Cluster Systems

Parking.ru as a cloud provider has the experience of providing not only services with “normal” reliability, but also high-availability hosting services built on a clustered duplicated infrastructure.

Having significant experience in building such infrastructure projects, we decided to offer it not only to selected customers (who have been using these services for many years), but to make a standardized offer for everyone.

Parking.ru launched a number of cluster solutions built on a reliable duplicated infrastructure and based on a variety of solutions: from virtual machines to a group of physical servers. Special attention should be paid to the proposal for GEO clustering in two different data centers, united by duplicated communication channels.



Briefly, within the framework of the proposal, there are the following typical cluster schemes:

High Availability cluster

Created to ensure high availability of the service provided by the cluster. The excessive number of nodes included in the cluster guarantees the provision of the service in case of failure of one or more servers. The minimum number of nodes is two, but may be more.

Typically, a High Availability cluster is built for Microsoft SQL servers, which supports databases of Internet projects. High Availability Cluster can be built for Exchange systems.

There is another kind of High Availability SQL cluster - “database mirroring” or database mirroring. This type of cluster does not require dedicated disk storage, but for automatic switching in the event of an accident, you need another SQL server - witness / witness. Such a cluster is ideal for WEB applications and requires less creation costs.

Network Load Balancing (NLB)

The principle of operation of NLB clusters is the distribution of incoming requests to several physical or virtual server nodes. The initial goal of such a cluster is performance, however, they are also used to increase reliability, since the failure of one node will simply lead to an even increase in the load of the remaining nodes. A collection of cluster nodes is often called a cluster farm. The minimum number of nodes in a farm is two. The maximum is 32.

When hosting highly loaded web projects in NLB mode, a web server farm is built on IIS 7.x

Virtual Machine Clusters

The most affordable and scalable solution is to build a cluster based on virtual machines on the Hyper-V platform.

As the web boxes of the NLB cluster, virtual machines with Windows Web Server 2008 installed on them (IIS7.x, user application) are used.

As a database cluster, two virtual machines of the required capacity are used on Windows Server 2008 Standard Edition and SQL Server 2008 Standard Edition.

Fault-tolerant single storage based on Storage System from NetApp or HP.

To ensure greater reliability, all cluster nodes are located on different physical servers / cluster nodes.

The scalability of the solution is achieved by increasing the power of the virtual machines used (up to 100% of the physical server capacity), as well as by adding new nodes to the NLB cluster.

Using online migration tools, over time, it is possible to transfer cluster nodes to new, more modern physical servers without loss of operability and without downtime of any node.

This cluster is the best solution in the price / quality ratio and is recommended both for business-critical applications and for relatively loaded web-projects (~ up to 30000-50000 visitors daily).

Clusters on physical servers

Web projects with a load of more than 50,000 visitors, projects with special security requirements require the construction of cluster solutions on dedicated servers without loss of physical server virtualization capacities.

The scheme for constructing such clusters is similar to the scheme for building clusters on virtual machines, only dedicated physical servers are used as nodes.

Geoclusters

When building local clusters, a single point of system failure is the data center infrastructure itself. Parking.ru offers a unique solution in the Russian market - the construction of a geographically distributed cluster, the nodes of which are located in different data centers Parking.ru.

Each of the cluster nodes has an independent Internet connection, but from the data network, the cluster looks like a single server with a single address and content.