Jan 21

Embedded SQL in a C program on IBM i.

Quick post about my experiences and hopefully a guide to others who are starting to look at the possibilities of embedding SQL in C Programs.

First note: Not a lot of samples or good tutorials out there.
Second note: Remember to use the CRTSQLCI command and not the CRTCMOD etc commands
Third note: CRTSQLCI creates a module, so then need to run the CRTPGM/CRTSRVPGM commands to create run-able object.
Forth note: Remember to add FOR UPDATE to the select statement if you need a cursor to allow updates/deletes.

So the documentation provided by IBM is very extensive, but it is a tad difficult to find what you need from it. I spent a whole day just getting this very simple program to work. The problem arose because of a need from a client that has an huge IFS tree structure which had to be audited and repaired, they have over 2.6 million objects (*DIR/*STMF) in a single tree structure. The normal process of repairing audit failures had a number of problems because of the depth of the subtrees, basically saving each object would not work because the save of a directory would save all of its objects and sub directories at once, having some directories which have subtrees in the hundreds of directories was not going to make this easy. Also the total size of one of the top directories is about 21GB with all its subdirectories.

So we needed to come up with a process that would take the results of an audit against the directory and allow a directory by directory rebuild on the target system. Another major issue is the very poor save and restore process on the IBM i, what you saved is not what is left after a restore correctly completes (missing attributes and settings!) so we had to allow the entire structure to be deleted on the target before we started to rebuild it. When we looked at the contents of the file on the source system we had to do some filtering of the records, we wanted to only save and restore the directory object and its non directory objects. We did look at a Logical file to do the filtering but that ended badly and trying to move into the 21st century means we should embrace SQL technology where possible.

This is the SQL statement which gave us the desired results when run interactively.
SELECT * FROM ifsaudf WHERE ATTR like 'd%' and SYS = 'SRC' and FTYPE = 'M' ORDER BY PATH

Our program would need to run that request and then be able to build a synch request and delete the record once it had successfully been actioned. The following is the program we created.

#include <stdio .h>
#include <stdlib .h>
#include <string .h>
#include <sqlca .h>

/* IFS Audit failures */
#pragma mapinc("ifsaud","HA4I71/IFSAUDF(*ALL)","both")
#include "ifsaud"
HA4I71_IFSAUDF_IFSREC_both_t IFS_Aud_Rec;


int main(int qrgc, char **argv) {
char outp[5002];
char cmd[5002];

EXEC SQL
     INCLUDE SQLCA;
EXEC SQL DECLARE C1 SCROLL CURSOR FOR
    SELECT * FROM ifsaudf WHERE ATTR like 'd%' and SYS = 'SRC' and FTYPE
    = 'M' ORDER BY PATH FOR UPDATE;
    EXEC SQL OPEN C1;
    EXEC SQL WHENEVER NOT FOUND GO TO done1;
    do {
       EXEC SQL FETCH C1 INTO :IFS_Aud_Rec;
   if((IFS_Aud_Rec.PATHLEN > 0) && (memcmp(IFS_Aud_Rec.PATH,"    ",4) != 0)){
          memset(&IFS_Aud_Rec.PATH[IFS_Aud_Rec.PATHLEN],'\0',1);
          printf("%d %s\n",IFS_Aud_Rec.PATHLEN,IFS_Aud_Rec.PATH);
          sprintf(cmd,"SYNCIFS PATH('%s') SUBTREE(%s)",IFS_Aud_Rec.PATH,
                                                       argv[1]);
          if(system(cmd) == 0) {
             EXEC SQL
                  DELETE FROM IFSAUDF WHERE CURRENT OF C1;
             if(SQLCODE != 0)
                printf("SQLCODE = %d\n",SQLCODE);
             }
          else
             printf("%s\n",cmd);
          }
       }while(SQLCODE==0);
done1:
    EXEC SQL CLOSE C1;
exit(1);
}   

So that is our program which will read through the audit file, sort and filter the records, issue a command using the record content and then delete the record if the command is successfully actioned. Next step will be to add some additional error checking a message sending into the program but for now I think it shows some important elements of embedding SQL in a C program.

Chris…

Jan 02

PASE to the rescue..

I was working with a client over the Holidays looking at an issue where our save processes for the IFS kept failing to get a lock on a couple of IFS objects. The problem meant that the Sync Manager would constantly reload the request trying to get a hold of the objects which were never released so the request could never be fulfilled.

The objects only get updated a couple of times a day but the program which does the updating holds an exclusive lock on the objects at all times. Normally we could run the Save While Active request through the Sync Manager and it would capture the object OK, unfortunately in this instance (may be an IFS feature) the Save While Active process failed to capture the content of the file. Even if we ran a SAV command with the Save While Active parameters set the from the command line the save always failed with an “Object in Use” error.

Having spent a lot of time in the PASE environment recently I decide to try the pipe lining capabilities against the file to see if I could capture the content. I ran the command “cat FileName > NewFile”, this returned an error stating that it failed to copy the content but on review of the file I could see that the content had actually been copied. The directory is set up to automatically capture new object creations so when I checked the remote system I could see that the NewFile had been created in the directory on the target system, again in the PASE environment on the target system I ran a command to empty the file, this would ensure the content I captured would be the same once the second request completed. I changed to the working directory and ran the command “cat ” > FileName” which truncated the file to 0 bytes, I then copied the content of the NewFile to the FileName object using “cat NewFile > FileName”. I compared the content of the files on both systems which showed that everything was now in sync. To clean up all I had to do was delete the object on the source system and let HA4i clean up the target. Now the file is in sync between the systems and the client is happy.

I do not know the security implications of what we achieved and maybe its not meant to work that way, why the save process fails and yet the cat command is allowed access to the file is not clear. But maybe in the future it could find its way into the HA4i product as a method of re-syncing an IFS file without the Save While Active process, it may even work on objects in the /QSYS.LIB directories?

Chris…

Dec 22

First Node.js example

For me one of the main reasons to run Node.js on the IBM i is to access IBM i data and objects. I can already access all of these using PHP today so I wanted to see just how easy it was going to be with Node.js which is said to be one of the up and coming languages for building web facing interfaces. The documentation is pretty sparse and even more so when you are looking to use the IBM os400 package so these first baby steps were pretty challenging. I am not a JavaScript expert or even a good object oriented programmer so I am sure the code I generated could be improved significantly. However this is early days for me and I am sure things will get better and easier with practice.

