System Design | Implementation Rule Book | CheatSheet

Format: https://sequencediagram.org/ title Some Design Flow Application->Integration-System: Hydration \n Load(applicatio...

  Introduction In today’s fast-paced digital landscape, designing systems that are responsive, scalable, and flexible is more critical than ...

Localstack Installation:  download localstack:  https://app.localstack.cloud/download? # configure, optional aws configure set aws_access_ke...

  Introduction The "Too many file descriptors open" error in Linux often signifies that your system has exceeded its limit on op...

Correlation ID can be very useful for Logging in Microservices. We can benefit from Mapped Diagnostic Context or MDC manages contextual info...

-AWS Elastic cache flavor-> Redis  -Each url treated as key and redis store the result -This has fix lenngth of keys, and use LRU to remo...

netstat -tonp | grep CLOSE_WAIT   //CLOSE_WAIT means your program is still running, and hasn't closed the socket  netstat -p  // connect...

 Quite often your application is going out of memory. Here is what you need to check the following: Review the memory configuration 1. -Xmx ...

Variable Ordering in a class. Constant first then private variables public> private static> non-static final> non-final injected...

In this article we will talk about exposing java to Json serialization and how to instrument them   @JsonProperty( "fieldName" ) /...

 Optimize and Improve PostgreSQL Performance with VACUUM, ANALYZE, and REINDEX utility. VACUUM: -Reclaims storage occupied by dead tuples wi...

 In this article we would be fetching similar records with lookup details. Consider a retailer needs to know similar order placed along with...

1.  Install the Nginx server and the required packages. apt-get update apt-get install nginx openssl 2. Create a private key and the website...

 The rewrite Directive rewrite regex URL [flag]; eg: rewrite ^ $request_uri; server {     # ...     rewrite ^(/download/.*)/media/(\w+)\.?.*...

 ->Obtain an SSL Certificate within Certificate Manager.  Please note that this allows us to serve your content over https and is a servi...

What is the flow of  database connections in application?  Application asks the data source for a database connection.  Datasource uses the ...

Registering a module angular . module ( 'myApp' , []) . controller ( 'MyController' , [ 'myService' , function ...

Instance Type/Series : Use cases T3/T4 [ Free trial]- Micro service, dev environment,,low CPU utilization and occasional periods for high CP...

 For versioning and organizing your database changes there are vwaios devops tools available in market.  The most known ones are  Liquibase ...

Opens-source Library : When to use What ? Chatbot - Apache Tensor Avoid DB Load: ehcache, Elastic Search Intelligence, running queries from ...

OAuth 2.0 uses Access Tokens and Refresh Tokens to secure access to applications and resources. Here is the flow: Obtaining OAuth 2.0 access...

Problem: ES Update fails due to Index becomes readOnly Root cause: Elasticsearch automatically sets "read_only_allow_delete": ...

 Writing code which talks is something the developer would love to have it. In this blog, we will talk about some of the mechanism which mak...

 In RabbitMQ, data safety is being handled by the below two mechanism:  I. Consumer Acknowledgements II.  Publisher confirms Consumer Acknow...

  docker --version   docker pull <image_name>   docker images  docker run -it -d <image_name>   docker ps  docker ps -a  docker ...

 Runnable JDK 1.0  new Thread( () -> System.out.println("Runnable") ).start() Callbale Java 5 Callable callable = Executors.cal...

  Read Lock: Read lock allows multiple thread to acquire lock in read method when all the synchronizing threads are using only the read lock...

 AmazonEBS :   High-availability block-level storage volumes for Amazon Elastic Compute Cloud (EC2) instances.  - It is paired with an EC2 i...

You can not allow xhr call to cross domain. Otherwise it would be very risky to allow third party script in your domain code. Here we will g...

 Designing a resilient architecture can comprise of following paradigm: I. Does your application has retrial mechanism? II. Is there any mec...

 JMX specification supports the following types of Bean: Standard MBeans Dynamic MBeans Open MBeans Model MBeans MXBeans  Managing Resource ...

While developing Spring based application there are instances where we would like to get a control of the spring beans. It comes very handy ...