Friday, February 27, 2015


As network speed increases, offloading is becoming an important feature, and the ability to offload tasks from the host processor aids in the efficiency of the host and in overall system performance. To achieve a significant performance boost, most operating systems now a days offer a mechanism for the TCP/IP protocol stack to offload checksum calculations to the device.

Thursday, February 26, 2015

OpenStack overview


The OpenStack project is an open source cloud computing platform that supports all types of cloud environments. The project aims for simple implementation, massive scalability, and a rich set of features. Cloud computing experts from around the world contribute to the project.
OpenStack provides an Infrastructure-as-a-Service (IaaS) solution through a variety of complemental services. Each service offers an application programming interface (API) that facilitates this integration. The following table provides a list of OpenStack services:
Table 1.1. OpenStack services
ServiceProject nameDescription
DashboardHorizonProvides a web-based self-service portal to interact with underlying OpenStack services, such as launching an instance, assigning IP addresses and configuring access controls.
ComputeNovaManages the lifecycle of compute instances in an OpenStack environment. Responsibilities include spawning, scheduling and decommissioning of virtual machines on demand.
NetworkingNeutronEnables Network-Connectivity-as-a-Service for other OpenStack services, such as OpenStack Compute. Provides an API for users to define networks and the attachments into them. Has a pluggable architecture that supports many popular networking vendors and technologies.
Object StorageSwiftStores and retrieves arbitrary unstructured data objects via a RESTful, HTTP based API. It is highly fault tolerant with its data replication and scale out architecture. Its implementation is not like a file server with mountable directories.
Block StorageCinderProvides persistent block storage to running instances. Its pluggable driver architecture facilitates the creation and management of block storage devices.
Shared services
Identity serviceKeystoneProvides an authentication and authorization service for other OpenStack services. Provides a catalog of endpoints for all OpenStack services.
Image ServiceGlanceStores and retrieves virtual machine disk images. OpenStack Compute makes use of this during instance provisioning.
TelemetryCeilometerMonitors and meters the OpenStack cloud for billing, benchmarking, scalability, and statistical purposes.
Higher-level services
OrchestrationHeatOrchestrates multiple composite cloud applications by using either the native HOTtemplate format or the AWS CloudFormation template format, through both an OpenStack-native REST API and a CloudFormation-compatible Query API.
Database ServiceTroveProvides scalable and reliable Cloud Database-as-a-Service functionality for both relational and non-relational database engines.
This guide describes how to deploy these services in a functional test environment and, by example, teaches you how to build a production environment. Realistically, you would use automation tools such as Ansible, Chef, and Puppet to deploy and manage a production environment.