Windows Azure and dynamic elasticity - azure

Is there a way do do dynamic elasticity in Windows Azure? If my workers begin to get overloaded, or queues start to get too full, or too many workers have no work to do, is there a way to dynamically add or remove workers through code or is that just done manually (requires human intervention) right now? Does anyone know of any plans to add that if its not currently available?

Microsoft shipped the Autoscaling Application Block (Wasabi) to provide dynamic scaling. Some of the supported scenarios:
Autoscaling both web and worker roles in Windows Azure by dynamically changing instance counts or performing application throttling.
Autoscaling Windows Azure roles based on timetables.
Autoscaling Windows Azure roles based on metrics collected from the application and/or Windows Azure but constrained by upper and lower bounds on the instance count per role.
Preventing fast oscillations in the number of role instances with the stabilizer. The stabilizer can also help to optimize costs by limiting scaling up operations to the beginning of the hour and scaling down operations to the end of the hour.
Monitoring and logging autoscaling activity.
Sending notifications to preview any scaling operations before they take place.
Encrypting the rules and other configuration in Windows Azure blob storage or in local file storage.
Managing the autoscaler configuration by using Windows PowerShell.
A comprehensie sample application (Tailspin Surveys) showcasing all these features is provided (installation instructions are available here). Also, check out the Developer's Guide and the Channel9 video walkthrough.
The block is available as standalone download of binaries, source or via NuGet.
Here are a couple of talks/demos showing Wasabi in action:
CloudCover Episode on autoscaling
p&p symposium talk "Windows Azure app scaling to need"

There's a Service Management API, and you can use that to scale your application (from code running in Windows Azure or from code running outside of Windows Azure).
http://msdn.microsoft.com/en-us/library/ee460799.aspx and http://code.msdn.microsoft.com/Release/ProjectReleases.aspx?ProjectName=windowsazuresamples&ReleaseId=3233.

Windows Azure has just added the autoscaling feature built into the platform. Now it's trivially easy to configure your autoscaling rules right in the management portal:
See the announcement and the demo. I've also written a post comparing Windows Azure Autoscale to Wasabi and outlining the path forward.

Create a queue named autoscale.[your_role_name].instance_count
In the Management Portal, set the autoscale to Queue.
Set the Target Count field to 1.
Now you can use standard enqueue and dequeue operations on that queue to control the number of worker role instances. You've got 7 days to process a message before it expires, so you might want to create a worker role that can ensure that the number of messages in the queue is tracking your target instance count.
If you're after dynamic elasticity, you've probably already got a worker-role-based controller in mind already, so that's probably not a problem.

Lokad.Cloud open source project for Windows Azure contains distributed executor framework. Among other things it provides auto-scaling with VM provisioning feature.

Related

How to turn on/off Azure web apps during office hours [duplicate]

