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We have an S/390 mainframe at my new job that’s been running COBOL applications since the late 90’s. The mainframe is getting old enough that we need to migrate to a newer system. We’re a small enough business that we can’t warrant spending the money to upgrade to new mainframe hardware and the program logic has been a constant work in progress for 30+ years, so it has a lot of functional value. I’ve been considering moving the functionality to a Linux machine and using something like OpenCOBOL to recompile as an executable binary instead of trying to rewrite it in a newer language. I haven’t messed with a mainframe enough to have any clue how or where to access this information and the gentleman that wrote all of the programs is unfortunately no longer with us. I’ve read that SSH is an option, but I’m not even sure how to get the ball rolling on that with a mainframe. I use Linux on a fairly regular basis, so I’m familiar with SSH, but from my understanding those mainframes aren’t a simple OS that you can merely connect to and navigate the file system to retrieve data like we can in modern operating systems. Can anyone give me some pointers to get a sense of direction for accessing the source code for the COBOL programs? Are there default locations that they are stored, etc.? They’re somewhat simple programs that don’t use any DB2 functionality and will hopefully compile on a different system with relatively minimal debugging and fixes. I’m certain that I’ve left out necessary information that would help getting an answer to this question, and I can provide any additional information that is needed to help you all help me. I suspect that SSH isn’t enabled by default, but maybe I’m wrong there too. Any assistance is greatly appreciated. Thanks everyone!
Although not a programming question I'll provide some guidance I think might help you.
First, this is a business decision about where to invest.
Do we upgrade the system to a newer model and upgrade some software and acquire the skills to keep the system running? (System Programming, OS upgrade and cost of migration, newer platform (used z13 could be an economical option, storage systems to support the mainframe)
Migration of existing workloads to other platforms. (Cost to migrate code, sizing of performance needs, new technologies to replace existing access methods like VSAM or dare I say ISAM if the applications are old enough)
Status Quo ... leave things where they are and keep the lights on
In evaluating any option you have to assess the risk to the business and what would a disruption cost? IMHO, its less about a technology like SSH or COBOL on Linux but requires some serious assessment of the current state, the acceptable to be scenarios and the cost of pursuing one of those options.
My comments are not intended to instill fear but provide a framework of how do I approach analyzing a challenge of this magnitude.
There is no default location where source code is stored on z/OS (it is z/OS you're talking about, right?). Source code is usually stored in PDS data sets. The naming of those depends on the installation, i.e. the company, and whether or not any software like Endevor, ChangeMan, etc. is being used to maintain the sources.
Since this is old z/OS (OS/390) COBOL code, chances are the code is making use of OS specifics such as record level I/O, VSAM data sets, etc. These are the parts that will not work on a non-z/OS platform without major rewrite. So, you will need to look into the sources.
SSH is available on z/OS, but it needs to be configured and enabled. You need to check with your z/OS sysprog. FTP, and NFS are other options, but again, they need to be configured and enabled.
Transfering the sources is the least of your problems, I'd say.
I have to agree with the prior two answers, but have some additional suggestions. This is a business decision what to do on the system.
Finding the program to understand what it does is the first requirement. Since you know what program is running that may be the name of the source file. That you will need to find. The source file probably will be in some library manager, the first place to look is in the ISPF menu system. There will be an option for the library manager you are using if you are using one. Based on your description you may be using something called SCLM which would should up, or you might see Librarian or Panvalet. You will need to get into ISPF by connecting using a 3270 connection emulator. Once you find the file, using FTP or SFTP may be the best, or your emulator may just provide a transfer mechanism. You will need to find the related files as well, which should also be defined in the library manager.
Once you have the file, you will need to figure out what it uses as mentioned above, it will be working with some kind of data file, and that will be the biggest part to deal with.
If it is a batch program it is probably part of a schedule, and there are other programs also running that you will need to find and figure out how they fit together.
Once you have an understanding of all the parts then you can work to make the right business decision as to how this should be run. You may want to upgrade, you may want to look to getting z/OS as a cloud service if you don't want to upgrade but you want the function. Or it may be a simple program you could move. That will be much easier to figure out once you have the details.
You say the program logic has changing for 30+ years. Was it only one person making all the changes ? Would anyone on the team have some idea about the PDS's that the user had access to ? That might be one of the places to look for. As the previous answers suggested , most shops would have store the source code in some kind of config mgmt tool like SCLM or panvelet. If you have access to the load code, there are utilities that can be used to inspect the load member to get a CSECT listing which would have the names of the obj members that make up that load.You can check with your mainframe admins. That can get you the source code file names. We use SSH from USS in our shop to move code from a HFS folder to gitlab. I have also used plain FTP to just transfer source code files to my workstation . But yes, first you have to find where it is stored.
