A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a minimum level of service is maintained. The SLA should include not only an outline of the services to be provided and their expected service levels, but also metrics by which the services are measured, the duties and responsibilities of every party, the remedies or penalties for breach, and a protocol for adding and removing metrics. Now we have discussed 5 features of cloud SLA. “Based on policy guidance, autonomic system keep the system stable in unpredictable conditions and adapt quickly in new environmental conditions like software, hardware failures” (Singh, Chana, & Buyya, 2017).
Uptime: Some cloud providers will offer lower uptime than what they can actually achieve just to give themselves some breathing space in the event of a data incident. This may be adequate for some businesses that can handle a brief loss in productivity, but for healthcare providers and government agencies that need immediate access to data, it is still considered inadequate (Zhao, et.al., 2016).
Data Protection: Data protection processes, such as backup and disaster recovery, should be addressed in any SLA. The agreement should detail what each party is responsible for, acceptable performance parameters, which applications and services are covered, monitoring procedures and a schedule for remediation of outages whether by power outage, natural disaster, human error, or malware.
Exporting Data: Some cloud providers make it easy to migrate your data into their cloud, but charge large sums of money to return it to you—or they return it to you in an unusable format (we call this the Hotel California effect). So, you want to be sure you’re able to exit the contract if you need to and that there are no fees associated with doing so (or that they are minimal). You should also negotiate the export of your data in a predefined format (CSV, XLS, XML etc.). If you don’t have a skilled IT team that can make the export easy, you might also make it a condition that the provider assists you in the export. Finally, because some contracts require a notice of non-renewal within a certain period, make sure you understand the time period and if it seems unreasonable, try to talk it down or eliminate it altogether. “One of the main green cloud computing strategies used for the reduction of energy consumption consists in maximizing the utilization of a number of physical machines (PMs) and turning off or suspending unused servers” (Malekloo,, et. al.,2018).
Scalability: Many SLAs are designed to meet the needs of the customer at the time of signing, but we all know organizations can change dramatically in size over time. Make sure the SLA details intervals for reviewing a contract so that if your organization grows larger, your cloud capacity can grow with it and if your organization happens to grow smaller, you’ll want the option to reduce capacity; no sense it paying for unused capacity.
Data Location: Although cloud computing is all about the ease of accessing your data anytime, anywhere, it’s ultimately housed somewhere. Some providers may scatter your data across multiple locations, or house it overseas. Knowing where data physically resides is key when it comes to matters of compliance. “A Service Level Agreement (SLA) can be used to address these concerns, increasing trust in the purchased services through the clear description of the guarantees offered by the provider to the subscribers” (De Carvalho, et. al., 2017).
The agreement entered between the cloud service provider companies and the client or the user of the clouding service is cloud service level agreement (SLA). This is a type of a commitment that is signed between the service provider companies and the users of the clouding services. The agreement defines the different aspects of the services and responsibilities that are agreed on mutually between the service user and the service provider. It can between two or more parties. The agreement happened between the parties has many components which are defined from starting of the service till the termination of the agreement. Service level agreements helps in proper monitoring of the services in cloud computing. These define the quality of the service the company must provide to the customers till the end of the service agreement.
SLA is responsible for setting the security system required for management of the clouding space and free from intruders and vulnerabilities and also explains well about the backup plan the company has already set to prevent the data loss of any of the customers for the failure of the performances. There are many challenges associated with the clouding services which both provider and user face. SLA defines the terms and conditions which are agreed upon by both the parties for provisioning and consuming of the clouding service. SLA clearly defines and sets the expectations for both the parties. For the purpose of the development of an effective SLA, there are certain criteria which are needed to be established between both the provider and the user of the service. “Although there are many energy-aware resource management solutions for Cloud data centers, existing approaches focus on minimizing energy consumption while ignoring the SLA violation at the time of virtual machine (VM) deployment” (Zhou, 2018).
1) Cloud hardware and software: the cloud service provider must use all the essential hardware and the software devices required for providing the services effectively to the customers potentially. The agreement must include the hardware devices that the company would be using to provide the services. When the company knows the equipments and the software specifications of the hardware devices then it becomes easy for the providers to build the cloud construction environment and teach staff about it. “Resource overbooking is one way to reduce the usage of active hosts and networks by placing more requests to the same amount of resources” (Son, 2017).
2) Customer Responsibility: the clouding responsibility is not solely hold by the provider companies but it is shared between the user and the provider both. The provider companies should well explain about the roles and responsibilities of the users before entering into an agreement.
3) Disaster recovery and backup: the service provider companies should be well equipped with a disaster recovery plan so that there is not any kind of data loss of any customer. The system must be updated with automatic backup technology and must be mentioned about its use and blueprint into the agreement. This will make the user satisfied about the data saved in the clouding space provided by the service provider companies.
4) Data Ownership: the service level agreement must clearly specify the ownership status of the data to make everything clear and transparent between the user and the service provider and avoid any kind of future conflicts.
5) Availability: the service level agreement must clearly specify the provider’s promised availabilities. The network and the service must be same throughout the agreement and must not break in between the agreement. The promises made should be accomplished upto 99.99% successfully. “As SLAs are critical for cloud deployments and wider adoption of cloud services, the management of SLAs in cloud and IoT has thus become an important and essential aspect” (Mubeen, 2017).