'''Containerization''' is an [[operating system-level virtualization]] or application-level virtualization over multiple network resources so that software applications can run in isolated user spaces called ''containers'' in any [[Cloud computing|cloud]] or non-cloud environment, regardless of type or vendor.<ref>{{cite document |last1=Scheepers |first1=Mathijs Jeroen |title=Virtualization and Containerization of Application Infrastructure : A Comparison |date=2014 |s2cid=18129086 |url=https://thijs.ai/papers/scheepers-virtualization-containerization.pdf }}</ref>
== Usage ==
The ''containers'' are basically a fully functional and portable cloud or non-cloud computing environment surrounding the application and keeping it independent from other parallelly running environments.<ref>{{Cite web|title=What is containerization?|url=https://www.redhat.com/en/topics/cloud-native-apps/what-is-containerization|url-status=live|access-date=2021-07-10|website=www.redhat.com|publisher=[[RedHat]]|language=en|archive-url=https://web.archive.org/web/20210508174632/https://www.redhat.com/en/topics/cloud-native-apps/what-is-containerization |archive-date=2021-05-08 }}</ref> Individually each container simulates a different software application and runruns isolated processes<ref>{{Cite web|last1=Hinck|first1=Tim Maurer, Garrett|last2=Hinck|first2=Tim Maurer, Garrett|title=Cloud Security: A Primer for Policymakers|url=https://carnegieendowment.org/2020/08/31/cloud-security-primer-for-policymakers-pub-82597|access-date=2021-07-10|website=Carnegie Endowment for International Peace|language=en}}</ref> by bundling related configuration files, libraries and dependencies.<ref>{{Cite web|last=Rubens|first=Paul|date=2017-06-27|title=What are containers and why do you need them?|url=https://www.cio.com/article/2924995/what-are-containers-and-why-do-you-need-them.html|access-date=2021-07-10|website=CIO|language=en}}</ref> But, collectively multiple containers share a common [[Kernel (operating system)|OS Kernel]].<ref>{{Cite web|title=Containerization|url=https://www.ibm.com/in-en/cloud/learn/containerization|access-date=2021-07-10|website=www.ibm.com|language=en-in}}</ref>
In recent times, the containerization technology has been widely adopted by [[Amazon Web Services]], [[Microsoft Azure]] and [[Google Cloud Platform]] and IBM.<ref>{{Cite web|last=December 2019|first=Jonas P. DeMuro 18|title=What is container technology?|url=https://www.techradar.com/in/news/what-is-container-technology|access-date=2021-07-10|website=TechRadar India|date=18 December 2019|language=en}}</ref>
Container orchestration or container management is mostly used in the context of application containers. Implementations providing such an orchestration include [[kubernetesKubernetes]] and [[docker (software)|dockerDocker swarm]].
== Container cluster management ==
Container clusterclusters need to be managed. This includes functionality to create a cluster, to upgrade the software or repair it, balance the load between existing instances, scale by starting or stopping instances to adapt to the number of users, to log activities and monitor produced logs or the application itself by querying sensors. Open-source implementations of such a software include [[OKD (software)|OKD]] and Rancher. Quite a number of companies provide container cluster management as a managed service, like Alibaba, Amazon, Google, Microsoft.