I am a composer by profession and my computer science skills are limited though I program quite a bit of the software that I use.
What are the most reasonable ways to approach SQLite integration as a file format and database in an iOS app (it also needs to run on windows, but that is a secondary concern)?
I have been researching Hiberlite, which looks fantastic, but it seems to be little used and apparently it doesn't run well on embedded systems (iOS?) and chokes up when thousands of objects are in play. I haven't been able to get a sense of how severe those bottle necks are when running under those conditions.
The settings of thousands of objects (~50,000 though that number could expand) would be read every 1-10 seconds and written periodically. Read performance is more critical as write operations can stutter with out effecting the core operation of the app.
Given those conditions, how should I approach SQLite? My understanding is that without something like Hiberlite the entire database (many millions of entries) must be read and rewritten for every entry, is that less efficient. If that is the best approach is there a good resource to follow for implementing it?
Any advice would be greatly appreciated. My current software that I rely on is beyond buggy and needs refactoring, but due to my inexperience I am having a difficult time finding information about a reasonable approach.
I'm guessing you've probably found a solution for this by now, but I've been interested myself in embedding SQLite on Android and IOS, and I came across many C++-based ORM solutions.
Hiberlite looked possibly not fully mature (I didn't readily see a method of returning subsets of data, which is fairly standard). A framework which did draw my attention was the POCO:Data ORM library. It's based on the stream-based mechanism used in SOCI ORM. The POCO library is modular and optimised for embedded environments (I believe it also has a minimal external dependencies). Wikipedia has an article here, they outline some of its users, of which OpenFrameworks is one.
The WT ORM also looked pretty interesting.
I'm listing some of the other C++ ORM frameworks I found here, in no particular order:
http://soci.sourceforge.net
webtoolkit WT DBO ORM
http://debea.net
http://www.qxorm.com
http://sourceforge.net/apps/trac/litesql
http://otl.sourceforge.net
http://cppcms.com/sql/cppdb
http://dtemplatelib.sourceforge.net
http://code.google.com/p/qdjango
I'm wondering if anyone is currently utilizing Microsoft's Master Data Services? How you are utilizing it? Whether you find it useful? When you believe it would be useful? Thanks!
I have been working with MDS since it was first released as part of a feature pack for SQL Server 2008 R2. While MDS has some compelling features - most notably detailed data lineage, I am not confident in recommending it to clients yet.
My reason for this hesitation is the nature of the install and the tendendency to fail on upgrade or system change. I struggled mightily with the both the SQL Server 2012 RC0 MDS and the RTM installs. There are simply too many brittle aspects of the install (such as the hard requirement that the service be installed on a domain-joined machine and the need to install the Silverlight 5.0 SDK for the client to work properly). I also experienced flakiness in the the Excel add-in.
I see where Microsoft is going and I think the product will eventually be useful. Considering it's purpose (master data repository), MDS must be more 'rock solid' before I would use it in production.
We aren't using it currently in our office, however the presentation Microsoft did in town a while back seemed very interesting. I saw it as sort of a competitor to Oracle's OBAW warehouse. You've probably already looked at these, but Microsoft has a decent set of webcasts that cover how to install and use MDS out here:
http://www.msdev.com/Directory/SeriesDescription.aspx?CourseId=155
I'm anxious to see if anyone else is using it as well, we tend to have a hard time talking our management into letting us try these types of services without being able to point to other corporations that have successfully implemented said product.
We're just starting to investigate the use of MDS to support our consulting practice, specifically around data analytics and ETLs to deduplicate, standardize, and sanitize client data. It's probably just scratching the surface of MDS, but we were led to MDS initially for its inclusion of regular expression capabilities in SQL to transform free-form text data.
Before MDS/DQS, part of the sustainability / enduring-success of a custom database application was heavily dependent on one or both of the following items...
Having a full-time technical resource to manually update the master data. Someone who can work with the Business Experts and make the necessary adjustments to the data in the database.
Developing (in addition to the database/application/etc) a custom UI that is intuitive enough for the less-technical Business Experts to use for managing the master data themselves.
Neither of these were ideal from a cost-perspective. With MDS/DQS, a developer/contractor can come in, design an end-to-end Data Warehouse/BI solution including full integration with DQS/MDS (probably via SSIS packages) with relative ease. The Business-Experts can be trained to manage the master data using a UI they are already very familiar with (ex. Excel), and the developer/contractor can move on to the next project/client.
