Synthetics: Major Aug/Sept 2021 Update
Lots of additions in August and September 2021 in the Synthetic Monitoring department.
Almost every area of the product got new additions: from additional test frequencies (sub-second for the win !) to Page Load Test enhancements to Synthetic Test based dashboards, there's a lot for everyone, see for yourself !
More Test Frequency Options
We now offer more test frequency options. We have added 2 minute, 10 minute, 15 minute and 30 minute options to the existing (1 second, 15 second, 1 minute and 5 minute) options when configuring tests.
Ignore TLS Option
Network teams told us that they often don’t care about catching bad certificate issues and would rather “bypass” these failures to continue testing network performance. To achieve this, we have added support for ignoring TLS errors and exposed the option to configure this through the advanced settings for HTTP/API test types and Page Load test types.
Standard Deviation-based Custom Thresholds
Previously, custom test thresholds were based on static values only. While this worked well on the surface, static thresholds are limited in practical use. Specifically, static thresholds cannot be used in mesh-type tests because each pair of agents would likely need a different value. Similarly, with multi-agent tests to a single target, if the agents are in different geographic locations, the expected latency for each is different, and it isn’t possible to specify a single value that satisfies them all. For all those reasons, we have added the option to specify thresholds for latency (including HTTP latency and DNS resolution time) and jitter that are based on a multiple of the baseline measurement.
By default, the new algorithm computes a baseline for latency and jitter measurements. It uses that to determine whether to mark a particular measurement as a warning (if it is more than 1.5x the baseline) or critical (if it is more than 3x the baseline). Similarly, for packet loss we default to warning when there is any packet loss (that is >0%) and to critical if it is higher than 50%.
DNS Performance Dashboard Preset Tab
To build on our commitment to include tests to common infrastructure services that network teams rely on, we now include a new DNS Performance tab as a preset on the Synthetics Performance Dashboard.
This tab is built using the “DNS density grid” type of synthetic dashboard and features availability and uptime checks to 7 of the top/common DNS service providers from 15 geographically distributed global agents. Where available, two IPv4 and two IPv6 DNS servers are tested for each service. This allows customers to quickly rule out (or in) any DNS failures they see from “general issues” with the specific provider.
SaaS Performance Tab Migrated to HTTP GETs
The SaaS Performance tab on the performance dashboard was the very first preset tab when we launched Synthetics back in October 2020. At that time, this was a basic “hostname” test which is essentially just a ping and trace. Since then we have introduced much better tests that are capable of testing both HTTP layer and network layer performance, so in the spirit of “upgrading” to the latest, we have migrated all our existing SaaS performance tests to the HTTP or API test type.
Page Load Asset Validation
Our browser Page Load tests (only supported on app agents) are enhanced with “Asset Validation.”
- Users have the option of specifying one or more CSS selectors during the test configuration.
- The agent/test will look for those CSS selectors in the web page assets that it loads as part of the tests and if it finds them all it will indicate a PASS, but even if one of them isn’t present in the results, it will return a FAIL. Note that as with other results in the table, a grey color indicates that this metric is not used in computing test health (which ultimately drives alerts and notifications).
- To figure out how many loaded, and which selectors did not load at what points of time, the user can click through the “View Details” button to see a time-series chart. It shows the total returned selectors relative to the total configured, and by hovering over the chart, shows which ones were found and which were not found.
Dashboard Widgets for Aggregated Test Results
One of the common use cases for Synthetics is to benchmark one’s own performance against competitors as well as to compare and contrast one’s services’ performance from different parts of the world. Customers will often configure multiple tests (one set for their services and one for competitors, or tests in different parts of the world, labeled by regions) and will want to see an aggregated view. To help, we are leveraging the Kentik dashboards (Library).
There are two possible widget types:
- Table view: Great for comparing the performance of your service between different regions of the world from where your users may be accessing the service
- Gauge view: Great for comparing the overall average performance of your service (globally) relative to that of one or more of your competitors
When creating a custom dashboard widget with Synthetic data, users now have the option to choose a “Panel Type,” which may be either “Single Test” (the existing type) or the new “Multiple Test” type, which aggregates data across multiple tests. When the “Multiple Test” option is selected, the user has the option to specify the “Test Type,” “Display Type” and “Metric” that they want to aggregate data on. Optionally they can also specify agent labels that will be used to group results by in the table.
Results are displayed either as a table with each row showing aggregated values for the selected metric grouped by agent labels (user configurable).
Or as gauges showing the average metric:
These widgets can be combined with the existing widget types to produce some useful dashboards.
Notifications for BGP Monitor
We now have notifications available for BGP tests via email and other notification channels.