I believe many of you aware about great Eric Brewer theorem which says that any net­worked shared-data system can have only two of three desirable properties: Consistency or high Availability or tolerance to network Partitions (i.e. this property means that network may loose any packet/message ) – this theorem usually called CAP-theorem. This theorem is quite important (or even very fundamental) for many distributed workloads like computational and data grids and “2 of 3” principle is basis for many architectural decisions in cloud world. Below I combine couple of great links around that topic which surely may shred some light on that principle as well as give you more insights how that basic rule is changed nowadays . And yes, by the way CAP theorem  is key thing for most of NoSQL or any other data distributed solutions – below you might good reading about that topic, including some new views on that topic.

Easy explanation of CAP theorem

SWAP partitions in Azure are quite interesting thing – SWAP space can be created on the local resource disk with the Linux Agent by enable swap in /etc/waagent.conf. It will automatically use the resource disk (which comes with every VM) to create the swap ( i.e. there’s no need to create a disk for it and also it means that please do not use swap on OS or data disk ). Good links which surely may help here – it’s not a rocket science, just changing Azure Linux Agent configuration file.

There’s a recommendation regarding where should be SWAP placed – we highly recommend to use resource disk for that ( i.e. /mnt/resources ) and not using system drive for that purpose. There’s several reason why it should be like that and all of them are about performance ( so yes, technically you can do it, but consequences of that configuration will be bad and non-so-predictable performance ):

  • OS drive is a storage account backed entity and it saved during restarting/moving VMs. So it’s not good idea to slow down that account by additional workloads.
  • OS drive is optimized almost for fast boot and other additional workloads will make performance of that resource not so good ( or very bad even ).
  • OS drive is from technical side is a remote storage, so latency might be higher compared to local resources.
  • Resource disk is located locally and not survived during host changed, but it’s much faster and this is a place designed especially for swap-like workloads.

Also we support a way inject a script or other metadata into a Microsoft Azure virtual machine at provision time – it’s custom data and cloud-init :


Examples of configuration :

As you know we recently add DNS services into preview mode and you can subscribe to this service using Request-AzureProvideFeature like that

Request-AzureProvideFeature -ProviderNamespace Microsoft.Network -FeatureName azurednspreview

So good question here is about how get list of all possible available options for FeatureName ?

Continue reading ‘List of all available preview services in Azure’ »

I will describe how this schema works for single VM with running Linux/Jelastic. So first of all let check that do we have for that VM by using Get-AzureDeployment command and then let go deep that happened inside that file

Continue reading ‘All about Azure Service Configuration Schema .cscfg’ »

Get-AzureVM | Where-Object {$_.InstanceSize -ne 'Basic_A0'} | Set-AzureVMSize "Basic_A0" | Update-AzureVM

Q: How to get Azure VM external IP address ( if you not use PublicIP service ) ?

A:  If you’re not using ReservedIP service field PublicIP will be empty ( as soon as there’s no reserved IP ) for command Get-AzureVM. I using Swtich-AzureMode just in case to be sure that we’re in right Azure mode in powershell right now.

PS C:\> Switch-AzureMode -Name AzureServiceManagement
PS C:\> Get-AzureVM

ServiceName                             Name                                    Status
———–                             —-                                    ——
abokov-jelastic                         abokov-jelastic                         ReadyRole

PS C:\> Get-AzureVM -ServiceName "abokov-jelastic" | Select-object  Name, DNSName, *IP*

Name                    : abokov-jelastic
DNSName                 : http://abokov-jelastic.cloudapp.net/
IpAddress               :
PublicIPAddress         :
PublicIPName            :
PublicIPDomainNameLabel :
PublicIPFqdns           : {}
OperationDescription    : Get-AzureVM


You may see that this VM have DNS name, internal IP, but public IP is empty, nevertheless that there’s is an external IP address which is linked to that VM. To get external IP you may use command Get-AzureEndPoint which returns all information about all endpoints for that cloud service – in my case I have 7 open ports and to make this more readable I select only few fields from output.

PS C:\> Get-AzureVM -ServiceName "abokov-jelastic" | Get-AzureEndPoint | Select-Object Name, Port , *ip*

Name Port Vip VirtualIPName
—- —- — ————-
dns-TCP 53
dns-UDP 53
http 80
http4848 4848
https 443
https4949 4949
ssh 22


First of all you need to have Microsoft Azure PowerShell SDK installed, after this step is done you may type
and this will authenticate you via web browser in Azure account ( you need to have working Azure account obviously ). Alternatively you may use PublishSettings :

    1. Open that link to Donwload Azure Publish Settings Profile: https://manage.windowsazure.com/publishsettings , then save you credentials.
    2. Open Microsoft Azure Powershell and run Import-AzurePublishSettingsFile :