I have decided to use express as my framework of choice, I did review a few of the others but felt that it has the most examples to work with and does offer a lot of functionality. The installation of Node.js and npm has already been carried out, I have used putty as my terminal interface into the IBM i for starting the processes and RDi v9 for my IDE to update the scripts etc. I did try RDi V8 but the code highlighting is not available. I also tried Dreamweaver with its FTP capabilities which worked as well but decided that as I am developing for IBM i it would be better to use RDi.

First we need to install the express package. Change directory to the Node installation directory ‘/QOpenSys/QIBM/ProdData/Node’ and run the following command.
npm install -g express
Next we need the express-generator installed which will generate a formal structure for our application.
npm install -g express-generator
Once that has installed you can install a new project in your terminal session using the following command:
express my-app1
You should see something similar to the following output.

$ express my-app1

create : my-app1
create : my-app1/package.json
create : my-app1/app.js
create : my-app1/public/stylesheets
create : my-app1/public/stylesheets/style.css
create : my-app1/public
create : my-app1/routes
create : my-app1/routes/index.js
create : my-app1/routes/users.js
create : my-app1/public/javascripts
create : my-app1/views
create : my-app1/views/index.jade
create : my-app1/views/layout.jade
create : my-app1/views/error.jade
create : my-app1/public/images
create : my-app1/bin
create : my-app1/bin/www

install dependencies:
$ cd my-app1 && npm install

run the app:
$ DEBUG=my-app1 ./bin/www

One of the problems we found was that the initial port used for the default caused issues on our system so we need to update it. The port setting is set in the www file which is in the bin directory, open up the file and update it so it looks like the following and save it.

#!/usr/bin/env node
var debug = require('debug')('my-app1');
var app = require('../app');
// changed the port to 8888
app.set('port', process.env.PORT || 8888);

var server = app.listen(app.get('port'), function() {
  debug('Express server listening on port ' + server.address().port);
});

Before we go any further we want to install of the dependencies found in the package.json file, this will ensure if we save our application all of the dependencies will be available. Change to the my-app1 directory and run the following, it will take some time and create quite a lot of output.
npm install
We should now have an application that can be run, simply run ‘npm start’ in your ‘my-app1′ directory and point you browser at the IBM i and port defined (ours is running on shield7 and port 8888) ‘http://shield7:8888/’ You should see a very simple page with the following output.

Express
Welcome to Express

Next we want to edit the dependencies to add the db2i support, this is set in the app.js file located in the root directory of you application ‘Node/my-app1′. Add the db2i support using the following snippets.

// db2
var db = require('/QOpenSys/QIBM/ProdData/Node/os400/db2i/lib/db2');
// make the db available for the route
app.use(function(req,res,next){
   req.db = db;
   next();
});

Now the file should look something like:

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

// db2
var db = require('/QOpenSys/QIBM/ProdData/Node/os400/db2i/lib/db2');

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

// make the db available for the route
app.use(function(req,res,next){
   req.db = db;
   next();
});

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});


module.exports = app;

I want to be able to display a list of the customers in the QIWS.QCUSTCDT file (Its what IBM used as their sample in the docs) and I want it to be referenced by the http://shield7:8888/custlist URL so I need to update the routes file to respond to that request.

var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res) {
  res.render('index', { title: 'Express' });
});
/* get the customer list */
router.get('/custlist', function(req, res) {
   var db = req.db;
   db.init();
   db.conn("SHIELD7");
   db.exec("SELECT * FROM QIWS.QCUSTCDT", function(rs) {
	  var hdr = Object.keys(rs[0]);
	  num_hdrs = hdr.length;
	  var out = '<table border=1><tr>';
	  var i;
	  // show header line
	  for(i = 0; i < num_hdrs; i++){
		  out += '<td>' + hdr[i] + '</td>'; 
	  }
	  // now for the records
	  var j;
	  for(j = 0; j < num_hdrs;j++) {
		out += '</tr><tr>';
	     for(var key in rs[j]){
		    out += '<td>' + rs[j][key] + '</td>' 
	     }
	  }
	  out += '</tr></table>';
	  res.set('Content-Type','text/html');
	  res.send(out);
      });
   db.close();
});  
module.exports = router;

Now we need to run the application again using ‘npm start’ in out application library and requesting the url from a browser. You should see something similar to the following:
my-app1

Couple of things we have come across during this exercise, firstly the terminal sessions to the IBM i need careful setup to allow you to run the requests, we have posted previously some of the commands we used to set the PATH variables to allow things to run. We still cannot set up the .profile file to set the PS1 variable correctly, not sure if this is an IBM problem or a putty problem (that’s another challenge we will address later). getting my head around a JSON object was a real challenge! I started off by using the JSON.stringify(JSONObj); and outputting the result to the screen, if you want to see a much clearer output use the padding option so JSON.stringify(JSONObj,null,4); and output that, in this case you would see something like:

