When your application relies on file downloads or Alibaba Cloud CDN-accelerated delivery, slow transfers or CDN misconfigurations can degrade user experience across regions and networks. Synthetic Monitoring in Application Real-Time Monitoring Service (ARMS) lets you create scheduled tasks that simulate file uploads and downloads from distributed monitoring points, so you can detect transfer bottlenecks, measure CDN acceleration effectiveness, and identify availability issues before your users encounter them.
Unlike general HTTP monitoring, this task type provides dedicated controls for transfer size limits and download engine selection (cURL vs. WinInet).
Starting June 1, 2024, Synthetic Monitoring no longer offers pay-as-you-go billing or subscription resources for new users. For details, see Discontinuation of the activation of Synthetic Monitoring.
Prerequisites
Before you begin, make sure that you have:
An Alibaba Cloud account with ARMS activated
A target file URL that is accessible and starts with
http://orhttps://, or uses theIP address:port numberformat
Create a task
Log on to the ARMS console.
In the left-side navigation pane, choose Synthetic Monitoring > Scheduled Tests.
On the Synthetic Tasks page, click New Task.
On the Create Synthetic Task page, click File Transfer & CDN Speed Test.
In the STEP1 section, configure the basic task settings.
Parameter Description Task name A descriptive name for the task. Use a name that identifies the target resource and test purpose, such as CDN-download-prod-assets.Target Address The URL or IP address of the resource to test. Supported formats: a URL starting with httporhttps, or an address in theIP address:Port numberformat.Dialing Frequency How often the task runs. Frequency: the interval between consecutive test runs. Custom: turn on the Custom switch to restrict test runs to specific time periods. In the STEP2 section, select monitoring points. Monitoring points are the geographic locations from which Synthetic Monitoring runs the test. Choose points that reflect your actual user distribution for the most meaningful results.
NoteIPv6 web applications cannot be monitored from data center locations.
Parameter Description Monitoring point type Select PC End or Mobile End to match the device type of your target users. Monitoring Point Group Choose a predefined or custom group. Recommended Monitoring Point Group: commonly used points recommended by the system. All Monitoring Point Group: every available point. Custom Monitoring Point Group: points you have saved for reuse. Select Monitoring Point Add individual carriers to the Selected Monitoring Point section on the right. To reuse this selection later, save it as a custom monitoring point group. In the STEP3 section, configure advanced settings. Advanced settings control network behavior, timeouts, request customization, and result validation.
Parameter Description IP Protocol The IP protocol used by the servers that access the website. Automation: randomly tests over IPv4 or IPv6. IPv4: tests over IPv4 only. IPv6: tests over IPv6 only. Download Kernel The engine used to download files. curl: a cross-platform open source library that supports Windows, Linux, and macOS. Recommended for testing server or macOS download speed. WinInet: a Windows-native API library. Recommended for testing Windows download speed. Protocol The protocol used by the selected download kernel. Monitoring Related Items Redirect: whether to continue browsing after a redirection. Ignore Certificate Errors Skip specific SSL certificate errors during the handshake: Ignore Certificate Status Error, Ignore Certificate Untrusted, Ignore Host Invalid Error. Parameter Description Monitoring Timeout Maximum task duration in milliseconds. If the task exceeds this limit, it stops. Default: 60000(60 seconds).Connection Timeout Maximum wait time for a TCP connection in milliseconds. If the connection is not established within this limit, a message with error code 601is returned. Default:5000(5 seconds).Transfer Size Maximum file size to download during the test. Maximum value: 20 MB. Parameter Description Custom Header Add or modify HTTP request header fields. Enter header values in the field. Customize host The custom host mode. Select Poling or Random mode, then enter IP addresses separated by commas. Example: 192.168.1.11,192.168.1.12:www.a.domain. If a colon (:) is used, the URL before the colon is automatically resolved.Parameter Description Verify Keywords Validate the response header against expected content. String Verification: checks that the response data contains a specified string. If absent, an error is reported. MD5 Verification: saves the response data as a file and computes its MD5 hash, which must match the expected value exactly. Hijack Parameters DNS Hijack Whitelist: define trusted IP addresses or CNAME records for a domain. If DNS resolution returns an IP or CNAME not in the whitelist, DNS hijacking is flagged. Format: domain name:matching rule. Matching rules support exact IP addresses, wildcards, subnet masks, or CNAME records, separated by vertical bars (|). Example:www.aliyun.com:202.0.3.55|203.3.44.67-- any resolved IP other than these two is considered hijacked.Availability Assertion Conditions that determine whether the monitoring result is considered available. The task is marked as available only when the response meets all specified conditions. Parameter Description Resource Group The resource group to assign the task to. For information about creating a resource group, see Create a resource group. Click Create Task. After the task is created, you are redirected to the Synthetic Tasks page.
What's next
View file transfer performance metrics on the task dashboard. For details, see View the dashboard of a file transfer and CDN speed test task.