GDC backward compatibility

[Huy H.]

Over the years, whenever we release a new version of our product, we always make sure that the version of GDC/GRE/BDL/GAS are of the same version number because we want to make sure they are compatible.  However, someone recently had advised me that GDC is backward compatible.  Meaning, I should be able to run GDC 3.10.x against BDL/GAS 3.00.x or similarly, GDC 3.20.x against BDL/GAS 3.10.xx.  What is FourJ's take on this?

We've had some success running a more up to date version of GDC against older BDL/GAS internally during our development (just due to laziness more than anything).  But we've also countered some explainable glitches that we just brushed off as version compatibility.

The reason we are asking about this is because we've had some issues that we reported in GDC 3.10.xx that had been fixed in 3.20.xx.  Most of the time we like the fix to be ported back to GDC 3.10, but sometimes that's not always possible. 

[Reuben B.]

As per the documentation http://4js.com/online_documentation/fjs-genero-manual-install-html/#genero-install-topics/c_gdc_install_gcompat.html

Also one of the reasons for introducing GDC Auto-Update is to simplify the deployment process of the GDC so that you can use the latest GDC. http://4js.com/online_documentation/fjs-gdc-manual-html/#gdc-topics/c_gdc_autoupdate.html

[.]

Hello Huy
Indeed, backward compatibility is something supported for GDC 3.xx as it was the case in for GDC 2.50 regarding Genero 2.xx. If you still have access to the slides I presented in Cancun 2017 (I am unable to find them on the web site, I should be bad in searching), you may see that I talk about that during my presentation.
Last frontend (GDC, GMA, GMI, GBC) is intended to be compatible with any Genero 3.x server (GAS+BDL).
Olivier.

[Reuben B.]

... If you still have access to the slides I presented in Cancun 2017 (I am unable to find them on the web site, I should be bad in searching), you may see that I talk about that during my presentation.
...

4js.com/wwdc is the easy to remember URL for our WWDC conferences, both before and after the event posts.  That saves having to find conference posts in amongst https://4js.com/news/events/.  For each individual conference page, copies of presentations  are on the right side, unless you are on a narrow device in which case the responsive layout moves them to the bottom of the page.

In any event, this documentation https://4js.com/online_documentation/fjs-genero-manual-install-html/ (from which I sent the previous link) should have the definitive compatibility and system requirements entries for our products, and should be the first place you look with any compatibility, system requirement type questions, rather than using conference slides.

Reuben

[Huy H.]

Thank you gentlemen for the information and confirmation.  It is good to know that the option is available should we choose to use it. 

Our reason for always trying to stay with the GDC version that bundled with the initial product release is that we're more confident that we are not introducing new issues.  There's always unknown factors when it comes to GDC's behaviour that we do not know until it gets installed on a new environment.  For instance, during our last product upgrade, we had to manually set a few QT_ environment variables on some machines that was crashing due to OpenGL 2.0 error.  This is the sort of problems where we cannot test for before releasing the product. 

I hope you take that into consideration when you fix an issue and decide for one reason or another to not port the fix back to the current GDC version.  If you decide to not port the fix back to the previously released version of GDC, you're putting us in a difficult situation: our customers getting annoyed with us because we cannot provide a timely fix, or we are forced to update to a newer version of GDC that has not been "battle tested" with potential unknown issues.

[.]

We always take care of our customer constraints but we try to compromise the best. Backporting minor bug fix or features has a cost and may be risky too. You need to know that GDC depend on QT and QT life cycle is quite tight. When you are staying on old GDC it may happen that we fall into an unsupported situation from QT point of view. Thus it is always desirable for you (customer) to be as close as possible to our last release.
AFAIK in most case we do not refuse to backport annoying bug fix in older releases but when we know you are in a development stage we propose you that you upgrade the GDC version. If we did not understood correctly the situation, feel free to reopen the support case and explain us your constraints.

[Huy H.]

Thanks Olivier.  I just want to clarify that some of the issues we reported are from our current product that has been released for over 6 months, it is not a product in development.  We have several products that are in different cycles.  We have no issues when the product is in development stage.  But it is the released product that we are more concern about.  Thanks.