Akka Ask

Posted on Leave a commentPosted in Akka, Java

On all our previous example we have been using Tell method to send messages to actors, in Akka this is known as fire-and-forget. Which means you send a message and there is no blocking, Actors, handle a separate thread to handle the actual work. But what happens when you need a return value? you pass a […]

Identity Access Management

Posted on Leave a commentPosted in AWS

IAM (Identity and Access Management) Amazon service that enables you to do the following: Create users Manage users and their access Create Federated User (Temporary Users) Free of charge IAM User Management Create, Delete, List Users Manage group memberships, credentials permissions default 100 groups limit, 5000 users limit Users in this context, Users are individual […]

VPC Peering

Posted on Leave a commentPosted in AWS

Credits to http://aclo What is VPC  Peering?  Connection between two VPCs (single or with other AWS Account) within a single region. This is done via private IP address. Technology used is existing infrastructure of VPC, it is neither a gateway or a VPN connection. Example  VPC Peering: Transitive Peering NOT Supported – VPC A cannot […]

Well Architectured Framework

Posted on 2 CommentsPosted in AWS

5 Pillars of Well Architected Framework Security Design Principles: Apply Security at all layers Enable traceability Implement principle of least privilege Focus on securing your System (Data, Operating System, Application) Automate Security Events Definition: Use Detective Controls Infrastructure protection Data Protection Incident Response Questions to ask for this pillar How are you protecting access to […]

Exam Notes part 3

Posted on Leave a commentPosted in AWS

Glacier – 10 gb free retrieval under free tier Instance stores – cannot be in stopped state; they are either terminated or running EC2 Instance states lifecycle: pending running rebooting stopping stopped shutting-down terminated Cloudfront request if files is not in cache: holds the request until origin server serves it in the cache of the […]

Exam Notes part 2

Posted on Leave a commentPosted in AWS

CloudTrail You can use AWS CloudTrail to get a history of AWS API calls and related events for your account. This includes calls made by using the AWS Management Console, AWS SDKs, command line tools, and higher-level AWS services. Cloudfront Amazon CloudFront can handle data transfer rate 1,000 Mbps and 1000 requests per second. S3 […]

AWS Limits

Posted on Leave a commentPosted in AWS

Amazon Web Services Soft Limits – they are the limits by default but this can be increased by sending a request to Amazon IAM 100 Groups  250 Roles 5000 users RDS 40 DB instance 100 TB Total Storage 35 days maximum backup DynamoDB 400kb item limit size 1 read unit – 4kb 1 write unit […]

Additional Notes p1

Posted on Leave a commentPosted in AWS

Amazon Kinesis – real time processing of streaming data at massive scale ie website clickstream, application logs, social media feeds Uses: Used to consume big data – can analyze from big amount of data, for example twitter can scan all the tweets for negative/positive comments Processing large amount of data Exam tips Business Intelligence – […]


Posted on Leave a commentPosted in AWS

Cloudwatch – enables you to monitor AWS resources and applications you run in real time, Sends notification How it works: Concepts: Namespaces- container of cloudwatch Metrics – represents time ordered set of data points published to cloudwatch Metrics can’t be deleted, automatically expire after 15 months  Time stamps Metrics retention period 60 seconds – available […]


Posted on Leave a commentPosted in AWS

Kinesis enables to collect and process streams of data records in real time. What you can you do: accelerated log and data feed intake and processing -ie large amount of applicaiton logs, market data feeds, web clickstream data, social media real-time metrics and reporting real-time data analytics Complex stream processing High level architecture Terminologies: Stream […]