The goal of this writing was to illustrate how to restore backup before the patch would be applied. The alert notes that:

The risk can be avoided by applying journals from the beginning of the journal file that was switched to at the start of the backup, rather than accepting the default of starting from the journal marker position.

Having non-patched Caché 2015.1.4, I ran sample database backup and restore just to get where I should answer "No". Collecting journal info from the backup log:

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· Dec 4, 2015 3m read
Atelier Beta Cloud Infrastructure

A few people wrote to me asking about the infrastructure behind the Atelier Server implementation. Its neat and a worthwhile story to share so I am writing it up here as a post on the community. I want to go in to a little detail on why it was needed and then I will outline in detail how we went about implementing this.

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This text is a continuation of my article where I explained the structure a Caché database. In this article, I described the types of blocks, connections between them and their relation to globals. The article was purely theoretical. I made a project that helps visualize the block tree - and this article will explain how it works in great detail.

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Article
· Oct 4, 2016 1m read
How to Parse a URL in Caché

How to parse a URL in Caché:

Let's pretend you are working on a project where you may be retrieving a URL for some purpose and you have the need to be easily able to parse apart that URL to get the various components that make up the URL.

Here's how to do that:

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Article
· Oct 6, 2016 4m read
RESTful Exception Handling

A beginner’s guide to Exception Handling in RESTful web services. The article gives an example how the various error conditions during processing a service request can be handled.

We expect our client – server communication working in a flawless operational condition, running error free software. But we are prepared to handle exceptions. Are we? So far in the examples of the previous sessions were not. We did not care about exceptions. The result? In any error incident it took ages to figure out what the problem is and more importantly how to fix it.

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Article
· Oct 5, 2016 13m read
RESTful way of data transfer

This article gives a brief introduction how a RESTful service consumer and a RESTful service provider exchange data. It is a beginner’s guide. Data is transferred from a consumer to a provider as parameters of the service. Parameters are part of a service request. The result of the service action a response is returned from a provider to a consumer. Both the service request and response are standard HTTP messages. Since HTTP is a flexible standard regarding to the message contents, RESTful services also enjoy the versatility of data transfer methods.

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· Aug 31, 2016 1m read
DeepSee cubes building troubleshooting

Hi!

Sometimes you see that call to DeepSee cube building method:

w ##class(%DeepSee.Utils).%BuildCube("CubeName")

does nothing.

Here are my 2 cents on possible reasons.

1. Run DeepSee Reset method in certain Namespace:

NAMESPACE> w ##class(%DeepSee.Utils).%Reset()

and try again.

2. Make sure, that all the indices in your base class for the cube are rebuilt, rebuild them and run it again:

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NewBie's Corner Session 27 Traversing A Global with $Order Part 1

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

Traversing A Global

Perhaps the most difficult concept in Caché/MUMPS is its Global Structure. This session and several that follow it deals with the Global Structure. However, just presenting the material will not guarantee your understanding of it. You must experiment with the data and concepts that are presented.

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NewBie's Corner Session 28 Various Methods to Traverse a Global

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

Judging from the number of responses to Session 27 Traversing A Global, developers are passionate about their methods. I am not here to judge the merit of the various methods.

Over the next few pages I will demonstrate a number of methods to Traverse a Global. If you don't already have a favorite they may help you pick one.

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Article
· Sep 30, 2016 1m read
ECP Magic

I saw someone recently refer to ECP as magic. It certainly seems so, and there is a lot of very clever engineering to make it work. But the following sequence of diagrams is a simple view of how data is retrieved and used across a distributed architecture.

For more more on ECP including capacity planning follow this link: Data Platforms and Performance - Part 7 ECP for performance, scalability and availability

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Checking if Directory or File Exists:

Outlined below is an example of how to check if a directory exists:

Set directoryName="c:\temp\nosuchdir"

/* Check for existence of a directory - Return Value:  0 - directory does not exist;  1 - directory does exist  */

Set directoryExists=##class(%File).DirectoryExists(directoryName)

If ('directoryExists)  // do the processing for when a directory does not exist


Outlined below is an example of how to check if a file exists:

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Cross-origin Resource Sharing (CORS) is one of the basic security features built into browsers. CORS controls accessing resources from a HTML page in domains other than the original domain. It is particularly important for AJAX calls. Since RESTful services can be used as data provider to any AJAX call, you have to be able to control cross-origin access. By default services are not allowed to do CORS. You are going to learn how to enable it for Ensemble RESTful services.

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NewBie's Corner Session 29 Documentation on the Caché/MUMPS Global Structure

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

This post contains several links to very good documentation of the Caché Globals Structure.

Like I said, "Perhaps the most difficult concept in Caché/MUMPS is its Global Structure."

universalNoSQL.pdf - http://mgateway.com/docs/universalNoSQL.pdf

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We're developing Ensemble PoC and one day our frontend developer (who doesn't have Ensemble production running) said that Populate just doesn't cut it and he needs to see the real data. He needed only one object, but the problem was - it's a big object. Still, I checked ids of everything related and wrote this command (parts omitted, but you get the idea):

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Preface: our small, but very ambitious company called “Black Mushroom Studio” came up with an idea for an e-commerce project and a mobile app that would let users pay for certain goods/services via a payment aggregator.

What we had initially: an Android app skeleton that, of course, liked communicating via HTTP and JSON, and a payment system with an API – web services with SOAP content.

Goal: make it all work together.

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NewBie's Corner Session: 9 Documentation and books

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

To access your documentation:

Assuming you have installed Caché, (see NewBie's Corner, Session:1),

Click on the InterSystems cube in the Windows system tray, then choose Documentation.

Or – another method you can use to access your documentation:

Assuming you have installed Caché, (see NewBie's Corner, Session:1),

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Article
· Sep 21, 2016 7m read
REST in Pieces

A beginners guide to develop Ensemble RESTful web services.

Background

Before you start reading this short introduction please go through the on-line documentation of Ensemble with special attention to chapter “Creating REST services and clients with Ensemble”.

The approach in the documentation is undisputable the fastest and easiest way to create RESTful services. As a beginner I went through the documentation and I had several questions. This short article is listing those questions plus my humble answers.

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· Sep 20, 2016 4m read
Diagnosing Framing Errors

Framing refers to the characters that mark the start and end of an HL7 message (or other types of framed messages). Most HL7 services and operations have a Framing setting that allows the user to define this framing. The most common choices are available as defaults, but with the AsciiMM/NN setting, components can be configured to recognize any framing characters.

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Article
· Sep 14, 2016 4m read
Creating a Dummy SOAP Web Service

A “Dummy” SOAP Web Service

When dealing with SOAP in Caché, it is sometimes necessary to debug errors by directly accessing (and sometimes editing) the XML which is sent, i.e. the SOAP request and subsequent SOAP response. If you’re debugging a Caché web service, it is often useful to use a tool such as SoapUI (https://www.soapui.org/) to manually create and control the SOAP request, so that the effect of adjustments can easily be seen on the Caché web service.

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NewBie's Corner Session 26 Globals and Arrays Part 2

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

Globals, Arrays, and Variables Part 2

A thorough understanding of Globals, Arrays, and Variables is foundational for every Caché developer.

Uniqueness of the Caché Global Structure or database

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