I recently get to know grails and start to using it, I know that grails is a great language and it is very helpful for rapid development, but I cant understand why grails dont have a good backward compatibility, I use grails 2.3.8 and grails 2.4 for my projects but many of sample codes in the internet are 2.2 or less, and it isn't time efficient to convert them to 2.3.8 or 2.4 because there are many changes from one version to another. And some times although I do any things right and every thing must work like it works with grails 2.1 or 2.2 but some things still remains.
Am I wrong? I skipped some things that make converting version so hard?
And above all this, what are the guaranties that projects I'm developing right now will be compatible with higher versions of grails that comes in the future?
Joshua Moore is right with his answer, but I do not see it as passimistic as he does.
The grails development team is brave enough to make changes which break with the past. I consider this as a great feature - Grails does not ride dead horses.
For me, most of the changes don't seem to bee too radical. Most of the time, I skip 2-3 version and then upgrade my apps to the current stable version in less than a day. This also helps me to get to know the new features.
If you don't know how to upgrade, the safest way is to use the grails upgrade command. Just increase you version number step by step and do an upgrade and re-run your test (yes, tests help you in your upgrade process :-). If tests fail, take a look at the great changelogs and the "What new in Grails x.y?" sections of the documentation.
Often it is also helpful to compare your old grails version app with a new and empty target version project with a good comparison tool like BeyondCompare. This way you easily spot changed configurations.
Hope that helps
Update: When you are new to "all those webconcepts" you should first decide on the platform you want to work on. If it is the java ecosystem, Grails is the best webframework on the market :-) Otherwise PHP, Rails, DJango etc. could also be a match.
So if you want to learn Grails (and with Grails all those webconcepts), I would suggest to start reading the Guide which will tell you how Grails works. If you need more examples, I can suggest the "The Definitive Guide to Grails 2" published by Apress. It covers basically the same content as the guide, but it does so by walking you through a process of building a sample application.
When it comes to the samples you find on the net... as soon as you get to know the framework better, you will probaply know ho to handle the examples - but there is no silver bullet...
Nothing guaranties that your projects will be compatible with future versions of Grails. In fact, from my own experience, they won't. Often things change, and sometimes radically too, as Grails matures into higher versions.
The same holds true of backwards compatibility as well.
All you need do is take a look at the introduction section of the Grails documentation to see how often things change significantly between versions. A lot of times these changes require significant refactoring of older projects to upgrade them. I still have several large projects running on the 1.3.x branch of Grails because we don't have the resources (time) to go through and upgrade them.
Often this upgrade process involves creating a new empty project then slowly moving the code from the old project into the new project, updating code to reflect newer means of doing the same thing and testing. It's not easy for projects where you have 100+ Domain classes, 1000+ GSPs, 50+ Services and several hundred thousand lines of tests.
Related
I have my project on rails3.2.13 and I am having around 80 gems in it,now I need to migrate my project to rails 4,what are the steps I need to follow for successfully upgrading without any gems conflicts and errors.
With so many gems in your codebase I suspect this is a large app and its not going to be a quick upgrade and unless you have been given a large amount of time to do this, your best bet is to break things down and do updates in stages on the old version and then upgrade when you feel the codebase is in a better state.
Before attempting the upgrade I would consider these points and make small changes / releases before any big upgrade project. The less code you have to actually change at the final upgrade stage the less risks you have.
Gems: The more gems you have, the more code that you have worry about and more more code you have to upgrade. Is your app using all these gems and if not can you remove the un-used ones. Are any of the gems really which are pretty basic and can you do the same functionality with just rails / ruby functionality and actually remove some gem altogether. The less gems you have, the less pain you will have when it comes to upgrading.
Tests: Whilst you are working on the code, write tests for any new code that you add or alter and write tests for any core parts of the code.
Latest 3.2 release: Get your coebase running on the latest 3.2 release, this will then include extra warnings of things which may not work that you can sort out sooner.
Deprecated: Are there any deprecated warnings in the logs, if so fix these before attempting any upgrade.
Old code: Is there any code that you know wont work on the later versions, can this be replaced with something that will work on both.
When you feel that the codebase is in a state where it can be upgraded, consider these points.
I would suggest not trying to do to much at the same time: Think about breaking out any ruby upgrade into a separate project from the rails upgrade.
Maybe consider moving up slowly, getting your app onto 4.0 or 4.1 and then re-evaluating things using the points above could prevent less risk to things breaking.
Regardless of how many automated tests you have, get a software tester to run over your app. they will find errors that your automated tests will have missed.
There are plenty of upgrade guides out there that you should take a read of before performing any upgrade.
Good luck.
Help! I'm porting a large ruby app to Grails - but the Grails startup of my application takes more than 2 minutes.
I've already set dbCreate to "read" I've ensured my high end dual processor desktop windows box gives Grails needed RAM (1 Gig). I have no plugins installed. I have 170 domain classes that used to be ruby classes.
