Month: February 2019

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You want to use a CDN with Sitecore huh?

First things first! Do we need a CDN at all when Sitecore is your platform of choice. Not really, you can actually do pretty awesome good in terms of performance with good caching, scheduled publishing, uploaded good imagery and rock solid code with few best practices followed. But, what if you have to use a CDN? There will be various situations in which you may have to due to business reasons or may be the audience that is very spread out across the globe or if the site is down right very media heavy.

Various questions pop up when folks bring up CDN. Where exactly is this going to sit in the bigger picture? What is the plan to use for CDN for? What do we do on Sitecore to make this happen? Are the assets on CDN? What happens behind the scenes? Now, it is more than likely that most of us already know answers for this. So, I will not bore you all explaining what are questions that need to addressed and understood when thinking about CDN with Sitecore.

Instead, what I would like to do is provide a quick comparison cheat sheet based on various features and capabilities when you have made your decision to use CDN with Sitecore. Recently, I was researching and finding information about what is the best way to integrate CDN with Sitecore in most efficient and easiest way possible. Couple years ago, I remember that integrating with CDN was still considered considerable amount of work. But, with Sitecore 9.1+ it should be real simple if of course the basic OOTB functionality that around CDN is enough for your business needs. I also explored one more option which is not bad either if you have time to make the legacy code work with newer versions of Sitecore.

Option 1: CDN Connector

  • Reference URL – https://github.com/NTTDATA/SitecoreCDN
  • Multi Site Support – Yes
  • Sitecore 9.1 Support – Unknown, but, some of our team suggested they did make this work on 8.2 and hence conceptually with that fix that we have to get this working on 8.x should probably and hypothetically work for 9.1 as well. I would recommend a POC if you are going to use the connector. As you can see from source url, the code base is very outdated almost 6 years ago. But, turns out with few fixes it may still work and does the job well. 🙂
  • Media Versioning – Yes. it does stamp the media with an incremental value based on date of publish which would help knock cache and have good versioning in play
  • File Versioning – yes. Based on documentation, it does support file versioning for static assets as well. But, this is something I highly recommend testing quickly before confirming that in fact it does this fine.
  • Other advanced features – It actually does more than this set and if you are curious of full functionality you should read this great resource https://github.com/NTTDATA/SitecoreCDN/blob/master/NTT%20DATA%20Sitecore%20CDN%20Connector.pdf
  • One important thing to note which was pointed out by my peer is that the connector actually checks to see when to load a resource from CDN vs when not to. For instance, if there are goals set up on a download of specific pdf for instance, it should be loaded from Sitecore media library and not from CDN. The connector handles this, but, obviously the code might be subtly outdated. Easy to fix this though if not working and I totally think this should be done if personalization is actively used in your sitecore instance. You can check that additional logic here if curious.
    https://github.com/NTTDATA/SitecoreCDN/blob/master/Code/Providers/CDNMediaProvider.cs

Option 2 – Sitecore Media Library CDN

  • Sitecore 9.1 actually comes with a special package to enable CDN
  • Reference url – https://doc.sitecore.com/developers/91/sitecore-experience-management/en/sitecore-media-library-cdn-overview.html
  • Multi Site Support – No. If you pay attention to config file in the package that Sitecore provides you will see couple of settings that enable CDN use on media library. But, these are not site specific and are global. Hence, this does not support different settings for different sites.
  • Sitecore 9.1 support : obviously, Yes. 🙂
  • Media Versioning – Yes
  • File Versioning – No. You can see an added note of no such capability here, scroll to the bottom of the page. https://doc.sitecore.com/developers/91/sitecore-experience-management/en/sitecore-media-library-cdn-overview.html
  • Screenshot of settings for reference in CDN.config which is the only thing on the package provided on downloads section

Now, there is no wrong or right way. It depends on your requirements and what would be most efficient path to choose. It is great that Sitecore actually has some option now to plug and play and use CDN OOTB in some level. Only hope is that OOTB we get more settings and flexibility to choose CDN configuration that comes OOTB than to implement some thing to fit needs that has become a new normal these days. I am sure we will get there soon. But, for now, pick and choose. If these do not fit your needs, feel free to make something custom. Custom solution actually takes me back to really old versions of Sitecore that needed custom solution to fit in CDN in-between media library, server and end user.

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Coveo new GUID generation issue

Thursday last week, one of my team member ran in to an issue which was preventing XHR request to fire off to Coveo and get the results back. He struggled to overcome the issue almost whole day long and at that time as his lead it became my responsibility to help solve the issue. I was actually quite doubtful about it and unsure if I could help solve or not, but, as a lead, rule is you can not pass on fear to your team, you have to no matter you feel pass confidence that – ‘Yes, we will get over this’. Challenge Accepted!

Here is a sneak peek of the issue. So, in older versions of Coveo and in more fond memory on Legacy framework implementation, each interface element had a unique ID that you would need to pass from presentation details via properties on your rendering. If you do not do much about it, a unique identifier will be generated when you create a new content item that has the presentation of Coveo embedded. With hive, it is actually not so different, pretty similar, only the properties are on data sources. The issue on hand is that, on the interface view HTML, the @Model.ID was actually coming back as ‘$GenerateNewUniqueID’ instead of DOM Element ID noted on presentation. You can see this below on the screenshot.

Error on JS for generating unique ID.

So, as with any issue, it becomes very important to replicate the issue on local especially when you can not get your brain juices flowing on call on tough problems like this. See the steps I did to crack this thing

  1. Why would Coveo not replace this in first place? It should automatically happen. My team mate stumbled upon few Q&A and checked the pipeline related that does this behind the scenes to ensure that is in place and hooked properly.
  2. We checked the presentation again very carefully and datasources to ensure DOM ID is present and is unique
  3. Ensure this is copied over properly to Final Layout on Sitecore as well and indeed there is a correct data source being passed in presentation.
  4. Then we ran an ugly experiment to actually replace standard value as it seemed like Coveo for some reason was taking that. No luck, still same issue.
  5. Re-installed Coveo For Sitecore package relating to our Sitecore version and published everything. Still Nothing!
  6. This was working just fine on our UAT server, so, just to try our luck ported over all packages from UAT related to bare bone Coveo templates, layouts, etc., Nope! Did not work.
  7. Ran out of all options!

One little detail from my team mate sparked an experience from the past. He said when he installed a package that has just one item while he was experimenting did something and though the XHR request was still having lot of issues, he could now see the ID replaced now. That reminded me that in the past when we ran in to weird issues where presentation was not updated even if the presentation did look right on Coveo end, an IIS Reset had solved all problems. Went ahead and tried that and knocked out browser cache just in case and boom, everything started working.

I should have probably done IIS reset first before trying anything, but, with more knowledge you gather you would want to explore that rather than blind belief that a restart or reset would solve things. 🙂

This whole debugging experience got me thinking if I was not a Software Engineer, I would have made one awesome FBI Agent for some reason. It almost felt like I was connecting from past and paying attention of little detail on hand to solve the issue. Quite a few memories of great crime investigation series flashed in my brain. lol