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2017-09-06 |
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The Content Delivery Network (CDN) is a collection of edge servers that are distributed through various parts of the country or the world. Their web content is served from an edge server, which is located in the geographic area closest to the customer who requests the content. This technique lets the users receive the content with less delay than we could achieve by delivering the content from one centralized location. It delivers a better overall experience for your customers.
CDN achieves its purpose by caching web content on edge servers around the world. When a user requests web content, the content request is routed to the edge server that is geographically closest to that user. By reducing the distance the content must travel, the CDN offers optimized throughput, minimized latency, and increased performance.
Your account is created during the CDN order process, when you click on Select after going through the "Vendor selection" menu.
Update your DNS record so that your website points to the CNAME associated with your new CDN mapping.
Note: It may take up to 15-30 minutes for the update to become active. Check with your DNS provider to obtain an accurate time estimate.
You are billed for bandwidth used per CDN. If no bandwidth is used by your CDN, no charges are incurred. Bandwidth prices vary, depending on the regional location of the edge server.
CDN billing occurs according to the billing period established in your {{site.data.keyword.BluSoftlayer_notm}} Account.
You can view metrics and usage on the Overview page, which can be reached by selecting your CDN from the Content Delivery Networks page. Note: After you create your CDN, it may take up to 48 hours for metrics to appear.
Yes. Metrics can be gathered for a minimum of 7 days. Metrics can be viewed for a maximum of 90 days. For those using the API, it is recommended to use 89 days as the maximum, to account for any differences in time zones.
The wildcard certificate is the most economical way to deliver web content to your end-users securely. To use the wildcard certificate, the customer must use the CNAME hostname as the service's entry point (for example, https://example.cdnedge.bluemix.net). After the CDN mapping is enabled for HTTPS using the wildcard certificate, the edge server contacts the Origin Server through HTTPS. If the Origin Server is specified as a hostname, the edge server uses the origin domain as the Server Name Indication (SNI) header for the Transport Layer Security (TLS) neogotiation with the Origin Server, by default. However, if the origin domain is specified as an IP address, the CDN's hostname will be used as the SNI header. The origin certificate must be signed by a recognized Certificate Authority (CA).
When HTTPS Port is selected, the user can only use the CNAME to access the service.
No; it will only delete that CDN. Your account still exists, and you can create additional CDNs.
Content Caching is done using an origin pull model. Origin Pull is a method by which data is "pulled" by the edge server from the Origin Server, as opposed to manually uploading the content onto the edge server.
The maximum value for Time To Live is 2,147,483,647 seconds, which equates to roughly 68 years! The minimum value is 30 seconds.
If the caching time expires for a content, the edge server will try to fetch the content from the Origin Server. If for some reason the Origin server is down or cannot be contacted, the edge server can serve the stale content, if that option is set, which is what most customers prefer. Currently our CDNs can only be configured with this option set to Yes as default. Changing the option to No will not have any impact: the Serve Stale Conent option will continue to be set to Yes.
Yes, the combined limit is 75 entries per CDN.
Yes, you can have a limit of 10 CDNs per account.
Yes, Firefox and Chrome are the recommended browsers, at their latest versions.
If you provide a path while creating a CDN, it allows you to isolate the files that can be served through CDN from a particular Origin Server.
Run the following 'curl' command by replacing "origin.cdntesting.net/assets/ibm_3d.gif" with respective file path on your origin:
curl -I -H "Pragma: akamai-x-cache-on, akamai-x-cache-remote-on, akamai-x-check-cacheable, akamai-x-get-cache-key, akamai-x-get-extracted-values, akamai-x-get-nonces, akamai-x-get-ssl-client-session-id, akamai-x-get-true-cache-key, akamai-x-serial-no" origin.cdntesting.net/assets/ibm_3d.gif
If the output of the command matches the following format, the CDN is working as expected:
HTTP/1.1 200 OK
Server: nginx/1.13.0
...
X-Cache: TCP_HIT from a199-117-103-28.deploy.akamaitechnologies.com (AkamaiGHost/9.0.2.1-20488781) (-)
X-Cache-Key: /L/1363/535014/1d/origin.cdntesting.net.ibm.com/assets/ibm_3d.gif
X-True-Cache-Key: /L/origin.cdntesting.net.ibm.com/assets/ibm_3d.gif
...
...
X-Akamai-Session-Info: name=WSD_BEST_PRACTICES_TD_TYPE; value=PATTERNS_BASED_PARENT_MAP
X-Serial: 1363
Connection: keep-alive
X-Check-Cacheable: YES
Please refer to the 'Getting Help and Support' page, or open a ticket in the Customer Portal 
.
Click on the CDN to get to the Overview Page. On the right corner you can see a Details section with the CName information.
Yes. There can only be 5 active purge requests at a time.
My Purge Request for a given file path is in Progress. Can I submit a new request for the same file path?
No. There can only be one active Purge request for a given file path at a time.
IPv6 (or dual stack support) is supported by Akamai's Edge servers. It is designed to help customers with IPv4 only origin to accept connections from IPv6 clients, convert from IPv6 to IPv4 at the Edge and go forward to the origin with IPv4.
Note: Creating a CDN using an IPv6 address as the Origin Server Address is not supported.
The Hostname input string should be alphanumeric, ending with a valid top-level domain name, and less than 512 characters in length.
The CNAME input string should be alphanumeric, less than 64 characters, and unique. (It cannot be in use by any other IBM CDN.)
For Create CDN, the path string is optional. If provided, the path must begin with a '/' and it must be less than 1000 characters in length
For Add Origin, the path is mandatory. Also if the CDN was created with a path, the path for Add Origin must start with the CDN path as the prefix. For example, if the CDN path was specified as /storage, to invoke Add Origin with a path called /examplePath, the path provided would be /storage/examplePath'.
File extensions should be comma separated. For example, the list "txt, jpg, xml" is a valid list. Any particular extension cannot be longer than 10 characters.
For the Akamai vendor, only certain port numbers are allowed: 72, 80-89, 443, 488, 591, 777, 1080, 1088, 1111, 1443, 2080, 7001, 7070, 7612, 7777, 8000-9001, 9090, 9901-9908, 11080-11110, 12900-12949, 20410, and 45002
The path for a CDN mapping or for the origin is treated as a directory. Therefore, users trying to access the origin path should access it as a directory (with a slash). For example, if CDN www.example.com is created using the path that includes the /images directory, the URL to reach it should be www.example.com/images/
Omitting the slash, for example, using www.example.com/images will result in a Page Not Found error.
Hit ratio represents the percentage of times the content was delivered from the Edge Server Cache, rather than being delivered from the Origin Server. It is calculated as follows:
((Edge hits - Ingress hits)/Edge hits) * 100
where:
Edge hits is defined as "All hits to the edge servers from the end-users"
Ingress hits is defined as "Origin or Ingress hits are for traffic from your origin to Akamai edge servers"
Because Hit Ratio is calculated at the Account level, not per CDN, the Hit Ratio will be the same for all the CDNs in your account. This fact also explains why the Hit Ratio may be non-zero when the number of Edge hits for a particular CDN is zero.
Currently HTTPS is supported only through a Wildcard certificate. As a result of this limitation, the connection must be made using CNAME; trying to connect using the Hostname will result in failure.