Your student could be the next Doogie Howser of Cloud Computing with free training and cloud computing resources

Students with any interest in Information Technology or Computer Science are going to be joining a world dominated by Cloud Computing. And of course the major cloud service providers (CSP) would all love to see the young people embrace their cloud platform to host the next big thing like Facebook, Instagram or SnapChat. The top three CSP all have free offerings for students, hoping to win their minds and hearts.

But before you jump right in to cloud computing, the novice student might want to start with some basic fundamentals of computer programming at one of the many free online resources, including Khan Academy.

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Microsoft is offering free Azure services for students. There are two different offerings. The first is targeted at high school students ages 13+ and the second is geared towards college students 18+.

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Microsoft Azure for Students Starter Offer is for those high school students that are interested in building applications in the cloud. While there are not as many free services or credits as being offered at the college level, there is certainly enough available for free to really get some hands on experience with some cutting edge technology for the self starter. How cool would it be for your high school to start a Cloud Computing Club, or to integrate this offering into some of the IT classes they may already be taking.

Azure for Students is targeted at the college level student and has many more features available for free. Any student in computer science or information technology should definitely get some hands on experience with these cutting edge cloud technologies and this is the perfect way to do it with no additional out of pocket expense.

A good way to get introduced to the Azure Cloud is to start with some free online training courses Microsoft delivers in partnership with Pluralsight.

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AWS Educate. Not to be outdone, AWS also offers some free cloud services to students and educators. These seem to be in terms of free cloud credits, which if managed properly can go a long way. AWS also delivers an educational program that can be combined with an AP class in Computer Science if your high school wants to participate.

 

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Google Cloud Platform (GCP) also has education grants available for computer science majors at accredited universities. These seem to be the most restrictive of the three as they are available for Computer Science Majors only at accredited universities.

GCP does also offer training, but from what I can find I don’t see any free training offerings. If you want some hands on training you will have to register for some classes. The plus side of this is that these classes all seem to be instructor led, either online or in an actual classroom. The downside is I don’t think a lot of 13 year olds are going to shell out any money to start developing on the CGP when there are other free training opportunities available on AWS or Azure.

For the ambitious young student, the resources are certainly there for you to be the next Doogie Howser of Cloud Computing.

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Your student could be the next Doogie Howser of Cloud Computing with free training and cloud computing resources

Help! I can’t connect to my SQL Server multi-subnet failover cluster

I get that kind of call or email from customers all the time. I have a generic response as follows…

This has everything you need to know.

They don’t go into great detail about what to do if your connection does not support multisubnetfailover=true. If your connection does NOT support that parameter, then set registerallprovidersip to false and cleanup DNS. That procedure is described best here.
I figure I get this question often enough I probably should just flesh out my response a bit, hence the reason for this post.
In general people just aren’t aware of how multi-subnet failover clusters work. Multi-subnet failover clustering support was added in Windows Server 2012 with the addition of the “OR” technology when defining cluster resource dependencies. This allowed people to allow a Cluster Name resource to be dependent upon IP Address x.x.x.x OR IP Address y.y.y.y.
x.x.x.x would be an a cluster IP resource valid in Subnet A and y.y.y.y would be a cluster IP address valid in Subnet B. Only one address will be online at any given time, whichever address was valid for the subnet the resource was currently running on.
Microsoft SQL Server started supporting this concept starting with SQL Server 2012 with both failover cluster instances (FCI) using 3-party SANless clustering solutions like SIOS DataKeeper and SQL Server Always On Availability Groups.
By default if you create a SQL Server multi-subnet failover cluster the cluster should be automatically configured optimally, including setting up the two IP addresses, adding two A records to DNS and setting the registerallprovidersIP to true. However, on the client end you need to tell it that you are connecting to a multi-subnet failover cluster, otherwise the connection won’t be made.

