High-availability technologies mask the effects of hardware or software failure, so that perceived downtime for users and applications is minimized.

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17
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2answers
438 views

Is there a complete list of Online operations for each SQL Server version?

As we are about to change some of the large tables in our 5TB database I found myself needing a list of the operations that can be performed online and the which require full locks to be held while ...
12
votes
2answers
2k views

What is the modern way to partition PostgreSQL across machines, when the data is “naturally partitionable”

After several years of dwelling into the "NoSQL" space, now I have a problem that is quite "relational" in its nature. Today I see data stores with quite different eyes than before. Things like Riak ...
8
votes
4answers
6k views

SQL Server equivalent to functionality of Oracle RAC?

I did some Googling and couldn't find an answer to this question more recent than a few years ago, so I thought I'd ask. Oracle's RAC feature offers load-balancing for both read and write ...
8
votes
2answers
511 views

High Availability for postgresql

I'm new in PostgreSQL database. Recently our developer needed to do some upgrades in our systems. Because of that we are planning to implement some method in order to implement database failover. ...
7
votes
2answers
614 views

Can Availability Groups replace transactional replication?

I've been looking at the new features of SQL Server 2012, and how it can help my current situation. Currently we're on SQL Server 2008 R2, and replicate two OLTP servers' databases to a single ...
7
votes
1answer
1k views

Do schema changes “break” SQL Server 2012 AlwaysOn or are they handled transparently?

My organization is planning to adopt SQL Server 2012 AlwaysOn and I am trying to understand what impact (if any) it will have on our application upgrade process. We release application updates on an ...
5
votes
1answer
632 views

Recovery time effects of Availability Groups

We did different kinds of basic Tests and AlwaysOn passed in many tests. We finally did a heavy write test for AlwaysOn and it gave surprising results. The actual Test details are here, the goal is ...
5
votes
2answers
1k views

Recommended distributor architecture for transactional replication?

We are planning to create a Transactional replication on 2 nodes of SQL Server 2008 R2, each node will be a publisher and a subscriber. What is the best practice in order to have this scenario done? ...
4
votes
1answer
559 views

SQL Server 2012 - Always On

I am in the process of setting up always on high availability clusters for the first time. Can anyone explain to me from the networking perspective after configuring the group and testing to make sure ...
4
votes
2answers
5k views

What are the differences between Mirroring and Failover Clustering and when is each one recommended over the other?

What are the main differences between Mirroring and Failover Clustering? What kind of problem each one solves and in what kind of scenarios is each one recommended over the other?
4
votes
2answers
909 views

SQL Server replication for off site copy

We have our Primary SQL Servers in-house (15 primary servers at the moment (500 databases approx overall), most of the servers have hex core processors). These are mirrored to other backup servers in ...
4
votes
1answer
855 views

Transaction Log Truncation with Copy Only

I have a database backup job set to use full backup with the Copy only option on once daily. The copy only is on because from what I have read that is the only way to backup a database that is ...
4
votes
2answers
425 views

Is MySQL Clustering a viable option for a DB expecting 5TB of data in 5 years?

We plan to implement MySQL Clustering.The database should support 5 years of data and expected data/year is 1TB. When we created a test enviornment with the DB size as 200GB, NDB Cluster took more ...
4
votes
0answers
52 views

AlwaysOn Availability Group error after Windows Update in environment without a failover cluster

Our SQL Server service was down this morning which brought down some of our websites. When I went to check the Windows Event Viewer I saw the following errors: Script level upgrade for database ...
3
votes
1answer
213 views

Three Node Cluster that Allows For Two Failures

We are creating a three-node three-instance cluster with SQL 2008 R2 (not cutting edge, but that is what the application supports) and think it should be able to maintain quorum with two physical ...
3
votes
1answer
79 views

Effects of turning the transaction safety OFF

I am considering to turn off the transaction safety to maximize the performance. Before that i am interested in finding the current status of transaction safety. Is there any command that we can get ...
3
votes
1answer
354 views

SQL Server DR, mirroring or virtualise and mirror

I have a client with a small business server 2008 Premium installation. This obviously includes SQL Server 2008 standard on a separate 2008 server. On the SQL we run several line of business ...
3
votes
1answer
2k views

MySQL Replication and High Availability

I know this might not be a very good question to be asked in this site, but I really need some helps/hints to be directed to the right path. I want to have failover strategy for 2 MySQL servers which ...
3
votes
1answer
453 views

Availability mode - manual failover mode, best practice for availability mode?

