Robert Cemper · Feb 8, 2019 2m read
Client for WebSockets based on Node.js

WebSockets as a communication technology wins increasing importance.
In the SAMPLES namespace, you find a nice example for running a WebSocket Server.
There is also a useful example for a Browser Client. JavaScript does most of the work. 

My point is:
How to consume the output of a WebSocket Server in your application?

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As you know in Caché / IRIS you have the possibility to define a property as Multidimensional as documented here:
and the explanation of how to use it

Though the access is quite comfortable (in traditional COS sense) there are 2 main restrictions that hurt:

#1) It is not saved to disk unless your application includes code to save it specifically.
#2) It cannot be stored in or exposed through SQL tables
   there are some more
I'll show how to overcome these limits

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Robert Cemper · Jun 25, 2020 12m read
Backport %JSON.* to Caché


This is a coding example working on Caché 2018.1.3
It will not be kept in sync with new versions 
It is also NOT serviced by InterSystems Support !

Full backport from IRIS for Windows (x86-64) 2020.1 (Build 215U) Mon Mar 30 2020 20:14:33 EDT

IRIS brought us an excellent %JSON.Package
It is an essential component of the Project Manager (ZPM)
This backport makes it available also in Caché and builds a base to eventually backport also ZPM.

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Robert Cemper · Aug 5, 2017 3m read
Winning in GIS competition

   GIS stands for Geographic Information System.
  and it's not a typical arena for Caché. But it's definitely an environment with high data volume.

You see 3 major areas

- Visual front end:
   A mature area well covered by a bunch of commercial and open source products.
   No need for Caché there.

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The following steps show you how to display a sample list of metrics available from the /api/monitor service.

In the last post, I gave an overview of the service that exposes IRIS metrics in Prometheus format. The post shows how to set up and run IRIS preview release 2019.4 in a container and then list the metrics.

This post assumes you have Docker installed. If not, go and do that now for your platform :)

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The Amazon Web Services (AWS) Cloud provides a broad set of infrastructure services, such as compute resources, storage options, and networking that are delivered as a utility: on-demand, available in seconds, with pay-as-you-go pricing. New services can be provisioned quickly, without upfront capital expense. This allows enterprises, start-ups, small and medium-sized businesses, and customers in the public sector to access the building blocks they need to respond quickly to changing business requirements.


Updated: 2-Apr, 2021 

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Index to Articles

Published 2018-05-11 Last edit -

Hi All

I this article I detail some strategic issues that a new development UI will need to address - these are the ones that I can think of now - others may come to light during this journey.

See the webinar by Eduard Lebedyuk here from the last Global Summit describing  modern web development and Caché

And, as always, if I have missed something please comment....

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Robert Cemper · Mar 26, 2019 2m read
Synchronize Data with DSTIME

 For Data Synchronization inside Caché you have a range of ways to synchronize objects and tables.
At DB level you can use Shadowing  or Mirroring 

This works excellent and if you need just a part of your data to be synchronized you may split your
data into smaller pieces using Global mapping 
Or if you need bi-directional synchronization on Class/Table level you can use the Object Synchronization Feature 

The limit of all these excellent features:
They just work from Caché/IRIS to Caché/IRIS.

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Ansible helped me solve the problem of quickly deploying Caché and application components for Data Platforms benchmarks. You can use the same tools and methodology for standing up your test labs, training systems, development or other environments. If you deploy applications at customer sites you could automate much of the deployment and ensure that system, Caché and your application are configured to your applications best practice standards.

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++ Update: August 1, 2018

The use of the InterSystems Virtual IP (VIP) address built-in to Caché database mirroring has certain limitations. In particular, it can only be used when mirror members reside the same network subnet. When multiple data centers are used, network subnets are not often “stretched” beyond the physical data center due to added network complexity (more detailed discussion here). For similar reasons, Virtual IP is often not usable when the database is hosted in the cloud.

Network traffic management appliances such as load balancers (physical or virtual) can be used to achieve the same level of transparency, presenting a single address to the client applications or devices. The network traffic manager automatically redirects clients to the current mirror primary’s real IP address. The automation is intended to meet the needs of both HA failover and DR promotion following a disaster. 

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Importance and Collection of Exact Version Information ($zv / $zversion)
The explanation of:
- why collecting $zv is important (The WHY),
- what the components of $zv mean (The WHAT),
- and how to collect $zv (The HOW). 
(The Ultimate $zv Guide to the ISC Galaxy in large, friendly letters)
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Timothy Leavitt · Jul 8, 2020 7m read
Tips for debugging with %Status


If you're solving complex problems in ObjectScript, you probably have a lot of code that works with %Status values. If you have interacted with persistent classes from an object perspective (%Save, %OpenId, etc.), you have almost certainly seen them. A %Status provides a wrapper around a localizable error message in InterSystems' platforms. An OK status ($$$OK) is just equal to 1, whereas a bad status ($$$ERROR(errorcode,arguments...)) is represented as a 0 followed by a space followed by a $ListBuild list with structured information about the error. $System.Status (see class reference) provides several handy APIs for working with %Status values; the class reference is helpful and I won't bother duplicating it here. There have been a few other useful articles/questions on the topic as well (see links at the end). My focus in this article will be on a few debugging tricks techniques rather than coding best practices (again, if you're looking for those, see links at the end).

