How does load balancing work in Cloud Computing?

Categories: Cloud Computing

How does load balancing work in Cloud Computing?

Here, load refers to not only the website traffic but also includes CPU load, network load and memory capacity of each server. A load balancing technique makes sure that each system in the network has same amount of work at any instant of time. This means neither any of them is excessively over-loaded, nor under-utilized.

The load balancer mechanisms can exist as a:

1. Multi-layer network switch
2. Dedicated hardware appliance
3. Dedicated software-based system
4. Service agent 

SLA Monitor:

The SLA management system mechanism represents a range of commercially available cloud management products that provide features pertaining to the administration, collection, storage, reporting, and runtime notification of SLA data.

An SLA management system deployment will generally include a repository used to store and retrieve collected SLA data based on pre-defined metrics and reporting parameters. It will further rely on one or more SLA monitor mechanisms to collect the SLA data that can then be made available in near-real time to usage and administration portals to provide ongoing feedback regarding active cloud services The metrics monitored for individual cloud services are aligned with the SLA guarantees in corresponding cloud provisioning contracts.

– A cloud service consumer interacts with a cloud service (1). An SLA monitor Intercepts the exchanged messages, evaluates the interaction, and collects relevant runtime data in relation to quality-of-service guarantees defined in the cloud service’s SLA (2A). The data collected is stored in a repository (2B) that is part of the SLA management system (3). Queries can be issued and reports can be generated for an external cloud resource administrator via a usage and administration portal (4) or for an internal cloud resource administrator via the SLA management system’s native user-interface.

 Pay-per-use monitor:

The pay-per-use monitor mechanism measures cloud-based IT resource usage in accordance with predefined pricing parameters and generates usage logs for fee calculations and billing purposes.

Some typical monitoring variables are:

• request/response message quantity

• transmitted data volume

• bandwidth consumption

The data collected by the pay-per-use monitor is processed by a billing management system that calculates the payment fees.

Shows a pay-per-use monitor implemented as a resource agent used to determine the usage period of a virtual server.