[
{
“CUSNUM”: “938472”,
“LSTNAM”: “Henning “,
“INIT”: “G K”,
“STREET”: “4859 Elm Ave “,
“CITY”: “Dallas”,
“STATE”: “TX”,
“ZIPCOD”: “75217”,
“CDTLMT”: “5000”,
“CHGCOD”: “3”,
“BALDUE”: “37.00”,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “839283”,
“LSTNAM”: “Jones “,
“INIT”: “B D”,
“STREET”: “21B NW 135 St”,
“CITY”: “Clay “,
“STATE”: “NY”,
“ZIPCOD”: “13041”,
“CDTLMT”: “400”,
“CHGCOD”: “1”,
“BALDUE”: “100.00”,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “392859”,
“LSTNAM”: “Vine “,
“INIT”: “S S”,
“STREET”: “PO Box 79 “,
“CITY”: “Broton”,
“STATE”: “VT”,
“ZIPCOD”: “5046”,
“CDTLMT”: “700”,
“CHGCOD”: “1”,
“BALDUE”: “439.00”,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “938485”,
“LSTNAM”: “Johnson “,
“INIT”: “J A”,
“STREET”: “3 Alpine Way “,
“CITY”: “Helen “,
“STATE”: “GA”,
“ZIPCOD”: “30545”,
“CDTLMT”: “9999”,
“CHGCOD”: “2”,
“BALDUE”: “3987.50”,
“CDTDUE”: “33.50”
},
{
“CUSNUM”: “397267”,
“LSTNAM”: “Tyron “,
“INIT”: “W E”,
“STREET”: “13 Myrtle Dr “,
“CITY”: “Hector”,
“STATE”: “NY”,
“ZIPCOD”: “14841”,
“CDTLMT”: “1000”,
“CHGCOD”: “1”,
“BALDUE”: “.00″,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “389572”,
“LSTNAM”: “Stevens “,
“INIT”: “K L”,
“STREET”: “208 Snow Pass”,
“CITY”: “Denver”,
“STATE”: “CO”,
“ZIPCOD”: “80226”,
“CDTLMT”: “400”,
“CHGCOD”: “1”,
“BALDUE”: “58.75”,
“CDTDUE”: “1.50”
},
{
“CUSNUM”: “846283”,
“LSTNAM”: “Alison “,
“INIT”: “J S”,
“STREET”: “787 Lake Dr “,
“CITY”: “Isle “,
“STATE”: “MN”,
“ZIPCOD”: “56342”,
“CDTLMT”: “5000”,
“CHGCOD”: “3”,
“BALDUE”: “10.00”,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “475938”,
“LSTNAM”: “Doe “,
“INIT”: “J W”,
“STREET”: “59 Archer Rd “,
“CITY”: “Sutter”,
“STATE”: “CA”,
“ZIPCOD”: “95685”,
“CDTLMT”: “700”,
“CHGCOD”: “2”,
“BALDUE”: “250.00”,
“CDTDUE”: “100.00”
},
{
“CUSNUM”: “693829”,
“LSTNAM”: “Thomas “,
“INIT”: “A N”,
“STREET”: “3 Dove Circle”,
“CITY”: “Casper”,
“STATE”: “WY”,
“ZIPCOD”: “82609”,
“CDTLMT”: “9999”,
“CHGCOD”: “2”,
“BALDUE”: “.00″,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “593029”,
“LSTNAM”: “Williams”,
“INIT”: “E D”,
“STREET”: “485 SE 2 Ave “,
“CITY”: “Dallas”,
“STATE”: “TX”,
“ZIPCOD”: “75218”,
“CDTLMT”: “200”,
“CHGCOD”: “1”,
“BALDUE”: “25.00”,
“CDTDUE”: “.00″
},
{
“CUSNUM”: “192837”,
“LSTNAM”: “Lee “,
“INIT”: “F L”,
“STREET”: “5963 Oak St “,
“CITY”: “Hector”,
“STATE”: “NY”,
“ZIPCOD”: “14841”,
“CDTLMT”: “700”,
“CHGCOD”: “2”,
“BALDUE”: “489.50”,
“CDTDUE”: “.50″
},
{
“CUSNUM”: “583990”,
“LSTNAM”: “Abraham “,
“INIT”: “M T”,
“STREET”: “392 Mill St “,
“CITY”: “Isle “,
“STATE”: “MN”,
“ZIPCOD”: “56342”,
“CDTLMT”: “9999”,
“CHGCOD”: “3”,
“BALDUE”: “500.00”,
“CDTDUE”: “.00″
}
]

As I have said above this is very early days and moving from my procedural programming to object oriented as well and trying to pick up on what the express framework is doing has not made it easy. I do however feel it is something that I will grow to love as I increase my knowledge and test out new concepts. Unfortunately I find all of this very interesting and like the challenge that comes with new technology (its only new to the IBM i and me!), I cannot imagine sticking with what I know until I retire, life is too short for that.

The next step will be to work out how to use the express render capabilities to format the data in the page and add new functions such as being able to add,update and remove records etc. I have a lot to learn!

Chris…

Dec 09

High Availability Secret Weapons

I just read an article in the IT Jungle which made me smile to myself, basically it was stating how a competitor of our High Availability Products had a secret weapon with their simulated role swap process. Firstly its not secret, they use it to sell against their competition so its a feature.

The fact that it is showing the feature off as being one that no one else has is fine, but to then go on and trash someone else’s idea (Focal Point Solutions new Flashcopy process) stating that theirs is better made me take a closer look at the content of the “Story”. A few points really stuck in my mind as being a little misleading so I though I would give my own perspective on what is being said.

The main point is really that people who invest in High Availability hardly every test that it works as it should and so fail to deliver on the expectations the solution should provide. Having just been involved with a client who was running a competitive product of ours and not the one mentioned I fully agree with that statement, had this client actually bothered to test the environment at all they would have identified a number of significant issues prior to needing to use the backup system. The client actually failed to switch over correctly and lost a lot of time and data in the process. None of this was the fault of the High Availability Solution but simply that the client had failed to maintain the environment at all and the processes required to make the switch effectively were just ignored.

The next statement made me think, they say that this very important feature! yet it is only available in the Enterprise version? If its so important and so effective why is it only important for Enterprise level clients to get the use of this feature? The point that they are trying to enforce is that High Availability users need to test regularly, but in the next statement they state it is only available in their premier product? Surely it should be available in all their levels of product?

Simulated roleswap? Because they do not switch actual production processing to the target system, that means they are expecting the client to decide what to run on the target system to determine if the switch would actually work in the event a roleswap would be needed. So it won’t be running a real production environment which means they may not run everything that would run in a true production environment. This is normal and not something that should be a concern, but what is the difference between that and just turning off replication while a test is run and then creating a recovery position to start the replication again? Maybe its because it is automated. The point is that if it is not running a REAL production environment all that you are doing is testing the test you have developed runs! Roleswaps which have the actual PRODUCTION run on the system are the best way to check that everything is going to work as it should. Running a simulated roleswap is just a backstop to test new features and that the scripts which have been written to carry out the roleswap are going to work.

The Focal Point Solutions offering does allow the same level of testing that this simulated switch does, the comment about it not being a valid approach because the environment used to do the test is not what the client will eventually use is absolute bunkum! The biggest benefit the Focal Point Solutions has over this offering is that the Recovery Time Objective is not affected at all during the time any testing takes place. Their recovery position is totally protected at all times and if the client needs to switch mid way through testing they can do it without having to reset the target environment and then catch up and PRODUCTION changes which have been stored while the test was being set up and run. To me that is a far better solution than having to switch over to the target system for testing. Our LVLT4i product also offers a similar approach because we just take the backup and use it for testing and I see no additional benefits a simulated roleswap will offer? With the LVLT4i approach the comment made about not testing on the same machine you will use is also mute, the target system is only a backup for the iASP data, when a switch is required the data will be migrated to another system for the client to access and use. I have not dug to deep into the Focal Point Solutions offering but if it gets the High Availability Clients to test more, it has to be a better offering than one which does not provide such opportunities.

