People throw the terms “availability” and “uptime” around a lot, but depending on what you’re monitoring, the definition of these terms may change. In this article we use the narrow definition, accessible, to explore the various options Uptrends has for checking availability on websites, APIs, and servers.
What is availability?
Most of the time, people mean accessible when they refer to availability of a website, API, or server, but others take it a step further to add functional or performance to the requirement. We understand the inclusion of functionality and performance, for both are an important aspect of availability. However, for this article, we use the accessible definition of availability, but for those of you looking to add functional or performance to the definition, we can point you in the right direction too with Web Application Monitoring, Multi-step API Monitoring, or Web Performance Monitoring.
Measuring availability
Monitoring for availability means checking a site, server, or API frequently for a positive response. Depending on your availability goals, the more frequently you check something for availability, the more accurate your data. When setting up your availability monitors, we recommend one-minute intervals.
At one-minute intervals, you’ll capture downtime within the first few seconds of an outage. Using longer intervals means outages may last several minutes before you learn about them, and for short intermittent outages, you may not know about them at all.
Choosing the right monitoring locations
The reason Uptrends maintains so many checkpoint locations (and the reason we keep adding more) is to make sure you can use checkpoints close to your users’ locations. That may mean using all our checkpoints or a small subset. For example, if your website or web app only services Germany and Switzerland, you probably don’t care about availability in the United States. Instead, you’ll want to use the 21 checkpoints we have spread out through the two countries.
If your site is global, sure go ahead and set your monitor up to use the full set. However, outages may affect users based on regions. Setting up multiple monitors to check a single URL from a specific region allows you to bring localized issues to your attention faster than when using a single global monitor.
Always include a minimum of three checkpoints for uninterrupted monitoring. Checkpoints do undergo periodic maintenance, and by having at least three designated checkpoints, maintenance is less likely to affect your monitoring.
Website Availability Monitoring
Website availability is at the heart of Uptrends’ business. Our HTTP/HTTPS monitors have been busily checking websites and web services for more than 12 years. All you need is a URL or IP address, and you’re in business.
We recommend that you use your URL for monitoring. Using a URL over an IP address makes sure each check includes a DNS lookup. Using the IP address bypasses the resolve, and errors in the DNS lookup will go undetected.
Beyond a URL or IP, to refine your monitoring to fit, Uptrends includes several other settings for customizing your uptime monitors.
- Choose between IPv4 or IPv6. You can opt to check either protocol. When choosing IPv6, you can choose to use exclusively checkpoint servers that support IPv6. Alternately you can use all the servers, and our IPv4 only servers will emulate IPv6. If your site offers both, we recommend that you monitor each one separately. A website may be available for one protocol but down for another.
- Error condition options. Uptrends website uptime monitors let you check on response times, page size, conduct a content check, alert on error status codes, or look for a specific code. Sometimes it is more important to make sure a page isn’t accessible. Optionally check for SSL certificate errors (keep reading to learn more about our SSL Certificate Monitoring.)
- Add basic, NTLM, or digest authentication
- Choose a user agent or write your own request.
- Specify your TSL version
- Choose your checkpoints. Depending on your plan, you can choose from our global list of 220 checkpoints. Use them all, specific regions, countries, or cities.
API or Web Service Availability Monitoring
To be clear, Uptrends offers two API monitoring products. To check API responses beyond a single response code, use Multi-Step API Monitoring. Multi-step API can check entire API transactions with data reuse. On the other hand, Web Service Monitors make a quick test to check if the endpoint responds without errors. Web Service Monitors are perfect for tracking your API’s uptime.
Web service monitors check and alert you based on response codes, response times, content checks, SSL errors, or unexpected result codes. You can use basic, NTLM, or digest authentication just like with the website availability monitors (mentioned above), but you’ll find the differences between the two monitor types behind the scenes.
The difference between HTTP/HTTPS Website and HTTP/HTTPS Web Service monitors
On comparison, you won’t see any difference between Uptrends’ Website HTTP/HTTPS monitors and Web Service HTTP/HTTPS monitors. You set up website and web service monitors in the same way, but Uptrends web service HTTP/HTTPS is better suited for passing XML. Uptrends supports both REST and SOAP APIs. Setting up your request using a post, you can include things such as SOAP envelopes, specify a SOAPAction header, and include content-types.
Server Availability Monitoring
Uptrends has several other availability monitors for checking different types of web-facing servers externally. You’ll want to use these checks for your critical server operations.
- Email: If email servers go down, it means trouble on both sides of your firewall. Customers can’t reach you, and your staff’s key communication channel goes by the wayside. Uptrends Email Monitoring can check the availability of POP, SMTP, and IMAP email servers. You can check for error codes, and slow response times using secure or non-secure connections and authentication.
- Database: Uptrends’ Database Monitoring connects to the designated SQL Server or MySQL database and checks for an error-free, timely response.
- Network: Sometimes, you just need to make sure a network or device is findable, so using a Ping or a Connect monitor type can alert you to network latency issues.
- SFTP servers: Using your provided login credentials, you can connect to your SFTP, check for file availability, and download a file to verify that your SFTP server is working correctly.
- FTP servers: Check to make sure your server is running. You can also include credentials to check authentication. The FTP monitor doesn’t check for or download any files.
Advanced Availability Monitoring
Uptrends’ advanced availability checks capture issues that may affect your site’s availability directly or indirectly that you may overlook with regular availability.
DNS Monitoring
Your DNS records direct users to your site. They enter the URL, and based on your DNS records, the Domain Name System tells them where to find your content. A corrupted entry can affect all users or a subset of users. A hacker can do a lot of damage to your brand and your users if they gain access to your DNS records. Protecting them is important. Uptrends’ DNS Monitoring lets you check specific fields for changes. Besides your “A” or “AAAA” records, you may want to check fields, such as the SOA, TXT, or root server. Unexpected changes in your DNS records may mean a threat is imminent or already underway.
Your SOA record includes a serial number the gets incremented with each change to the DNS. You can set up a DNS monitor to compare the serial numbers, and if the number changes, you know that someone has made a change.
SSL Certificate Monitoring
Like everyone else, you’ve probably made the switch from unsecured HTTP to secured HTTPS connections. The switch to HTTPS means you’ve got SSL certificates to maintain. Uptrends’ SSL Monitoring reminds you in advance about upcoming certificate expiration dates, so your users don’t get invalid or expired certificate warnings. Also, SSL monitoring allows you to check certificate values to ensure you’re not the victim of hacks, such as certificate stripping attacks and man-in-the-middle attacks.
A word about SLAs (Service Level Agreements)
When it comes to monitoring and verifying availability for SLAs, Uptrends availability monitors provide you with the granularity you need for accurate reporting. Our special SLA tools allow you to define your SLA requirements, and you can see at a glance if any of your monitors are in danger of falling short of your goals.
Takeaways
Uptrends has the website, API, and server availability monitors to help you reach your uptime goals. With Uptrends’ dynamic alerting, you and your team will know about availability problems when they surface rather than after your users start to complain.
- Check as frequently as once per minute.
- Check either IPv4 or IPv6.
- Add content checks for extra protection.
- Check for response times for basic server responsiveness.
- Look for error codes or specified result codes.
- Choose from 220 checkpoint locations (Checkpoint options vary based on plan).
- Web Service HTTP/HTTPS monitors support REST and SOAP.
- DNS monitoring helps to identify issues, especially in the event of a hijacking or DDoS style attack.
- SSL monitoring checks key values to protect against certificate stripping, man-in-the-middle attacks, and warns you about pending expiration dates.