When it starts up it prints out the line "Running Grails App.." and then hangs for a long time before it then prints out the "Server running" line.
I just did something where I migrated all my ids to bigints. That seems to have worsened the problem. Now it takes about 10 minutes to startup.
I am new to grails would you please give me a few more details on what and where to log the events at startup? As to profiling the vm, its been a few years since I did a lot of Java. What do you recommend as the best profiling tool to use now?
What else can I do to speed up Grails startup?
Unfortunately, I am not sure too much can be done beyond what you already did. As you know, there is a lot going on when it starts up, with all the plugin resolution / loading, adding dynamic methods to your domain objects, and overall dynamic nature of Groovy.
I am not sure which version you are using, but I've asked for ability to turn off dependency checking when you start up in 1.2, since that adds a bunch of time to startup time as well.
I realize above isn't too helpful, so perhaps this will be: I split up my application into several plugins. One for domain objects, one for graphing capability, one for excel import, another for some UI constructs I needed. I didn't do it just because of slow startup times, but the advantage is that I can test parts of the system separately from each other before integrating everything together.
I am about to add a piece of new functionality that involves at least 10 new domain objects, and I am first developing them in a separate plugin by having stubs for the few objects they have to interact with from the core app. That allows me to both reduce startup times, and also have my code better isolated.
So if it's an option for you, try to separate out things so you can work on them separately, which will alleviate your issue somewhat. There may also be other benefits in terms of having your team work on smaller components separately, better modularization, etc.
Hope this is helpful.
170 domain classes is fairly large, but 2 minutes still seems really long to me. Do you have a ton of plugins installed? Potentially too verbose debug settings?
I'd be curious how long it took if you created a fresh grails app, copied in all of your domain objects (and the subset of plugins that the domain objects might need to actually operate) and see how long that takes to start.
Jean's suggestion about separating things out if possible is a good one. I've done something similar on previous projects where we have a domain plugin, and our other apps all rely on that domain plugin.
You could also use the grails events to log some timing information on start up to see where your bottlenecks are. Timing the "PluginInstalled" event should be good as I think that the hibernate plugin would be caught by this in addition to the other plugins.
You may have a dependency problem. If a plugin you use relies on a library in maven that has 'open ended' dependencies, grails will go and look each time if there are newer versions to download in the range. I have no idea why anyone would specify it like this. It seems it would lead to unreliable behaviour. For me, the culprit is Amazon's java aws library, naturally used by a plugin that talks to Amazon's cloud.
http://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk/1.2.10
note how some of its dependencies are like this
org.apache.httpcomponents httpclient [4.1, 5.0)
it appears that every time, grails is looking for a newer version (and downloading if it exists, I just noticed 4.2-alpha1 of httpclient come down when I ran this time).
By removing that dependency from the plugin and manually adding the required libraries to my .lib folder, I reduced my startup time from >30sec to <1sec
You might want to see if there are other knobs you can turn other than Grails in order to fix this.
Have you tried approaching this as a performance issue? You can a look at the box performance and try to find out what the bottleneck is. Is it CPU? Is it a disk read issue? Can you attach a profiler to the VM and find out what's using up most of your startup time?
Have you tried basics like these for further deployment to a servlet container of your choice or in-place .war bootstrapping?
grails -Ddisable.auto.recompile=true run-app
grails run-war
grails war
Have been developing with Grails for couple of weeks now,
Though I've loved the experience and the possibilities, I've seen following problems starting up.
Please share if you've had similar issues.. and remedies would help too.
Transaction management (in-built) doesn't seem to work in some circumstances.
AOP with domain objects doesn't work
Grails IDE-plugins are pretty primitive
GWT-Integration (with the plugin)
Plugin installation (fails unusually) probably cause plugins are not matured enough.
Lack of extensive documentation (though what is available is pretty good)
Debugging support
If you actually want solutions for these problems you should post a separate question for each with a lot more information than you've provided here. For example, I can't possibly diagnose the cause of the problem when all I know is
Transaction management (in-built)
doesn't seem to work in some
circumstances.
Here is my opinion on these issues:
Transaction management (in-built) doesn't seem to work in some circumstances.
I haven't noticed any such problem
AOP with domain objects doesn't work
I guess what you mean here is that meta-programming domain objects doesn't work. I have encountered this and haven't found any solution. If you really meant AOP then I can't help you as I've never used it with Groovy.
Grails IDE-plugins are pretty primitive
The IntelliJ plugin is very, very good. The Netbeans plugin is OK. Last time I tried the Eclipse Groovy plugin it was awful. However, I believe that a new Eclipse Groovy plugin has recently been released as part of the Spring Tool Suite (STS). It's supposed to be big improvement on the previous Eclipse Groovy plugin, but I don't think it has much Grails support yet
GWT-Integration (with the plugin)
I don't use GWT, so have no comment
Plugin installation (fails unusually) probably cause plugins are not matured enough.