With all of that being said, a test is a test is a test is a test! If you really have to switch due to a disaster the roleswap will be put under a lot more pressure and a lot of the testing you have carried out may not perform as it did during the test. No matter what type of testing you do its better than doing nothing, stating one method better than another is where you have to start looking at reality. We encourage everyone to take a look at the new products and features out there. High Availability is changing and peoples requirements are also changing, the need for Recovery Time Objectives that are in the minutes range are not for everyone and very rarely ever met when disaster strikes. Moving the responsibility for managing the High Availability Solution off to a professional organization that specializes in providing such services to clients may be a lot better and a lot cheaper than try to do it all yourself.

If you are interested in discussing your existing solution or want to hear about one of our products let us know. We are constantly updating our products and offerings to meet the ever changing needs of the IBM i client base.

Chris…

Dec 08

System Values and LVLT4i

System values are an important part of the working environment on the IBM i, therefore it is important that are correctly set ready for whenyou move to a recovery system. LVLT4i is working in an environment where the setting of the System Values as part of the replication process is not an option in just the same way we cannot replicate Profiles and authorities. So we had to come up with a process which would allow us to build the required environment as part of the recovery process.

When we first looked at how we could use LVLT4i we were thinking that the recovery process would use a system save process to recovery the clients environment and then restore the iASP data over it to bring the client data and objects up to the last transaction. That was one of the reasons that the Recovery Time Objective was going to be so long, it takes quite some time to restore a system save. Even if we used Image Catalogs for the restore it was still going to take a significant amount of time, this encouraged us to start looking at the options we had.

One of the major advantages we wanted to push for LVLT4i is the ability to take a backup of a clients applications and data from the iASP and use it for things such as DR testing, application upgrade and OS upgrade testing. To do this we envisage the Managed Service Provider having a recovery partition running the correct level of OS for the clients, the back-up of the iASP could be copied over to the running environment and the client could do their testing without affecting their current DR position. Once the test was completed the system could be scratched and made ready for the next client to use. As part of the discussions we looked at how we could speed up the save and recovery processes (see our Blog entry on saving to a QNAP NAS) using the image catalog technology so that the Recovery Time Objective could be reduced to an absolute minimum. Those programs we created for the testing are actually in use in our environments and have significantly reduced the save times plus provide us with a much faster recovery time should we ever need to set in motion a recovery.

Profiles and Passwords were our first priority because they tend to change a lot, we came up with a process that allows the Managed Service Provider to restore the iASP data and then using automated scripts recover the User Profiles and Passwords before setting the authority. Profile recovery has already been implemented in LVLT4i and testing shows that the process is very effective and fast. The next item we wanted to cover was system values, again as with User Profiles they cannot be replicated to the target system from the client. Using the experience we gained with the storage of the profile data etc. we have now built a retrieval process that will capture all of the system values and then keep those system values in sync. When the client recovery is required scripts will be run that will allow all of the captured system values to be set on the recovery partition.

We believe that LVLT4i is a big step forward in being able to provide a recovery process for many IBM i users, even if they have an existing High Availability product in use today they will see many benefits from using it as their preferred recovery tool. We are noticing that many of those companies that implemented a High Availability Solution are not able to keep up with the changing technology being provided, this means that the recovery capabilities of the solution are being eroded and their value is no longer what it used to be. Data protection is the most important point of any availability solution so managing it needs to be a top priority, having a Recovery Time Objective of 4 – 12 hours should be more than enough for most of the IBM i community so paying for a Recovery Time Objective of minutes is not practical or beneficial.

LVLT4i when managed by a reputable Managed Service Provider should provide the users with a better recovery position and at a price that meets even the tightest of budgets. We believe that Recovery solutions are better managed by those who are committed to them and who continue to develop the skills to maintain them at all times. Although we are not big “Cloud” supporters, we think LVLT4i and the services offered by a Manage Service Provider could make the difference in being able to see value from a properly managed recovery process, offloading the day to day management to a service provider alone should show significant savings.

If you would like to know more about LVLT4i and its capabilities please call us and we will be happy to discuss. If you prefer to use Email we have a contact process on our website under contact us that you can use.

Chris…

Dec 02

Getting the most from LVLT4i

While it is early days for the LVLT4i product we have already had a number of interesting conversations with IBM i users and Managed Service Providers about how we see it being deployed to the smaller IBM i user base.

Price advantages
For the smaller IBM i user the thought of going to a full blown High Availability Solution has always been one that comes with thoughts of big budgets and lots of heartache. The clients need a duplicate system plus the infrastructure required to allow the replication processes to sync data and objects between the systems. Add to this licenses for the High Availability Product, OS and ISV software means that many clients believe availability protection at this level as a viable option.
Even if they identify a Managed Service Provider who could offer the target environment, they still see this is as something beyond their budget.
LVLT4i is aimed at easing that problem, this a Managed Service offering with subscription based pricing based on the clients system (IBM Tier group), this allows the MSP to grow the business without having to invest in up front licensing costs while providing a hardware platform which meets their customers requirements. The iASP technology also reduces the costs for the Managed Service Provider because they can run many clients on a single target LPAR/system removing the one to one relationship generally seen in this scenario. The client will only pay a monthly fee, he will have no upfront capital expense to get signed off and will probably find the target systems are much faster and newer than his existing systems.

Skills advantages
We have been involved with IBM i (and its predecessors) for nearly 25 years in the High Availability market and we have carried out a lot of High Availability software implementations. During that time we have seen a lot of the problems people encounter when trying to implement and manage a High Availability environment. Moving that skill requirement to a Managed Service Provider will bring a number of benefits. The client staff will not have to keep up with the changing capabilities of the High Availability Product, they can concentrate on their main focus which is providing a IT infrastructure to meet the business’s needs. Installation and ongoing management of the replicated environment will be managed by the Managed Service Provider, no more consultancy fees to the High Availability Software provider every time you need to make a minor change. The Managed Service Provider will have a lot of knowledge spread throughout their team and many of that team will have specialist skills that can be brought in to figured out problems.

