Online training

We provide training on Amazon Web Services

1. AWS Architecture and different models of Cloud Computing 

2. Compute Services: AWS EC2, Auto Scaling and Load Balancing, AWS Lambda, Elastic Beanstalk

3. Storage Services : AWS S3, AWS EBS,  AWS Glacier, AWS CloudFront, Storage Gateway,AWS Snowball

4. Database Services: AWS RedShift, AWS RDS,  ElastiCache, AWS DynamoDB

5. Security and Identity Services: IAM, KMS

6. Networking Services: Route 53, Amazon VPC, Direct Connect

7. Management Tools: AWS CloudTrail, Trusty Advisor, AWS CloudWatch, CloudFormation, OpsWorks

We also provide training on Angular, NodeJS, MongoDB, MySQL, Android, iOS

you can reach us:    srinivas.n462@gmail.com. 

Read More

Installing MongoDB on Ubuntu 16.04

MongoDB is  included in Ubuntu package repositories, but official MongoDB repository provides most upto date version.

We use official version of MongoDB

$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927

The output should look like this

ubuntu@ip-192-41-15-154:~$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927

Executing: /tmp/tmp.u96cXK2VEb/gpg.1.sh --keyserver

hkp://keyserver.ubuntu.com:80

--recv

EA312927

gpg: requesting key EA312927 from hkp server keyserver.ubuntu.com

gpg: key EA312927: public key "MongoDB 3.2 Release Signing Key <packaging@mongodb.com>" imported

gpg: Total number processed: 1

gpg:               imported: 1  (RSA: 1)

We add MongoDB repository to Apt, so that apt know where to download the repository

echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list

Output:

deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse

Update the Apt 

$ sudo apt-get update 

Output:

Hit:1 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial InRelease

Get:2 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]

Ign:3 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 InRelease

Get:4 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]

Get:5 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release [3,457 B]

Get:6 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release.gpg [801 B]

Get:7 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/main Sources [258 kB]

Get:8 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [573 kB]

Get:9 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [504 kB]

Ign:6 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release.gpg

Hit:10 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease

Get:11 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]

Get:12 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 Packages [5,870 B]

Get:13 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse arm64 Packages [5,872 B]

Fetched 1,658 kB in 1s (938 kB/s)

Reading package lists... Done

W: GPG error: http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AC711F9BA35703V6

W: The repository 'http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release' is not signed.

N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.

N: See apt-secure(8) manpage for repository creation and user configuration details.

Install MongoDB

$ sudo apt-get install mongodb-org

Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  mongodb-org-mongos mongodb-org-server mongodb-org-shell mongodb-org-tools
The following NEW packages will be installed:
  mongodb-org mongodb-org-mongos mongodb-org-server mongodb-org-shell mongodb-org-tools
0 upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 66.8 MB of archives.
After this operation, 270 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
WARNING: The following packages cannot be authenticated!
  mongodb-org-shell mongodb-org-server mongodb-org-mongos mongodb-org-tools mongodb-org
Install these packages without verification? [y/N] Y
Get:1 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 mongodb-org-shell amd64 3.4.6 [7,981 kB]
Get:2 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 mongodb-org-server amd64 3.4.6 [14.2 MB]
Get:3 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 mongodb-org-mongos amd64 3.4.6 [8,110 kB]
Get:4 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 mongodb-org-tools amd64 3.4.6 [36.5 MB]
Get:5 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse amd64 mongodb-org amd64 3.4.6 [3,556 B]
Fetched 66.8 MB in 3s (20.3 MB/s)
Selecting previously unselected package mongodb-org-shell.
(Reading database ... 108006 files and directories currently installed.)
Preparing to unpack .../mongodb-org-shell_3.4.6_amd64.deb ...
Unpacking mongodb-org-shell (3.4.6) ...
Selecting previously unselected package mongodb-org-server.
Preparing to unpack .../mongodb-org-server_3.4.6_amd64.deb ...
Unpacking mongodb-org-server (3.4.6) ...
Selecting previously unselected package mongodb-org-mongos.
Preparing to unpack .../mongodb-org-mongos_3.4.6_amd64.deb ...
Unpacking mongodb-org-mongos (3.4.6) ...
Selecting previously unselected package mongodb-org-tools.
Preparing to unpack .../mongodb-org-tools_3.4.6_amd64.deb ...
Unpacking mongodb-org-tools (3.4.6) ...
Selecting previously unselected package mongodb-org.
Preparing to unpack .../mongodb-org_3.4.6_amd64.deb ...
Unpacking mongodb-org (3.4.6) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up mongodb-org-shell (3.4.6) ...
Setting up mongodb-org-server (3.4.6) ...
Adding system user `mongodb' (UID 113) ...
Adding new user `mongodb' (UID 113) with group `nogroup' ...
Not creating home directory `/home/mongodb'.
Adding group `mongodb' (GID 118) ...
Done.
Adding user `mongodb' to group `mongodb' ...
Adding user mongodb to group mongodb
Done.
Setting up mongodb-org-mongos (3.4.6) ...
Setting up mongodb-org-tools (3.4.6) ...
Setting up mongodb-org (3.4.6) ...

