Alibaba Cloud CDN Test

Alibaba Cloud Content Delivery Network (CDN) is a scalable and high-performance content delivery service for accelerated distribution of content to users across the globe. You can use content delivery network (CDN) to deliver content to users from the nodes that are nearest to them, accelerating the response to user requests and increasing the response rate. CDN also resolves the delivery latency problem that is usually caused by distribution, bandwidth, and server performance issues. CDN has been applied in multiple scenarios, including site acceleration, on-demand streaming, and live streaming.

Typically, CDN is built over the bearer network and contains edge nodes deployed in different regions. Resources are retrieved from origin servers and cached on the edge nodes. When clients request the resources, the requests do not need to be redirected to the origin servers. Instead, Alibaba Cloud CDN automatically retrieves the resources cached on the CDN nodes (i.e., edge nodes) closest to the clients and returns the resources to the clients. This is how, CDN offloads network traffic from origin servers and prevents network congestion.

To ensure a more than satisfactory user experience with the Alibaba cloud, administrators should make sure that the Alibaba Cloud CDN is performing at its best at all times! For instance, if the CDN nodes are unable to service requests effectively, then the traffic to/from origin servers will increase, choking the network in the bargain. Likewise, if many errors are noticed in HTTP responses to an accelerated domain, user experience is bound to suffer. To avoid such anomalies, administrators should keep an eye on the status, request load, cache usage, and HTTP responses of each domain that is configured for content delivery acceleration in the Alibaba Cloud CDN, proactively detect issues, and promptly initiate corrective measures. This is where the Alibaba Cloud CDN Test helps!

This test auto-discovers the accelerated domain names and tracks the status of each domain name. Domains that suffered configuration and validation failures can be identified in the process. Additionally, the test tracks the requests to each accelerated domain and measures how well the CDN nodes service these requests. Ineffective cache usage (if any) is thus revealed. The HTTP responses to every accelerated domain are also tracked, so that error-prone domains can be isolated.

Target of the test : An Alibaba Cloud Account

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each accelerated domain

Configurable parameters for the test
Parameters Description

Test period

How often should the test be executed

Host

The host for which the test is to be configured.

Alibaba Access Key and Alibaba Secret Key

This test makes REST API requests to the Alibaba cloud to pull the metrics. For this purpose, the test needs to be configured with an AccessKey pair. An AccessKey pair is typically used to call an operation of an Alibaba Cloud service. It is also used to initiate an API request or use a cloud service SDK to manager cloud resources. An AccessKey pair is characterized by an AccessKey ID and an AccessKey Secret. The AccessKey ID is used to identify a user/cloud account. The AccessKey Secret is used to verify a user/cloud account.

The first step to configuring the eG agent with an AccessKey pair is to create an AccessKey pair for the target cloud acount. To achieve this, follow the steps below:

  1. Log on to the RAM console by using an Alibaba Cloud account.
  2. In the left-side navigation pane, click Users under Identities.
  3. On the Users page, click the username of the RAM user for which you want to create an AccessKey pair in the User Logon Name/Display Name column.

  4. On the page that appears, click Create AccessKey in the User AccessKeys section.

    Note:

    You must enter a verification code if you create an AccessKey pair for the first time.

  5. Click Close.

    Note:

    • The AccessKey secret is displayed only when you create an AccessKey pair.

    • If the AccessKey pair is leaked or lost, you must create a new one. You can create a maximum of two AccessKey pairs.

  6. Make note of the AccessKey ID and AccessKey secret, once they are displayed.
  7. Then, configure the Alibaba Access Key parameter of the test with the AccessKey ID, and the Alibaba Secret Key parameter with the AccessKey Secret you made note of.

If you failed to make note of the AccessKey ID and AccessKey Secret at the time of creating the AccessKey pair, then you can obtain the same at a later point in time. Similarly, if an AccessKey pair pre-exists for the target cloud account, then you do not have to create another one. Instead, you can obtain the AccessKey ID and AccessKey Secret of the existing AccessKey pair and configure the eG agent with the same. For this, follow the steps below:

  1. Use an Alibaba Cloud account to log on to the Alibaba Cloud Management console.
  2. Move the pointer over the profile picture in the upper-right corner, and click AccessKey.
  3. In the Security Tips message that appears, click Continue to manage AccessKey. AccessKey ID and AccessKey Secret are displayed. 
  4. Make note of the displayed ID and secret.
  5. Then, configure the Alibaba Access Key parameter of the test with the AccessKey ID, and the Alibaba Secret Key parameter with the AccessKey Secret you made note of.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Status

Indicates the status of this accelerated domain.

 

The values that this measure reports and their corresponding numeric values are listed below:

Measure Value Numeric Value
Activating 1
Configuring 2
Checking 3
Deactivating 4
Configuration failed 5
Checking failed 6

Note:

This measure reports the Measure Values listed in the table above to indicate the current status of an accelerated domain. In the graph of this measure however, the same is indicated using the numeric equivalents only.

Use the detailed diagnosis of this measure to view additional details about the CDN. This includes when the CDN was created and when it was last modified.

CDN Type

Indicates the purpose for which CDN has been applied for this accelerated domain.

 

The values that this measure reports and their corresponding numeric values are listed below:

Measure Value Numeric Value
Web 1
Download 2
Video 3
Livestream 4
HTTPS delivery 5

Note:

This measure reports the Measure Values listed in the table above to indicate the purpose for which CDN has been applied on a domain. In the graph of this measure however, the same is indicated using the numeric equivalents only.

Is SSL enabled?

Indicates whether/not SSL has been enabled for this accelerated domain.

 

The values that this measure reports and their corresponding numeric values are listed below:

Measure Value Numeric Value
Yes 1
No 0

Note:

This measure reports the Measure Values listed in the table above to indicate whether/not SSL has been enabled foran accelerated domain. In the graph of this measure however, the same is indicated using the numeric equivalents only.

Total access requests

Indicates the number of requests received by this accelerated domain every second.

Number

This is a good indicator of the request load on a domain. By comparing this measure across domains, you can identify the domain that is receiving the maximum requests.

Peak bandwidth

Indicates the maximum bandwidth used by this accelerated domain.

Kbps

 

Bytes hit rate

Indicates the percentage of requests to this accelerated domain that is serviced by the cached resources on the CDN nodes.

Percent

Higher the cache hit rate, better will be performance. Therefore, a value over 80% is ideal for this measure. A very low value for this measure is indicative of poor cache usage. This can increase traffic to origin servers, thus slowing down content delivery.

Percent of 4xx status codes

Indicates the percentage of HTTP responses sent by this accelerated domain with the status codes in the range 400-499.

Percent

The value 0 is desired for this measure. A high value indicates that many client errors - eg., Bad Request errors, Unauthorized errors, resource not found errors, etc. - have occurred.

Percent of 5xx status codes

Indicates the percentage of HTTP responses sent by this accelerated domain with the status code in the range 500-599.

Percent

The value 0 is desired for this measure. A high value indicates that many server errors - eg., Bad Request errors, Unauthorized errors, resource not found errors, etc. - bad gateway errors, service unavailable errors, internal server errors etc. - have occurred.

Downstream traffic

Indicates the amount of data downloaded by this accelerated domain.

MB