I thought one of the advantages of Azure was that I could turn services on and off depending on when I want them to be available.
However I cant see how to pause my App Service Plan.
Is it possible?
I want to use the S1 tier so that I can play with what it offers. However I want to be able to pause the cost accumulation when I am not using it.
I see from the app service pricing help that an app will still be billed for even though it is in the stopped state.
Yet the link also clearly states that I only pay for what I use. So how does that work?
If you put your hosting plan onto the free tier, you will stop being charged for it. However if you have things like deployment slots and certificates these will be deleted.
The ability to turn services on and off, is more to do with being able to scale services, so if you need 50 servers for an hour you can easily do that.
What you can do to make your solution temporary is to create a deployment script, using Powershell or Resource manager Templates then you can deploy your solution for exactly as long as you need it and then delete it again when you don't. In this sense you can turn your services on and off at a whim.
Azure provides building blocks for you to create the solution you need, it is up to you to figure out how to best use those building blocks to create the solution you seek.
Edited to answer extended question.
If you want to use the S1 pricing plan, and not have it charge when you are not using it, the only way of achieving that is by using automation. Fortunately, this is reasonably trivial to achieve.
If you look at this template it is pretty much all configured to deploy a website from Github to Azure on demand. If you edit that to configure it to your needs you can have a new Azure website online with 2 minutes of running the script.
Then you would have another script that deleted it once you had finished.
Doing it this way you would loose no functionality, and probably learn quite a bit about what is possible with Azure along the way.
App Service Plan
An app service plan is the hardware that a web app runs on. In the free and shared tier your web apps share an instance with other web apps. In the other tiers you have a dedicated virtual machine. It is this virtual machine that you pay for. In that case it is irrelevant whether or not you have web apps running on your app service or not, you still have a virtual machine running and you will be charged for that.
To change the App Service Plan via PowerShell, you can run the following command
Set-AzureRmAppServicePlan -ResourceGroupName $rg -Name $AppServicePlan -Tier Free
I was able to accomplish this using the dashboard by selecting the App Service Plan, clicking Scale up (App Service Plan), and then from there if you click Dev/Test you can select the Free tier.
As others have mentioned, you need to script this. Fortunately, I created a repository with one-click deployment to your Azure resources.
https://github.com/jraps20/jrap-AzureVerticalScaling
The steps are intended to be as simple and generic as possible:
Execute the one-click deployment from the repo readme
Select the subscription, resource group etc.
Deploy resource to Azure
Set up your schedule to scale up and scale down as-needed
The scripting relies on runbooks and variables to maintain the previous state of each App Service Plan and App Services within those plans. Some App Services cannot be scaled due to specific settings being used (AlwaysOn, Use32BitWOrkerProcess, ClientCertEnabled, etc.). In those cases, the previous values are stored as variables prior to down scaling and then the original values are reapplied when the services are scaled up.
For more clarity, I have written a blog post that goes into detail. The post is pertaining to Sitecore, but applies to any App Service setup- Drastically Reduce Azure PaaS Hosting Costs in Non-Prod Environments With Scheduled Vertical Scaling. It also includes a brief video tutorial to show its use case.
Myself and others have been using this repository/approach for well over a year and it works great. I mostly use it for POC's to reduce costs when I'm not actively working on something. However, its main intention was for targeting non-prod environments to save costs during non-work hours.
Azure App Service Plan is just an logical concept of a set of features and capacity that you can share across multiple apps. I don`t think you can "pause" a plan, instead you can pause your service. and depends on billing model of each service, you might or might not get charged.
Pausing = Delete or lower tier.
Scripting is the key.
Design Diagram
Use scripts to create (also consider shared resources)
Delete using scripts
Use scripts to recreate.
eg: If we use resource group properly per environment then
Export-AzureRmResourceGroup will create a template for us (everything in the resource group will be pulled out as script). So we can delete it and recreate it anytime.
To pause a VM and stop billing you need to shut is down and deallocate it. Just shutting down still has the capacity reserved as if its running.
Storage can't be shutdown - it can be moved to lower cost tiers.

Worker Role vs Azure Batch

We have a scenario for on prem to upload a bunch of pdf/tiffs then service on the cloud to process them. In the same time a queue is populated with metadata on processing instructions.
We are trying to decide if whether the worker role or the Azure Batch is the right choice for this. Our primary goal are,
need to scalable base on queue size
scale ramp up time need to be quick
of course cost is another factor
You should not use PaaS cloud services for new workloads. There are various options depending on the complexity of the processing you need to do. The following are likely better choices than Azure Batch: Azure Web Jobs, Virtual Machine Scale Sets. The first is easier to use, and is based on the Web Apps technology, while the second is the (preview) way to provide scale-out VMs.
PaaS cloud services are classic now, you can use webjobs with appservices. Another interesting option is AZURE STACK which is really good for hybrid cloud. refer this link
https://azure.microsoft.com/en-us/overview/azure-stack AZURE STACK is really good for hybrid cloud, As if now it is in Technical preview.

