---
title: "General information about the Availability Check service"
sidebar_label: "General information"
sidebar_position: 1
description: "Basic information about the Availability Check service: description, checks, cost"
---

import Formbricks from '@theme/MDXComponents/Formbricks'
import {CustomTable} from '@selectel/docux/components'

# General information about the Availability Check service

With the Availability Check service (formerly Monitoring), you can check the availability of various services from multiple locations on the Internet and set up notifications about the result of the checks.

You can also order the [managed services](/managed-services/about-managed-services.mdx) solution, so that Selectel specialists can set up a monitoring system for your services.

## Checks \{#checks}

A check is a set of conditions for verifying the availability of a service from different locations on the Internet.

There are 17 types of checks available.

<CustomTable>
  <table>
    <tbody>
      <tr>
        <th>PING</th><td>Checking connectivity to the server; helps measure latency from the check point to the server</td>
      </tr>

      <tr>
        <th>TCP</th><td>TCP port status</td>
      </tr>

      <tr>
        <th>UDP</th><td>UDP port status</td>
      </tr>

      <tr>
        <th>SSH</th><td>Connection without authorization, SSH banner</td>
      </tr>

      <tr>
        <th>SMTP/POP3/IMAP</th><td>Mail availability over the selected protocol</td>
      </tr>

      <tr>
        <th>DNS</th><td>Correctness of domain name to IP address resolution</td>
      </tr>

      <tr>
        <th>HTTP GET</th><td>Response content and code, substring search in the returned data</td>
      </tr>

      <tr>
        <th>HTTP HEAD</th><td>Lightweight GET request, checks for the presence of a document on the server by response code without downloading the document body</td>
      </tr>

      <tr>
        <th>HTTP Basic Authentication</th><td>Basic authentication mechanism</td>
      </tr>

      <tr>
        <th>HTTP Digest</th><td>Digest authentication mechanism</td>
      </tr>

      <tr>
        <th>FTP</th><td>FTP server availability</td>
      </tr>

      <tr>
        <th>PostgreSQL</th><td>PostgreSQL database availability</td>
      </tr>

      <tr>
        <th>MySQL</th><td>MySQL database availability</td>
      </tr>

      <tr>
        <th>Redis</th><td>Redis database availability</td>
      </tr>

      <tr>
        <th>SSL</th><td>TLS(SSL) certificate expiration date for a domain name, more details in the [Setting up a TLS(SSL) certificate check example](/availability-check/ssl-check-example.mdx) guide</td>
      </tr>
    </tbody>
  </table>
</CustomTable>

## Cost \{#price}

The service is billed monthly; the cost depends on the number of created checks, regardless of the number of check requests. The first three checks per month are free.

You can view the cost and pay for checks in the [Control panel](https://my.selectel.ru/availability-check/): from the top menu, click **Products** → **Availability Check** → **Order checks**.

If you would like to receive notifications about health checks via SMS, you need to pay for additional SMS packages. You can view the cost and pay for SMS in the [control panel](https://my.selectel.ru/availability-check/reports): in the top menu click **Products** → **Health Check** → **Reports and Notifications** → in the top right corner click **Buy SMS**.

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