Also, if the business already has other data sources (via acquisitions or silo'd-yet-overlapping efforts or whatever), MDS can be used to manage all the master data in one centralized location.
It might not be the best MDS product available yet however it does come with SQL Server. Compared to most of the bespoke efforts for accommodating meta-data or master data in warehouse loads it's a pretty good option since most of the time is spent concentrating on the warehouse and the mastering of ancillary or other data isn't normally well accommodated for leaving questionable results. I prefer to use it than create some other flaky option that the customers will find it difficult to maintain. If you have budget however I would consider looking around for something more polished.
Like anything though give master data the respect it deserves. If it is going to be used then it's worth spending the time to model the entities, flow of data and usage correctly. The data stewards will need to savvy and will require training (it's not the most usable interface in the world - to say the least).
As we are a small consulting and development company we don't use MDS internally but we do implement it at customers with a focus on managing the Golden Record as the customers have a myriad of databases and applications all using the same data (customer, product …)
I agree with Lynn Langit's comment about installation and SilverLight dependency and the general comments about the UI. There are also a lot of smaller companies that don't run SQL Enterprise Edition but whom could benefit from MDS.
Those are the reasons why we are now developing a modern web application which we will host for our customers (probably on Azure).
If you're thinking about MDS I'd recommend to have a look at the API to replace (parts) of the UI.
Master Data Service is very useful for managing Master Data,
We have used Master Data Services 2012 and 2016, there are not too many features present in 2012 ,2016 is much better than 2012 with some new features , but I think still Microsoft needs to improve Master Data Services, they should include some flexibility in business rule's area.
I am starting to delve into the realm of ORMs, particularly NHibernate in developing .NET data-aware applications. I must say that the learning curve is pretty steep and that a lot of things should be noted. Apparently, it actually changes the way you do data-aware applications, manner of coding, development and just about everything.
Anyway, I want to ask if you do set some parameters when deciding to USE or NOT TO USE ORMs in your applications? How do you decide then the approach that one needs to make it valuable to your organization?
The organization which I work for now apparently has made a lot of SQL and Data Access thing running through back end and I must say that these class/methods/procedures have successfully performed their tasks of providing the data which is needed and when it is needed. I think it would be a tremendous effort just to map some of this into ORM and derive the same business value that the company has for the last few years.
Nevertheless, I know that ORM paves the way for applications to talk with database servers, if properly implemented. I must admit that I am at a learning stage and that I would possibly need all the help, resources and the guidance to make this transition. I was also thinking of buying the book from Manning but I feel that with so much changes to NHibernate, the book may be a bit outdated. Perhaps waiting for the Packt book on NHibernate (release on May 2010??) would help me better get up and running.
Kindly share your thoughts. By the way, if you could also point me in a small sample web app which uses NHibernate + Visual Web Developer 2008 Express and SQL Server, that would be highly appreciated.
Thanks.
For me, the short of it is the following:
If you don't use an established ORM, and you develop correctly (meaning you refactor out duplication and look to simplify where you can), you'll wind up building your own ORM through the evolution of your data access layer.
The question then becomes:
"Do I want my developers spending time learning the idiosyncrasies of my home-grown ORM or learning those of a well-documented and well-tested ORM?"
Furthermore:
"If I'm hiring a new developer, wouldn't it be nicer to bring in a developer that knows the established ORM tool we're using rather than having to train someone up on this thing I built?"
I use NHibernate, particularly Fluent - and it's great; if given the choice, I wouldn't develop on an RDBMS any other way.
To be successful with an ORM you must make sure to normalize correctly, and use the database for it's designed purpose, storing data.
I don't use an orm when:
I don't use a relation database (Relational databases are not the best choice of database for every application)
The database is has a very small amount of tables. (I might need less code without an orm)
I use a very simple database that can map to code with simple naming
conventions. (Mapping to dumb DTO classes and all queries like select * from tablename where id=#id)
Learning a good orm is worth the time and effort, it will save you writing a lot of code when you use relational databases a lot.
You can find example apps/tutorials/video's about NHibernate on with stackoverflow search. There is another book in progress by manning, maybe it's possible to read it with the early access program.
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Okay, I will shortly be starting down the path of windows mobile development. I know nothing about the subject really and I am looking for people with experience to let me know of any gottchas you may know of.
Right now I dont even have a breif of what is requied but the assumption is that the application will be very little more than a bunch of CRUD forms for updating data. The only other requirment knowladge I have is that the application will need to support offline storage when there is no signal avaliable. This in turn will obviously require some kind of syncronization when signal returns.
