Another year – Top 100 Oracle Blogs and Website

The best Oracle blogs from thousands of blogs on the web ranked by traffic, social media followers, domain authority & freshness.

Happy to share that my blog has been choosen for another year as the Top 100 Blogs around the world, the list contains talened, experience and professional people 🎉🎉🎉

Thank you all for the support.

Cheers

Osama

Deployment strategies

All-at-once

All-at-once deployments instantly shift traffic from the original (old) Lambda function to the updated (new) Lambda function, all at one time. All-at-once deployments can be beneficial when the speed of your deployments matters. In this strategy, the new version of your code is released quickly, and all your users get to access it immediately.

Canary

A linear deployment is similar to canary deployment. In this strategy, you direct a small amount of traffic to

In a canary deployment, you deploy your new version of your application code and shift a small percentage of production traffic to point to that new version. After you have validated that this version is safe and not causing errors, you direct all traffic to the new version of your code.

Linear

A linear deployment is similar to canary deployment. In this strategy, you direct a small amount of traffic to your new version of code at first. After a specified period of time, you automatically increment the amount of traffic that you send to the new version until you’re sending 100% of production traffic.

Comparing deployment strategies

To help you decide which deployment strategy to use for your application, you’ll need to consider each option’s consumer impact, rollback, event model factors, and deployment speed. The comparison table below illustrates these points.

DeploymentConsumer ImpactRollbackEvent Model FactorsDeployment Speed
All-at-onceAll at onceRedeploy older versionAny event model at low concurrency rateImmediate 
Canary/
Linear
1-10% typical initial traffic shift, then phased Revert 100% of traffic to previous deploymentBetter for high-concurrency workloadsMinutes to hours

Deployment preferences with AWS SAM

Traffic shifting with aliases is directly integrated into AWS SAM. If you’d like to use all-at-once, canary, or linear deployments with your Lambda functions, you can embed that directly into your AWS SAM templates. You can do this in the deployment preferences section of the template. AWS CodeDeploy uses the deployment preferences section to manage the function rollout as part of the AWS CloudFormation stack update. SAM has several pre-built deployment preferences you can use to deploy your code. See the table below for examples. 

Deployment Preferences TypeDescription
Canary10Percent30MinutesShifts 10 percent of traffic in the first increment. The remaining 90 percent is deployed 30 minutes later.
Canary10Percent5MinutesShifts 10 percent of traffic in the first increment. The remaining 90 percent is deployed 5 minutes later.
Canary10Percent10MinutesShifts 10 percent of traffic in the first increment. The remaining 90 percent is deployed 10 minutes later.
Canary10Percent15MinutesShifts 10 percent of traffic in the first increment. The remaining 90 percent is deployed 15 minutes later.
Linear10PercentEvery10MinutesShifts 10 percent of traffic every 10 minutes until all traffic is shifted.
Linear10PercentEvery1MinuteShifts 10 percent of traffic every minute until all traffic is shifted.
Linear10PercentEvery2MinutesShifts 10 percent of traffic every 2 minutes until all traffic is shifted.
Linear10PercentEvery3MinutesShifts 10 percent of traffic every 3 minutes until all traffic is shifted.
AllAtOnceShifts all traffic to the updated Lambda functions at once.

Creating a deployment pipeline

When you check a piece of code into source control, you don’t want to wait for a human to manually approve it or have each piece of code run through different quality checks. Using a CI/CD pipeline can help automate the steps required to release your software deployment and standardize on a core set of quality checks.

Reference

Redeploy and roll back a deployment with CodeDeploy

What is AWS Lambda?

Cheers

Osama

New Cloud Project

The Idea of this project the following :

You need to develop and deploy a python app that writes a new file to S3 on every execution. These files need to be maintained only for 24h.

The content of the file is not important, but add the date and time as prefix for you files name.

The name of the buckets should be the following ones for QA and Staging respectively:

qa-FIRSTNAME-LASTNAME-platform-challenge

staging-FIRSTNAME-LASTNAME-platform-challenge

The app will be running as a docker container in a Kubernetes cluster every 5 minutes. There is a Namespace for QA and a different Namespace for Staging in the cluster. You don’t need to provide tests but you need to be sure the app will work.

