When do replication subscribers and always on availability groups fail?

When do replication subscribers and always on availability groups fail?

Replication Subscribers and Always On Availability Groups (SQL Server) When an Always On availability group containing a database that is a replication subscriber fails over, the replication subscription might fail.

How to reconfigure a subscriber in Merge Replication?

For merge replication, a replication administrator must manually reconfigure the subscriber with the following steps: Execute sp_subscription_cleanup to remove the old subscription for the subscriber. Perform this action on the new primary replica (which was formerly the secondary replica).

How are distribution agent jobs created in replication?

This is because the distribution agent jobs only get created on the original subscriber (primary replica of the AG). For merge subscribers, a replication administrator must manually reconfigure the subscriber, by recreating the subscription.

How to create a transactional replication push subscription?

Using the script in the Creating a Transactional Replication Push Subscription section below, create the subscription using the name of the availability group listener of the subscriber.

Why is my logreader not working after AlwaysOn failover?

Problem of the day: Transactional Replication was configured on a database in AlwaysOn Availability Group. When the group was failed over to synchronized secondary node Transactional Log Reader stopped working. Initial LogReader errors when failover occurs. If configured correctly, LogReader will retry and reconnect to new Primary.

When does the log reader agent not process log records?

The Log reader Agent has the following changes. When a published database is a member of an availability group, by default the log reader will not process log records that have not already been hardened at all availability group secondary replicas.

Can a secondary database be a publisher in replication?

When the replication agent restarts after failover, the connection will automatically be redirected to the new primary. In an availability group a secondary database cannot be a publisher. Republishing is only supported when transactional replication is combined with Always On availability groups.

How are availability replicas hosted in SQL Server?

Each availability replica hosts a copy of the availability databases in the availability group. For a given availability group, the availability replicas must be hosted by separate instances of SQL Server residing on different nodes of a WSFC cluster. Each of these server instances must be enabled for Always On.

What happens when an always on availability group fails?

When an Always On availability group containing a database that is a replication subscriber fails over, the replication subscription might fail. For transactional subscribers, the distribution agent will continue to replicate automatically if the subscription is using the name of the availability group listener of the subscriber.

Can a distribution database be placed in an availability group?

Placing the distribution database into an availability group is supported with SQL 2016 and greater, except for distribution databases used in merge, bidirectional, or peer-to-peer replication topologies. For more information, see Configure distribution database in an availability group.

How to create or configure availability group Listener?

To create or configure an availability group listener In Object Explorer, connect to the server instance that hosts the primary replica of the availability group, and click the server name to expand the server tree. Expand the Always On High Availability node and the Availability Groups node.

When to use a listener to connect to a read-only secondary replica?

Using a Listener to Connect to a Read-Only Secondary Replica (Read-Only Routing) Read-only routing refers to the ability of SQL Server to route incoming connections to an availability group listener to a secondary replica that is configured to allow read-only workloads.

When to disable distribution agent in replication group?

When you create a pull subscription, with the subscription database in an Availability Group, after every failover, it is recommended to disable the distribution agent job on the old Primary replica and enable the job on the new primary replica.