In a nutshell, Dotcom-Monitor is doing one simple thing – trying to reach your website from different geographic locations at specified intervals and notify you of any issues. As simple as that! Well, in reality, you have a lot more control over this process. You can choose between different geographic locations, types of issues you want to be notified, ways to receive those notifications, etc.
In this article, we will look into more details of “Dotcom-Monitor trying to reach your website” and different ways this could be done.
There are plenty of web monitoring types you may use in order to ensure website performance. Dotcom-Monitor provides a comprehensive set of monitoring tasks to implement all types of web monitoring. Tasks can be combined to cover all sophisticated monitoring goals.
This article guides you in picking the right monitoring type and the related Dotcom-Monitor task.
Functionality or transaction monitoring allows you to script and record the critical steps, paths, or business tasks you expect your end users to complete. For example, you can record logging into a site, executing site searches, submitting forms, or walking through the online purchasing process in a real browser.
Dotcom-Monitor provides customers with the EveryStep Web Recorder, a macro recorder that can automatically record these steps in a browser through point-and-click scripting. Running the script opens web pages in a browser and interacts with a web application in the same way as a regular end-user would. In the case of network and server errors, web page element loading issues, or transaction step failures, an alert will be triggered.
To start functionality monitoring, set up a UserView task.
Dotcom-Monitor provides you with the tool to test a single URL, such as a landing page for connection speeds and browser load times.
Even if your web page is accessible and you’re sure that users can reach it at any time doesn’t mean that all elements on the page are rendered successfully and loaded with the optimal speed. For example, some images, Flash, or CSS elements on the page can fail to load while the page is loaded successfully.
A web page is tested using desktop or mobile browser engines to your choice. Detailed performance data is provided for each element on the page. Content validation, as well as basic authorization, are performed while monitoring. When a page or specific element on a page fails to perform as expected, an alert will be sent to let you react quickly.
Configure a BrowserView task to set up performance monitoring.
The basic way to make sure web services, domains, or a single page are accessible for users, is availability or uptime monitoring. In other words, if the goal is to monitor if your users can enter a specific URL, and do not receive any type of page errors, such as “Error 404: Page not found” but reach the address, this type of monitoring is the ideal method.
Dotcom-Monitor will check if the target web resource is responding without downloading the content into a browser – only the presence of the resource response is considered. Depending on your needs and the target resource type, you may perform SSL certificates validity as well as basic authorization features. If Dotcom-Monitor does not receive a response from the target URL, the site will be considered down and the corresponding alert will be triggered.
Websites and APIs (HTTP/S) Availability
An HTTP/S monitoring checks a single URL for availability, performance, proper content and errors. It supports POST and GET requests, cookies, form submissions, custom headers, password-secured sites (basic HTTP/S authorization as well as cookie/script authorization mechanisms), and timeout thresholds.
HTTP/S monitoring validates security certificates, check certificate authority, and check for expiration. It can also be configured to send you reminders when the certificate expiration date is approaching.
If the website or web application relies on an API, or use third-party API, API availability is a crucial part of monitoring. For example, you use an ID or other personal data validation software on your website to process user input. In this case, you need to be sure it’s available and returns proper data. Dotcom-Monitor will send a request to the API and evaluate its response for content, speed, and response codes. If the response does not fulfill the specified requirements, the alert will be sent out.
See Add/Edit an HTTP(S) Task to set up HTTP/S monitoring.
Server Port Availability
TCP port availability
To test connectivity to a web server through a certain TCP port, the easiest way is to use Telnet port availability monitoring.
For example, you can use Telnet monitoring to make sure that no firewalls are blocking incoming connections from applications to Internet services. Dotcom-Monitor will send a request to the TCP port with the specified number on the web server to make sure that the port is open and you can receive a response.
See also Add/Edit a Telnet Port Availability Task.
UDP Server port
If a web application provides voice or video transfer over the Internet over the User Datagram Protocol (UDP), UDP monitoring is useful to make sure a UDP server is reachable. Dotcom-Monitor can test UDP server availability by sending packets to a specified port and receiving a response.