Alternate to run window service in Azure cloud

We currently have a window service which send some notification emails to users after doing some processing on database(SQL database). Runs once in day.
We want to move this on azure cloud. One alternate is to put it on Azure VM as is. but I am finding some other best possible solution for that.
I study about recurring and on demand Web jobs but I am not sure is this is best solution.
Also is there any possibility to update configuration of service code in App.config without re-deploy the code of service on cloud. I means we can manage configuration from Azure portal.
Thanks in advance.
Update 11/4/2016
Since this was written, there are 2 additional features available in Azure that are both excellent choices depending on what functionality you need:
Azure Functions (which was based on the WebJobs described below): Serverless code that can be trigger/invoked in various ways, and has scaling support.
Azure Service Fabric: Microservice platform, with support for actor model, stateful and stateless services.
You've got 3 basic options:
Windows service running on VM
WebJob
Cloud service
There's a lot of information out there on the tradeoffs between these choices, but here's a brief summary.
VM - Advantages: you can move your service basically as it is without having to change much or any of your code. They also have the easiest connectivity with other resources in Azure (blob storage, virtual networks, etc). The disadvantage is you're giving up all the of PaaS advantages and are still stuck managing your own VM infrastructure
WebJob - Advantages: Multiple invocation options (queues, blobs, manually, queue receive loops, continuous while-loop style, etc), scheduled (would cover your case). Easy to deploy (can go with website, as a console app, automatically through Kudu), has some built in logging in Azure portal - and yes, to answer your question, you can alter the configuration in the portal itself for connection strings and app settings.
Disadvantages - you'll need to update code, you don't have access to underlying resources (if you need that), and more of something to keep in mind than a disadvantage - it uses the same resources as the webapp it's deployed with.
Web Jobs are the newest of the options, but at the same time appear to have active development going on to increase the functionality and usefulness.
Cloud Service - like a managed VM, has some deployment options, access to underlying VM if needed. Would require some code changes from your existing service.
There's nothing you've mentioned in your use case that makes me think a Web Job shouldn't be first thing you try.
(Edit: Troy Hunt has a great and relatively recent blog post illustrating most of the points I've mentioned about Web Jobs above: http://www.troyhunt.com/2015/01/azure-webjobs-are-awesome-and-you.html)

How to measure memory consumption in Azure web roles

The Azure management dashboard gives you the possibility to monitor metrics such as CPU utilization, network in/out, response time, among others.
But how can you measure consumption/availability of memory? I am running a web app that is memory intensive, and it is hard for me to gauge which instance types (or number of instances) I should provision without having an understanding of the memory situation across time.
Yes, my service is a web role on Azure cloud services, I am not talking about VMs (IaaS) here.
Thanks
In your Azure project, in the Roles folder you'll find a folder for each of your Roles. If you use the latest version of the SDK you'll find a file called diagnostics.wadcfg. This is where you'll be able to configure Performance Counters, like \Memory\Available Bytes. This file will also allow you to configure the sample rate (ex: every 30 sec) and the scheduled transfer period (how frequently the logs should be transferred to your Storage Account).
Then you can use a tool like the Azure Diagnostics Manager to view memory consumption over time.
More information: Using performance counters in Windows Azure
A way to do this from the Management Console:
On the Configure tab for your web role, in the monitoring section, change level to Verbose.
On the Monitor tab at the bottom, click Add Metrics
With monitoring set to Verbose, the available metrics should include Memory Available.

Windows Services into Azure WorkerRoles

What is established best practice in porting a Windows Service to Azure? Should it be changed into a Worker Role or moved into a VM Role? Are there other options? Assume that my services write to external persistence sources (MSMQ, databases, WCF) rather than to the file system directly.
You are far better off converting your Windows Services to Worker-Roles than VM roles. VM roles are meant to house applications that require complex un-automatable installation procedures. They are also a bigger pain to manage and you want to stay away from VM roles as much as possible. If you can find a way to automate deployment of your existing Windows Services via Worker-Roles, it is definitely the way to go.
You can also looking into HPC roles and depending on the on-prem/off-prem and load/compute requirements, adding Azure machines to your HPC cluster maybe of benefit.
All types of Roles (Web/Worker/VM/HPC) are stateless and require to be able to spin-up or tear-down from scratch on demand. All types of Roles are meant to run more than one VM instance at a time.
HTH
I wrote a blog post about this a while back. It is here:
http://blogs.msdn.com/b/golive/archive/2011/02/11/installing-a-windows-service-in-a-worker-role.aspx
Note that a Windows Service won't communicate directly with the fabric controller, so you need to ping it periodically to check health, then take remediative actions as needed.
Putting a Windows Service into a worker or web role is accepted practice. The main reason to go with VM Role is if there is significant (>10 minutes) setup required. My blog post details how to install your service.
Of course, if you want to move the code into a worker role, that's also fine. In this case you don't need any special steps to ensure the fabric controller is aware of its health.
If cost is an issue, combining functions into web/worker is also accepted practice. And you can save by not working over your code to get it into a web/worker.
Azure has a special type of Web Role called "WCF Service Web Role" which corresponds to a Windows WCF Service. This is a good point for migrating existing services.
Ideally the migration should be followed by taking advantage of Azure specific features, for instance using queues and work roles to maximise perfromance and scalability.

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