I've never had problems installing plugins, though if I update a plugin, I sometimes need to manually remove the old version from the .grails directory.
Lack of extensive documentation (though what is available is pretty good)
I think the level of documentation for Grails is way ahead of most OS projects. There is a wide range of Grails books available, there's an active mailing list, and the official document is 176 page long.
Debugging support
Again, it depends on the tools you're using. With IntelliJ, debugging a Grails app is as easy as debugging a Java app with Eclipse.
My own pet peeves about Grails development are:
Upgrading from one version to another is often a very painful process due to lack of backward compatibility. When I upgraded from 1.0.4 to 1.1.1 about 20% of my tests started failing
Application reloading is very hit and miss.
My feedback after few months with Grails:
Didn't happen to me.
I don't use AOP
Wrong. IntelliJ is very good and especially the last beta version. You can download it for a free trial. I know that Eclipse support is very limited and NetBeans becomes better but still behind IntelliJ
I can't say. I don't use it
Agree. My piece of advice here is to follow these following principles: 1.Use plugins as few as you can. Your application will be lighter and more maintainable. Also, you will upgrade Grails version more easily. 2.if you want to use a plugin, test it before with a dummy project. It takes few minutes for creating a grails application and you could test your next plugin rapidly. Be aware that sometimes plugins have compatibility issues between theselves so, do not hesitate to install all of the plugins you need into your dummy project
Agree. Grails is a very complex framework and documentation does not cover every aspect of Grails. But what is available is well explained. Also, grails community is very responsive, so if you don't find something you will easily have an answer in Grails forum or even on StackOverflow
Definitely Agree. Again, with IntelliJ you can debug easily but it is resource-consuming and takes time when reloading your app. So usually, I end up with logging traces and I debugg my full stack of exceptions like that! IMHO, this is one of the major shortcomings of Grails.
I have been a user of Rails for a while and used version 2.3.4 recently.
Rails 3 Beta just came out recently and it seems have significant performance improvement especially with the merge with Merb.
I'm planning on building an application that will take 4-6 months. Should I use Rails 3 for it starting with beta? Knowing that it will be buggy until full release?
Performance is definitely an important requirement for my application.
You can help me if you can provide insight in the following questions:
1- Do you think Rails 3 will be out in 4-6 months?
2- Will it be easy to migrate code should I choose to go for Rails 2.3.5?
There are certain aspects to consider:
Does your application depend on 3rd party plugins/gems? If so than you should check if those are already Rails 3 compatible. You're probably gonna find libraries which are incompatible as yet but there is a big chance that these are gonna "get fixed" sooner or later.
Also, it really depends on what kind of application you are talking about. Personally I'm porting one of my 2.3.5 based sites to Rails 3 but only for preparing and learning purposes. Since Rails 3 is only public beta as yet, IT IS DEFINITELY NOT CONSIDERED TO BE PRODUCTION READY. You can download it, use it and play with it but that's pretty much it for now.
If you decide to upgrade one of your existing projects (which I'd encourage you to do) than have a look at Geoffrey Grosenbach's screencast which will guide you through the upgrading process.
There's also an official plugin which contains a handy script that you can use to find out which parts of your application need to be upgraded.
afaik there is no definite release date set yet. another point to consider is on how many rails plugins does your project depend on as i think most of them will need to be upgraded too ...
I think you should do it for version 2.3.5 but always think about Rails 3. Read release notes. For example use this plugin to escape html by default.
Try to use plugins that are ready for Rails 3. Check list here.
Use unobtrusive javascript.
I've a portal project built in Rails 1.2.3. I've finished it at end of 2006.
The project are using the following plug-ins:
acts_as_attachment
acts_as_ferret
betternestedset
simple_http_auth
I know all plug-ins (or dependencies) was changed today, or doesn't exists anymore. The DHH says: Don't overestimate the power of versions. But I'm worrying about this.
If I update the rails version, all things will gonna fail. I can change my application to work with new rails version. I think I can read what's now deprecated and change it. But now I need to support all dependencies by myself or change it to other dependencies (Eg: acts_as_attachment to atachment_fu or paperclip). What to say about tomorrow?
My doubt isn't only about Rails, it's about using dependencies to increase productivity. In other projects I've used pure Python code, or even pure Ruby code, or pure Php code. Today I can run it in latest versions of "language/environment" without (or few) changes.
These projects haven't external dependencies, it's just the application code. Maybe using some web framework just as skeleton, but not external projects.
What do you think about this?
When you use someone else's code you pay with your independence for the ready-baked solution for a problem. So it's up to you to decide in each case what's more important to you - build your own stuff and lose time on it now (probably - a lot of time), or use someone else's projects and get the job done right now, but keep tied to them or pay with your time for upgrade/migration later on.
You've said the project worked for you for three years already - and I think it's great, if you need to bring it up to date - it's natural that you have to invest some time to do it, three years is a long timeframe in this area.