I found a paper about DBMind for openGauss, DBMind: A Self-Driving Platform in openGauss. However on the openGauss website it's hard to find how to run the AI features. Is this in-house feature or released for community?
Sounds cool. As you said, DBMind is a part of openGauss. However, currently, DBMind represents as a directory rather than an independent repository. Therefore, this form seems unfriendly to some developers due to its unclear representation. But openGauss aims to separate AI functionalities from openGauss main repository. At present, the AI functionalities of openGauss are loose-packed in the community, and you have to read each manual for each functionality. As I said, this form is temporary, a unified and serviced platform is coming. This autonomous O&M platform is deeply similar to the descriptions of the paper you mentioned. Alright, it is debugging in-house but coming.
Here are some useful channels to learn more:
Mail-list has an AI talk group: https://opengauss.org/en/community/onlineCommunication.html
Archived implementations of AI ability: https://gitee.com/opengauss/openGauss-AI
Related
I want to build a free app to become familiar with what is required, but I was always confused about the steps one needs to take to START a software project.
What are the steps required in order to develop a mobile app?
I will list some of the things I think should be done but I don't necessarily know how to do. Any advice, details and technologies you have to accomplish these steps would be awesome.
Decide which platform you want to develop. What are some of the pros and cons in this area for android vs iOS vs Windows8?
How to test the app - can you get free hardware to test with a well detailed app plan? Emulator?
Detail what you want the app to do and which functionalities you want.
Research if this app already exists. What are some areas of concerns in terms of not breaking the law such as patent infringement etc?
Setup a source repository such as git (google a guide I guess?)
Look at guides to familiarize yourself with APIs and write sample code to learn what you need?
Start the development and keep doing the above as needed.
Starting a software project can be as easy as start writing code. Most programmers will have an intuition as to what needs to be done and how it could be done. The other extreme of starting a software project is to start with talking to a client (or looking at the world) and figuring out what the problem is. I find that a thorough understanding of the problem you are trying to address with a project is already a long way into getting the project done painlessly. It'll give you a good understanding of what is required for you to call your project done.
So I guess point number one becomes: know what the problem is you're solving. Knowing this will also tell you if any existing app solves the same problem to a satisfying standard.
NOTE: I am not that familiar with the Windows 8 platform so my answer mostly talks about iOS and Android. The issues raised however are broad enough to cover large parts of the Windows platform.
Platform
Selecting a deployment platform is an important part of a launching a product, and a lot of other decisions depend on the platform. We are in the unfortunate state that two major mobile OSes exist that are separate in terms of code development and reuse. When considering selecting your deployment platform you'll want to think about the audience, and the (potential) sub set of the audience that is willing to pay for your application. Android might have to most devices out there but iPhone makes the most money (also for developers). However, remember that there are lots of apps out there and most developers don't ever make any (or not enough) money out of their apps.
Getting into app development with the aim of getting rich is going to leave you dissappointed. That's not very likely, then again someone always wins the lottery as well. It is a good way though to get employed and make some money that way.
Then there is the question of programming language (Java, Objective-C or C#). This is largely decided on what you are already familiar with, and if you aren't then refer back to the previous point.
Testing
Testing the product is a tricky thing. You'll have to start off with the emulator (which is usually provided with the development pack). Sooner or later however you'll have to test the app on hardware. I doubt you'll get your hands on free hardware but borrowing from friends and relatives is always an option. There may also be businesses that rent out test hardware to developers, if there isn't then I suppose that's one business idea to work on.
The platform choice will affect this also. Android is running on a much wider range of hardware than iOS.
Patent infringment
I don't know that much about patent issues, other than software patents are nasty. As a single developer I wouldn't be too worried about infringing on patents, the main purpose of them is to keep competitors at bay. What usually ends up happening is that big companies kill off competition with patent lawsuits, or they buy a smaller company that holds a nice collection of patents.
If you want to be on the safe side (meaning you own a company and are really doing this to make money) then talk to patent lawyers.
Code repository
A code hosting service like GitHub is fantastic in that it not only provides a place to have you code, but it also provides issue trackers for keeping notes on the functionality that is still missing or bugs that have crept up in your software.
The best places to start learning about Git are git-scm.com and the GitHub help pages.
