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Cluster Archives - Page 2 of 3 - Blog dbi services

David Barbarin

Windows Server 2016: Introducing stretch cluster functionality

By | Database Administration & Monitoring, Hardware & Storage | One Comment

Let’s continue with the new high available functionality shipped with the next Windows version. In my previous blog, I talked about the new site awareness feature that provides more flexibility to configure failover resources priorities and more granular heartbeat threshold as well by introducing the new site concept. This time, we’ll talk about stretch cluster. What’s that? Let’s introduce the concept with some customer experiences for which we introduced high availability with the implementation of…

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David Barbarin

SQL Server AlwaysOn and availability groups : how to isolate the replication traffic from other networks?

By | Database Administration & Monitoring | 12 Comments

A couple of days ago, I was involved in a project about implementing availability groups with SQL Server 2014. My customer wanted to isolate the replication traffic from the public network. The idea behind was to get a better control of the network bandwidth as well as to be sure that the replication can be done without any latency issues in case of heavily network traffic issued by other applications or backup activities for instance….

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Daniel Westermann

ACFS on Oracle Linux 7.1

By | Database Administration & Monitoring | 2 Comments

Recently we wanted to create an ACFS filesystem on a brand new GI installation on Oracle Linux 7.1. According to the documentation this should not be an issue as “Oracle Linux 7 with the Unbreakable Enterprise kernel: 3.8.13-33.el7uek.x86_64 or later” is supported. The “or later” is the important point. In our case: uname -a Linux racp1vm1 3.8.13-55.1.6.el7uek.x86_64 #2 SMP Wed Feb 11 14:18:22 PST 2015 x86_64 x86_64 x86_64 GNU/Linux   Should be fine as…

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David Barbarin

SQL Server 2016 : availability groups and load balancing features

By | Hardware & Storage | 6 Comments

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 Automatic failover enhancements   This time I’ll talk about read-only secondaries and the new load-balancing support that will be introduced by SQL Server 2016. First of all, SQL Server 2014 improved the read-only secondary availability by solving the issue related to secondary accessibility when…

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David Barbarin

Windows Cluster vNext and cloud witness

By | Operation systems | No Comments

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 achieve a truly resilient quorum. Let’s imagine the following scenario that may concern the implementation of either an SQL Server availability group or a SQL Server FCI. Let’s say you have to implement a geo-cluster…

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Alain Lacour

High availability in the Oracle landscape

By | Hardware & Storage | No Comments

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 minimal or no downtime) Detection of failures when they arrive If those principals are met, end users may never realize about a failure. The aim of that blog is not to dive into too much…

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Grégory Steulet

MySQL high availability management with ClusterControl

By | Database management | No Comments

Installing and managing a highly available MySQL infrastructure can be really tedious. Solutions to facilitate database and system administrator’s task exist, but few of these cover the complete database lifecycle and address all the database infrastructure management requirements. Severalnines’ product ClusterControl is probably the only solution that covers the full infrastructure lifecycle and is also able to provide a full set of functionalities required by database cluster architectures. In this article, I will show how…

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David Barbarin

SQL Server 2014: Availability groups failover impossible with Failover Cluster Manager

By | Hardware & Storage | 2 Comments

A couple of weeks ago, I worked for a customer that wanted to implement SQL Server 2012 (and not SQL Server 214) AlwaysOn with availability groups. During our tests we performed a bunch of failover tests and the customer tried to perform a failover of one of the installed availability group by using the failover cluster manager (FCM). Of course, I told him this is not best practice because the failover cluster manager is not…

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Stéphane Savorgnano

How to avoid Failover Cluster with PowerShell scripting

By | Application integration & Middleware | No Comments

One of my colleague asked me some days ago if I could create a PowerShell script to get rid from Windows Server Failover Cluster. The reason is that it has, in some specific cases, the bad habit to failover a resource or a service even when we don’t want it. To be honest, I use a lot the Failover Cluster feature of Windows Server without any problems as a SQL Server DBA, but for this specific…

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