Github HERE

Cheers

Osama

 APAC Groundbreakers Virtual Tour 2021

I will have two presentation about the DevOps

  • Database Automation, Is this even possible ?
  • Kuberenetes in Depth but in simple way

You can register here

The hashtag in use is #APACGBT2021

Enjoy

Cheers

Migrating to Serverless

we’ll look at considerations for migrating existing applications to serverless and common ways for extending the serverless

At a high level, there are three migration patterns that you might follow to migrate your legacy your applications to a serverless model.

Leapfrog

As the name suggests, you bypass interim steps and go straight from an on-premises legacy architecture to a serverless cloud architecture

Organic

You move on-premises applications to the cloud in more of a “lift and shift” model. In this model, existing applications are kept intact, either running on Amazon Elastic Compute Cloud (Amazon EC2) instances or with some limited rewrites to container services like Amazon Elastic Kubernetes Service (Amazon EKS)/Amazon Elastic Container Service (Amazon ECS) or AWS Fargate.

Developers experiment with Lambda in low-risk internal scenarios like log processing or cron jobs. As you gain more experience, you might use serverless components for tasks like data transformations and parallelization of processes.

At some point in the adoption curve, you take a more strategic look at how serverless and microservices might address business goals like market agility, developer innovation, and total cost of ownership.

You get buy-in for a more long-term commitment to invest in modernizing your applications and select a production workload as a pilot. With initial success and lessons learned, adoption accelerates, and more applications are migrated to microservices and serverless.

Strangler

With the strangler pattern, an organization incrementally and systematically decomposes monolithic applications by creating APIs and building event-driven components that gradually replace components of the legacy application.

Distinct API endpoints can point to old vs. new components, and safe deployment options (like canary deployments) let you point back to the legacy version with very little risk.

New feature branches can be “serverless first,” and legacy components can be decommissioned as they are replaced. This pattern represents a more systematic approach to adopting serverless, allowing you to move to critical improvements where you see benefit quickly but with less risk and upheaval than the leapfrog pattern.

Migration questions to answer:

  • What does this application do, and how are its components organized?
  • How can you break your data needs up based on the command query responsibility (CQRS) pattern?
  • How does the application scale, and what components drive the capacity you need?
  • Do you have schedule-based tasks?
  • Do you have workers listening to a queue?
  • Where can you refactor or enhance functionality without impacting the current implementation?

Application Load Balancer vs. API Gateway for directing traffic to serverless targets

Application Load BalancerAmazon API Gateway
Easier to transition existing compute stack where you are already using an Application Load BalancerGood for building REST APIs and integrating with other services and Lambda functions
Supports authorization via OIDC-capable providers, including Amazon Cognito user poolsSupports authorization via AWS Identity and Access Management (IAM), Amazon Cognito, and Lambda authorizers
Charged by the hour, based on Load Balancer Capacity UnitsCharged based on requests served
May be more cost-effective for a steady stream of trafficMay be more cost-effective for spiky patterns
Additional features for API management: 
Export SDK for clients
Use throttling and usage plans to control access
Maintain multiple versions of an APICanary deployments

Consider three factors when comparing costs of ownership:

  • The infrastructure cost to run your workload (for example, the costs for your provisioned EC2 capacity vs. the per-invocation cost of your Lambda functions)
  • The development effort to plan, architect, and provision resources on which the application will run
  • The costs of your team’s time to maintain the application once it is in production

Reference

Cheers

Osama

AWS Site-to-Site VPN and AWS Client VPN

AWS VPN is comprised of two services: 

  • AWS Site-to-Site VPN enables you to securely connect your on-premises network to Amazon VPC, for example your branch office site. 
  • AWS Client VPN enables you to securely connect users to AWS or on-premises networks, for example remote employees. 

AWS Site-to-Site VPN

ased on IPsec technology, AWS Site-to-Site VPN uses a VPN tunnel to pass data from the customer network to or from AWS.

One AWS Site-to-Site VPN connection consists of two tunnels. Each tunnel terminates in a different Availability Zone on the AWS side, but it must terminate on the same customer gateway on the customer side. 