Software development plan
Your last point explodes to a thing called software engineering. There has been lots of research into different ways of managing software development projects. The idea being that software development tends to be extended over long periods of time, the requirements of the project change during the project (as you learn more) and the project can involve anything from 1 to 100s of developers. Some way coordinating work between those developers (and all other parties involved like customers) has to be formalised, enter software engineering. The aim is to define a methodology and project structure that guides the development process and makes it more likely that the requirements are met at the end of the project.
Some models worth looking into include (Test Driven Development and other agile methods).
Finally I would add to the list of things that need to be done
Research libraries, note that this comes before familiarising yourself with the APIs of those libraries.
What software already exists that does a part of what you want to achieve. This goes partly back to the question of what platform to use. Apple has put a lot of attention in developing easy to use frameworks to support iOS app development. I am not that familiar with Andoird's or Windows 8 but the less code you have to write the faster the product will be done.
1 http://mobiledevices.about.com/od/kindattentiondevelopers/tp/Android-Os-Vs-Apple-Ios-Which-Is-Better-For-Developers.htm
There is only one step needed: Just start that project!
You are going to develop a free application, so it should be fun to do that. Choose whatever you like and keep going:
Make sure you are productive enough -- 10 Laws of Productivity
Avoid complexity -- Occam's razor, KISS principle
Let CI system do the boring stuff -- Machines should work; people should think.
Read books and improve yourself.
Please also avoid blind decisions. If you simply try several available options you'll eventually find the best way to achieve your goals. Do some PoC and decide. Nowadays 1-2 hours should be enough to start with any technology. This is the rule of maturity. You have your own goals, so it is better to avoid immature solutions.
Happy coding.
CPlayer I came to this forum with the same question since I am new to mobile app design and want to make my own app. I realize it is important to take certain steps in the correct order so that wasted time is minimized or eliminated. I did some research and came across two online sources I believe, if they are put together as one, will make one better source. The links are:
http://answers.oreilly.com/topic/2311-a-mobile-app-development-checklist/
http://mobiledevices.about.com/od/kindattentiondevelopers/ht/How-To-Create-An-App-For-The-Iphone.htm
Good Luck,
laroice
I joined a new company using Mainframes (z/os) for developement, documentation, design and testing. Now we are planning to migrate the whole system to ClearCase for version control.
My question is: are there any connectors I can use to connect the mainframe to ClearCase, so that the user can checkin/checkout straight in to their mainframe environment?
I am looking for a couple of solutions to do this, like tools I can use and so on.
If you're talking about storing the stuff in Clearcase on a distributed platform and having it accessible from z/OS, I'm not aware of any way to do that but, since z/OS comes with a full blown UNIX environment built in with access to both the UNIX file systems and z/OS data sets, it may well be doable.
What is doable, since we've done it (and, in fact, we developed large chunks of it) is to access data on the mainframe from a distributed platform.
RD/z (Rational Developer for System z, although it may have changed names by now) has a plug-in which allows Eclipse to tie in to the mainframe quite easily. It uses a started task to communicate with SCLM as its primary library manager but, from memory, you can directly access the non-SCLM data sets as well.
If you combined that with a Clearcase Eclipse plug-in, you could quite easily put together a system which, while it kept everything in a Clearcase repository, could quite easily push it up the the mainframe and build it automatically, pulling down the built artefacts if you also wanted them stored in Clearcase.
All from one environment. Of course, the dinosaurs will question your sanity at storing their 'precious' in a flaky distributed system - that fact that both products come out of IBM in no way alleviates the rivalry between mainframers and lesser mortals :-)
If that's not ideal and the company has a mainframe (and it appears they do), they will also have a support contract with IBM. Best bet would be to raise a Q&A with IBM to see if there are any solutions already out there - please don't raise a PMR for this, it's not a bug and that just annoys support/development and makes the monthly targets harder to meet :-) Alternatively, ask the people that would know. IBM developers monitor these forums and should be able to help you out more than I.
On the off-chance that you don't have a developerWorks account, keep an eye on this question that I started on your behalf. I'm actually interested in the results myself, since part of my day job is the marrying of the mainframe and distributed worlds. Although, unfortunately, it sometimes seems like it's about as successful as most Hollywood or other celebrity marriages :-)
Quantitative Analysts or "Quants" predict the behavior of markets to maximize profits. I am interested in the software that they use to accomplish this. Are there development platforms, libraries, languages or Data Mining suites specifically tailored to Financial Modeling?
