High availability

SQL Server 2016 : availability groups and load balancing features

Let’s continue with this third post about SQL Server AlwaysOn and availability groups. Others studies are available here: New database issue level detection for automatic failover Potential features in standard edition(…)

SQL Server 2016 : availability groups and automatic failover enhancements

Let’s continue with this study of the new availability group enhancements. Others studies are available here: New database issue level detection for automatic failover Potential features in standard edition This time we’ll(…)

SQL Server 2016 : availability groups and the new potential support for standard edition

In my first blog about availability groups with SQL Server 2016, I talked quickly about the new interesting option: DB_FAILOVER. In this blog post, I will continue by introducing the new potential support of availability groups in a standard(…)

Weird issue with sys.fn_hadr_backup_is_preferred_replica() function

A couple of days ago, I faced a weird backup issue with SQL Server AlwaysOn and availability groups at one of my customer (thank to him to point out this issue 🙂 ). After installing our DMK tool (Database(…)

Windows Cluster vNext and cloud witness

The next version of Windows will provide some interesting features about WFSC architectures. One of them is the new quorum type: “Node majority and cloud witness” which will solve many cases where a third datacenter is mandatory and missing to(…)

12c: shutdown abort a PDB?

By Franck Pachot . Can we shutdown abort a PDB? Let’s try: SQL> show con_id CON_ID ------------------------------ 3SQL> shutdown abort; Pluggable Database closed. But is it really a shutdown abort? The shutdown abort we know in non-CDB – or(…)

Is CDB stable after one patchset and two PSU?

By Franck Pachot . There has been the announce that non-CDB is deprecated, and the reaction that CDB is not yet stable. Well. Let’s talk about the major issue I’ve encountered. Multitenant is there for consolidation. What is the major(…)

SQL Server 2014: FCIs, availability groups, and TCP port conflict issues

After giving my session about SQL Server AlwaysOn and availability groups at the last French event “Les journées SQL Server 2014”, I had several questions concerning the port conflict issues, particularly the differences that exist(…)

SQL Server: Forced failover with AlwaysOn & Availability Groups

During a workshop at one of my customer about the implementation of SQL Server AlwaysOn and availability groups, I had an interesting discussion. It was about asynchronous replication between 2 replicas and the effect of the forced failover operation(…)

High availability in the Oracle landscape

It’s now several weeks I attended some event about high availability (HA). But what is actually high availability? According to our friend Wikipedia, HA is based on 3 main principals: Elimination of Single Point of Failure (SPoF) Reliable crossover (with(…)