlwaysOn cluster automatically fails over to Sync Commit Secondary on Primary data center. Here is the error message from Failover Cluster Manager->Cluster Events:
"Cluster has missed two consecutive heartbeats for the local endpoint xx.xx.xx.yy:~3343~ connected to remote endpoint xx.xx.xx.zz:~3343~"
"Cluster has lost the UDP connection from local endpoint xx.xx.xx.yy:~3343~ connected to remote endpoint xx.xx.xx.zz:~3343~"
I had our network engineer check all connections multiple times and he confirmed everything is fine. But he was also able to confirm (using monitoring tools) that right at the time of a failover, there is almost 2GB worth of traffic going from Primary Server to DR server. That happens every time. I had checked the times of all failovers and there is no job or process occuring that will produce 2GB worth of data. Also, this happens regardless of which server is primary.
Even though the failover works fine, this unexpected automatic failover due to missed heartbeats are occurring often (2-3 times a month).
Here is the list of errors from the Cluster Validation Report:
Under Network Section, I see the following error messages in Red:
Validate Network Communication
Network interfaces Server4 (DR) - SAN_Team and Server1 (Primary) - SAN_Team - VLAN 20 are on the same cluster network, yet address xx.xx.xx.pp is not reachable from xx.xx.xx.yy using UDP on port 3343.
Network interfaces Server4 (DR) - SAN_Team and Server2 (Secondary) - SAN_Team - VLAN 20 are on the same cluster network, yet address xx.xx.xx.qq is not reachable from xx.xx.xx.yy using UDP on port 3343.
I am trying to create a failover cluster without the log shipping in 2012 as i've done it with a static instance with some database.Is the "AlwaysON" feature the solution when an application creates random and numerous databases within the instance and we need a failover scenario ?
Today a vendor bluntly stated that VMWare provides the same failover and redundancy for SQL that would render "AlwaysOn" high availability unnecessary.
Essentially that VMWare would detect a problem and failover and have .9999 uptime .
I'm looking for a solution to have cross data center automatic failover in the event of a data center loss for highly critical databases. I would like to have local HA and also automatic failover to the DR site. This does not seem possible with AlwaysOn.
Is my only option for automatic cross data center failover to build a node in one data center and a node in the other data center with a node/FS at a third data center in order to maintain quorum? I'd like to have local HA in the mix but that doesn't seem possible.What pattern for the highest data security and also availability?
I had a cluster running on 3 nodes (windows failover cluster) with server 2012 and SQL server 2012 running in the cluster. Well, I thought I'd just go ahead and rename all 3 of the hosts with new hostnames and it apparently broke the cluster pretty bad. Now when I open failover cluster manager I cannot see anything nor can I connect to the cluster object in AD. I re-named all of the hosts back to their original names but that didn't work.
If there is a history kept somewhere of failover events of a database in an AO group? I have 2 replicas with automatic failover and I'm looking for a history of failovers.
I have 2 servers in a SQL Server Fail-Over Cluster. IOW I use always-on availability groups. I run backups - full, diff and log - regularly via SQL Agent on one server only depending on which is primary. If there is a fail-over, then backups will continue on the other server. If I have to restore a database in an availability group I probably would need some combination of full, diff, and log backups from each server. Would that actually work? I test the backups weekly however I just realized that I never tested that scenario.
We are implementing a multi-site (Windows Server Failover Cluster) WSFC to enable Always On between our primary and DR site. We are not going to use SQL clustered instances. We are not planning to use shared disks. Each node is running a standalone instance of SQL 2012.
I have successfully configured a 3 node multi-site Windows failover cluster with no shared storage. For quorum, I have defined a File Share Witness (FSW). The FSW has voting rights and is in the DR site. The setup looks like this –
WSFC –
•Node A – Site #1 (voting right = 1) •Node B – Site #1 (voting right = 1) •Node C – Site #2 (voting right = 0) •FSW – Site #2 (voting right = 1)
Again - There are no shared disks in our setup. We are not going to use SQL clustered instance. We are going to use Always On with these 3 nodes.
SQL Always On –
•Node A – Site #1 (Primary Replica) •Node B – Site #1 (Readable Secondary) •Node C – Site #2 (Readable Secondary)
All the setup including the “availability group” works properly under this setup. However, a failover to site #2 under DR situation is not working and I know why but don’t know what needs to be done to fix the problem.
