How does it work? - Protocols
A probe can check a website or a web server, but can also be set up to monitor many other systems. Learn how to set up a probe in your account, by clicking here.
We support the following internet protocols:
- HTTP
- HTTPS
- SMTP
- POP3
- Ping
- DNS
- FTP
- Connect
- SQL
- MySQL
- Other probe types
HTTP is the protocol used for viewing and interacting with web pages. It's the default probe type when you add a new probe, and you choose this type when you simply need to check a web page. In order to set this up, all you need to fill in - aside from choosing a name for your probe - is the URL (web address) of the web page.
When the probe executes, we will contact the web address, check for common network and HTTP errors, and download the content of the web page. Please note that this type of probe will only download the HTML content of the page: it does not include any images, scripts or other elements that are part of the page. If you are looking to check the complete content of a page, you can consider the Full Page Check probe type.
In addition to these basic checks, we can optionally check for:
- Load times: When you set time limits, we will check that the total amount of time it takes to load the web page, is within those limits. In other words: we can check that your web page loads as quickly as you expect.
- Size: We can test that the downloaded content is larger than the minimum number of bytes or characters you specify. This is useful when you want to make sure that a particular file on your web server (a generated image, for example) is not broken or empty.
- Content: Uptrends can verify that a particular word or phrase is actually present in the content of the page. This is a powerful way to check that your web page is showing the correct content.
- Choose a word or phrase that is an essential part of your page; something that won't be shown in case there is an error. Simply fill in your word or phrase in the Page content match field.
In some cases you might want to check for the absence of a word. You can do this by starting with an exclamation mark. For example, if you want us to verify that the word "error" is NOT present in the content, fill in !error.
HTTPS works exactly the same as HTTP. It verifies web pages in the same way, but you use HTTPS for checking secure web pages.
The SMTP protocol is used for connecting to mail servers, in order to test outgoing e-mail. Fill in the name or IP address of your mail server, the port number (we will use port 25 for this by default), and optionally a username and password. If you specify login credentials, we will attempt to log in; otherwise we will only connect to see if the mail server is running, and accepting login requests.
The POP3 protocol - like the SMTP protocol - is used to connect to mail servers, for testing the service that handles incoming e-mail. We fill in the default port 110, and if you specify a username and password, we will attempt to log in; otherwise we will only connect to see if the mail server is running, and accepting login requests.
Ping (or ICMP) is a very simple way to see if a server is still running and reachable. It will send so-called ICMP Echo requests, and see how long it takes for that request to reach the server. You can choose this option if you do not have any other services (web, database or mail) running on that server that are accessible through the internet. Please note that your network or server settings must explicitly allow ICMP requests.
DNS stands for Domain Name System, a system of computers that provides the infrastructure allowing browsing of the World Wide Web. In its most simple definition, the Domain Name System is a conglomeration of root servers that houses the Internet Protocol (IP) addresses of the DNS name servers that have authority over individual domains of every registered Internet domain name. Uptrends is able to monitor local, primary and specific DNS. More info about DNS can be found here.
You can also use our DNS check. This check allows you to perform various queries on a DNS name server. The most common thing to check, is whether your domain name (www.yourcompany.com) is still pointing to the IP address of your web server. Your provider’s name server is the primary, first-hand source of this information. By monitoring this DNS query directly, we will detect any DNS problems, even before your website becomes unavailable for your visitors and customers.
Uptrends' DNS probe lets you do extensive DNS health checks: verify your web site domain names (A and CNAME records), mail server domain name mappings (MX records), DNS zone delegates (NS records), authoritative information about DNS zones (SOA records) and other DNS information, contained in TXT records (including SPF information for e-mail authentication).
To create a DNS probe, follow these steps:
- Create a new probe, and select the DNS probe type.
- Enter the domain name or IP address of the DNS name server in the URL field.
- DNS queries use port 53 by default. You can change the port number if required.
- Select the DNS query type you want to use (A, CNAME, MX, NS, SOA, TXT). For basic domain name checking, use A.
- Enter the expected result. For basic domain name checking, this is the IP address of your web server.
- Test or Save the probe. We will start monitoring your DNS query immediately.
We can contact an FTP server over a port which you can set up yourself. We can also log into that server to access data that you can specify in the probe. What we (at the moment) can not do, is to actually retrieve files from that FTP server.
If no other protocol is suitable for your situation, you can use the Connect protocol to do a very simple test. If you specify a domain name or IP address of your server or firewall, and a port, we will attempt to open a simple connection to that combination of address and port.
Choose the SQL protocol if you want to verify that your Microsoft SQL server database is still running. Please note that this will only work for database servers that are directly accessible through the internet. At a minimum, you will need to specify the IP address of the server and a port (default 1433). Optionally, you can specify a username and password which we will use to log in. Additionally, you can specify a database name, so we can check if the database can be accessed using the login credentials you provided.
MySQL works in the same way as SQL, but it works for servers running the MySQL database engine. The default port for connecting to MySQL databases is 3306.
Use a Full Page Check to load everything that is part of a web page. Like a HTTP or HTTPS probe, it will download the content of the page, but it won't stop there. By loading the page in a real browser, we will interpret the content of the page, and load all images, scripts, stylesheets and other elements on that page. Any scripts that are part of the page (even third party ones, such as advertisement or web analytics scripts) will be executed and measured as well. In the waterfall chart, we show the individual load times of every element.
Use a Real Browser probe to load a page in a real browser.
Use a Transaction probe to monitor unlimited steps, such as login procedures and shopping carts.