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Please note, this article is considered deprecated, check out the new revision over here:

The goal of this post is to discuss working with Websockets in a Caché environment. We are going to have a quick discussion of what websockets are and then talk through an example chat application implemented on top of Websockets.

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This is a list of all the posts in the data platforms capacity planning and performance series in order. Also a general list of my other posts. I will update as new posts in the series are added.

You will notice that I wrote some of the posts before IRIS was released and refer to Caché. I will revisit the posts over time, but in the meantime; Generally, the advice for configuration is the same for Caché and IRIS. Some command names may have changed; the most obvious example is that anywhere you see ^pButtons command, you can replace it with ^SystemPerformance.

Capacity Planning and Performance Series

Generally posts build on previous, but you can also just dive in to subjects that look interesting.

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While the integrity of Caché and InterSystems IRIS databases is completely protected from the consequences of system failure, physical storage devices do fail in ways that corrupt the data they store.  For that reason, many sites choose to run regular database integrity checks, particularly in coordination with backups to validate that a given backup could be relied upon in a disaster.

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Robert Cemper · May 29, 2019 1m read
Simple Remote Server Control

This example is extracted from a long-running installation. The purpose is to have a simple monitoring of several servers at a rather primitive level. Just slightly more intelligent than a raw PING. But still easy to integrate. It avoids the overkill of information you are often confronted with while you are just interested in the number of active processes or similar basic figures.

The code is available for you here 

This is a coding example working on Caché 2018.1.3 and IRIS 2020.2 
It will not be kept in sync with new versions 
It is also NOT serviced by InterSystems Support !

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Robert Cemper · May 30, 2019 2m read
Background Jobs over ECP
This is a coding example working on Caché 2018.1.3 and IRIS 2020.2 
It will not be kept in sync with new versions 
It is also NOT serviced by InterSystems Support !

Running a Background Job using JOB command is a well-known feature.
Using ECP to distribute databases to several servers is also well know.
But using the combination of both to run a process on a different server
seems to be a rare case.

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Eduard Lebedyuk · Mar 4, 2016 7m read
Weather station on Arduino

It was InterSystems hackathon time and our team, consisting of Artem Viznyuk and me had Arduino board (one) and various parts of it (in overabundance). And so like that our course of action was set - like all other Arduino beginners, we decided to build a weather station. But with data persistent storage in Caché and visualization in DeepSee!

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The field test of Caché 2016.2 has been available for quite some time and I would like to focus on one of the substantial features that is new in this version: the document data model. This model is a natural addition to the multiple ways we support for handling data including Objects, Tables and Multidimensional arrays. It makes the platform more flexible and suitable for even more use cases.

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Globals, these magic swords for storing data, have been around for a while, but not many people can use them efficiently or know about this super-weapon altogether.

If you use globals for tasks where they truly shine, the results may be amazing, either in terms of increased performance or dramatic simplification of the overall solution (1, 2).

Globals offer a special way of storing and processing data, which is completely different from SQL tables. They were first introduced in 1966 in the M(UMPS) programming language, which was initially used in medical databases. It is still used in the same way, but has also been adopted by some other industries where reliability and high performance are top priorities: finance, trading, etc.

Later M(UMPS) evolved into Caché ObjectScript (COS). COS was developed by InterSystems as a superset of M. The original language is still accepted by developers' community and alive in a few implementations. There are several signs of activity around the web: MUMPS Google group, Mumps User's group), effective ISO Standard, etc.

Modern global based DBMS supports transactions, journaling, replication, partitioning. It means that they can be used for building modern, reliable and fast distributed systems.

Globals do not restrict you to the boundaries of the relational model. They give you the freedom of creating data structures optimized for particular tasks. For many applications reasonable use of globals can be a real silver bullet offering speeds that developers of conventional relational applications can only dream of.

Globals as a method of storing data can be used in many modern programming languages, both high- and low-level. Therefore, this article will focus specifically on globals and not the language they once came from.

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Sascha Kisser · Oct 24, 2016 4m read
DeepSee Troubleshooting Guide

The goal of this “DeepSee Troubleshooting Guide” is to help you track down and fix problems in your DeepSee project.

If the problem can’t be fixed by following the guidelines, you will at least have enough information to submit a WRC issue with DeepSee Support and provide all the evidence to us, so we can continue the investigation together and resolve it faster!

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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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Last week, we announced the InterSystems IRIS Data Platform, our new and comprehensive platform for all your data endeavours, whether transactional, analytics or both. We've included many of the features our customers know and loved from Caché and Ensemble, but in this article we'll shed a little more light on one of the new capabilities of the platform: SQL Sharding, a powerful new feature in our scalability story.

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