Recently, a partner company started to develop an Angular client for their Cache application. Together, we decided to leverage the power of Caché dynamic objects to exchange JSON encoded data between client and server parts. However, we realized that currently there is a gap in Cache JSON implementation that prevents simple use of traditional registered and persistent classes to exposed their data with the same ease as with XML. I wrote a small JSON adapter, that does the job and bridgers the gap. It's purpose is simple expose data described by a regular Cache class in a one-to-one fashion to a %DynamicObject. On the other hand, when a serialized JSON data comes in, it can be easily deserialized into dynamic object and subsequently bound to regular class by the newly created adapter.

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In this post I would like to talk about the syslog table.  I will cover what it is, how you look at it, what the entries really are, and why it may be important to you.  The syslog table can contain important diagnostic information.  If your system is having any problems, it is important to understand how to look at this table and what information is contained there.

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Katherine Reid · Aug 26, 2016 2m read
TLS v1.2 support in Caché


What version of Caché supports TLS v1.2? 


Caché 2015.2 announced support for TLS v1.1 and v1.2.  In this version, the SSL/TLS configuration page provides checkboxes for TLS v1.1 and v1.2, which allows the versions to be configured individually.  This allows sites to, for example, require TLS v1.2 only.

Additionally, some earlier versions of Caché provide undocumented support for TLS v1.1 and v1.2, specifically Caché 2014.1.3 and above and 2015.1, on Windows, Linux and Unix.

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In this series of articles, I'd like to present and discuss several possible approaches toward software development with InterSystems technologies and GitLab. I will cover such topics as:

  • Git 101
  • Git flow (development process)
  • GitLab installation
  • GitLab Workflow
  • Continuous Delivery
  • GitLab installation and configuration
  • GitLab CI/CD
  • Why containers?
  • Containers infrastructure
  • CD using containers

In the first article, we covered Git basics, why a high-level understanding of Git concepts is important for modern software development, and how Git can be used to develop software.

In the second article, we covered GitLab Workflow - a complete software life cycle process and Continuous Delivery.

In the third article, we covered GitLab installation and configuration and connecting your environments to GitLab

In the fourth article, we wrote a CD configuration.

In the fifth article, we talked about containers and how (and why) they can be used.

In the sixth article let's discuss main components you'll need to run a continuous delivery pipeline with containers and how they all work together.

In this article, we'll build Continuous Delivery configuration discussed in the previous articles.

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Eduard Lebedyuk · Oct 18, 2016 7m read
Macros in the InterSystems Caché

In this article I would like to tell you about macros in InterSystems Caché. A macro is a symbolic name that is replaced with a set of instructions during compilation. A macro can “unfold” in various instruction sets each time it is called, depending on the parameters passed to it and activated scenarios. This can be both static code and the result of ObjectScript execution. Let's take a look at how you can use them in your application.

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The object and relational data models of the Caché database support three types of indexes, which are standard, bitmap, and bitslice. In addition to these three native types, developers can declare their own custom types of indexes and use them in any classes since version 2013.1. For example, iFind text indexes use that mechanism.

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The Management Portal allows you to Export one or more globals to a file that you can then Import into that or another namespace.  However, the Management Portal can only be used to export entire globals.  For exporting selected nodes or subtrees within a global, a different utility is necessary.   This utility is the Export() classmethod in the %Library.Global class, which can export an entire global but also has the ability to export selected nodes or subtrees.

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Isaac Aaron · Jun 21, 2016 1m read
Simple Cache systemd Unit


I have noticed that Cache (2016.1 at the time of writing) doesn't come with a systemd startup script for RHEL7.

Here is a small example script I have built.

Description=Intersystems Cache

ExecStart=/bin/bash -c '/usr/cachesys/cstart 2>&1 | logger -t cache_start'
ExecStop=/bin/bash -c '/usr/cachesys/cstop quietly 2>&1 | logger -t cache_stop'


The file should be placed as /usr/lib/systemd/system/cache.service

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There are several options how to deliver user interface(UI) for DeepSee BI solutions. The most common approaches are:

  • use native DeepSee Dashboards, get web UI in Zen and deliver it in your web apps.
  • use DeepSee REST API, get and build your own UI widgets and dashboards.

The 1st approach is good because of the possibility to build BI dashboards without coding relatively fast, but you are limited with preset widgets library which is expandable but with a lot of development efforts.