Technology advantages
LVLT4i uses iASP technology on the target system, the clients system will continue to use *SYSBAS so no changes are required for the clients applications. When the client needs to test or recover the iASP data is saved and restored back to *SYSBAS. This brings some added advantages because the content of those iASP’s can be saved and restored at any time to another LPAR/System for testing. This will allow you to test a new release of software without impacting your current production or recovery position, LVLT4i will continue to keep the recovery partition in sync. Recovery testing will be improved because you will be able to check that the recovery procedures you have developed work, all of this while your existing recovery protection is maintained. Being able to check if a new application update works, check out your application on a new release, check the migration of data to a new release/application, all of these can be carried out without affecting your production or recovery position. If you need extra backups to be taken these can be carried out on the target system at any time during the day, suspending the apply processes while the backup is performed or doing a save while active is not a problem.
The technology which is implemented at the Managed Service Provider will probably be much newer and faster than the client would invest in, this means the advantages of running on the newer systems and OS could be shown to the clients management and maybe convincing them that their existing infrastructure should be improved.
JQG4i will be implemented for those who need job queue content recovery and analysis, this means you can re-launch jobs that did not complete or start using the exact same parameters they were launched with on the source.

LVLT4i is the next level of protection for those who currently use tapes and vaulting for recovery. The Recovery Point Objective is already the same as a High Availability offering (at the transaction level) while the Recovery Time Objective in the 4 – 12 hours which is better than existing tape and vaulting solutions. We are not stopping there, we are already looking at how we can improve the Recovery Time Objective through additional automation and new replication processes, in fact we have already added additional features to the product that will help reduce the time it takes to recover a clients system to the recovery partition at the Managed service Provider. The JQG4i offer adds a new dimension to the recovery process, it brings a very important technology to the users that is not available in many of the High Availability offerings today, this could mean the difference between being able to recover or not.

Even if you already run a High Availability solution today you should look at this offering, having someone else manage the environment and provide a Recovery Point Objective/Recovery Time Objective this offers could be what you need. Many are running a High Availability solution to meet the Recovery Point Objective and not interested in a Recovery Time objective of minutes, this could be costing you more than its worth to maintain. LVLT4i and a Managed Service could offer significant benefits.

If you are interested in knowing more about LVLT4i and the Managed Service Providers we are working with let us know. We are actively seeking more Managed Service Providers who are interested in helping us build a better recovery solution for the IBM i user base.

Chris…

Nov 27

Operational Assistant backup to QNAP NAS using NFS

After a recent incident (not related to our IBM i backups) we decided to look at how we backed up our data from the various systems we deploy. We wanted to be able to store our backups in a central store which would allow us to recover data and objects from a know point in time. After some discussion we decided to set up a NAS and have all backups copied to it from the source systems. We already use a QNAP NAS for other data storage so decided on a QNAP TS-853 Pro for this purpose. The NAS and drives were purchased and set up with Raid 6 and a hot spare for the Disk Protection which left us around 18TB of available storage.

We will use a shared folder for each system plus a number of sub-directories for each type of save (*DAILY *WEEKLY *MONTHLY), the daily save required a day for each day Mon – Thu as Friday would either be a *WEEKLY or *MONTHLY save as per our existing tape saves. Below is a picture of the directories.

Folder List

Folder List

We looked at a number of options for transporting the images off the IBM i to the NAS such as FTP, Windows shares (SAMBA) and NFS. FTP would be OK but managing the scripts to carry out the FTP process could become quite cumbersome and probably not very stable. The Windows share using SAMBA seemed like a good option but after some research we found that the IBM i did not play very well in that area. So its was decided to set up NFS, we had done this before using our Linux systems but never a QNAP NAS to an IBM i.

We have 4 systems defined Shield6 – 9 each with its own directory and sub-tree for storing the images created from the save. The NAS was configured to allow the NFS server to use the share the Folders and provide secure access. At first we had a number of problems with the access because it was not clear how the NFS access was set, but as we poked around the security settings but we did find out where you had to set the access. The pictures below shows how we set the folders to be accessible from our local domain. Once the security was set we started the NFS server on the NAS.

Folder Security Setting

Folder Security Setting

The NAS was now configured and ready to accept mount requests, there are some additional security options which we will review later but for the time being we are going to leave them all set up to the defaults. The IBM i also needs to be configured to allow the NFS mounts to be added, we chose to have the QNAP folders mounted over /mnt/shieldnas1 which has to exist before the MOUNT request is run. The NFS services also have to be running on the IBM i before the MOUNT command is run otherwise it cannot negotiate the mount with the remote NFS server. We started all of the NFS Services at once even though some were not going to be used (The IBM i will not be exporting any directories for NFS mounts so that service does not need to run) because starting the services in the right order is also critical. We mounted the shared folder from the NAS over the directory on the IBM i using the command shown in the following display.

Mount command for shared folder on NAS

Mount command for shared folder on NAS

The following display shows the mapped directories below the mount once it was successfully made.

Subtree of the mounted folder

Subtree of the mounted folder

The actual shared folder /Backups/Shield6 is hidden by the mount point /mnt/shieldnas1, when we create the mount points on the other systems they will all map over their relevant system folders ie /Backups/Shield7 etc so that only the save directories need to be added to the store path.

We are using the Operational Assistant for the backup process, this can be setup using the GO BACKUP command and taking the relevant options to set up the save parameters. We are currently using this for the existing Tape saves and wanted to be able to carry out the same saves but have the target set to an Image Catalog, once the save was completed we would copy the Image Catalog Entries to the NAS.

One problem we found with the Operational Assistant backup is that you only have 2 options for the IFS save, all or nothing. We do not want some directories to be saved (especially the image catalog entries) so we needed a way to ensure that they are never saved by any of the save processes. We did this by setting the *ALWSAV attribute for the directory and subtree to *NO. Now when the SAV portion of the save runs it does not save the Backup directory or any of the other ones we do not need saved.

The image catalog was created so that if required we could generate physical tapes from the image catalog entries using DUPTAP etc. Therefore settings had to be compatible with the tapes and drive we have. The size of the images can be set when they are added and we did not want the entire volumes size to be allocated when it was created, setting the ALCSTG to *MIN only allocates the minimum amount of storage required which when we checked for our tapes was 12K.

For the save process which is to be added as a Job Schedule entry we created a program in ‘C’ which we have listed below, (you could use any programming language you want) taht would run the correct save process for us in the same manner as the Operational Assistant Backup does. We used the RUNBCKUP command as this will use the Operational Assistant files and settings to run the backups. The program is very quick and dirty but for now it works well enough to prove the technology.