Configuring the client

Configuring the client is done by adding multisubnetfailover=true to the connection string. This Microsoft documentation is a great resource, but if you just search for multisubnetfailover=true you will find a lot of information about that setting.
However, not every application will support adding that to the connection string. If you find yourself in that situation you should ask your application vendor to add support for that or show you how to do it.
However, all is not lost if you find yourself in that situation. You will want to change the behavior of the cluster so that upon failover DNS is update so that the single A record associated with the cluster client access point is updated with the new IP address. This is in lieu of having two A records in DNS, one with each cluster IP address, which is the default behavior in an multi-subnet cluster.
This article reference SharePoint, you can ignore that, the rest of the article is pretty well written to describe the process you should follow.
The highlights of that article are as follows…
Get-ClusterResource “[Network Name]” | Set-ClusterParameter RegisterAllProvidersIP 0
After restarting the cluster-name-object (basically restarting the role) & cleaning up all “A” records manually (clean-up isn’t done automatically) we can see our old A-records are still in DNS so we’ll need to delete those manually.
In addition to those steps I’d advise you to reduce the TTL on the HostRecordTTL as described in this article.
The highlight of that article is as follows.
PS C:\> Get-ClusterResource -Name cluster1FS | Set-ClusterParameter -Name HostRecordTTL -Value 300
With a Value of 300 you could potentially be waiting up to 5 minutes for your clients to reconnect after a failover, or even longer if if have a large Active Directory infrastructure and AD replication takes some time to update all the DNS servers across your infrastructure.
You are going to want to figure out what the optimal TTL is to facilitate quick client reconnections without over burdening your DNS servers with a bunch of DNS Lookup requests.
This type of configuration is common in disaster recovery configurations where your DR site is in a different subnet. It is also very common in HA deployments in AWS because different Availability Zones are in different subnets.
Let me know if you have any questions. You can always reach me on Twitter @daveberm
Help! I can’t connect to my SQL Server multi-subnet failover cluster

STORAGE SPACES DIRECT (S2D) FOR SQL SERVER FAILOVER CLUSTER INSTANCES (FCI)?

With the introduction of Windows Server 2016 Datacenter Edition a new feature called Storage Spaces Direct (S2D) was introduced. At a very high level, this solution allows you to pool together locally attached storage and present it to the cluster as a CSV for use in a Scale Out File Server, which can then be accessed over SMB 3 and used to hold cluster data such as Hyper-V VMDK files. This can also be configured in a hyper-converged (HCI) fashion such that the application and data can all run on the same set of servers.  This is a grossly over-simplified description, but for details, you will want to look here.

 

Storage Spaces Direct StackImage taken from https://docs.microsoft.com/en-us/windows-server/storage/storage-spaces/storage-spaces-direct-overview

The main use case targeted is hyper-converged infrastructure for Hyper-V deployments. However, there are other use cases, including leveraging this SMB storage to store SQL Server Data to be used in a SQL Server Failover Cluster Instance

Why would anyone want to do that? Well, for starters you can now build a highly available 2-node SQL Server Failover Cluster Instance (FCI) with SQL Server Standard Edition, without the need for shared storage. Previously, if you wanted HA without a SAN you pretty much were driven to buy SQL Server Enterprise Edition and make use of Always On Availability Groups or purchase SIOS DataKeeper and leverage the 3rd party solution which lets you build SANless clusters with any version of Windows or SQL Server. SQL Server Enterprise Edition can really drive up the cost of your project, especially if you were only buying it for the Availability Groups feature.

In addition to the cost associated with Availability Groups, there are a number of other technical reasons why you might prefer a Failover Cluster over an AG. Application compatibility, instance vs. database level protection, large number of databases, DTC support, trained staff, etc., are just some of the technical reasons why you may want to stick with a Failover Cluster Instance.

Microsoft lists both the SIOS DataKeeper solution and the S2D solution as two of the supported solutions for SQL Server FCI in their documentation here.

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https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sql/virtual-machines-windows-sql-high-availability-dr

When comparing the two solutions, you have to take into account that SIOS has been allowing you to build SANless Clusters since 1999, while the S2D solution is still in its infancy.  Having said that, there are bound to be some areas where S2D has some catching up to do, or simply features that they will never support simply due to the limitations with the technology.

Have a look at the following table for an overview of some of the things you should consider before you choose your SANless cluster solution.

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If we go through this chart, we see that SIOS DataKeeper clearly has some significant advantages. For one, DataKeeper supports a much wider range of platforms, going all the way back to Windows Server 2008 R2 and SQL Server 2008 R2. The S2D solution only supports the latest releases of Windows and SQL Server 2016/2017. S2D also requires the  Datacenter Edition of Windows, which can add significantly to the cost of your deployment. In addition, SIOS delivers the ONLY HA/DR solution for SQL Server on Linux that works both on-prem and in the cloud.

