CometChat Interview Questions and Answers

Kubernetes can be implemented on AWS using Elastic Kubernetes Service (EKS) or self-managed Kubernetes clusters.

• EKS is a managed Kubernetes service provided by AWS

• Self-managed Kubernetes clusters can be set up using EC2 instances and other AWS services like Elastic Load Balancing, Elastic Block Store, etc.

• AWS provides tools like kops and eksctl to simplify the deployment and management of Kubernetes clusters on AWS

Docker Swarm is a container orchestration tool that is simpler to use than Kubernetes.

• Docker Swarm is built into Docker Engine, while Kubernetes requires additional installation.

• Docker Swarm is easier to set up and manage than Kubernetes.

• Kubernetes is more powerful and flexible than Docker Swarm, with more advanced features for scaling and managing containers.

• Kubernetes has a larger community and more third-party tools...read more

AWS architecture consists of various components such as compute, storage, database, networking, security, and management tools.

• Compute: EC2, Lambda

• Storage: S3, EBS, EFS

• Database: RDS, DynamoDB

• Networking: VPC, Route 53

• Security: IAM, KMS

• Management Tools: CloudFormation, CloudWatch

EKS is a managed Kubernetes service, ECS is a container orchestration service, and Beanstalk is a PaaS for deploying web applications.

• EKS is best for running Kubernetes workloads on AWS

• ECS is best for running containerized applications on AWS

• Beanstalk is best for deploying web applications without worrying about infrastructure

• EKS and ECS both offer auto-scaling and load balancing capabilities

• Beanstalk supports multiple...read more

ELB services of AWS are load balancing services that distribute incoming traffic across multiple targets.

• ELB stands for Elastic Load Balancer

• There are three types of ELB services: Classic Load Balancer, Application Load Balancer, and Network Load Balancer

• Classic Load Balancer is used for distributing traffic across EC2 instances, while Application Load Balancer is used for routing HTTP/HTTPS traffic to different target...read more

Github basic commands and their usecases

• git clone : clones a repository to local machine

• git add : adds a file to staging area

• git commit -m : commits changes to local repository

• git push: pushes changes to remote repository

• git pull: fetches and merges changes from remote repository

• git branch: lists all branches in the repository

• git checkout : switches to a different...read more

To maintain maximum availability of databases in AWS, we can use various methods such as Multi-AZ deployment, Read Replicas, and Elastic Load Balancing.

• Multi-AZ deployment ensures that a standby replica of the primary database is always available in a different availability zone.

• Read Replicas can be used to offload read traffic from the primary database and improve performance.

• Elastic Load Balancing can distribute traf...read more

Create a plan to troubleshoot and resolve the issue as quickly as possible.

• Identify the root cause of the failure

• Check AWS service health dashboard for any known issues

• Check CloudWatch logs for error messages

• Rollback changes if necessary

• Restore from backups if data is lost

• Implement preventive measures to avoid similar issues in the future

AWS provides various monitoring services to monitor resources and applications.

• CloudWatch is a monitoring service for AWS resources and applications

• CloudTrail provides event history of AWS account activity

• AWS Config provides inventory of resources and configuration history

• Trusted Advisor provides best practices and recommendations

• X-Ray helps debug and analyze distributed applications

Route53 is a DNS web service provided by AWS that routes internet traffic to the appropriate resources.

• Route53 is used for domain registration, DNS routing, and health checking of resources

• It can be used to route traffic to EC2 instances, S3 buckets, and load balancers

• Route53 also supports routing policies such as weighted, latency-based, and geolocation-based routing

Code to separate userid and domain in email

• Use the split() method to split the email address at the '@' symbol

• The first part of the split result is the userid, and the second part is the domain

• Handle cases where there are multiple '@' symbols in the email address

Code to check for absence of a specific pattern in strings

• Use regular expressions to define the pattern to be avoided

• Use the 'not' operator to check if the pattern is absent in the string

• Implement the code in the language of your choice

Kubectl issues can arise from configuration, connectivity, or permissions. Troubleshoot systematically to resolve.

• Check if kubectl is installed: Run 'kubectl version' to verify installation.

• Verify kubeconfig file: Ensure the correct context is set using 'kubectl config current-context'.

• Check cluster connectivity: Use 'kubectl cluster-info' to see if the cluster is reachable.

• Inspect permissions: Ensure your user has the...read more

Beanstalk uses Elastic Load Balancer (ELB) instead of creating its own load balancer.

• Beanstalk is a platform as a service (PaaS) that automates the deployment of applications.

• It uses Elastic Load Balancer (ELB) to distribute traffic to instances.

• ELB provides more features and flexibility than a custom load balancer.

• Beanstalk also supports other load balancers like Application Load Balancer (ALB) and Network Load Balanc...read more

A service in ECS is a group of tasks that are defined to run together. A task is a set of container instances.

• A service is used to define the desired state of a task and maintain it

• A task is a set of container instances that run together on a single EC2 instance or across multiple instances

• Services can be scaled up or down based on demand

• Tasks can be defined using task definitions which specify the container images, po...read more

Additional security can be added in ECS by implementing security groups, IAM roles, and VPCs.

• Implement security groups to control inbound and outbound traffic

• Use IAM roles to manage access to AWS resources

• Create VPCs to isolate resources and control network traffic

• Enable encryption for data at rest and in transit

• Implement multi-factor authentication for user access

AWS networking architecture is based on Virtual Private Cloud (VPC) which allows users to create isolated virtual networks.

• VPC allows users to create subnets, route tables, and network gateways

• Security groups and network access control lists (ACLs) can be used to control traffic flow

• AWS Direct Connect and VPN can be used to connect on-premises networks to VPC

• Elastic Load Balancing and Amazon Route 53 can be used for lo...read more

NLB and ALB are both ELBs but differ in their routing capabilities.

• NLB routes traffic based on IP addresses and ports, while ALB routes traffic based on HTTP/HTTPS requests.

• NLB is better suited for TCP/UDP traffic, while ALB is better suited for HTTP/HTTPS traffic.

• ALB supports advanced routing features like path-based routing and host-based routing.

• NLB is more performant and can handle higher traffic loads than ALB.

• Bot...read more

In case of a worker node failure in Docker Swarm, take steps to identify, recover, and ensure service continuity.

• Check the status of the worker node using 'docker node ls' to confirm its failure.

• Investigate logs and metrics to identify the cause of the failure.

• If the node is unresponsive, consider removing it from the swarm using 'docker node rm <node-id>'.

• Deploy a new worker node to replace the failed one, ensur...read more

Packages in Lambda are libraries or modules that can be used to extend the functionality of the code. Environment variables are used to store sensitive data.

• Packages can be installed using pip or uploaded as a zip file

• Environment variables can be set in the Lambda console or using AWS CLI

• They can be accessed in the code using os.environ['variable_name']

• Examples of sensitive data that can be stored in env variables are ...read more

I joined cometchat because of its innovative approach to communication and its strong reputation in the industry.

• Cometchat offers cutting-edge technology and solutions for real-time communication.

• The company has a proven track record of success and a strong reputation in the industry.

• I was impressed by the company's commitment to innovation and staying ahead of the curve.

• Cometchat provides a collaborative and dynamic w...read more

DevOps engineers are responsible for bridging the gap between development and operations teams.

• Automating deployment processes

• Monitoring system performance

• Collaborating with development and operations teams

• Ensuring system security and reliability

• Implementing continuous integration and delivery

• Managing infrastructure and configuration

• Troubleshooting issues and providing solutions