Analyze edge node performance in Microsoft Azure CDN

Important

This is a feature of Azure CDN Premium from Verizon only, and is not available with Azure CDN standard products. For a comparison of CDN features, see Azure CDN product features.

Overview

Edge performance analytics provides granular information traffic and bandwidth usage for the CDN. This information can then be used to generate trending statistics, which allow you to gain insight on how your assets are being cached and delivered to your clients. In turn, this allows you to form a strategy on how to optimize the delivery of your content and to determine what issues should be tackled to better leverage the CDN. As a result, not only will you be able to improve data delivery performance, but you will also be able to reduce your CDN costs.

Note

All reports use UTC/GMT notation when specifying a date/time.

Reports and log collection

CDN activity data must be collected by the Edge Performance Analytics module before it can generate reports on it. This collection process occurs once a day and it covers the activity that took place during the previous day. This means that a report's statistics represent a sample of the day's statistics at the time it was processed, and do not necessarily contain the complete set of data for the current day. The primary function of these reports is to assess performance. They should not be used for billing purposes or exact numeric statistics.

Note

The raw data from which Edge Performance Analytic reports are generated is available for at least 90 days.

Dashboard

The Edge Performance Analytics dashboard tracks current and historical CDN traffic through a chart and statistics. Use this dashboard to detect recent and long-term trends on the performance of CDN traffic for your account.

This dashboard consists of:

  • An interactive chart that allows the visualization of key metrics and trends.
  • A timeline that provides a sense of long term patterns for key metrics and trends.
  • Key metrics and statistical information on how our CDN network improves site traffic as measured by overall performance, usage, and efficiency.

Accessing the edge performance dashboard

  1. From the CDN profile blade, click the Manage button.

    CDN profile blade manage button

    The CDN management portal opens.

  2. Hover over the Analytics tab, then hover over the Edge Performance Analytics flyout. Click on Dashboard.

    The edge node analytics dashboard is displayed.

Chart

The dashboard contains a chart that tracks a metric over the time period selected in the timeline that appears directly below it. A timeline that graphs up to the last two years of CDN activity is displayed directly below the chart.

Using the chart

  • By default, the cache efficiency rate for the last 30 days will be charted.
  • This chart is generated from data collated on a daily basis.
  • Hovering over a day on the line graph will indicate a date and the value of the metric on that date.
  • Click Highlight Weekends to toggle an overlay of light gray vertical bars that represent weekends onto the chart. This type of overlay is useful for identifying traffic patterns over weekends.
  • Click View One Year Ago to toggle an overlay of the previous year's activity over the same time period onto the chart. This type of comparison provides insight into long-term CDN usage patterns. The upper-right hand corner of the chart contains a legend that indicates the color code for each line graph.

Updating the chart

  • Time Range: Perform one of the following:
    • Select the desired region in the timeline. The chart will be updated with data that corresponds to the selected time period.
    • Double-click the chart to display all available historical data up to a maximum of two years.
  • Metric: Click the chart icon that appears next to the desired metric. The chart and the timeline will be refreshed with data for the corresponding metric.

Key metrics and statistics

Efficiency metrics

The purpose of these metrics is to see whether cache efficiency can be improved. The main benefits derived from cache efficiency are:

  • Reduced load on the origin server which may lead to:
    • Better web server performance.
    • Reduced operational costs.
  • Improved data delivery acceleration since more requests will be served directly from the CDN.
Field Description
Cache Efficiency Indicates the percentage of data transferred that was served from cache. This metric measures when a cached version of the requested content was served directly from the CDN (edge servers) to requesters (e.g., web browser)
Hit Rate Indicates the percentage of requests that were served from cache. This metric measures when a cached version of the requested content was served directly from the CDN (edge servers) to requesters (e.g., web browser).
% of Remote Bytes - No Cache Config Indicates the percentage of traffic that was served from origin servers to the CDN (edge servers) that will not be cached as a result of the Bypass Cache feature (HTTP Rules Engine).
% of Remote Bytes - Expired Cache Indicates the percentage of traffic that was served from origin servers to the CDN (edge servers) as a result of stale content revalidation.

Usage metrics

The purpose of these metrics is to provide insight into the following cost-cutting measures:

  • Minimizing operational costs through the CDN.
  • Reducing CDN expenditures through cache efficiency and compression.

Note

Traffic volume numbers represent traffic that was used in calculations of ratios and percentages, and may only show a portion of the total traffic for high-volume customers.