But beyond the cost and platform limitations, I think the most glaring gap comes when we start to consider disaster recovery options for your SANless cluster. Allan Hirt, SQL Server Cluster guru and fellow Microsoft Cloud and Datacenter Management MVP, recently posted about this S2D limitation. In his article Revisiting Storage Spaces Direct and SQL Server FCIs  Allan points out that due to the lack of support for stretching S2D clusters across sites or including an S2D based cluster as a leg in an Always On Availability Group, the best option for DR in the S2D scenario is log shipping!

Don’t get me wrong, log shipping has been around forever and will probably be around long after I’m gone, but that is taking a HUGE step backwards when we think about all the disaster recovery solutions we have become accustomed to, like multi-site clusters, Availability Groups, etc.

In contrast, the SIOS DataKeeper solution fully supports Always On Availability Groups, and better yet – it can allow you to stretch your FCI across sites to give you the best HA/DR solution you could hope to achieve in terms of RTO/RPO. In an Azure environment, DataKeeper also support Azure Site Recovery (ASR), giving you even more options for disaster recovery.

The rest of this chart is pretty self explanatory. It basically consist of a list hardware, storage and networking requirements that must be met before you can deploy an S2D cluster. An exhaustive list of S2D requirements is maintained here.  https://docs.microsoft.com/en-us/windows-server/storage/storage-spaces/storage-spaces-direct-hardware-requirements

The SIOS DataKeeper solution is much more lenient. It supports any locally attached storage and as long as the hardware passes cluster validation, it is a supported cluster configuration. The block level replication solution has been working great ever since 1 Gbps was considered a fast LAN and a T1 WAN connection was considered a luxury.

SANless clustering is particularly interesting for cloud deployments. The cloud does not offer traditional shared storage options for clusters. So for users in the middle of a “lift and shift” to the cloud that want to take their clusters with them they must look at alternate storage solutions. For cloud deployments, SIOS is certified for AzureAWS and Google and available in the relevant cloud marketplace. While there doesn’t appear to be anything blocking deployment of S2D based clusters in Azure or Google, there is a conspicuous lack of documentation or supportability statements from Microsoft for those platforms.

SIOS DataKeeper has been doing this since 1999. SIOS has heard all the feature requests, uncovered all the bugs, and has a rock solid solution for SANless clusters that is time tested and proven. While Microsoft S2D is a promising technology, as a 1st generation product I would wait until the dust settles and some of the feature gap closes before I would consider it for my business critical applications.

STORAGE SPACES DIRECT (S2D) FOR SQL SERVER FAILOVER CLUSTER INSTANCES (FCI)?

Protecting Business Critical Apps By @DaveBerm | @CloudExpo [#Cloud]

Protecting Business Critical Apps By @DaveBerm | @CloudExpo [#Cloud] — Gartner predicts that the bulk of new IT spending by 2016 will be for cloud platforms and applications and that nearly half of large enterprises will have cloud deployments by the end of 2017. The benefits of the cloud may be clear for applications that can tolerate brief periods of downtime, but for critical applications like SQL Server, Oracle and SAP, companies need a strategy for HA and DR protection. While traditional SAN-based clusters are not possible in these environments, SANless clusters can provide an easy, cost-efficient alternative.

Read more at http://www.sys-con.com/node/3334102/blog#

Attend my session at Cloud-Expo on June 11th at the Javits Center in NYC – http://www.cloudcomputingexpo.com/event/session/2854

 

Protecting Business Critical Apps By @DaveBerm | @CloudExpo [#Cloud]

#Azure Storage Service Interruption…Time for “Plan B”

Yesterday evening Pacific Standard Time, Azure storage services experienced a service interruption across the United States, Europe and parts of Asia, which impacted multiple cloud services in these regions.

As part of a performance update to Azure Storage, an issue was discovered that resulted in reduced capacity across services utilizing Azure Storage, including Virtual Machines, Visual Studio Online, Websites, Search and other Microsoft services.