My initial thoughts are that the application will primarily be a front end to interact with a web service layer. Im assuming that WCF will be an appropriate technology for building these services? I also thought that SQL Server CE would be a good route to go down with regards to the offline storage issues.
Any knowlage that you feel is useful within this domain would be appreciated. Advice, links, books anything appreciated.
EDIT: It has been noted that there are two ways to go with off-line synchronization. To either use some form of message queuing or to use SQL synchronization tools. Could anyone offer a good comparison and introduction to these?
EDIT 2: After a little more digging I get the impression that there are basically 3 different approaches I can use here:
Emmbeded Database to query against then syncronization online, when able
MSMQ along with .NET remoting
WCF with ExchangeWebServiceMailTransport bindings using Exchange Server.
Now, there has been a nice few points raised on the first issue, and I think I understand at some level the issues I would face. But I'd like to get a little more information regarding MSMQ implementations and using WCFs new bindings.
Here a few words from my experience so far (about 9 months) of .net Windows Mobile development.
Well you are occasionally connected. (Or more likely occasionally disconnected). You have to choose whether you are going to use messaging with queues (i.e. WCF/SOAP/XML or something like it) or database synchronisation. I choose the SQL synchronisation route so I can't really comment on messaging. The SQL synchronisation route is not hassle free!
If you go down the sync route with SQL compact like me you basically have two choices. SQL Server merge replication or the newer ADO.NET Synchronisation services. If you choose the former you need to be really careful with your DB design to ensure it can be easily partitioned between mobile subscribers and the publisher. You really need to think about conflicts, and splitting tables that wouldn't normally be split in a normalised DB design is one way of doing that. You have to consider situations where a device goes offline for some time and the publisher DB (i.e. main DB) and/or a subscriber alters the same data. What happens when the device comes back online? It might mean resolving conflicts even if you have partitioned things well. This is where I got burnt. But SQL Merge Replication can work well and reduces the amount of code you have to write.
Roll your own DAL. Don't attempt to use datareaders etc. directly from UI code and don't use typed datasets either. There may be third party DALs that work with Windows Mobile (i.e. I know LLBLGEN does, might be worth a look) but Linq-to-SQL is not supported and anyway you need something lightweight. The chances are the DAL won't be too big so roll it yourself.
If you are using .net you'll probably end up wanting some unimplemented platform features. I recommend using this inexpensive framework to give you what your missing (especially as related to connectivity and power management) - http://www.opennetcf.com/Products/SmartDeviceFramework/tabid/65/Default.aspx
Windows Mobile devices partially switch off to save power when not in use. If you are doing a polling type design you'll need to wake them up every x mins. A normal .net timer class won't do this. You'll need to use a platform feature which can be used from OpenNetCF (above). The timer class is called LargeIntervalTimer and is in the OpenNetCF.WindowsCE assembly/namespace (I think).
Good Luck!
SqlCE is only one of the options available for local data storage on a Windows Mobile device, and although it's an excellent database it has limitations. For one thing, SqlCE will not work (period) under encryption (in other words, if your user encrypts the location where your SDF file is, you will no longer be able to access the data).
The second (and most critical) weakness of SqlCE lies in the RDA/Merge Replication tools. SqlCE Merge Replication is not 100% reliable in situations where the network connection can drop during replication (obviously very common in Windows Mobile devices). If you enjoy trying to explain missing or corrupted data to your clients, go ahead and use SqlCE and merge replication.
Oracle Lite is a good alternative to SqlCE, although it too doesn't work properly under encryption. If encryption is a potential problem, you need to find a database engine that works under encryption (I don't know of one) or else write your own persistence component using XML or something.
Writing a WM application as a front end that primarily interacts with a web service in real time will only work in an always-connected environment. A better approach is to write your application as a front end that primarily interacts with local data (SqlCE, Oracle Lite, XML or whatever), and then create a separate Synchronization component that handles pushing and pulling data.
Again, SqlCE merge replication does this pushing and pulling beautifully and elegantly - it just doesn't work all the time. If you want a replication mechanism that works reliably, you'll have to write your own. Oracle Lite has something called a snapshot table that works very well for this purpose. A snapshot table in Olite tracks changes (like adds, updates and deletes) and allows you to query the changes separately and update the central database (through a web service) to match.
This thread I just posted on SO a few days ago has proven to be a great resource for me thus far.
Also the Windows Mobile MSDN WebCasts are a wealth of information on everything from just getting started up to advanced development.
I would suggest Sqlite for local storage. From the last benchmark I ran it was much better than SqlCe and you don't have to do stupid things like retain an open connection for performance improvements.