We don't want automatic failover for our availability group, but I have set availability mode to Synchronous, was that a mistake? The availability group runs on vmware with windows 2012R2, and I got ...
3
votes
2answers
846 views

SQL Server Database Mirroring is going to die. How can I guarantee high availability now?

The Database Mirroring feature of SQL Server is going to die: This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan ...
3
votes
2answers
2k views

SQL Server 2012 High Availability on VMware virtualization

We're going to host a large SQL Server 2012 under a VMware virtualization and we need it to be highly available. These are the three options I found supported, but couldn't find a lot of info and ...
3
votes
2answers
511 views

Best high availability solution to avoid maintenance downtime?

We currently only have one production SQL Server 2008 server. Anytime we need to perform maintenance or install patches, it causes downtime as the server reboots. In addition, if the server ever ...
3
votes
1answer
128 views

timeline 2 of the primary does not match recovery target timeline 1

I want to create a configuration with postgresql and pgpool to get height availability (HA). I want to do this: .-----. .--------. | | W | DB | | APP ...
3
votes
1answer
3k views

PostgreSQL High Availability/Scalability using HAProxy and PGBouncer

I have multiple PostgreSQL servers for a web application. Typically one master and multiple slaves in hot standby mode (asynchronous streaming replication). I use PGBouncer for connection pooling: ...
3
votes
1answer
662 views

Robust Mysql failover using free tools

I am looking for a free solution to set up Mysql in an active/passive configuration, in order to provide high-availability. In particular, a Bugzilla installation, and MediaWiki needs to stay alive ...
3
votes
1answer
181 views

Which database?

We have to launch a new service in my company with a big database. And I currently don't have that much knowledge. We did a small preview of the service and our biggest table had more than 2 100 000 ...
3
votes
1answer
4k views

Do Availability Groups support Active/Passive?

I am looking into the licensing of SQL Server 2012 when using Availability Groups with 2 servers. It is not clear to me if Availability Groups are only available as Active/Active and not ...
3
votes
1answer
714 views

AG and SQL Backups

I am using always on in sql 2012 and have an AG setup. I would like to know if i were to backup the primary database and restore it would that be allowed without taking the cluster down etc. ...
3
votes
1answer
1k views

Configured MySQL replication but its not working

I have configured MySQL master and slave replication setup on 5.5.x. But for some reason data is not getting replicated properly. What might be the reason? At Master: /etc/my.cnf [mysqld] ...
3
votes
3answers
146 views

Replication with FileStream

I need to setup database replication (for high availability) on a database that uses FileStream. This is on SQL Server 2012 Standard Edition, so Always On or Peer-to-Peer replication is not an option. ...
3
votes
0answers
122 views

ENABLE_BROKER vs NORECOVERY

I have two nodes with MSSQL2012 which work with AlwaysOn High Availability After some crash I had to remove db from availability group on the one of the nodes. For restoration I've made backup ...
2
votes
3answers
148 views

How to check history of primary node in AlwaysOn HA environment?

How do I see history of failovers of the primary node in cluster? I'm trying to figure out at what point secondary node started to act as primary. We are running Windows Server 2012 with SQL Server ...
2
votes
2answers
512 views

Oracle symmetrical one-way replication for cheap HA: unfashionable or technically unfeasible?

We have two smallish unrelated databases on two big Oracle Enterprise servers. Instead of buying more licenses and servers for high-availability replicas, can we replicate database B to server A and ...
2
votes
1answer
136 views

Failover Cluster Diagnostic Logs

I know there must be a simple answer to this question, but I cannot find it anywhere. Our SQL 2012 FCI have SQLDIAG .XEL files in their MSSQL\LOG folder. In some instances, these files are often ...
2
votes
3answers
258 views

Standard Edition High Availability without Shared Storage

I'm a software dev with little experience managing SQL Server so please bear with me. We are developing a piece of software that needs to be highly available, with a significant degree of resilience. ...
2
votes
2answers
1k views

MySQL cluster - how many hosts are needed for full HA?