Statistical Modeling:
First, there are statistical computing languages like R which is powerful and open-source, with lots of packages for analysis and plotting.
You will find some R packages that relate to finance:
http://www.quantmod.com/
https://www.rmetrics.org/
https://www.rmetrics.org/ebooks-tseries
Machine Learning and AI to train the system on past data:
Weka Data Minig: http://www.cs.waikato.ac.nz/ml/weka/
libsvm (data classifiers http://www.csie.ntu.edu.tw/~cjlin/libsvm/)
"Artificial Intelligence: Modern Approach" book (code: http://aima.cs.berkeley.edu/code.html)
Backtesting the trading system on past data:
More often that not, broker trading platforms will provide facilities for trading automation, in form of scripts and languages with which you can program the logic of the trading "strategy" (some use common languages like Java, some use proprietary ones). They will also provide some minimal support to test the strategy on past data, and get a detailed report on the taken trades and their outcome.
Connection to broker and System Testing:
Either you use some broker-proprietrary trading API, or go with the more standardized FIX.
Building a FIX server that does a quotation ticks playback to your trading system (which in this case will be a FIX client) is also a very good form of validation of the system. Most reputable ECNs will provide FIX access. So this is more portable than any other interface.
QuickFIX/J is a full featured
messaging engine for the FIX protocol.
It is a 100% Java open source
implementation of the popular C++
QuickFIX engine.
http://www.quickfixj.org/
There aren't any full blown platforms/applications per-se, since pretty much all software in this field is developed in-house, and usually behind the firewall (obviously for competitive advantage; in a fiercely competitive industry)
A well known library that includes a lot of algorithms and pricing models, and makes for a suitable starting point for a framework or app is called quantlib.
The Strata project from OpenGamma provides a comprehensive open source Java library for market risk, including all the basic elements a quant would need to manage things like holidays, trades, valuation and risk measures. Disclaimer, I am an author.
I've been working on a project, which is a combination of an application server and an object database, and is currently running on a single machine only. Some time ago I read a paper which describes a distributed relational database, and got some ideas on how to apply the ideas in that paper to my project, so that I could make a high-availability version of it running on a cluster using a shared-nothing architecture.
My problem is, that I don't have experience on designing distributed systems and their protocols - I did not take the advanced CS courses about distributed systems at university. So I'm worried about being able to design a protocol, which does not cause deadlock, starvation, split brain and other problems.
Question: Where can I find good material about designing distributed systems? What methods there are for verifying that a distributed protocol works right? Recommendations of books, academic articles and others are welcome.
I learned a lot by looking at what is published about really huge web-based plattforms, and especially how their systems evolved over time to meet their growth.
Here a some examples I found enlightening:
eBay Architecture: Nice history of their architecture and the issues they had. Obviously they can't use a lot of caching for the auctions and bids, so their story is different in that point from many others. As of 2006, they deployed 100,000 new lines of code every two weeks - and are able to roll back an ongoing deployment if issues arise.
Paper on Google File System: Nice analysis of what they needed, how they implemented it and how it performs in production use. After reading this, I found it less scary to build parts of the infrastructure myself to meet exactly my needs, if necessary, and that such a solution can and probably should be quite simple and straight-forward. There is also a lot of interesting stuff on the net (including YouTube videos) on BigTable and MapReduce, other important parts of Google's architecture.
Inside MySpace: One of the few really huge sites build on the Microsoft stack. You can learn a lot of what not to do with your data layer.
A great start for finding much more resources on this topic is the Real Life Architectures section on the "High Scalability" web site. For example they a good summary on Amazons architecture.
Learning distributed computing isn't easy. Its really a very vast field covering areas on communication, security, reliability, concurrency etc., each of which would take years to master. Understanding will eventually come through a lot of reading and practical experience. You seem to have a challenging project to start with, so heres your chance :)
The two most popular books on distributed computing are, I believe:
1) Distributed Systems: Concepts and Design - George Coulouris et al.
