Cloud computing theory and practice Flashcards
Summarize the content of the homonym book
5 characteristic of cloud computing
On demand self service access
Broad network access
resource pooling
rapid elasticity
measured service
Entities involved in cloud computing
customer
provider
carrier (ISP)
broker (manage use performance and delivery of cloud services)
auditor (performs security audit)
DBaaS
Database as a service, db are stored in the cloud provider infrastructure, provides scalability self service
IaC
Infrastructure as code, a way to automate cloud infrastructure through code, most used tools are ansible and terraform
S3
Simple storage system, service from AWS, stores data in objects inside buckets
EBS
Elastic Block store, provide storage volumes to EC2 instances, an instance can have more volumes but not the opposite
Lambda
AWS service that provide serverless execution of code on demand
Availability zones
Datacenter with 50 000 to 80 000 servers, each region has at least 2 AZ
WSC (Warehouse scale computer)
Computers in cloud provider’s datacentes composed by cells and racks, WSC can be managed through Borg (Cluster management system)
Borg
Is a cluster management system for WSC, it include a Borgmaster (controller) and Borglets (controlled machines)
Kubernetes
it’s a cluster manager for containers, includes a master server that manage workload on minions or workers
Kubernetes scheduler
It allows management of workers resources by the master server
Kubernetes Pods
Are groups of container used as a unit of scheduling, deployment and replication, pods allow multiple containers to run an application
2 types of VM
Process VM - executed for a specific process once terminated the VM will be stopped
System VM - VM with an OS and many processes
Hybrid hypervisor
hypervisor that shares the hardware with another os
QEMU
QEMU can virtualize or emulate any components on a physical machine
Virtualization vs emulation
1) virtualization is based on an hypervisor that abstract the hardware so that it can be shared between multiple VMs, the VMs run on a portion of the hardware
2) Emulation is the process with which you alterate the hardware via a software to make a program that didn’t support the hardware run on it
QEMU 4 modes
- usermdoe emulation for code compilation and debugging
- system emulation supports VMs on a physical emulated system
- KVM hosting supports deployment and migration of KVM images
- Xen hosting emulates the hardware and allows execution of VMs with Xen
KVM
Kernel based virtual machine, is an hypervisor buildt with linux kernel
KVM components
KVM-loadable module provides management of the hardware
KVM platform emulation provided by a version of QEMU
KVM advantages
Open source
Performance
Cross-platform
Simplicity
Paravirtualization
The guest OS knows it’s running on a virtualized environment that allows VMs to communicate with the hypervisor via API, that results in better performance
Xen
Hypervisor that use QEMU as device emulator and supports paravirtualization
Nested virtualization
situation where an hypervisor is a guest OS of another hypervisor