PS C:\> Import-AzurePublishSettingsFile C:\tools\azure\my_settings.publishsettings
Id : c09f1074-6e2e-45be-aeee-935d6642424d
Name : Windows Azure MSDN - Visual Studio Ultimate
Environment : AzureCloud
Account : 24636FAB2C68B96D43777561A3CD728092912C03
Properties : {[SupportedModes, AzureServiceManagement]}

Then you need to keep in mind that Azure PowerShell (from 0.8.0 ) contains many modules, here we will talk about three main modules ( complete list of eveything which is inside SDK is here – see Azure SDK CmdLets reference ):

  • AzureProfile : operates with profiles commands like Add-AzureAccount, Get-AzureSubscription, and Switch-AzureMode. Complete list of commands in AzureProfile module is availalbe here – see Azure Profile Cmdlets. Commands from AzureProfile are always available – not like two next modules which are not designed to be used in the same PowerShell session.


  • Azure ( or AzureServiceManamagement ): contains commands which operated by core ( or basic :-)) cloud functionality like virtual machines, web sites, storage accounts and  so on. Complete list of commands inside this module is here – see Azure Service CmdLets. You can switch to that module using Switch-AzureMode -Name AzureServiceManagement


 Note: sometimes ( it happened with me as well ) default installation of Azure SDK cmdlets do not include some modules ( in my case it happened with DNS and Azure SQL Database ), then you have choice how to install them – first of all you always may use Azure powershell sources on github to get full and latest one version of cmdlets or you also may check files inside “C:\Program Files (x86)\Microsoft SDKs\Azure” folder and try to import modules from there like this ( it worked for me ):

 import-module "C:\Program Files (x86)\Microsoft SDKs\Azure\PowerShell\ResourceManager\AzureResourceManager\AzureResourceManager.psd1"


Using PowerShell scripts may give you a lot of power and here’s some nice things which I found very useful for myself. For example we have Azure SDK command ‘Get-AzureLocation’ which give you a complete list of cloud resource types and their locations. For me output of that command looks a little bit complex ( adding ‘more‘ makes it a little bit better ) :
Get-AzureLocation output example

A lot of information, isn’t it ?  So what I really want is just list where my VMs can be deployed. To make this list I’m going to filter this output only with “*compute*” mask and I will do it only for first column. Before I will do it I need to figure out name of first column ( if it’s printed under ‘Name’ column it not always means that objects returned by Get-AzureLocation are under exact that name ), so I will check that properties of object do we have for that output with Get-Member:

PS C:\temp> Get-AzureLocation| Get-Member
TypeName: Microsoft.Azure.Commands.Resources.Models.PSResourceProviderLocationInfo
Name MemberType Definition
---- ---------- ----------
Equals Method bool Equals(System.Object obj)
GetHashCode Method int GetHashCode()
GetType Method type GetType()
ToString Method string ToString()
Locations Property System.Collections.Generic.List[string] Locations {get;set;}
LocationsString Property string LocationsString {get;set;}
Name Property string Name {get;set;}

Okay so here we have three properties : Locations, LocationsString and Name. So let’s print everything which is about my VMs ( can be filtered with ‘*compute*’ ) using Where-Object : Get-AzureLocation | Where-Object Name -like "*compute*

Get-AzureLocation output example

Okay, so now it’s much better. Just in case if that command doesn’t work try to switch into AzureResourceManager mode ( it might happen that you’re now in AzureServiceManagement mode which works in a little bit different way ) :

Switch-AzureMode -Name AzureResourceManager


We can improve that by printing only ‘LocationsString’ property by Select-Object :
Get-AzureLocation | Where-Object Name -like "*compute*" | Select-Object LocationsString

Get-AzureLocation print compute only resources

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Just check it out Visual studio 2015 preview

Recently we made an update in CDN network, so right now it’s 29 nodes all around the world ( more than before ) and there’s some changes in locations. Full list of Azure CDN nodes is here Azure Content Delivery Network (CDN) Node Locationsand also you may take a look on them here – CDN node locations on bing map

Azure CDN points in Europe

For some people ( who doing Azure-related presentations and slides a lot like me :-) ) this may be useful – now we have 17 datacenters ( including 2 in Australia and 2 Gov datacenters in US ), so here’s updated map :
Microsoft Azure datacenter locations and CDN locations map

Windows Azure portal - now and three years ago

update : Also take a look on Forbes analitycs : Identifying The Tech Leaders In LTE Wireless Patents

“They’ll ask abt ur skillz and propr kmand of ze English lng” :-) Continue reading ‘Job interview via facebook – they’ll ask abt ur skillz and propr kmand of ze English lng’ »

Cloud computing humor

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Short how-to:

root@215003:~# mysql -u root -p
Enter password:
mysql> CREATE DATABASE s_db;
mysql> GRANT ALL PRIVILEGES ON s_db.* to 's_user'@'localhost' IDENTIFIED BY '12345678';
mysql -u s_user -p s_db < database.sql

Hello world c++

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via Email vs Wiki