See also Add/Edit a UDP Task.
Traceroute and ping tools help you quickly identify and diagnose network-related outages and issues for servers and other network devices. The ping command sends an ICMP echo request to a target name or IP address, helping you to verify IP-level connectivity.
These types of monitoring are useful for ensuring the integrity of routers, firewalls, and multiple Internet appliance devices, and is an important component of your remote network monitoring services.
SOAP Web Service Availability
If you need to test a SOAP-based web service for availability, errors, and proper content, select the SOAP monitoring task. SOAP is a lightweight protocol for the exchange of information in a decentralized, distributed environment. It is an XML-based protocol that consists of three parts:
- An envelope that defines a framework for describing what is in a message and how to process it
- A set of encoding rules for expressing instances of application-defined data types
- A convention for representing remote procedure calls and responses.
A SOAP task assigns agents to replicate one or more client requests and monitor the web services. Based upon the preferences selected in the device setup, Dotcom-Monitor will send alerts if an issue is detected.
See also Add/Edit a SOAP Task.
Usually, a web resource comes with a number of other web services or infrastructure elements such as API software, mail servers, FTP services, etc., that also can be tasted with the Dotcom-Monitor tools.
FTP(S)/SFTP Server Uptime and Availability
The FTP monitoring agent connects to the specified FTP server, logs on to the FTP server using a user name and password you provide, and a directory listing command is issued to retrieve a specific directory. After the contents of that directory are listed, the monitoring service checks if specified files exist on the server in that specific directory. If our remote monitoring agents detect a problem at any point in the process, Dotcom-Monitor will notify you via the notification process.
See also Add/Edit an FTP/SFTP/FTPS task.
Mail Server Monitoring
SMTP Server uptime monitoring
Whenever you send an email, your email client interacts with the SMTP server. Simple Mail Transfer Protocol (SMTP) is the Internet protocol for electronic mail delivery that most mail servers today use to deliver email. The SMTP server on your host may communicate with other SMTP servers to actually deliver the email.
During an SMTP monitoring, the agents monitor the SMTP server by connecting to the specified mail server and performing an SMTP handshake. If a remote server does not respond to a handshake or is unavailable, an error condition will be triggered. If you have alerts configured, you will receive an alert.
See also Add/Edit an SMTP task.
POP3/IMAP connection monitoring
To verify that users can access their email account via POP3 or IMAP protocols, POP3 / IMAP monitoring is an option. Dotcom-Monitor connects to a mail server (POP3 or IMAP) and logs in using a user name and password you provide. For example, when you check your email, your email client connects to a POP3 server using port 110. The POP3 server requires an account name and a password. Once you have logged into the POP3 server, it opens your email store and allows you to access it. Dotcom-Monitor uses the same protocol to monitor your POP3 servers for errors and sends an alert when a monitoring agent detects an issue.
See also POP3/IMAP task.
Microsoft Exchange Server uptime monitoring
To monitor your Microsoft Exchange Servers for errors and receive an alert when a monitoring agent detects an issue, ActiveSync Email monitoring can be used. Dotcom-Monitor checks a remote mail server to verify that users can access their email account via Microsoft Exchange ActiveSync protocol then sends an email to check for the successful delivery of the email message. After the email delivery has been deemed successful, the email is deleted. Any error detected during the monitoring check is reflected in the report with an Error Code and appropriate description.
A monitoring check follows these steps with no issues for a successful response:
- Connect to a specified mailbox
- Send a test email from the specified mailbox to the same address
- Check for the test email within the mailbox.
See also Add/Edit an ActiveSync Task.
Complete end-to-end mail server availability monitoring
If the goal is to perform end-to-end availability monitoring of your mail servers, use SMTP-POP3/IMAP monitoring. First, a monitoring agent tests the SMTP server by sending an email to the specified email address. After that email is sent, the agent attempts to log in and retrieve the email from a POP3/IMAP server. If the SMTP or POP3/IMAP steps experience an error, or the email is not found within a specified time-out period, an error is recorded. If you have alerts configured, you will receive an alert.