2) Distributed Systems: Principles and Paradigms - A. S. Tanenbaum and M. Van Steen
Both these books give a very good introduction to current approaches (including communication protocols) that are being used to build successful distributed systems. I've personally used the latter mostly and I've found it to be an excellent text. If you think the reviews on Amazon aren't very good, its because most readers compare this book to other books written by A.S. Tanenbaum (who IMO is one of the best authors in the field of Computer Science) which are quite frankly better written.
PS: I really question your need to design and verify a new protocol. If you are working with application servers and databases, what you need is probably already available.
I liked the book Distributed Systems: Principles and Paradigms by Andrew S. Tanenbaum and Maarten van Steen.
At a more abstract and formal level, Communicating and Mobile Systems: The Pi-Calculus by Robin Milner gives a calculus for verifying systems. There are variants of pi-calculus for verifying protocols, such as SPI-calculus (the wikipedia page for which has disappeared since I last looked), and implementations, some of which are also verification tools.
Where can I find good material about designing distributed systems?
I have never been able to finish the famous book from Nancy Lynch. However, I find that the book from Sukumar Ghosh Distributed Systems: An Algorithmic Approach is much easier to read, and it points to the original papers if needed.
It is nevertheless true that I didn't read the books from Gerard Tel and Nicola Santoro. Perhaps they are still easier to read...
What methods there are for verifying that a distributed protocol works right?
In order to survey the possibilities (and also in order to understand the question), I think that it is useful to get an overview of the possible tools from the book Software Specification Methods.
My final decision was to learn TLA+. Why? Even if the language and tools seem better, I really decided to try TLA+ because the guy behind it is Leslie Lamport. That is, not just a prominent figure on distributed systems, but also the author of Latex!
You can get the TLA+ book and several examples for free.
There are many classic papers written by Leslie Lamport :
(http://research.microsoft.com/en-us/um/people/lamport/pubs/pubs.html) and Edsger Dijkstra
(http://www.cs.utexas.edu/users/EWD/)
for the database side.
A main stream is NoSQL movement,many project are appearing in the market including CouchDb( couchdb.apache.org) , MongoDB ,Cassandra. These all have the promise of scalability and managability (replication, fault tolerance, high-availability).
One good book is Birman's Reliable Distributed Systems, although it has its detractors.
If you want to formally verify your protocol you could look at some of the techniques in Lynch's Distributed Algorithms.
It is likely that whatever protocol you are trying to implement has been designed and analysed before. I'll just plug my own blog, which covers e.g. consensus algorithms.
Our company has a point of sale system with many extras, such as ordering and receiving functionality, sales and order history etc. Our main issue is that the system was not designed properly from the ground up, so it takes too long to make fixes and handle requests from our customers. Also, the current technology we are using (Progress database, Progress 4GL for the language) incurs quite a bit of licensing expenses on our customers due to mutli-user license fees for database connections etc.
After a lot of discussion it is looking like we will probably start over from scratch (while maintaining the current product at least for the time being). We are looking for a couple of things:
Create the system with a nice GUI front end (it is currently CHUI and the application was not built in a way that allows us to redesign the front end... no layering or separation of business logic and gui...shudder).
Create the system with the ability to modularize different functionality so the product doesn't have to include all features. This would keep the cost down for our current customers that want basic functionality and a lower price tag. The bells and whistles would be available for those that would want them.
Use proper design patterns to make the product easy to add or change any part at any time (i.e. change the database or change the front end without needing to rewrite the application or most of it). This is a problem today because the Progress 4GL code is directly compiled against the database. Small changes in the database requires lots of code recompiling.
Our new system will be Linux based, with a possibility of a client application providing functionality from one or more windows boxes.
So what I'm looking for is any suggestions on which database and/or framework or programming language(s) someone might recommend for this sort of product. Anyone that has experience in this field might be able to point us in the right direction or even have some ideas of what to avoid. We have considered .NET and SQL Express (we don't need an enterprise level DB), but that would limit us to windows (as far as I know anyway). I have heard of Mono for writing .NET code in a Linux environment, but I don't know much about it yet. We've also considered a Java and MySql based implementation.
To summarize we are looking to do the following:
Keep licensing costs down on the technology we will use to develop the product (Oracle, yikes! MySQL, nice.)
Deliver a solution that is easily maintainable and supportable.