AWS Site-to-Site VPN components

Customer gateway

A resource you create and configure in AWS that represents your on-premise gateway device. The resource contains information about the type of routing used by the Site-to-Site VPN, BGP, ASN and other optional configuration information.

Customer gateway device

A customer gateway device is a physical device or software application on your side of the AWS Site-to-Site VPN connection. 

Virtual private gateway

A virtual private gateway is the VPN concentrator on the Amazon side of the AWS Site-to-Site VPN connection. You use a virtual private gateway or a transit gateway as the gateway for the Amazon side of the AWS Site-to-Site VPN connection.

Transit gateway

A transit gateway is a transit hub that can be used to interconnect your VPCs and on-premises networks. You use a transit gateway or virtual private gateway as the gateway for the Amazon side of the AWS Site-to-Site VPN connection.

AWS Site-to-Site VPN limitations

  • IPv6 traffic is partially supported. AWS Site-to-Site VPN supports IPv4/IPv6-Dualstack through separate tunnels for inner traffic. IPv6 for outer tunnel connection not supported.
  • AWS Site-to-Site VPN does not support Path MTU Discovery. The greatest Maximum Transmission Unit (MTU) available on the inside tunnel interface is 1,399 bytes.
  • Throughput of AWS Site-to-Site VPN connections is limited. When terminating on a virtual private gateway, only one tunnel out of the pair can be active and carry a maximum of 1.25 Gbps. However, real-life throughput will be about 1 Gbps. When terminating on AWS Transit Gateway, both tunnels in the pair can be active and carry an aggregate maximum of 2.5 Gbps. However, real-life throughput will be 2 Gbps. Each flow (for example, TCP stream) will still be limited to a maximum of 1.25 Gbps, with a real-life value of about 1 Gbps.
  • Maximum packets per second (PPS) per VPN tunnel is 140,000.
  • AWS Site-to-Site VPN terminating on AWS Transit Gateway supports equal-cost multi-path routing (ECMP) and multi-exit discriminator (MED) across tunnels in the same and different connection. ECMP is only supported for Site-to-Site VPN connections activated on an AWS Transit Gateway. MED is used to identify the primary tunnel for Site-to-Site VPN conncetions that use BGP. Note, BFD is not yet supported on AWS Site-to-Site VPN, though it is supported on Direct Connect. 
  • AWS Site-to-Site VPN endpoints use public IPv4 addresses and therefore require a public virtual interface to transport traffic over Direct Connect. Support for AWS Site-to-Site VPN over private Direct Connect is not yet available. 
  • For globally distributed applications, the accelerated Site-to-Site VPN option provides a connection to the global AWS backbone through AWS Global Accelerator. Because the Global Accelerator IP space is not announced over a Direct Connect public virtual interface, you cannot use accelerated Site-to-Site VPN with a Direct Connect public virtual interface.

In addition, when you connect your VPCs to a common on-premises network, it’s recommend that you use nonoverlapping CIDR blocks for your networks. 

Client VPN

Based on OpenVPN technology, Client VPN is a managed client-based VPN service that lets you securely access your AWS resources and resources in your on-premises network. With Client VPN, you can access your resources from any location using an OpenVPN-based VPN client. 

Client VPN components

Client VPN endpoint

Your Client VPN administrator creates and configures a Client VPN endpoint in AWS. Your administrator controls which networks and resources you can access when you establish a VPN connection. 

VPN client application

This is the software application that you use to connect to the Client VPN endpoint and establish a secure VPN connection.

Client VPN endpoint configuration file

This is a configuration file that is provided to you by your Client VPN administrator. The file includes information about the Client VPN endpoint and the certificates required to establish a VPN connection. You load this file into your chosen VPN client application. 