Field Description
Ave Bytes Out Indicates the average number of bytes transferred for each request served from the CDN (edge servers) to the requester (e.g., web browser).
No Cache Config Byte Rate Indicates the percentage of traffic served from the CDN (edge servers) to the requester (e.g., web browser) that will not be cached due to the Bypass Cache feature.
Compressed Byte Rate Indicates the percentage of traffic sent from the CDN (edge servers) to requesters (e.g., web browser) in a compressed format.
Bytes Out Indicates the amount of data, in bytes, that were delivered from the CDN (edge servers) to the requester (e.g., web browser).
Bytes In Indicates the amount of data, in bytes, sent from requesters (e.g., web browser) to the CDN (edge servers).
Bytes Remote Indicates the amount of data, in bytes, sent from CDN and customer origin servers to the CDN (edge servers).

Performance Metrics

The purpose of these metrics is to track overall CDN performance for your traffic.

Field Description
Transfer Rate Indicates the average rate at which content was transferred from the CDN to a requester.
Duration Indicates the average time, in milliseconds, it took to deliver an asset to a requester (e.g., web browser).
Compressed Request Rate Indicates the percentage of hits that were delivered from the CDN (edge servers) to the requester (e.g., web browser) in a compressed format.
4xx Error Rate Indicates the percentage of hits that generated a 4xx status code.
5xx Error Rate Indicates the percentage of hits that generated a 5xx status code.
Hits Indicates the number of requests for CDN content.

Secure Traffic Metrics

The purpose of these metrics is to track CDN performance for HTTPS traffic.

Field Description
Secure Cache Efficiency Indicates the percentage of data transferred for HTTPS requests that were served from cache. This metric measures when a cached version of the requested content was served directly from the CDN (edge servers) to requesters (e.g., web browser) over HTTPS.
Secure Transfer Rate Indicates the average rate at which content was transferred from the CDN (edge servers) to requesters (e.g., web servers) over HTTPS.
Average Secure Duration Indicates the average time, in milliseconds, it took to deliver an asset to a requester (e.g., web browser) over HTTPS.
Secure Hits Indicates the number of HTTPS requests for CDN content.
Secure Bytes Out Indicates the amount of HTTPS traffic, in bytes, that were delivered from the CDN (edge servers) to the requester (e.g., web browser).

Reports

Each report in this module contains a chart and statistics on bandwidth and traffic usage for different types of metrics (e.g., HTTP status codes, cache status codes, request URL, etc.). This information may be used to delve deeper into how content is being served to your clients and to fine-tune CDN behavior to improve data delivery performance.

Accessing the edge performance reports

  1. From the CDN profile blade, click the Manage button.

    CDN profile blade manage button

    The CDN management portal opens.

  2. Hover over the Analytics tab, then hover over the Edge Performance Analytics flyout. Click on HTTP Large Object.

    The edge node analytics reports screen is displayed.

