Tale from inside TransactionScope

One of the last things you want to get from your Commerce site is that the order data is gone. What can be more confused than if your log shows that the cart has been converted into a purchase order, you even got the PO number, but after that, the order disappears? It’s nowhere to be found, even if you look into database. It’s kind of magic, but not the kind of magic you would want to have.

But everything happens for a reason. And actually it’s with a good reason: data consistency.

Episerver Commerce has the concept of TransactionScope. Simply put, it allows two or more database operations to be done as atomic: Either all of them succeed, or all of them will revert back. If a TransactionScope contains 3 operations A, B, C, then even if A, B succeeded, but C is yet to commit, and something goes wrong, then A and B would be reverted.

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PS4 firmware 4.5 wifi problem fixed

And finally the much anticipated 4.5 firmware of PlayStation 4/4 Pro has arrived, with some very neat features: extended storage, custom themes. It’s a big improvement for PS4 users, well, almost: the firmware comes with a big problem for ones who are using wifi: the download speed is now terrible, and even worse, the lag in game is making the games unplayable. Before 4.5, I had no problem joining matches on Uncharted 4, and playing Titanfall was very smooth – ping is never more than 100ms. After 4.5, I can’t hardly join a match on Uncharted 4 (errors in connections), and the lag in Titanfall spikes to more than 2000ms, making the game totally unplayable. Test Internet Connection shows that I have a a few hundred Kbps upload and download, when the wifi connection is supposed to be 130Mbps (PS4 ony has 2.4Ghz wifi 802.11 b/g/n, only PS4 Pro has 5Ghz wifi), and my internet connection is 250/100Mbps, so that must be a big problem somewhere.

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The Catalog UI trade-off: performance or better UI

I supposed this is a well known feature, but I was asked more than once about it, so it’s better to write something here to clarify the confusions.

If you have some very, very big catalogs, you probably have seen this “notification” in Catalog UI

By default, the Catalog UI groups a product and its variations in a parent-children view (they are not exactly parent-children, by the way). However, to do that, it needs to know about all the entries in that specific category. If it’s a small category, it should be no problem, but if it’s big one, then it’s inevitable slow. The lazy loading which the catalog content list only loads the contents when you scroll to them is not helping in this matter. Moreover, the grouping introduces an overhead for the UI, and having too many groups can severely affect the performance. Trust me, you won’t like a sluggish UI.

This improvement was introduced way back – 7.11 if I remember correctly – thanks to my colleague Magnus Rahl. To this day it’s still valuable – the performance was improved – but not that much to remove the threshold completely (And the improvement to the catalog versioning in Commerce 9 should have nothing to do with this).

When you see this notification, and if you’re unhappy with it, you have two (primary) options: Either to sub-categorize your category – i.e. introduce sub categories so each will have a smaller number of entries. Or increase the value of threshold.

Each approach has its own disadvantages. Sub-categorizing might break your SEO, while the second approach will undoubtedly effect the UI performance. Your call!

Now – the tricky part – which number to configure in SimplifiedCatalogListingThreshold setting. Obviously, it must be greater than the biggest number of entries in a category. But how to obtain that number? I’ve seen the confusion to raise that value to 3000, 5000, or even 10000 and it’s still not working. No, you can’t guess, you have to know for sure.

One simple option is to look at Commerce Manager Catalog Management. There is a small text in right corner of the list which shows the number of entries in that category (No, it’s not available in the Catalog UI, but I assume it would be helpful?)

 

The nuke option is to look at the database. Usually we recommend to avoid manipulate the database directly, as it can be dangerous – but here is a little code which only queries data (so practical harmless)

Now you know the biggest number of the entries in a category – just change the threshold in setting. Try it and see if the UI Performance is acceptable to you.

1600 vs 1400 vs 1200 rpm washing machine

I got this question before – and now I bought one, I hope I can help you choosing the right washing machine.

You might have read other answers on the Internet – and yes most of them are saying a 1200 rpm washing machine is as good as a 1600 rpm one, in term of the dryness of the clothes.

Wrong!

That might be true with synthetic clothes – which are the easiest ones to dry. But for cotton, it’s a big different. I tried same clothes with both 1400 rpm and 1600 rpm and my clothes are noticeable drier when it comes out of 1600 rpm mode. 1200 rpm, of course, is not even close.

That means the time you need to dry it, as well as the consumption of the dryer, will be less.

And to endure 1600 rpm spinning speed, the washing machine must be sturdier and more balanced. In other words, it must be built better – so you can expect it to last longer. You can see that in same series, the higher model which supports 1600 rpm is always heavier than the lower end models. Yes – it’s to support the faster rotation.

So if you have cotton clothes, and if you can afford it, I would suggest to go to 1600 rpm one.

May I trust your site?

If your site has exceeding ads, or you ask me to disable my adblocker, then no.

If your site ask me to subscribe to your newsletter after 5 seconds, then no.

If your site has no comment section, then no.

If you don’t moderate your comment section and it’s full of spam, then no.

If your site open pops up, then no.

If you site doesn’t have HTTPS, then that might raise suspects. (Yes you should look up in the address, this site is not HTTPS-enabled, and that’s entirely my fault, but I would never ask for your information more than a name and an email address (you don’t have to give a real one)). I know, I should have spent time to enable HTTPS on this site, I’m just too busy writing content (another way to say I’m lazy).