Client VPN limitations

  • Client VPN supports IPv4 traffic only. IPv6 is not supported.
  • Security Assertion Markup Language (SAML) 2.0-based federated authentication only works with an AWS provided client v1.2.0 or later. 
  • SAML integration with AWS Single Sign-On requires a workaround. Better integration is being worked on. 
  • Client CIDR ranges must have a block size of at least /22 and must not be greater than /12. 
  • A Client VPN endpoint does not support subnet associations in a dedicated tenancy VPC. 
  • Client VPN is not compliant with Federal Information Processing Standards (FIPS).
  • Client CIDR ranges cannot overlap with the local CIDR of the VPC in which the associated subnet is located. It also cannot overlap any routes manually added to the Client VPN endpoint’s route table.
  • A portion of the addresses in the client CIDR range is used to support the availability model of the Client VPN endpoint and cannot be assigned to clients. Therefore, we recommend that you assign a CIDR block that contains twice the number of required IP addresses. This will ensure the maximum number of concurrent connections that you plan to support on the Client VPN endpoint. 
  • The client CIDR range cannot be changed after you create the Client VPN endpoint. 
  • The subnets associated with a Client VPN endpoint must be in the same VPC.
  • You cannot associate multiple subnets from the same Availability Zone with a Client VPN endpoint. 
  • AWS Certificate Manager (ACM) certificates are not supported with mutual authentication because you cannot extract the private key. You can use an ACM server as the server-side certificate. But, to add a client certificate to your customer configuration, you cannot use a general ACM certificate because you can’t extract the required private key details. So you must access the keys in one of two ways. Either generate your own certificate where you have the key or use AWS Certificate Manager Private Certificate Authority (ACM PCA), which gives the private keys. If the customer is authenticating based on Active Directory or SAML, they can use a general ACM-generated certificate because only the server certificate is required.

Cheers
Osama

Use "sudo" Command without password Prompt

Sometimes you need to run Linux command without password prompt using sudo command.

to learn more about this command read the link here.

For Example i need to run the following command without password prompt, However there are three sudo commands I want to run without entering password:

  • sudo reboot
  • sudo shutdown -r now
  • sudo shutdown -P now
to do this follow the below steps :-
  • edit the following /etc/sudoers file.
  • you find the following lines depend on the username and hostname for the server.

user host = (root) NOPASSWD: /sbin/shutdown
user host = (root) NOPASSWD: /sbin/reboot

This will allow the user user to run the desired commands on host without entering a password. All other sudoed commands will still require a password.

Notes:

  • Always use the command visudo to edit the sudoers file to make sure you do not lock yourself out of the system for example 

sudo visudo -f /etc/sudoers.d/shutdown

  • Using /etc/sudoers.d instead of modifying /etc/sudoers, you could add the two lines to a new file in /etc/sudoers.d for example  /etc/sudoers.d/shutdown.
  • If you did not use visudo to edit your files and then accidentally messed up /etc/sudoers or messed up a file in /etc/sudoers.d then you will be locked out of sudo.to fix it use command pkexec.
Cheers
Osama Mustafa

My Days As an Oracle ACED : BGOUG

12 – 14 June save the date because it’s Bulgarian Oracle User group Events, this is my first time in Bulgaria and my first time as an oracle ACE director in any events :).

My Trip Planned to be from Jordan to Bulgaria – Sofia  and as usual i need to stop in one of world airport to reach my destinations first which i really hate because it’s wasting of time and tiring me.
my stop was in Frankfurt airport and to be there i had to spent 5-6 hours in the plane to reach there and then wait another 5 hours in the airport and reach Sofia 3 hours in the plane. but lucky me the plane is delayed in Jordan and i waited for 2 hours only :).
I reach Sofia but i was really exhaust and tired from traveling because my trip started early morning and it’s took us 2 hours to reach the hotel from the airport but even with this i have to thanks one of the best organizer i ever seen Milena Gerova She organized everything very well the hotels, the taxi, the appreciation events & sessions.
I had 2 presentation there about Fusion middleware and like usual i organized RAC ATTACK On Saturday, The audience was really amazing and asking very good questions. 
I had so much fun in Bulgaria and one of the best events i attended, simply it’s really Green every where you look it’s green, and I learned some Bulgarian dance  because i knew everyone in Bulgaria should dance 🙂 Even Tom Kyte was dancing,Svetoslav and Heli as well so why not ? 
It’s really nice to meet old friends and meeting new one  🙂 

Cheers
Osama Mustafa