Create mongodb.service configuration file

$ sudo nano /etc/systemd/system/mongodb.service

Start MongoDB as Daemon

$ sudo systemctl start mongod

Check status of MongoDB

$ sudo systemctl status mongod

Output:

 mongodb.service - High-performance, schema-free document-oriented database

   Loaded: loaded (/etc/systemd/system/mongodb.service; disabled; vendor preset: enabled)

   Active: active (running) since Thu 2019-07-16 03:25:42 UTC; 1min 43s ago

 Main PID: 13102 (mongod)

    Tasks: 20

   Memory: 34.8M

      CPU: 408ms

   CGroup: /system.slice/mongodb.service

           └─13102 /usr/bin/mongod --quiet --config /etc/mongod.conf




Jul 13 03:25:42 ip-192-31-13-143 systemd[1]: Started High-performance, schema-free document-oriented database.

Enable process start for MongoDB when system reboot

$ sudo systemctl enable mongodb

Output:

Created symlink from /etc/systemd/system/multi-user.target.wants/mongodb.service to /etc/systemd/system/mongodb.service.

Read More

Amazon VPC

What is Aws VPC ?

VPC is a virtual private cloud or virtual private network which you can define on Amazon cloud and create logically isolated sections on amazon cloud  which supports IPv4 and IPv6 supports hardware VPN connections.

You can have full control of AWS architecture. We can control the selection of ip range.

With VPC, you can able to increase the capacity of existing on-premises infra for your organisation.

Launch the disaster recovery environment.

Launch the testing environment.

Serve the virtual desktop apps with your organisation.

Read More

AWS DynamoDB

DynamoDB is no sql, fully managed database.
What is the difference between relational database and nosql database.

Relational database stores the data in table format where as no sql database stores the data as document for high scalability.
NoSQL database stores the data as key value.

There are many no sql database available in the market like mongodb, Cassandra, Redis etc.

What is the difference about DynamoDB.

With dynamoDB, you never worry about database maintanance and administration.

You can use the local version of DynamoDB to developer your app locally. Then use DynamoDB service to scale globally.

It is great for bigdata, gaming, mobile apps etc for high availability.
It takes backup with regular intervals.  You dont need to follow ACID properties.
It is accessed by web services.

Read More

AWS Lambda and Pricing

Lambda is a compute service where you can upload your code to and your code will be executed on your behalf using Amazon infrastructure.

Each piece of your code is called a function on the Lambda platform.Using Lambda is bit like porting your code to a server except that you don’t have to manage that and your don’t have to worry about scaling or availability.

Lambda functions can be written in Java, Python or Nodejs.

All the functions you upload to lambda are stateless.

All persistence data you can store using S3 and DynamoDB to store stateful information.

Lambda will automatically scale the  incoming events and scale back down when needed. There is no autoscaling is configured. Everything is automatically handled by Amazon.

How can we trigger a Lambda function ?

Lambda functions can be trigger by events from other AWS services.

For example, you can trigger a lambda function when a new file is uploaded to S3 bucket. You can also trigger through HTTP.

Pricing :

Free Tier Available

1M requests

3M seconds of compute time each and every month.

No usage -  no cost

First Lambda function in Nodejs

Go To AWS Console

Go to Compute Section and open Lambda

Choose runtime as NodeJS 4.3 , this is the latest stable version, please do not pick NodeJS older version - which is a legacy version.

We will go with simple hello-world function

Configure trigger section - we not going to set up triggers right now.

We just set up the function and in future, we are going to connect this function to api gateway.

Configure function section -

Name : Your function name    example: random-number-generator

Description : Simple Lambda function

Runtime : NodeJS 4.3

you have options here

you can edit the code, you can upload the code.

‘use strict’

exports.handler = (event, context, callback) =>{

console.log(‘value1=’,event.key1);

callback(null,event.key1);

};

Read More

Create Docker image and push it to Docker Hub

In this tutorial, you will learn about docker containers, creating docker images and push the docker images to Docker Hub(hub.docker.com/)registry.

What is docker and what is a container ?

Docker is a tool, which allows deploying the applications in a container to run on the host operating system.
Container allows developer to package an application with all the required modules into a single standard unit.

Containers shares the resources in the operating system where for virtual machines need to allocate the resources.

Here am going to explain with hello world application using nodejs.

The command used to build the image using dockerfile.
docker build -t dockerhub-username/container-name

Below command is  used to run the container after generating the img from the dockerfile.

docker run -p 3000:3000 dockerhub-username/container-name

Push the docker image to Docker Hub.

Login into the docker

docker push dockerhub-username/container-name

 I have created a simple hello world app using nodejs. Deploying the application with dockerfile and the docker commands.

https://github.com/SrinivasNidadavolu/docker-nodejs-dockerhub

Read More

Route 53 pricing

AWS charges only for configured Hosted zones and number of dns queries aws answers.

Per Month :
$0.50/hosted zone upto 25 hosted zones

After 25 hosted zones,

$0.10/hosted zone will be charged.

Traffic Flow :

Aws charges $50.00/policy record / month.

Standard Queries /month :
$0.40/million - first 1 Billion queries
$0.20/million - over 1 Billion queries

Geo DNS queries :
$0.70/million queries - first 1 Billion queries
$0.30/million - over 1 Billion queries

Latency Based Routing queries :
$0.60/million queries - first 1 Billion queries
$0.30/million - over 1 Billion queries

Health Checks :
Basic health checks for AWS Endpoint $0.5/healthcheck/month,
Non AWS Endpoint $0.75/healthcheck/month

Domain Name registration price varies based on market value.

Read More