The following works fine –
•Automatic failover between nodes A and B (same site – site #1) •Forced failover to node C in site #2 provided at least one of the nodes in site #1 is up (non – DR situation) - this will ensure the cluster is up
The following is not working –
•Forced failover to node C in site #3 when both nodes in site #1 are lost (true DR situation) – This is because the cluster is not up at this point.
I know I have to bring the cluster up somehow and I have not been able to do so by restarting the cluster service.
I tried to run the command to start cluster service.
Question –
How can I FORCE the cluster to come up in Site #2 on node C when it has no voting rights?
I have always worked with even number of nodes and shared disks with traditional clustering. I am not sure what needs to be done in this scenario with 3 nodes and a FSW.
Prod - shared storage between server 1 and 2 Server1: clustered SQL instance with availability group as primary Server2: Passive server for clustered instance of PROD
DR - shared storage between server 1 and 2 Server1: Clustered SQL instance with availability group as replica Server2: Passive server for clustered instance of DR
Approach 2: Using replicated SAN Prod - Server 1: Standalone instance with availability group as Primary Server 2:Standalone instance with availability group as replica
DR - Server 1: Offline until Disk group 1 (Prod server 1) has been broken and brought online at DR Server 2: Offline until Disk group 2 (Prod server 2) has been broken and brought online at DR
Both these approaches will work wont they? I have only built and played with normal availability groups across servers, not mixing it with clustered instance replicated SAN
Let's say I have a two node AG, Server A and Server B. Server A is normally the primary and Server B is the replica. Whenever the primary fails over from A to B or from B to A, I'd like to automatically run a script that will restart the SQL Agent service on the new replica.
How can we find the cluster failover count in always on ?
As my AG is configured as synchronous mode , AG went offline and we manually restarted the AG service when we check the properties on AG role they r in default setting ?
An automatic failover set exists. This set consists of a primary replica and a secondary replica (the automatic failover target) that are both configured for synchronous-commit mode and set to AUTOMATIC failover.Configured the both AG Group database automatic failover and synchronous-commit mode.But automatic Failover failed also Cluster service not started automatically at Node2. It got connected through AO Listerner after starting Node1. As below SQL Error log during shutdown Node1
Date,Source,Severity,Message 10/27/2015 10:44:20,spid37s,Unknown,AlwaysOn Availability Groups: Waiting for local Windows Server Failover Clustering node to come online. This is an informational message only. No user action is required. 10/27/2015 10:44:20,spid37s,Unknown,AlwaysOn Availability Groups: Local Windows Server Failover Clustering node started.
I am new to SQL Server 2012 clustering.I added a new instance to one of the two nodes.when I try to move it to the other node it fails.Do I need to install it on both?If so, what options do you install on the second node?
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?
I've setup a two node Cluster Server (non-shared storage) with a file sharing witness. I'm testing some of the different failover scenarios to see that everything is working properly. Everything works fine until I try testing the failure of the SQL Server service. When I stop the SQL Service on the primary server, it fails over to the secondary server as expected. I then start the service on the (now) secondary server and it comes back online as the secondary server. I then try to test that the service will fail back over when I stop the service on the new primary server.
However, when I stop the service, the secondary server now shows "resolving" and never comes back online. When I bring the service back up on the primary server, the secondary now shows as secondary instead of resolving. So to see if it's something about failing over from one server to another, I do a manual failover making the original primary server the primary again and everything is as it was originally.
I then stop the service on the primary server, but the secondary server now says resolving and the AG will not become available again until I start the service on the primary server.
It seems that when I first configured the quorum it worked fine the first failover scenario, then stopped working. I then added the file sharing witness, and failover worked the first time again, but not after that. For some reason after the initial failover it won't automatically failover again after that.
Config:
Servers: Windows Server 2012 Standard SQL : SQL Server 2012 Enterprise SP1
it is possible to create Linked server with Failover partner option. I can query when primary server and getting the error when I set the DB Fail over. I have tried with following script and also gone through different sources, but failed. Please see the script and error below.
In QA we have a two-node cluster with four instances of sql. In trying to add a fifth, I was given an IP address already in use so the install hung.
I removed it from the cluster but it is still there in the registry etc on the node I was working on.
I read about using the maintenance tab of the sql server install to "remove a node" but the terminology is confusing. To me a node is a physical server and an instance is an instance of sql server -- not the same at all but they are often referred to as the same thing.
I definitely don't want to remove one of the servers from the cluster.