#include<stdio.h>
#include<string.h>
#include <stdlib.h>
#include<time.h>

int main(int argc, char **argv) {
int dom[12] = {31,28,31,30,31,30,31,31,30,31,30,31}; /* days in month */
char wday[7][3] = {"Sun","Mon","Tue","Wed","Thu","Fri","Sat"}; /* dow array */
int dom_left = 0; /* days left in month */
char Path[255]; /* path to cpy save to */
char Cmd[255]; /* command string */
time_t lt; /* time struct */
struct tm *ts; /* time struct GMTIME */
int LY; /* Leap year flag */

if(time(&lt) == -1) {
printf("Error with Time calculation Contact Support \n");
exit(-1);
}
ts = gmtime(&lt);
/* if leap year LY = 0 */
LY = ts->tm_year%4;
/* if leap year increment feb days in month */
if(LY == 0)
dom[1] = 29;
/* check for end of month */
dom_left = dom[ts->tm_mon] - ts->tm_mday;
if((dom_left < 7) && (ts->tm_wday == 5)) {
system("RUNBCKUP BCKUPOPT(*MONTHLY) DEV(VRTTAP01)");
sprintf(Path,"/mnt/shieldnas1/Monthly");
/* move the save object to the NAS */
sprintf(Cmd,
"CPY OBJ('/backup/MTHA01') TODIR('%s') TOCCSID(*CALC) REPLACE(*YES)",
Path);
}
else if(ts->tm_wday == 5) {
system("RUNBCKUP BCKUPOPT(*WEEKLY) DEV(VRTTAP01)");
sprintf(Path,"/mnt/shieldnas1/Weekly");
/* move the save object to the NAS */
sprintf(Cmd,
"CPY OBJ('/backup/WEKA01') TODIR('%s') TOCCSID(*CALC) REPLACE(*YES)",
Path);
}
else {
system("RUNBCKUP BCKUPOPT(*DAILY) DEV(VRTTAP01)");
sprintf(Path,"/mnt/shieldnas1/Daily/%.3s",wday[ts->tm_wday]);
/* move the save object to the NAS */
sprintf(Cmd,
"CPY OBJ('/backup/DAYA01') TODIR('%s') TOCCSID(*CALC) REPLACE(*YES)",
Path);
}
if(system(Cmd) != 0)
printf("%s\n",Cmd);
return 0;
}

The program will check for the day of the week and the number of days in the month, this allows us to change the Friday Backup to *WEEKLY or *MONTHLY if it is the last Friday of the month. Using the Job Scheduler we added the above program to an entry which will run at 23:55:00 every Monday to Friday (we do not back up on Saturday or Sunday at the moment) and set it up to run.

On a normal day, our *DAILY backup runs for about 45 minutes when being carried out to a tape, the weekly about 2 hours and the monthly about 3 hours. From the testing we did so far, the save to the image catalog took about 1 minute for the *DAILY and more surprisingly only 6 minutes for the *MONTHLY save (which saves everything). The time it took to transfer the our *DAILY save to the NAS (about 300MB) was only a few seconds, the *MONTHLY save which was 6.5 GB took around 7 minutes to complete.

We will keep reviewing the results and improve the program as we find new requirements but for now it will be sufficient. The existing Tape saves will still run in tandem until we prove the recovery processes. The speed differential alone makes the cost of purchase a very worthwhile investment, getting off the system for a few hours to complete a save is a lot more intrusive than doing it for a few minutes. We can also copy the save images back to other systems to restore objects very easily using the same NFS technology and speeding up recovery. I will also look at the iASP saves next as this coupled with LVLT4i could be a real life saver when re-building system images.

Hope you find the information useful.

Chris…

Oct 29

Integrating IBM i CGI programs into Linux Web Server

We have been working with a number of clients now who have CGI programs (mainly RPG) that have been used as part of web sites which were hosted on the IBM Apache Server. These programs build the page content using a write to StdOut process. They have now started the migration to PHP based web sites and need to keep the CGI capability until they can re-write the existing CGI application to PHP.

The clients are currently running the iAMP server (they could use the ZendServer as well) for their PHP content and will need to access the CGI programs from that server. We wanted to test the process would run regardless of the Apache server used (IBM i, Windows,Linux etc) so we decided to set up the test using our Linux Apache server. The original PHP Server on the IBM i used a process that involved the passing of requests to another server (ProxyPass) which is what we will use to allow the Linux Server to get the CGI content back to the originating request. If you want to know more about the Proxy Process you can find it here.

First of we set up the IBM Apache Server to run the CGI program which we need. The program is from the IBM knowledge center called SampleC which I hacked to just use the POST method (code to follow) which I complied into a library called WEBPGM. Here is the content of the httpd.conf for the apachedft server.


# General setup directives
Listen 192.168.200.61:8081
HotBackup Off
TimeOut 30000
KeepAlive Off
DocumentRoot /www/apachedft/htdocs
AddLanguage en .en
DefaultNetCCSID 819
Options +ExecCGI -Includes
CGIJobCCSID 37
CGIConvMode %%EBCDIC/MIXED%%
ScriptAliasMatch ^/cgi-bin/(.*).exe /QSYS.LIB/WEBPGM.LIB/$1.PGM

The Listen line states that the server is going to listen on port 8081. Options allows the execution of CGI progrmas (+ExecCGI). I have set the CGI CCSID and conversion mode and then set up the re-write of any request that has a url with ‘/cgi-bin/’ and has a extension of .exe to the library format required to call the CGI program.

The program is very simple, I used the C version of the program samples IBM provides and hacked the content down to the minimum I needed. I could have altered it even further to remove the write_data() function but it wasn’t important. Here is the code for the program which was compiled into the WEBPGM lib.


#include <stdio.h> /* C-stdio library. */
#include <string.h> /* string functions. */
#include <stdlib.h> /* stdlib functions. */
#include <errno.h> /* errno values. */
#define LINELEN 80 /* Max length of line. */

void writeData(char* ptrToData, int dataLen) {
div_t insertBreak;
int i;

for(i=1; i<= dataLen; i++) {
putchar(*ptrToData);
ptrToData++;
insertBreak = div(i, LINELEN);
if( insertBreak.rem == 0 )
printf("<br>");
}
return;
}

void main( int argc, char **argv) {
char *stdInData; /* Input buffer. */
char *queryString; /* Query String env variable */
char *requestMethod; /* Request method env variable */
char *serverSoftware; /* Server Software env variable*/
char *contentLenString; /* Character content length. */
int contentLength; /* int content length */
int bytesRead; /* number of bytes read. */
int queryStringLen; /* Length of QUERY_STRING */

