Locations: countries, regions, availability zones, pools, and data center addresses
With Selectel's products and services, you can create an infrastructure that meets all fault tolerance and security requirements.
Selectel infrastructure is hosted in different locations.
A location is the physical placement of your infrastructure within Selectel's infrastructure, which includes:
Choosing a location affects how you manage availability, fault tolerance, and load balancing in your infrastructure.
Currently, you can choose from 4 countries for hosting infrastructure in Selectel, which are divided into 6 regions, 11 availability zones, and 26 pools.
You can check the availability of Selectel products and services in different locations in the availability matrices.
Country
Country (example: Russia) is one or several regions hosted within a single state.
In most cases, the division into countries does not affect anything, and the primary infrastructure separation occurs at the region level. In specific cases, there are restrictions for regions in different countries:
- when using a global router, you cannot configure network connectivity between products hosted in different countries. You can configure product and service connectivity only between different regions within one country;
- in S3, different domains are used for each country, and TLS (SSL) certificates are country-specific — the certificate only works for buckets hosted in the region of the certificate's country.
Region
Region (example: St. Petersburg) is a number of availability zones with Selectel and partner data centers hosted within a major city's metropolitan area.
Data centers within a single region are usually located relatively close to each other—within tens of kilometers. They are connected by a fiber-optic communication line with data redundancy, and minimal signal latency is ensured between data centers within the region. Read more about data centers on the Data Centers page on selectel.ru.
Data centers in different regions, by contrast, can be located hundreds or even thousands of kilometers apart. Each region is completely isolated from others: independent connection to power lines, autonomous power supply and cooling sources, and dedicated communication channels. This allows for geographical infrastructure distribution and fault tolerance.
Selectel provides connectivity between regions through redundant high-speed communication channels.
To host your application, we recommend choosing the region closest to your users as your primary one. You can place resources in different regions — this way, the infrastructure can survive possible provider issues with minimal downtime, for example, Internet outages at the border level, natural disasters, and emergencies.
You can view the list of regions in the Selectel Infrastructure table.
Availability zone
Availability zone (example: Availability zone 1 in Moscow) — is one or more data centers within a single region. Availability zones within a single region can be located at different distances from each other — from a few meters to tens of kilometers. Each data center in an availability zone is equipped with autonomous power and cooling sources and its own redundant communication channel with ultra-low latency.
Selectel reserves all critical system elements in an availability zone: power supply, cooling, and network infrastructure. Each availability zone is provided with 24/7 physical security and monitoring. Equipment maintenance is not performed simultaneously in multiple availability zones within the same region.
We recommend that you reserve critical parts of your infrastructure in multiple availability zones. Availability zones do not have a single point of failure, except for a failure of the entire region. This will protect your system in the event of a failure in one of the zones, such as a power outage in a data center, fire, or natural disasters.
You can view the list of availability zones in the Selectel Infrastructure table.
Pool
In each data center and, consequently, each availability zone, there are several pools. Each pool is isolated from hardware and software failures in other pools.
Network connectivity within a single-zone or multi-zone pool is provided by an L2 connection. To set up connectivity between pools, you can use the Selectel global router.
For cloud infrastructure, pools are further divided into pool segments (example: ru-2a, ru-2b). Segments provide additional fault tolerance — infrastructure of different segments is placed in different racks within one pool. The failure domain of a segment for servers and storage systems is a separate rack. Network infrastructure operates at the pool or availability zone level.
You can view the list of pools and segments in the Selectel Infrastructure table.
Single-zone pool
Single-zone pool (example: ru-9, SPB-4) is a part of infrastructure in one of the data centers of an availability zone.
Single-zone pool segments are located in different racks within the same data center of an availability zone.
Placing infrastructure in multiple pools protects against network hardware and software failures (for example, network equipment failure or power circuit failure) and reduces the likelihood of data loss or service downtime. The single point of failure for single-zone pools is failures within the availability zone.
Multi-zone pool
Multi-zone pool (example: ru-6) is a part of infrastructure in several data centers across different availability zones.
Multi-zone pool segments are located in several data centers across different availability zones.
Hosting infrastructure in a multi-zone pool:
- protects against the impact of natural disasters and fires in data centers;
- protects against network hardware and software failures (for example, network equipment failure or power circuit failure);
- reduces the likelihood of data loss and service downtime.
A single point of failure for a multi-zone pool is represented by failures in all availability zones where pool segments are located.
Improve fault tolerance
You can improve infrastructure fault tolerance at the level of:
- hosts;
- racks or pool segments;
- pools;
- availability zones;
- or regions.
For example, to improve the fault tolerance of cloud servers at the host level, you can place cloud servers on different hosts in a placement group. To increase fault tolerance at the rack and pool segment level, you can migrate a dedicated server to a different rack, and a cloud server to a different pool segment. For fault tolerance at the availability zone level, you can place servers in different availability zones, and also use segments of the multi-zone pool ru-6 for cloud servers.
Selectel infrastructure
Russia
Uzbekistan
Kazakhstan
Kenya
St. Petersburg
Moscow
Novosibirsk
Data center addresses from the state address system (FIAS)
Official cadastral addresses of Selectel data centers for contracts, official correspondence, letters, government requests, or internal documentation. Addresses on maps may differ from legal addresses.
St. Petersburg
Moscow
Novosibirsk