The attached file contains two $system.Event examples that processes work asynchronously using persistent queues:

• Events_Simple.prj.xml
• Events_PubSub.prj.xml - updated this example has been published on https://github.com/intersystems-ib/cache-iat-pubsub

Events_Simple

This is a very basic example that creates some worker processes and then enqueue messages to them using $system.Event.

NewBie's Corner Session 1 Installing Caché

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

In part I of this series we have introduced MapReduce as a generic concept, and in part II we started to approach Caché ObjectScript implementation via introducing abstract interfaces. Now we will try to provide more concrete examples of applications using MapReduce.

I was recently asked whether we have a function to convert LDAP date time stamps into $HOROLOG format or other formats and the answer is not at the moment, but there is a simple method to do the conversion.

Let us look at the facts and figures involved...

1) Active Directory's (AD) date 0 (zero) is 1601-01-01 00:00:00.000 or January 1st, 1601 at midnight (00:00:00)

2) AD timestamps are calculated as the number of 100 nanosecond intervals from date 0

3) 864000000000 is the number of 100 nanosecond intervals per day

NewBie's Corner Index - Links to connect to all NewBie posts.

NewBie's Corner Session 1 Installing Caché

I have posted to aid others in diagnosing problem with SSL/TLS connections to superserver port from .NET client executable.

The cache instance this appeared on is quite old - 2011 - so I do not know if Intersystems have added a better error message in a later version

The actual fault was due to the certificate in the %SuperServer SSL/TLS configuration having expired.

The unhelpful message that appeared in the .NET client included the following partial stack trace.

When my COS code is executing in a Caché process it might want to interact with the host operating system. For the purpose of this post I'm focusing on a Windows host, but much of it applies to other host OS platforms as well.

A common example of host OS interaction is when my process wants to read from or write to a file. What credentials will apply when Windows is checking whether or not to allow me access to the file?

To answer that we need to consider another question. How did our process start?

In most cases, if one class depends on another, the class compiler will detect this and determine the correct compilation order. For example:

I am pleased to announce the field test of Caché and Ensemble 2016.3 - with many new improvements.

The product team at InterSystems looks forward to your participation in the field test and feedback over the coming months.

Some of the more signification changes in 2016.3 are new RESTful APIs for iKnow and broader APIs for programmatic control of multiple servers (enterprise manager). As always, there are a host of scalability and performance improvements, including improvements to the core database and SQL. And hundreds of smaller improvements and corrections.

This sample class will add parameter DSINTERVAL to each class containing the parameter DSTIME

To execute it from a Terminal :

Context:

mirrored configuration with one primary member and one async member (without failover/backup member)

Purpose:

replace the CACHE.DAT of a mirrored database on the primary member.

Steps to follow:

Interesting anecdote I want to share. Not 100% Caché related, but I hope it would be useful.

When CSP Gateway is configured on IIS, opening CSP Gateway Configuration page is prohibited by default -- as IIS blocks URLs with '/bin' in it.

In our documentation we advise to add <remove segment="bin" /> to applicationHost.config file.
That is correct.

Process-private Globals can be used as a data global in storage definition. That way, each process can have its own objects for the class with ppg storage. For example lets define a pool, which can:

• add elements to a pool (ignoring duplicates)
• check if an element exists in the pool

Here's the class:

Here you have an easy way to write and execute COS code from your unix scripts. This way one does not need to write routines or even open Studio or Atelier. It can be an option for simple and small actions for instance things like installation tasks or compiling.

See sample bash script (compile.sh) to compile classes: