AWS, BIG DATA, JAVA

 I had MacOS Mojave.  It needed multiple versions of pythons esp. I needed a version of Python between 2.6.x and 3.0.x.  I came across this nice article  https://medium.com/faun/pyenv-multi-version-python-development-on-mac-578736fb91aa I followed all steps but when I tried to install 2.7.0 and 2.7.1 I ran into this issue. ERROR : The Python ssl extension was not compiled. Missing the OpenSSL lib? I had openssl installed but it seems it was not the version it was looking for. Eventually I was able to install python version 2.7.15. Looks like 2.7.15 was using the openssl lib which I had it installed hence no issues.  bash-3.2$ pyenv install 2.7.15 python-build: use openssl@1.1 from homebrew python-build: use readline from homebrew Downloading Python-2.7.15.tar.xz... -> https://www.python.org/ftp/python/2.7.15/Python-2.7.15.tar.xz Installing Python-2.7.15... python-build: use readline from homebrew python-build: use zlib from xcode sdk Installed Python-2.7.15 t...

https://www.freecodecamp.org/news/here-is-the-most-popular-ways-to-make-an-http-request-in-javascript-954ce8c95aaa/

I followed up following blog post for installing active directory in my own AWS account.  https://www.ecloudture.com/en/use-ec2-to-build-windows-active-directory-2/ I ran into one issue. When I tried to add machine(PC01 in the post )  into  domain(ADLAB.com) I got an error. When I looked into  AD Server Manager.  on AD DS Service , DFS replication was failing with following error:  Additional Information: Error: 1355 (The specified domain either does not exist or could not be contacted.) DNS Service was also showing a error/warning complaining that it was waiting for some signal from AD DS.  After some research I came across this post.  https://community.spiceworks.com/topic/1726627-the-specified-domain-either-does-not-exist-or-could-not-be-contacted One of the answers on this post, recommends following procedure on this. https://support.microsoft.com/en-us/kb/947022 I did follow the procedure and after that I was able to add the machine to the do...

Interesting article on Hash Functions  Consistent Hashing is a strategy used in system design esp. in scaling the backend data stores.  The typical hash based sharding used to horizontally scale the databases doesn't handle the adding/removing of shards in efficient manner. Consistent hash sharding takes care of that.  Here is a nice article comparing different sharding strategies.

  Angular Recently came across this framework.  It lets you do lots of cool things, which are difficult otherwise. 1. Getting javascript object values written to DOM or html field names. <label  ng-repeat="obj in objCollection" class="radio-inline">        <input name="obj" id="obj-{{$index}}" value="{{obj.value}}" ng-model="scopedObj.val" type="radio">      {{obj.label}}     <label> objCollection is the collection of obj objects.  objCollection and scopedObj are both in the scope. 2.  If there an object available in scope , you can directly access it using a URL. 3. similar to jQuery  , you can make ajax calls easily.         var uri = "http://mydomain/uri";         var $http = angular.element('html').injector().get('$http');         $http.get(uri, {   ...

Okta is Cloud based Identity and Access Management platform. Below  are some notes from a whitepaper published on Okta website.  Okta can be used as foundation for implementing Zero Trust within organizations.  Zero Trust is a security framework developed by Forrester Research.   Zero Trust => never trust, always verify Zero Trust framework evolved later  into ZTX ( Zero Trust Extended Ecosystem ) . The focus has shifted from network perimeter to  access ( who is accessing the system ). The focus has shifted to Identity and Access Control.  There are four stages of Zero Trust implementation: Fragmented Identity Unified IAM Contextual Access : Context based access policies Adaptive Workforce : Risk based access policies, continuous and adaptive authn and authz Services Offered By OKta Okta Universal Directory Okta SSO  Okta Advanced Server Access Okta Adaptive MFA Okta also integrates with number of vendors in security ecosystem.  That...

Azure Functions is equivalent to AWS Lambda.  Azure Functions can be triggered by HTTP and also respond to HTTP request as of now but it does not have input binding for HTTP. It cannot take input from HTTP