Report Description
Daily Summary Allows you to view daily traffic trends over a specified time period. Each bar on this graph represents a particular date. The size of the bar indicates the total number of hits that occurred on that date.
Hourly Summary Allows you to view hourly traffic trends over a specified time period. Each bar on this graph represents a single hour on a particular date. The size of the bar indicates the total number of hits that occurred during that hour.
Protocols Displays the breakdown of traffic between the HTTP and HTTPS protocols. A donut chart indicates the percentage of hits that occurred for each type of protocol.
HTTP Methods Allows you to get a quick sense of which HTTP methods are being used to request your data. Typically, the most common HTTP request methods are GET, HEAD, and POST. A donut chart indicates the percentage of hits that occurred for each type of HTTP request method.
URLs Contains a graph that displays the top 10 requested URLs. A bar is displayed for each URL. The height of the bar indicates how many hits that particular URL has generated over the time span covered by the report. Statistics for the top 100 requested URLs are displayed directly below this graph.
CNAMEs Contains a graph that displays the top 10 CNAMEs used to request assets over the time span of a report. Statistics for the top 100 requested CNAMEs are displayed directly below this graph.
Origins Contains a graph that displays the top 10 CDN or customer origin servers from which assets were requested over a specified period of time. Statistics for the top 100 requested CDN or customer origin servers are displayed directly below this graph. Customer origin servers are identified by the name defined in the Directory Name option.
Geo POPs Shows how much of your traffic is being routed through a particular point-of-presence (POP). The three-letter abbreviation represents a POP in our CDN network.
Clients Contains a graph that displays the top 10 clients that requested assets over a specified period of time. For the purposes of this report, all requests that originate from the same IP address are considered to be from the same client. Statistics for the top 100 clients are displayed directly below this graph. This report is useful for determining download activity patterns for your top clients.
Cache Statuses Gives a detailed breakdown of cache behavior, which may reveal approaches for improving the overall end-user experience. Since the fastest performance comes from cache hits, you can optimize data delivery speeds by minimizing cache misses and expired cache hits.
NONE Details Contains a graph that displays the top 10 URLs for assets for which cache content freshness was not checked over a specified period of time. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
CONFIG_NOCACHE Details Contains a graph that displays the top 10 URLs for assets that were not cached due to the customer's CDN configuration. These types of assets were served directly from the origin server. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
UNCACHEABLE Details Contains a graph that displays the top 10 URLs for assets that could not be cached due to request header data. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
TCP_HIT Details Contains a graph that displays the top 10 URLs for assets that are served immediately from cache. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
TCP_MISS Details Contains a graph that displays the top 10 URLs for assets that have a cache status of TCP_MISS. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
TCP_EXPIRED_HIT Details Contains a graph that displays the top 10 URLs for stale assets that were served directly from the POP. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
TCP_EXPIRED_MISS Details Contains a graph that displays the top 10 URLs for stale assets for which a new version had to be retrieved from the origin server. Statistics for the top 100 URLs for these types of assets are displayed directly below this graph.
TCP_CLIENT_REFRESH_MISS Details Contains a bar chart that displays the top 10 URLs for assets were retrieved from an origin server due to a no-cache request from the client. Statistics for the top 100 URLs for these types of requests are displayed directly below this chart.
Client Request Types Indicates the type of requests that were made by HTTP clients (e.g., browsers). This report includes a donut chart that provides a sense as to how requests are being handled. Bandwidth and traffic information for each request type is displayed below the chart.
User Agent Contains a bar graph displaying the top 10 user agents to request your content through our CDN. Typically, a user agent is a web browser, media player, or a mobile phone browser. Statistics for the top 100 user agents are displayed directly below this chart.
Referrers Contains a bar graph displaying the top 10 referrers to content accessed through our CDN. Typically, a referrer is the URL of the web page or resource that links to your content. Detailed information is provided below the graph for the top 100 referrers.
Compression Types Contains a donut chart that breaks down requested assets by whether they were compressed by our edge servers. The percentage of compressed assets is broken down by the type of compression used. Detailed information is provided below the graph for each compression type and status.
File Types Contains a bar graph that displays the top 10 file types that have been requested through our CDN for your account. For the purposes of this report, a file type is defined by the asset's file name extension and Internet media type (e.g., .html [text/html], .htm [text/html], .aspx [text/html], etc.). Detailed information is provided below the graph for the top 100 file types.
Unique Files Contains a graph that plots the total number of unique assets that were requested on a particular day over a specified period of time.
Token Auth Summary Contains a pie chart that provides a quick overview on whether requested assets were protected by Token-Based Authentication. Protected assets are displayed in the chart according to the results of their attempted authentication.
Token Auth Deny Details Contains a bar graph that allows you to view the top 10 requests that were denied due to Token-Based Authentication.
HTTP Response Codes Provides a breakdown of the HTTP status codes (e.g., 200 OK, 403 Forbidden, 404 Not Found, etc.) that were delivered to your HTTP clients by our edge servers. A pie chart allows you to quickly assess how your assets were served. Detailed statistical data is provided for each response code below the graph.
404 Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a 404 Not Found response code.
403 Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a 403 Forbidden response code. A 403 Forbidden response code occurs when a request is denied by a customer origin server or an edge server on our POP.
4xx Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a response code in the 400 range. Excluded from this report are 403 Not Found and 404 Forbidden response codes. Typically, a 4xx response code occurs when a request is denied as a result of a client error.
504 Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a 504 Gateway Timeout response code. A 504 Gateway Timeout response code occurs when a timeout occurs when an HTTP proxy is trying to communicate with another server. In the case of our CDN, a 504 Gateway Timeout response code typically occurs when an edge server is unable to establish communication with a customer origin server.
502 Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a 502 Bad Gateway response code. A 502 Bad Gateway response code occurs when an HTTP protocol failure occurs between a server and an HTTP proxy. In the case of our CDN, a 502 Bad Gateway response code typically occurs when a customer origin server returns an invalid response to an edge server. A response is invalid if it cannot be parsed or if it is incomplete.
5xx Errors Contains a bar graph that allows you to view the top 10 requests that resulted in a response code in the 500 range. Excluded from this report are 502 Bad Gateway and 504 Gateway Timeout response codes.

See also