printf("Content-type: text/html\n");
printf("\n");
printf("<html>\n");
printf("<head>\n");
printf("<title>\n");
printf("Sample AS/400 HTTP Server CGI program\n");
printf("</title>\n");
printf("</head>\n");
printf("<body>\n");
printf("<h1>Sample AS/400 ILE/C program.</h1>\n");
printf("<br>This is sample output writing in AS/400 ILE/C\n");
printf("<br>as a sample of CGI programming. This program reads\n");
printf("<br>the input data from Query_String environment\n");
printf("<br>variable when the Request_Method is GET and reads\n");
printf("<br>standard input when the Request_Method is POST.\n");
requestMethod = getenv("REQUEST_METHOD");
if ( requestMethod )
printf("<h4>REQUEST_METHOD:</h4>%s\n", requestMethod);
else
printf("Error extracting environment variable REQUEST_METHOD.\n");
contentLenString = getenv("CONTENT_LENGTH");
contentLength = atoi(contentLenString);
printf("<h4>CONTENT_LENGTH:</h4>%i<br><br>\n",contentLength);
if ( contentLength ) {
stdInData = malloc(contentLength);
if ( stdInData )
memset(stdInData, 0x00, contentLength);
else
printf("ERROR: Unable to allocate memory\n");
printf("<h4>Server standard input:</h4>\n");
bytesRead = fread((char*)stdInData, 1, contentLength, stdin);
if ( bytesRead == contentLength )
writeData(stdInData, bytesRead);
else
printf("<br>Error reading standard input\n");
free(stdInData);
}
else
printf("<br><br><b>There is no standard input data.</b>");
printf("<br><p>\n");
serverSoftware = getenv("SERVER_SOFTWARE");
if ( serverSoftware )
printf("<h4>SERVER_SOFTWARE:</h4>%s\n", serverSoftware);
else
printf("<h4>Server Software is NULL</h4>");
printf("</p>\n");
printf("</body>\n");
printf("</html>\n");
return;
}

Sorry about the formatting!

That is all we had to do on the IBM i server, we restarted the default apache instance and set to work on creating the content required for the Linux Server.
The Linux Server we use is running Proxmox, this allows us to build lots of OS instances (Windows,Linux etc) for testing. The Virtual Server is running a Debian Linux build with a standard Apache/PHP install. The Apache servers are also running Virtual hosts (we have 3 Virtual Linux servers running Apache), this allows us to run many websites from a single server/IP address. We created a new server called phptest (www.phptest.shield.local) running on port 80 some time ago for testing our PHP scripts so we decided to use this server for the CGI test. As the Server was already running PHP scripts all we had to do was change the configuration slightly to allow us to pass the CGI requests back to the IBM i Apache server.

The sample code provided by IBM which will run on the Linux Server is listed below.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body>
<form method="POST" action="/cgi-bin/samplec.exe">
<input name="YourInput" size=42,2>
<br>
Enter input for the C sample and click <input type="SUBMIT" value="ENTER">
<p>The output will be a screen with the text,
"YourInput=" followed by the text you typed above.
The contents of environment variable SERVER_SOFTWARE is also displayed.
</form>
</body>
</html>

When the url is requested the following page is displayed.

sampleC

Sample C input page


The Server needs to know what to do with the request so we have to redirect the request from the Linux Server to the IBM i server using the ProxyPass capabilities. You will notice from the code above that we are using the POST method from the form submission and we are going to call ‘/cgi-bin/samplec.exe’. This will be converted on the target system to our program call. The following changes were made to the Linux Apache configs and the server was restarted.

ProxyPreserveHost On
ProxyPass /cgi-bin/ http://192.168.200.61:8081/cgi-bin/
ProxyPassReverse /cgi-bin/ http://192.168.200.61:8081/cgi-bin/

This allows the Linux Server to act as a gateway to the IBM i Apache server, the client will see the response as if it is from the Linux server.
When we add the information into the input field on the page and press submit the following is displayed on the page.
samplec-out

Output from CGI program

Note:
Those reading carefully will notice the above page shows a url of www1.phptst.shield.local not www.phpest.shield.local as shown in the output screen below. This is because we also tested the iAMP server running on another IBM i to link to the same IBM Apache Server used in the Linux test using exactly the same code.

This is a useful setup for being able to keep existing CGI programs which are being presented via the IBM Apache Server while you migrate to a new PHP based interface. I would rather have replaced the entire CGI application for the clients with a newer and better PHP based interface, but the clients just wated a simple and quick fix, maybe we will get the opportunity to replace it later?

Note:-
The current version of iAMP which available for download from the Aura website does not support mod_proxy so if this is something you need to implement let us know and we can supply a version which contains the mod_proxy modules. I hope Aura will update the download if sufficient people need the support which will cut us out of the loop.

If you need assistance creating PHP environments for IBM i let us know. We have a lot of experience now with setting up PHP for IBM i and using the Easycom toolkit for access IBM i data and objects.

Chris…

Oct 24

PowerHA and LVLT4i.

We have had a number of conversations about LVLT4i and what it offers to the Managed Service Provider(MSP). As part of those discussions the IBM solution PowerHA often comes up as it also uses iASP technology but that is really where the similarity ends.

PowerHA uses the iASP to isolate the objects that are to be replicated to another system/storage device and it has an exact copy of the iASP from the source on the target. Changes are captured at the hardware level and are sent to the remote system as they occur.

LVLT4i only replicates objects to a remote iASP, it uses either Audit journal triggers or the Remote Journal technology to capture and send the data. The source object resides in *SYSBAS and the target object in an iASP, it is used primarily to allow multiple copies of the same library/object combination to be stored on a single system. The remote iASP is always available to the user.

iASP is not widely implemented at customer sites, this is in part due to the lack of support for iASP’s built into many of the applications that run on the IBM i today (many of the applications were built before iASP technology was available). For a customer to migrate an application to allow iASP use there are a number of constraints which have to be considered plus each users environment has to be adjusted to allow the iASP content to be used (SETASPGRP etc). This has further limited the use of iASP as many do not feel the benefits of moving to the iASP model out-weight the cost of migration. Another issue is you are now adding an additional storage management requirement, the iASP is disk based which will require protection to be added in some form. With LVLT4i you can leave your system unchanged, only the target system is going to need iASP setup and that will be in the hands of your Managed Service Provider. The decision about what to replicate is yours, with some professional help from a Managed Service Provider who knows your application it should be pretty bullet proof when it comes to recovery.

If you implement PowerHA you are probably going to need to set up an Admin Domain, this is where any *SYSBAS objects such as system values, profiles and configuration objects are managed. in LVLT4i we do not manage system values or configuration objects (configuration objects can be troublesome especially with TCP/IP) or system values. We have however just built in a new profile and password process to allow the security aspects of an application to be managed across systems in real time. Simple scripts can capture configuration and system value settings many of which are not important to your application so LVLT4i has you covered. If we find a need to build in system value or configuration management we will do so fairly rapidly.