 

 

EntryContentBase, MetaObject, CatalogEntryDto, Entry: which should you use?

It can be pretty confusing for new Commerce developers to understand how to work effectively with entries in Commerce. There are many things which represent the same concepts, however they are different and their APIs are not compatible. So which is which and what should you use?

Which is which

    • CatalogEntryDto is the DataSet to represent one or more entries (CatalogEntryDto can of course be empty). Beside the basic information like Name, Code, or MetaClassId, depends on how did you load it, a CatalogEntryDto can contain information about the assets, the associations or the variations (you can specify what to load by using CatalogEntryResponseGroup parameter. CatalogEntryDto, however, does not contain information of the metadata system of an entry – for example, if you add a metafield named “Description” to your entry metaclass – that is not available in a CatalogEntryDto.
      CatalogEntryDto can be loaded or saved by ICatalogSystem methods.

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    I was with the EMVPs, and that was a fantastic experience

    If there is anything I regret being an Episerver employee, is that I can’t be an EMVP – the gang of awesome Episerver developers which their contributions are widely recognized by the community (I don’t consider myself to be “awesome”, but I try (to be)). The EMVPs can be seen as the evangelists of Episerver frameworks and technologies, they spread their wisdom, experience and best practices to help developers build better solutions, and they give valuable feedback to us to build better frameworks.

    EMVP Summit is one of special treat Episerver gives to EMVPs, as a recognition for their contributions, and also a chance – directly than ever – for Episerver to listen to the feedback from their distinguish developers. As a software engineer in Commerce development team, I was sent to team up, to talk, to discuss and to socialize with the EMVP (after winning a small competition with my two teammates, and getting a grant from my wife 🙂 ).

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    Debug .NET memory dump with WinDBG – crash course. Part 1

    If you ask me what had I been doing the last two weeks – then the answer is I was pulling my hairs.  A customer had a problem with their site as the memory hiked up after catalog imports and stayed there “forever” – and in the end it slowed the site down. I jumped in and almost regretted that decision – had to spent days  messing around with WinDBG and memory dumps. In the end – I found the problem and it was fixed. A lot of hairs were loss in progress, but I learned something about WinDBG – and that’s what I’m sharing today.

    WinDBG is probably the most famous tool for debugging stuffs on Windows. Out of the box, it only works with native applications, aka assembly and such – but lucky for us, there are plenty of extensions to allow it to work with .NET application. The “standard” SOS and more advanced extension SOSEX. SOS is included in WinDBG, while you can download SOSEX from here (for 64 bit) or here (for 32 bit) . Download the zip file and extract the dll somewhere.

    WinDBG comes with the Windows SDK, not the standard .NET framework, so you’ll probably need to install it separately from here

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    Episerver Commerce CustomerContact Events

    This post was inspired by this question: http://world.episerver.com/forum/developer-forum/Episerver-Commerce/Thread-Container/2016/9/commerce-manager-contacts-events/

    and is an excerpt from my book: https://leanpub.com/proepiservercommerce

    You might notice the lacking of events in some parts of the system. We have events for catalog system, for order system, for prices and inventories changes, but that’s not enough. You might want to have events – or at least – the ability to know when something happens. For example, when a customer contact is changed, or edited, or deleted, it would be very nice to do some extra actions.
    Sending emails, updating external systems, etc.

    Such events are not available out-of-box, so we have to implement our own. How? We don’t have ICustomerContactService (or something similiar) interface where we can write our implementation to replace the default service (and even if there is, it would be a big task to do so). So there’s no “ordinary”, framework-way to do that. However, CustomerContact is built on Business Foundation system, and BF, at its core, is all above extensible and pluggable. We don’t have ICustomerContactService interface, but we have IPlugin
    who can do the same, and even more. As we learned in previous chapter, CustomerContact is just another EntityObject and all operations are still done via BusinessManager.Execute(Request) – even we have some nice wrapper methods to make working with it easier. And when Execute(Request) is called, it also runs all registered IPlugin modules.
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    Why am I leaving HBO (Nordics)

    I’m a fan of great TV shows and movies. With my very limited time, I always try to be selective – only top ones (well, based on IMDB – don’t judge) are on my watch-list. While Netflix has some very good content, and they have been adding great homegrown TV series (House of Cards, Daredevil, Stranger Things, Narcos, just to name a few), those have not been enough for me. I want to watch Games of Throne, The Wire, The Sopranos, Silicon Valley etc, but sadly, they are pretty HBO-exclusive. Fine, I decided to suspend my Netflix for a month a resume my HBO Nordics subscription. At least for one month to watch the good content there. Last year I did try HBO one month, for free, but I cancelled it – which I have no clear memory why I did. Right after I tried HBO again, it’s clear to me why I left HBO at the first place – and sadly, there are several reasons for that.

    No native apps

    I have two TVs, one LG which runs its own OS – which I’m not sure which is, but probably WebOS, and one Panasonic, which runs FirefoxOS. Both have Netflix native apps and they runs smoothly – my Panasonic is even 4K and there have been no problems with Netflix (as long as the network is OK then the streaming is just fine). Guess what? HBO have no apps on both of the OSes. The only option I have is to install an app on my PlayStation 4, and then watch HBO from there (and that’s even new, it was not there last year).

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