The 2nd provides you the way to use any comprehensive js framework (D3, Highcharts, etc) to visualize your DeepSee data, but you need to code widgets and dashboards on your own.

Today I want to tell you about yet another approach which combines both listed above and provides Angular based web UI for DeepSee Dashboards -  DeepSee Web library.

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EnsLib.HL7.Message.cls provides many API methods for manipulating an HL7 message.  RemoveSegmentAt(), for example, can be used to remove a segment by path or index, but only one segment at a time.   There may be times that you'll need to remove all segments within a group or even many groups of segments from the HL7 message.  Surely you can iterate through each segment in each group and remove them one by one, but there's a much easier way. 


With just one command, like below, you can remove all OBX segments in an ORU_R01 message (msg):

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to dismount/mount a database, use Dismount() and Mount() methods in SYS.Database class available in %SYS namespace.
NB: the database ID is its Directory

You'll find  some examples of how to dismount/mount and check if a database is mounted (Mounted=1) or not (Mounted=0), and quickly see all the attributes of a database (via zwrite)

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From the first glance, the task of configuring LDAP authentication in Caché is not hard at all – the manual describes this process in just 6 paragraphs. On the other hand, if the LDAP server uses Microsoft Active Directory, there a few non-evident things that need to be configured on the LDAP server side. Those who don’t do anything like that on a regular basis may get lost in Caché settings. In this article, we will describe the step-by-step process of setting up LDAP authentication and cover the diagnostic methods that can be used if something doesn’t work as expected.

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InterSystems products (IRIS, Caché, Ensemble) already include a built-in Apache web server. But the built-in server is designed for the development and administration tasks and thus has certain limitations. Though you may find some useful workarounds for these limitations, the more common approach is to deploy a full-scale web server for your production environment. This article describes how to set up Apache to work with InterSystems products and how to provide HTTPS access. We will be using Ubuntu, but the configuration process is almost the same for all Linux distributions.

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DTL Transformations and GetValueAt/SetValueAt calls on HL7 messages will truncate any fields longer than 32K.  To avoid this, the methods GetFieldStreamRaw and StoreFieldStreamRaw must be used when dealing with fields that might be larger than 32K.  OBX:5 is a frequent example.  These methods have some subtleties and must be used carefully.

This can't be done by simply dragging from left to right in a DTL.  It must be done with a code action.  Also, the StoreFieldStreamRaw call must be the last edit made to the segment because the segment becomes immutable after that.

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What if you could serialize/deserialize objects in whatever format: JSON, XML, CSV,...; attending different criteria: export/import some properties and not others, transform values in this or that way before exporting/importing,...; and all of this without having to change the class definition? Wouldn't that be great??

Well, perhaps it's a goal too ambitious to reach 100% but, exploring this idea, I've developed a bunch of classes that I thought it was good to share. If you want to test, change, modify or improve the code, or just take a look at it, you can do it here. There you'll find a more detailed explanation (see

Be aware, this is a proof of concept for myself done in spare times, sure it's not robust enough or it can be done much better... but, I was just playing...ok, I could just wait to the new JSON Adaptor (coming soon!) that sure is going to resolve much more scenarios in a cleaner way, but... meanwhile... :-) ...

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One of the most important features during application development is the ability to debug your code easily. Because of the asynchrnous nature, a standard Node.js application server works single-threaded by default. When you are developing applications using an IDE like Visual Studio Code, you can very easily debug your Node.js process:

First, download the free Visual Studio Code IDE (@code) and install it on your development machine.

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The DeclarativeCOS project is a heartfelt cry about programming in the COS language.

The purpose of the project is to draw attention of the public to improving the inner core of COS.

The idea of the project is the support of a laconic syntax for cycles and collections.

So what is this laconic something that I have come up with? Welcome to the examples below!


The key concept underlying the project is the declarative approach to writing code. You need to specify WHAT should be used and HOW.

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Note (June 2019): A lot has changed, for the latest details go here

Note (Sept 2018): There have been big changes since this post first appeared, I suggest using the Docker Container version, the project and details for running as a container are still in the same place  published on GitHub so you can download, run - and modify if you need to.

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In this article, I would show how you can upload and download files from InterSystems products via http.

The questions about working with files over http arise fairly often on community and I'm usually linking to my FileServer project which demonstrates file upload/download but I'd like to talk a bit more on how we can serve and receive files from InterSystems products.

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