I need some clarification on MySQL-Cluster (NDB) setup I want to achieve full HA but I'm low on server budget and can't afford to rent a dozen of servers for simple solution that I'm working on. ...
2
votes
1answer
555 views

Failover Cluster and AlwaysOn Availability Groups across Data Centers

We have two 3 node clusters in separate data centers, let's call them ClusterP and ClusterS. ClusterP is our primary and ClusterS is our secondary for disaster recovery. Each cluster has multiple ...
2
votes
1answer
2k views

MySQL: Alter Table on very active table gives “Waiting for table metadata lock”

At my work, we've recently upgraded to MySQL 5.5 and since then, have been bitten a few times by the new (and intended) behavior of metadata locking. Basically, whenever we run an ALTER TABLE ...
2
votes
1answer
370 views

When changing startup parameters on a cluster, does each node have to be updated manually?

When moving a SQL 2005 instance to new disks on a two-node Windows 2003 cluster, I changed startup params on the active node to reflect the new paths for the master DB files and error logs. I ...
2
votes
1answer
406 views

AlwaysOn Availability Groups: Confusion with some concepts

In Sql Server 2012, I am trying to install Failover Clustering to configure AlwaysOn Availability Groups. When I run Cluster Validation test wizard, it comes back with a lot of errors. One of them ...
2
votes
1answer
3k views

JBoss don't fail over MySQL slave using datasource

I'm trying to set up an high available MySQL cluster, using a Master / Slave configuration. I want to the slave become master (e.g. not read-only but writeable) if the first node come down (like in ...
2
votes
1answer
444 views

Is it possible to automate the configuration of dataguard broker?

We deploy a number of oracle databases every year and a good percentage of them require a dataguard configuration. I've developed a script which is able to perform the database synchronization very ...
2
votes
1answer
36 views

Effects of renaming FC and using its original name for AG network name

We have a Failover Cluster, named MainSQL consisting of MainSQL01 and MailSQL02 which are default named instances and we can connect to whichever is the active node with just simply MainSQL. If we ...
2
votes
1answer
98 views

AlwaysOn AG and Cross-Database/Server Transactions

We're about to move from SQL Server 2008 R2 Standard to SQL Server 2012 Enterprise and are reviewing or HA as part of process. Right now we use DPM and log shipping every 15 mins. Our MS partner is ...
2
votes
0answers
93 views

AlwaysOn FCI + HA Setup Question

I am planning to create FCI + HA solution in the same datacenter, but running into some problems. I'd really appreciate if someone can provide some guidance. Here is the current configuration (All ...
2
votes
1answer
172 views

Listener pointing to incorrect AlwaysOn Availability Group

All, Thanks in advance I have two instances of SQL Server 2012 SP1 on a three node WSFC with a HAdr group on each instance with a corresponding listener. Instance 1's listener points to Instance 1, ...
2
votes
0answers
959 views

SQL Server connection with multiSubnetFailover fails, claims mirroring is enabled

I have two SQL Server instances in an availability group. They are not mirrored. I'm trying to connect to the AG using the MS JDBC drivers (4.0) with a connection string including ...
2
votes
0answers
569 views

SQL Server Database Mirroring : strange client application behavior upon failover

I am putting a HA SQL server environment up based on three SQL Server 2008 R2 machines and database mirroring. I'll name them : principal.company.intra mirror.company.intra witness.company.intra ...
1
vote
3answers
119 views

HA - MySQL Master Master replication - Duplicate entry errors

I am running Percona MySQL 5.5.39 on two masters with keepalived monitoring a VIP which will failover to the standby master if the primary master goes dark. While testing the fault tolerance of my ...
1
vote
1answer
81 views

Does “Synchronous-Commit Availability Mode” ensure consistency between Replicas?

If one refers to the MSDN documentation, on Synchronous-Commit Availability Mode, you may read: Under synchronous-commit availability mode (synchronous-commit mode), after being joined to an ...