Availability groups

SQL Server 2016 AlwaysOn: Direct seeding and backup considerations

As promised in my prior blog post, we’ll talk now about direct seeding feature and backups. We found an interesting LIMIT_CONCURRENT_BACKUPS value for current state of the hadr_automatic_seeding_state_transition event. As said last time, this value is(…)

SQL Server 2016 AlwaysOn: Direct seeding and performance considerations

This blog post follows the previous one about new direct seeding feature shipped with SQL Server 2016. As a reminder, I had some doubts about using direct seeding with large databases because log stream is not(…)

SQL Server 2016 AlwaysOn: distributed availability groups

This time, I will talk about distributed availability groups. What’s that? In short, a group of availability groups. Sounds good right? But in which cases may we need such architecture? Firstly, let’s say that(…)

SQL Server 2016 AlwaysOn: Add DBs in AGs with direct seeding

In this blog I would like to talk about two new features shipped with SQL Server 2016 for AlwaysOn availability groups. The first one concerns the new direct seeding capability and the seconde one introduces distributed availability groups(…)

SQL Server AlwaysOn: is my database ready for failover?

In this blog post I just want to clarify values that we may find from the is_failover_ready column of the sys.dm_hadr_database_replica_cluster_states DMV. A couple of days ago, I had an interesting discussion with one of my customers during which he(…)

SQL Server AlwaysOn: when a listener becomes the cluster and vice versa

Let’s talk about a funny story that concerns an interesting issue that I faced a couple of months ago at one of my customers. Initially, the problem concerned only the creation of an availability group listener but after deleting the(…)

SQL Server AlwaysOn and availability groups : session timeout parameter

Have you ever faced to timeout issues with SQL Server availability groups? If you take a look at the timeout parameters for an availability group, you will find a plenty of configuration settings. Indeed, you have timeout parameters(…)

SQL Server 2016 – availability groups and gMSAs

This blog post will probably not concern customers where either password policy change rules are not defined for service accounts or Kerberos authentication is not used. But I’m sure that the number of these customers has decreased over at least(…)

SQL Server 2016 : availability groups with no domain dependencies

Are you aware about the new features of the next Windows version? Currently we’re in TP3 and during my investigation, I was very happy to see the new features for Windows clustering (cf. this blog post from Microsoft). By(…)

SQL Server AlwaysOn : readable secondary replicas and index rebuild online vs offline

A couple of weeks ago, I was involved in a discussion on the French forum developpez.com about SQL Server AlwaysOn and availability groups, index strategies and the impact on the readable secondary replicas. During this discussion,(…)