Video Streaming Monitoring
Streaming media monitoring checks video and audio streaming services for performance, errors, and availability.
If the goal is to check both web page availability and the video streaming placed on it, it’s best practice is to combine the Streaming Media Task and HTTP task in one device. This ensures that not only the video is rendered and available on the page, but the page by itself is loaded properly and vice versa.
VoIP/SIP monitoring tasks create monitoring agents that connect to a specified VoIP server using the supplied credentials to ensure that the service is available. To accomplish this, SIP monitoring is provisioned as either an extension or a client on the VoIP system and configured to call a specific number using a specified SIP server with certain parameters. The expected result of the call is set up as “Answer,” “No Answer,” “Busy,” or an error condition (if there is an unexpected result).
If an error is detected, SIP monitoring records all properties of the error, which helps to pinpoint where the error condition is occurring. SIP monitoring reports these error properties as blobs of text accessible in online reports:
- SIP Final Response:408
- SIP Final Response Description: Request Timeout
- Media: False
- TimedOut: True
See also Add/Edit a VoIP SIP Task.
Verification of Domain Name Resolution (DNS)
DNS Server monitoring queries a specified DNS server in order to resolve a specific internet protocol (IP) address.
See also Add/Edit a DNS task.
Domain name presence on multiple DNS Blacklists
A DNSBL task polls major domain name service (DNS) Blacklist (DNSBL) databases for an IP or a hostname you specify. If the IP or hostname is found in one of the DNSBL databases, an error will be flagged. If you have alerts configured, an alert will be triggered.
The technology is built on top of the Internet Domain Name System. DNSBLs publish lists of addresses linked to spamming. Most mail transport agent (mail server) software can be configured to reject or flag messages which have been sent from a site listed on one or more of these DNSBLs.
If your mail servers are included in a DNSBL database, it will cause other companies to deny email delivery from your servers. It’s important to know if your servers are listed in DNSBLs, so you can quickly request removal and find the root cause of the DNSBL listing.
The DNSBL task references the following authoritative blacklists:
If your mail server or IP address are detected on any of these blacklists, you may need to contact the specified blacklist directly in order to determine why your address is listed and request to be removed from the list.
See also Add/Edit a DNSBL Blacklist Task.
At some point, hardware resources might be critical for your server performance to prevent any hardware-side issues before they affect your website or application. Monitoring of hardware performance counters allows keeping track on resources of web servers or devices connected to the Internet (CPU load, memory usage statistics, disk space, bandwidth saturation, and more).
In combination with web performance monitoring, resource monitoring allows correlating the results for comprehensive analysis. For example, by monitoring a back-end server resources, you can correlate CPU temperature and disk I/O with the speed of a shopping cart in your mobile application.
Dotcom-Monitor MetricsView services support Linux, Windows, Custom Performance Counters, as well as monitoring devices not connected to the Internet.
The MetricsView Windows service enables Windows computer or server monitoring, as well as allowing users to monitor a test or production environment, using data from Windows Performance Counter (WPC) and set alerts when limits are exceeded.
To set up monitoring, refer to these articles from the Windows Performance Monitoring category of the Knowledge Base.
The MetricsView Linux monitoring service enables Linux computer or server monitoring, as well as allowing users to set thresholds for data from Collectd performance counters and set alerts when those thresholds are exceeded.
To set up the monitoring, refer to these articles from the Linux Performance Monitoring category of the Knowledge Base.
SNMP Capable Devices
Enables tracking of SNMP capable devices using SNMP V1, V2 or V3.
To set up the task, refer to these articles from the SNMP Monitoring category of the Knowledge Base.
Allows users to monitor the performance of any custom metrics available for collecting on a server or device.
To set up custom collectors and configure monitoring, refer to these articles from the Custom Collectors category of the Knowledge Base