One of my colleagues at InterSystems encountered an unexpected issue when running InterSystems IRIS on a Macintosh in a container using Docker for Mac. I’d like to share what we found, so you might avoid running into similar issues.
The Problem
The task at hand was running a Java application with XEP to do a large data load into IRIS. When running the data load, the write daemon hung soon after starting the job, with messages like these in messages.
Here are a few examples of conversions and operations you might need, along with links to documentation where you can learn more.
At the time I wrote this, Eastern Daylight Time was in effect for my Caché system.
Caché has a simple time format, with a longer range of recognized dates compared to some other technologies.
The current time is maintained in a special variable $HOROLOG ($H):
USER>WRITE $H 64146,54027 USER>
The first integer is the count of days since December 31, 1840. The second integer is the count of seconds since midnight of the current day.
The Update Checklist for v2015.1 recommends setting the TZ environment variable on Linux platforms and points to the manpage for tzset. This is recommended to improve the performance of Cache’s time-related functions. You can find out more about this here:
https://community.intersystems.com/post/linux-tz-environment-variable-not-being-set-and-impact-caché
The manpage on my CentOS 7 test system (RHEL 6 says the same) has this to say:
“The tzset() function initializes the tzname variable from the TZ environment variable.