PowerHA is priced by Core, so you license it for each Active Core on each system. Using CBU licensing, PowerHA can utilize lower active cores on the target and only activate them when the system is required. Unfortunately in a HA environment you are probably switching regularly so you will have the same number of active cores all the time. LVLT4i is priced by IBM tier regardless of the number of active cores. The target system license is included with the source system license regardless of the target system tier so a Manage Service Provider who has a P30 to support many P05 clients is not penalized.
PowerHA also comes in a few flavors which are decided on by the type of set up you require. Some of the functionality such as Asynchronous mirroring is only available in the Enterprise edition so if you need to ensure your application is not constrained by remote confirmation processing (waiting for the remote system to confirm it has the data) your are going to need the Enterprise edition which costs more per core. LVLT4i comes in one flavor and is based on a rental model, the transport of data over Synchronous/Asynchronous remote journals is available to all plus it supports any geographic model.

Because the iASP is always available the ability to backup at any time is possible with LVLT4i. With PowerHA you have to use a Flashcopy to make another disk based copy of the iASP which can then be used for the back up to tape etc. That requires a duplicate set of disks to match the iASP content. With LVLT4i you can use Save While Active or suspend the apply process for point in time saves, the remote journal will still be receiving your application updates which can be applied once the save has completed so data protection is not exposed.

RPO is an important number which is regularly banded around by the High Availability providers, PowerHA states it is 0 because everything is replicated at the hardware level. We believe LVLT4i is pretty close to the same but there are a couple of things to consider.

First of all, RPO of 0 will require synchronous delivery of changes, if you use an Asynchronous delivery method queued changes will affect that for either solution. LVLT4i uses Remote journalling for data changes, so if you use Synchronous mode I feel the two are similar in effect.

Because we use a different process for object changes, any object updates are going to be dependent on the level of change activity being processed by the object replication processes. The amount of data being replicated is also a factor as a single stream of object changes is used to transfer the updates. We have done a lot of work on minimizing the data which has be be sent over the wire such as using commands instead of save restore, pipe-lining changes so multiple updates to an object are optimized into a single action and compression within the save process. This has greatly reduced the activity and therefore bandwidth requirements.

PowerHA is probably better at object replication because of the technology IBM can access, plus it is going to be carried out in line with the data changes. The same constraints about using synchronous mode affect the object replication process so bandwidth is going to be a major factor in the speed of replication etc. Having said that, most of the smaller clients we have implemented any kind of availability for (HA4i/DR4i) do not see significant object activity and little to no backlogs in the object replication process.

The next recovery figure RTO talks about how long it will take from making the decision to switch, to actually switching. My initial findings about iASP tended to show a fairly long role-swap time because you had to vary off the iASP and then on again to make it available. We have never purchased PowerHA so our tests are based around how long it took to vary off and then on again a single iASP on our P05 system (approximately 20 minutes). I would suspect the newer and faster systems have reduced the time it takes but it is still a fairly long time. LVLT4i is not a contender in this role because we expect the role-swap times to be pretty extended (4 – 12 hours) even if you do a lot of automation and preparation.

One of the issues which affect all High Availability Solutions is the management of batch, if you have a batch process running at the time of failure it could affect the integrity of the application data on the target system. LVLT4i and PowerHA both have this limitation as the capture of job queue content is not possible even in an iASP, but we have a solution which when integrated with LVLT4i will allow you to reload job queues and identify orphaned data which has been applied by a batch process. Our JQG4i product captures all activity for specific job queues and will track each job from load to completion. This will allow you to recover the entire application environment to a known start point and thereby ensure your data integrity is maintained. Just being able to automatically reload jobs that did not run before the system failure is a big advantage that many current users benefit from.

There are plenty of options out there to choose from but each has its own strengths and weaknesses. LVLT4i uses the same replication technology as out HA4i and DR4i products with enhancements to allow the use of iASP as the target disk. It is not designed to meet the same RTO expectations as PowerHA even though both make effective use of iASP technology. However, PowerHA is not necessarily the best option for everyone because it does have a number of dependencies that make it more difficult/costly to implement than a logical replication solution, you have to weigh up the pros and cons of each technology and make a decision about what is important.

If you are interested in knowing more or would like to see a demo of the LVLT4i product please let us know and we will be happy to schedule.

Chris…

Oct 23

SAVSECDTA timing?

We are looking at how to manage the recovery of profiles and passwords in an environment where the profiles cannot be managed constantly. When using our HA4i product we have the ability to constantly maintain the user profiles and passwords because the user profiles are allowed to exist on the target system. However in an environment such as that required for the LVLT4i product User Profiles cannot exist because they may conflict with other profiles from other clients (All user profiles have to exist in *SYSBAS)

The process we have tested involves using the SAVSECDTA command to save the data to a save file, this save file can be automatically replicated to the iASP on the target system. The Profile information is captured in a file which is also replicated to the target iASP using normal replication processes (Remote Journals). When the system needs to be rebuilt for recovery the information collected in the SAVSECDTA file will be restored, the profiles will be updated using the profile data we have collected and then the RSTAUT command will be run. This will bring the system and profiles up to the latest content available.

While we were testing the processes we noticed a very strange thing. The first time we ran the request on a system it took a little while to complete about 1 minute, but when we ran the request again it took only a couple of seconds? The content of the save file was the same (we even set the compression level to high with no significant impact) but why is it taking so long the first time? We thought that maybe it was because the save file was already available (we put it in QTEMP) but again signing off and on then retrying gave us the same results, it now only took a few seconds to complete the save? Signing onto another system and doing the exact same process yielded the same results, the first time took about 1 minute while subsequent tries only took a few seconds.

We do not know what is going on under the covers but it certainly seems like something gets lined up after the first save, this leads us to believe that doing a SAVSECDTA on a regular basis (nightly?) may not be a bad thing. If you have any information as to why, let us know as we are very curious.

LVLT4i is new and while we feel the product should attract a number of Managed Service Providers we are interested in knowing what you think. Would you be interested in a solution that provides a very low RPO (close to zero data loss) with a RTO in the 4 – 12 hours time frame? If you are interested let us know, we will be happy to put you in touch with one of the MSP’s we have been working with. If you are a MSP and would like to know more or even see a demo of the product let us know as well, we are excited by the opportunities this could bring.

Chris…