A solution that has a component capable of running on "old" hardware through a CHUI front end. (some of our customers have 40+ terminals which would be a ton of cash in order to convert over to a PC).
Suggestions would be appreciated.
Thanks
[UPDATE]
I should note that we are currently performing a total cost analysis. This question is intended to give us a couple of "educated" options to look into to include in or analysis. Anyone who could share experiences/suggestions about client/server setups would be appreciated (not just those who have experience with point of sale systems... that would just be a bonus).
[UPDATE]
For anyone who is interested, we ended up going with Microsoft Dynamics NAV, LS Retail (a plugin for the point of sale and various other things) and then did some (and are currently working on) customization work on top of that. This setup gave us the added benefit of having a fully integrated g/l system, which our current system lacked.
Java for language (or Scala if you want to be "bleeding edge", depending on how you plan to support it and what your developers are like it might be better, but also worse)
H2 for database
Swing for GUI
Reason: Free, portable and pretty standard.
Update: Missed the part where the system should be a client-server setup. My assumption was that the database and client should run on the same machine.
I suggest you first research your constraints a bit more - you made a passing reference to a client using a particular type of terminal - this may limit your options, unless the client agrees to upgrade.
You need to do a lot more legwork on this. It's great to get opinions from web forums, but we can't possibly know your environment as well as you do.
My broad strokes advice would be to aim for technology that is widely used. This way, expertise on the platform is cheaper than "niche" technologies, and it will be easier to get help if you hit a brick wall. Of course, following this advice may not be possible if you have non-negotiable technology already in place at customers.
My second suggestion would be to complete a full project plan, with detailed specs and proper cost estimates, before going with the "rewrite from scratch" option. Right now, you're saying that it would be cheaper to rewrite the system than maintain it, and you don't really know how much it would cost to re-write.
I suggest you use browser for the UI.
Organize your application as a web application.
There are tons of options for the back-end. You can use Java + MySQL. Java backend will save you from windows/linux debate as it will run on both platforms. You won't have any licensing cost for both Java and MySQL. (Edit: Definitely there are a lot of others languages that have run-times for both linux & windows including PHP, Ruby, Python etc)
If you go this route, you may also want to consider Google Web Toolkit (GWT) for creating the browser based front-end in a modular fashion.
One word of caution though. Browsers can be pesky when it comes to memory management. In our experience, this was the most significant challenge in doing browser based POS You may want to checkout Adobe Flex that runs in browser but might be more civil in its memory management.
What is CHUI? Character-UI, as in VT terminals? Or even 3270 style?
It sounds like you need a 3-tier system - the database backend, a middle-layer that runs the bulk of the back-end business processes, and a front-end layer for the CHUI / GUI / data-gateway.
All three layers can reside on one machine; or you can distribute the tiers out to various servers. The front-end layer would control the actual terminals, whether they are VT-terminals, or a web-browser, or a custom-written 'client' application.
Make sure you have considered the hardware needs here -- are you going to have barcode scanners, cash drawers, POS debit/credit terminals, et cetra? If you are using a standard browser, it might be hard to reliably integrate those items. (At the very least, you're likely going to have to write special applets to handle them.)
Finally, consider the possibility of a thin-client technology on Windows. It greatly simplifies system management, since you only have to upgrade the software centrally. Thin-client PC's are cheap -- sub $200.
Golden Code Development (see www.goldencode.com) has a technology that does automated conversion of Progress 4GL (the schema and code... the entire application) to a Java application with a relational database backend (e.g. PostgreSQL). They currently support a very complete CHUI environment and they do refactor the code. For example, the conversion separates the UI, the data model and the business logic into separate Java classes. The entire result is a drop-in replacement that is compatible with the original (users don't need retraining, processes don't need to be modified, the data is migrated too). This is possible because they provide an application server and a set of runtime classes that provide that compatibility. The result of the automated conversion is not something that needs further editing before you can compile and run it. True terminal support is included so hardware terminals still work (it requires a small JNI library to access NCURSES from Java). All the rest of the code in the runtime is pure Java. No Progress Software Corp technology is used in the resulting system and it runs on Linux.
At least one converted system is already in production, running a 24 by 7 mission critical environment. It is a converted ERP system that their mid-sized pilot customer uses to run their entire business.