A practical guide to completing your TLS certificate chainTL;DRSpring Boot Admin showed my application as REGISTERED → OFFLINE because the server certificate I presented during the health‑check was missing the intermediate CA.Re‑exporting the keystore (PKCS #12 / JKS) with the full chain—leaf + intermediate (+ root)—cleared the error and the instance now sits happily in the UP state.The SymptomRight after deployment my Spring Boot app registered...
This series is dedicated to helping developers prepare for the Kubernetes Certified Application Developer (CKAD) exam. In Part 1, the focus is on the essential Kubernetes concepts, such as Pods, Services, and Deployments, that are crucial for the CKAD. This guide is designed to provide clear insights and strategies for mastering these topics, making the path to certification more manageable.
Note: Kubernetes uses some Docker-like containers tool so remember you won’t be able to run a Windows-based container on a Docker host with Linux on it – because Docker uses the host machine kernel.However, there are ways to work around this limitation:Docker for Windows with WSL2: Docker Desktop for Windows can use the Windows Subsystem for Linux 2 (WSL2)...
Docker commands:docker runis like docker create + docker start-it – interactive; will connect to the standard input of the container – thus allowing for interacting using the keyboardwe can run docker run -it sh – this will override the default image command and just start a shellusually, you run the container with its default command and then...
KinesisKinesis vs KafkaKinesisKafkaDeployment typesMay use 2 modes:- Provisioned mode- On-demand mode (new) – capacity is adjusted on demand; default capacity is 4MB/sec, maximum 200MB/s write and 400MB/s per consumer readRetention1-365 daysUnlimitedStream Topic ShardPartitionRecord partition keyRecord keyRecord dataRecord dataApproximateArrivalTimestampTimestamp ?Shard id (string)Partition number (number)Sequence number (meaningless number)Offset (per partition sequential (usually, but not a rule) number)Messages orderPreserved ar shard levelPreserved at partition levelCompressionNoAvailableEncryption...
https://speakerdeck.com/vitalieb/efficient-logs-with-elastic-stackDemo code available at https://github.com/vitalieb/ElasticStackPresentation
IntroductionChannels are used for routing messages to endpoints.Channels do the routing and endpoints perform the operations.Spring Integration (SI) provides numerous adapters for communication between different systems.SI uses 3 types of components to construct its messaging architecture:MessageChannelEndpointEndpoint > Channel (passes a Message) > EndpointSpring Integration mirrors everything from "Enterprise Integration Patterns"; so If you're familiar with those you can easily...
Advanced class design:
Anonymous classes are implicitly final and it can never be static.static method > default methoddefault method > abstract methoddefault method > default method (re-declared with different implementation)default method > static methodstatic method > non-static methodnon-static method > static methodStatic methods can never be abstract.Static interface methods must be invoked using the interface name instead of reference variable - otherwise...
What is Spring Boot?
Spring Boot is a set of preconfigured framework that works on top of Spring Framework and simplifies configuring a Spring application.
What are the advantages of using Spring Boot?
Most important advantage is easy configuration of Spring application.Additional to this it provides something more:Integrated web containers that allow for easy testing
Starters - sets of dependencies that help...