Read the whole report on the Azure blog. http://azure.microsoft.com/blog/2014/11/19/update-on-azure-storage-service-interruption/

So what does this outage mean to those thinking about a cloud deployment? Global “interruptions” of this magnitude certainly cannot occur on any regular basis for any cloud provider that intends to remain in the cloud business, whether they are Microsoft, Amazon, Google or other. However, as a cloud architect or person responsible for a cloud deployment, you have a responsibility to your customer to have a “Plan B” in your back pocket in case the worst case scenario actually happens.

What exactly is a “Plan B”? Plan B involves having a documented procedure for recovering data and services in an alternate location in the event of a wide spread outage that impacts a cloud provider’s ability to deliver their service, despite deploying what you thought was a highly resilient cloud deployment designed to keep running even in the event of localized outages within a region, availability zone or fault domain.

At a high level you should be concerned about three things: Data Recovery, Application Recovery, and Client Access. There are many ways to address these concerns, some more automated than others and some with a better Recovery Time Objective (RTO) and Recovery Point Objective (RPO) than others.

It was just last week that I blogged about how to create a multisite cluster that stretched between the AWS cloud and the Azure cloud. This type of configuration is just what is needed in the event of an outage of the magnitude that we just experienced yesterday in the Azure cloud. https://clusteringformeremortals.com/2014/11/18/cloud-resiliency-for-sqlserver-failover-clusters-aws-to-azure-multisite-cluster/

Figure 1 – Example of a Cloud-to-Cloud Multisite Cluster Configuration

Another alternative to the “cloud-to-cloud” replication model is of course utilizing your own datacenter as a disaster recovery site for your cloud deployment. The advantages of this is that you have physical ownership of your data, but of course now you are back in the business of managing a datacenter, which can negate some of the benefit of a pure cloud deployment.

Figure 2 – Hybrid Cloud Deployment Model

If you are not ready to go full on cloud, you can still make use of the cloud as a disaster recovery site. This is probably the easiest and most cost effective way to implement an offsite datacenter for disaster recovery and to start taking advantage of what the cloud has to offer without fully committing to moving all your workloads into the cloud.

Figure 3 – Using the Cloud as a Disaster Recovery Site

The illustrations shown above make use of the host based replication solution called DataKeeper Cluster Edition to build multisite SQL Server clusters. However, DataKeeper can be used to keep any data in sync, either between different cloud providers or in the hybrid cloud model.

Microsoft is not alone in dealing with cloud outages as outages have impacted Google, Microsoft, Amazon, DropBox and many others just this year alone. Having a “Plan B” in place is a must have anytime you are relying on any cloud service.

#Azure Storage Service Interruption…Time for “Plan B”

Amazon EC2 Storage and Instance Size Considerations

When you launch a new instance you only have two options for the OS storage: Standard or Provisioned IOPS. Both are EBS volumes persistent across reboots. Many instances come with a bunch of extra ephemeral drives attached, which are NOT persistent. I usually delete these ephemeral drives so I am not tempted to store data on them. You will have to add additional EBS volumes for additional persistent storage.

This article seems to indicate that you can launch AMI’s based on the “EC2 Instance Store”, which is NOT persistent, but I’ve never seen that option. All of my instances have always had root devices that are EBS based; I have not seen one that is not EBS based. I’m assuming they mean some of the instances in the Amazon Market Place may use non-persistent volumes. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/RootDeviceStorage.html

You’ll see the root device when you launch the instance, like I highlighted below. As long as EBS is the root device you are good to go and can be sure your changes will persist across reboots.

 

As far as instance size, it will depend on the needs of the application. The good thing about EC2 is that if you provision an AMI that is under powered, you can go back and increase the instance size, though it does require a reboot. If IOPS are important, you will want to make sure you choose an instance that is EBS optimized. See this page for the instance details. http://aws.amazon.com/ec2/instance-types/#instance-details . You’ll see the first instance type which is EBS optimized is M1.large.

Read this guide for additional tips for optimal storage configuration. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSPerformance.html . One of the best tips for increased IOPS is to use multiple smaller EBS volumes and put them together in a RAID 0 on the Windows server. Because the EBS volumes are RAID1 on the backend, you are essentially deploying RAID 1+0 in your VM for optimal performance and availability.

Amazon EC2 Storage and Instance Size Considerations