Emphasize that we’re primarily a news site and this has certain implications for the longevity of our content – more later…
Talk about why we optimize too. These are reasons for choosing Akamai DSD but we also optimize to hold the line on CapEx and OpEx growth.
Somewhere in here we want to talk about h uch of the CDN’s value is only realized when it serves > 50% of your content.
At the end of this we segue into the next slide by saying you place the needle on the spectrum by understanding your business context…
Content is frequently updated when news breaks Old news is irrelevant news – access patterns bear this out
The site – and the origin – must stay up no matter how much traffic hits. After that, the content must be fresh. To the business, stale content is worse than no content at all. Cost is mitigated through non-technical means, I.e. choosing a 95 th percentile billing model for DSD traffic so we don’t get hammered on cost by spikes.
We’ve been gradually refining our approach, tools, techniques and architecture over the last ten years and we’ve learned a lot. Executing dynamic code for identical requests is silly (Newsdelivery) Don’t ignore architectural changes that you should make at the origin – CDN can only help so much. If your origin stinks, the edge will too. TTL means the time that Akamai will wait before checking the origin for freshness – doesn’t mean that the object will necessarily be retrieved, if it is already in-cache and fresh.
Need to validate these numbers.
Point out that 83.6% of the requests are 304 Not-Modified, which bears out our strategy of heavily using If-Modified-Since
Blake Crosby Julian Dunn Media Operations and Technology CBC/Radio-Canada Cache Optimization & Origin Infrastructure Reduction Using Akamai Site Delivery
Instant results, no need to wait for Akamai configuration to deploy.
Ability to adjust TTLs on the fly during special events or emergency situations.
There are some situations which make controlling caching difficult. Here is how we’ve dealt with them.
Server Side Includes
Apache cannot calculate the last modified timestamp for files with server side includes (roughly 99% of all html pages on cbc.ca).
We’ve applied a blanket 2 min TTL on all files with the “text/html” content type
Server side customization of content will not work as it will be cached for all users.
We’ve mitigated this by having all customization occur on the client side. If a cookie does not exist, then the browser makes a POST request (which isn’t cached) to the origin to set a cookie which contains the users location.