Flashcards
Exame Cloud III
Cards in this deck (21)
- 1Advantages of Using Virtual Machines->Efficiency. A virtual machine allows to efficiently use resource and provides isolation
->Flexibility. Resources can be allocated as needed
->Performance and moving. Hypervisors support moving a virtual machine from one host to another in case - 2Virtual Machines Disadvantages->Performance overhead. A VM stack includes the guest OS, the hypervisor and potentially the host OS
->Efficient resource utilization. Using multiple OSs in the same hypervisor duplicates the used resources - 3What are containersContainers provide OS-level
virtualization.
Provides private namespace,
network interface and IP
address, file systems, etc. - 4Container PromisesFaster deployment
• Portability across machines
• Version control
• Simplified dependency management - 5Kernel namespacesKernel namespaces split kernel resources (processes, users,
network stacks, etc.) into one instance per namespace.
• mnt (mount points, filesystems)
• pid (processes)
• net (network stack)
• ipc (System V IPC)
• uts (hostname)
• user (UIDs) - 6Control Groups (cgroups)Cgroups are a mechanism for applying hardware resource limits and access controls to a process or collection of
processes.
Cgroups are used to limit the memory and CPU consumption of containers. A container can be resized by simply changing the limits of its corresponding cgroup. - 7What are the some of the cgroup subsystems?cpu, cpuacct, cpuset – allows to control the minimum and maximum CPU time of the processes in a cgroup, and to assign
processes to a cgroup.
memory – allows to limit the memory used by a cgroup.
devices – allows to control which processes may create devices and open them for eeading and writing.
freezer – allows to suspend and restore all processes in a cgroup.
blkio – controls and limits access to specified block devices.
perf_event – allows perf monitoring of the set of processes in
a cgroup.
hugetlb - supports limiting the use of huge pages by cgroups.
pids – allows limiting the number of process that may be created in a cgroup (and its descendants).
rdma - permits limiting the use of RDMA/IB-specific resources per cgroup. - 8UnionFSUnionFS is a copy-on-write file system that is the union of existing file systems.
Gives a unified view of the file system, that combines all stacked file systems. - 9What is the purpose of the Docker DaemonManage Docker objects like images, containers, networks or volumes
Docker client sends requests do the docker daemon - 10What is the purpose of the Docker Registry?The registry stores Docker Images. Docker searcher Docker Hub by default
An images is a template with instructions for creating a container - 11By Default all files created inside a container are written to a layer that is not persistent. What are the 2 options for Docker persistent storage?->Volumes: stored in a part of the host filesystem managed only by Docker
->Bind mounts: Binding a directory or file in the host system to a file in Docker - 12Docker Swarm and Docker ComposeCompose allows to define and run multi-container Docker applications
Swarm orchestrates a cluster of Docker instances on different machines:
When creating a service, you define its optimal state (number of replicas, network and storage resources available to it, ports the service exposes to the outside world, and more).
Docker works to maintain that desired state. For instance, if a
worker node becomes unavailable, Docker schedules that
node’s tasks on other nodes - 13What is the "Swarm Service"?The definition of tasks to execute on the manager of the Worker nodes. Which image to use and commands to execute
- 14How Load balancing is achieved in a swarm?Ingress Load Balancing;
Swarm manager automatically assign the service a PublishedPort or you can
configure a PublishedPort for the service.
External components, such as cloud load balancers, can access
the service on the PublishedPort of any node in the cluster - 15KubernetesKubernetes is an open-source platform for automating
deployment, scaling, and operations of application containers - 16Enumerate some properties of Kubernetes• Horizontal Scalability
• Self-healing
• Service Discovery
• Automated Rollbacks - 17What is a Kubernetes Pod?basic execution unit of a kubernetes application;
encapsulates an application’s container (or multiple containers), storage resources, a unique network IP, and
options that govern how the container(s) should run - 18What is a Kubernetes Service?abstraction which defines a logical set of Pods and a policy by which to access them;
For example, consider a stateless image-processing backend which is running with 3 replicas. Frontends do not care which backend they use and whether they change - 19Types of Kubernetes services->Cluster Type
->NodePort
->LoadBalancer: Exposes the Service externally using a cloud provider’s load balancer. NodePort and ClusterIP Services, to which the external load balancer routes, are automatically created.
->External Name - 20What is the Kubernetes Control Plane?The Kubernetes Control
Plane makes the cluster’s
current state match the
desired state, by performing a
variety of tasks automatically
– such as starting or
restarting containers, scaling
the number of replicas of a given application - 21Kubernetes VS SwarmKubernetes is more sophisticated than Swarm.
Swarm works only with Docker, Kubernetes can work with
other container services also.
Kubernetes is more complex to deploy and manage compared to Swarm.
Kubernetes is reported to have better scalability
Information
- Description
- Flashcards on Exame Cloud III, created by Bruno Penilo on 08/01/2020.
- Created by
- Bruno Penilo
- Views
- 2
- Rating