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Install K8S on VM and spring boot integration.

Installation Environment Vmware Workstation pro  It is recommended to use the  snapshot  to store the state of each installation stage to avoid installation failures and causing the installation to start from scratch. Ubuntu 22.04 windows 11 Hardware settings  create 3 VM: 4 cores and 4G memory and 100G capacity Before installing K8s (All use the root user) set host: 192.168.47.135 master 192.168.47.131 node1 192.168.47.132 node2 set root ssh connection: sudo su - echo "PermitRootLogin yes" >> /etc/ssh/sshd_config systemctl restart sshd sudo passwd ssh-keygen for i in {master,node1,node2}; do  ssh-copy-id root@$i; done set Ipvs and conf  create conf file: for i in {master,node1,node2}; do ssh root@$i 'cat << EOF > /etc/modules-load.d/containerd.conf overlay br_netfilter EOF'; done execute conf: for i in {master,node1,node2}; do ssh root@$i 'modprobe overlay;modprobe br_netfilter;'; done create 99-kubernetes-cri.conf file: for i in {maste...
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Java memeory model


The java memory model has multiple areas to do different jobs, this model is in user space because it has no I/O control.


There are these parts:

  • Program counter register:
    • For java multi-thread switching different threads, and same functionality as OS counters.
    • (PC) Registers are created every time a new thread is created. The PC holds a pointer to the current statement being executed in its thread. If the currently executing method is 'native', then the value of the program counter register will be undefined.
  • Stack:
    • Private for each thread.
    • It contains method-specific primitive values and references to objects referenced from methods in the heap.
    • Whenever we call a new method, a new block is created on top of the stack which contains values specific to that method
  • Native Method stacks:
    • JVM that supports native methods will have native method stacks. It is used for native methods, and created per thread. 
  • Heap:
    • Heap data area is used to store objects of classes and arrays. 
    • Heap memory is common and shared across multiple threads. 
    • This is where the garbage collector comes into picture.
  • Method area:
    • Method area is created at JVM startup and shared among all the threads.
    • Method area has per class structures and fields. Nothing but static fields and structures.
    • Runtime constant pool is part of method area.

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Install K8S on VM and spring boot integration.

Installation Environment Vmware Workstation pro  It is recommended to use the  snapshot  to store the state of each installation stage to avoid installation failures and causing the installation to start from scratch. Ubuntu 22.04 windows 11 Hardware settings  create 3 VM: 4 cores and 4G memory and 100G capacity Before installing K8s (All use the root user) set host: 192.168.47.135 master 192.168.47.131 node1 192.168.47.132 node2 set root ssh connection: sudo su - echo "PermitRootLogin yes" >> /etc/ssh/sshd_config systemctl restart sshd sudo passwd ssh-keygen for i in {master,node1,node2}; do  ssh-copy-id root@$i; done set Ipvs and conf  create conf file: for i in {master,node1,node2}; do ssh root@$i 'cat << EOF > /etc/modules-load.d/containerd.conf overlay br_netfilter EOF'; done execute conf: for i in {master,node1,node2}; do ssh root@$i 'modprobe overlay;modprobe br_netfilter;'; done create 99-kubernetes-cri.conf file: for i in {maste...
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ShardingSphere

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Kafka

Table of contents [ hide ] Kafka Apache Kafka is an open-source distributed event streaming platform used by thousands of companies for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications. Why use a Message Queue like Kafka 1. Asynchronous The program can continue execution without waiting for I/O to complete, increasing throughput. 2. Decoupling It refers to reducing the dependencies between different parts of the system so that each component of the system can be developed, maintained, and evolved relatively independently. The main goal of decoupling is to reduce tight coupling between components to improve system flexibility, maintainability, and scalability. 3. Peak clipping Peak clipping is essential to delay user requests more, filter user access needs layer by layer, and follow the principle of "the number of requests that ultimately land on the database is as small as possible". Basic Concept 1. Client Includi...
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