Trade-offs being that the toolset is less rich and the integration with other MSSql products is nil. :(
you might want to refer to this:
getting-started-with-windows-mobile-development
You shouldn't be intimidated for windows mobile development. It isn't much different from desktop development. I strongly recommend that you use .NET Compact Framework for development and not C++/MFC.
Some useful links:
Mobile section at the Code
Project. You would find a lot of
articles, a little digging is needed
to find the appropriate one.
Smart
Device Framework from OpenNetCF
offer valuable extensions to the
compact framework.
When you install
the Mobile SDK, you will find under the
Community folder links for the
Windows Mobile and CF framework
blogs. These are also valuable
resources.
Regarding your application, you are right about the WCF and the SQL Server CE. These are the proper ways for handling communication and storage.
Some hints for people coming from a desktop world:
You need to have some sort of power management. The device may automatically go to suspend state. Also, you shouldn't consume power when you don't have to.
Network connectivity is a difficult issue. You can register notifications for when a specific network (Wi-Fi, GPRS) becomes available or unavailable. You can also set the preferred means of communication.
Make the UI as simple as possible. The user uses his thumb and/or a pen and he is probably on the move.
Test in a real device as early as possible.
"24 Hours of Windows Mobile Application Development" from the Windows Mobile Team Blog has some good resources
If you can, try to start from the user use cases and work back to the code, rather than vice versa. It's really easy to spend a lot more time working on the tools than working on the business problem. And thinking through user requirements will help you consider alternate strategies, because a lot of the patterns you know from normal .NET don't apply.
I've done lots of intermittent application development of exactly the type you are describing, and an on-board database works just fine. The MSMQ/WCF stuff just adds conceptual overhead without adding much value. You need a logical datastore locally anyway, and replication at this level is a simple concept that you want to keep simple, so the audit trail is easily monitored and debugged. MSMQ and WCF tend to hide things in unfamiliar places.
I upvoted the SqlLite suggestion BTW. MS doesn't have their persistence story stabilized yet for CE.
For the database replication bit I highly recommend Sybase Ultralite. In terms of flexibility and performance it knocks the socks off SQL CE
I had to do this once. Weird setup with Macs for development, and we were all Java programmers. And a short deadline. PowerPC macs too, so no chance to install Windows for Visual Studio development, never mind that the money for this would never have appeared.
We ended up writing applications using Java, running on the IBM J9 virtual machine, with SWT for a user interface. Entirely free development stack. Easy to deploy. Code ran on any platform we desired, not just PocketPC/WinMob.
Most of the work was on the server side anyway - the database, the web service server. The logic. The reporting engine. The client side wasn't totally simple however - would get the form templates from the server (because they changed frequently), the site details (multi-site deployment), generate a UI from the form template (using some SWT GUI components that are wonderful for PocketPC development, like the ExpandBar), gather data with a point and click interface (minimising keyboard entry where possible), and then submit it back to the server.
For offline storage we used XML files on the device itself. More than enough for our needs, but yours may differ. Maybe consider SQLite?
There are a couple links you can check out to start with:
http://developer.windowsmobile.com
http://msdn.microsoft.com/en-us/windowsmobile/default.aspx
If you have a sticking point while developing, there are also Windows Mobile dedicated chats on MSDN that you can attend and ask your questions. The calendar hasn't been updated yet, but the next ones should be in January. You can find the schedule here: http://msdn.microsoft.com/en-us/chats/default.aspx
I am going to add an additional question to this post, as its been active enough and hopefully will be helpful to others as well as me. Ok, so after playing around I now realize that standard class libraries cannot be included in windows mobile applications.
Now the overwhelming advice here seems to be use an embedded database, though I now do have use cases and it appears that I will need to have document synchronization as well as relational data. With this in mind service layer interaction seems inevitable. So my question is how would I share common domain objects and interfaces between the layers?
"Document synchronization" - does that mean bidirectional? Or cumulative write-only? I can think of mobile architectures that would mainly collect and submit transactions for a shared document - if that's your requirement, then we should discuss offline - it's a long (and interesting) conversation.
Owen you can share code from Compact Framework -> Desktop, it's only Desktop -> Compact Framework that has compatability issues if you use certain objects that are not supported by the CF.
While a desktop lib doesn't work on CF a CF lib WILL work on the desktop, you can also run CF.exes on the desktop!
Just create a CF library as the project that defines your base objects / interfaces etc.
This book sshould e essential reading for all Windows Mobile developers: http://www.microsoft.com/learning/en/us/books/10294.aspx
For developing windows mobile applications you must have the basic tools like silverlight, visual studio, windows phone emulator and sqlite as your database storage.