• Guru: Regular Expressions, Part 1

  July 25, 2022 Mike Larsen

  In the first part of this series, I will show how to replace characters in a string using SQL and regular expressions. I know I can replace characters using RPG or SQL, and they work great, but there are some cases where I find using regular expressions is a bit easier.

  For the examples I’ll show, I’m using the REGEXP_REPLACE function. REGEXP_REPLACE allows me to search for a particular value within a string and replace it with another value.

  In the first example (Figure 1), I want to search a string that has both letters and digits and I want …

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• Guru: IBM i Experience Sharing, Case 5 – Using IBM i PDI Charts To Answer Performance Questions

  July 18, 2022 Satid Singkorapoom

  During my long career as an IBM i performance specialist, it was natural for people to ask me performance-related questions of various kinds. But in many cases, it seemed to me that the customer could not understand my answers, and I could not provide supporting evidence due to the lack of a performance reporting tool that could produce easy-to-understand explanatory information. The situation changed for the better with the availability of IBM i Performance Data Investigator (PDI) tool as of release 6.1. I would say that the PDI tool provides charts of information that resemble those used by business people …

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• Reader Feedback On Guru: The Finer Points of Exit Points

  July 12, 2022 Bruce Bading

  Hey, Alex:

  Hope you are doing well. I was reading this article about exit points and found some technical inaccuracies.

  The Socket Exit can be used to cover the following: You can use exits block all unwanted ports blocked. I will be happy to talk with author of this article to explain how this works.

  • Not all services have exit points available.
  • User defined ports do not have exit points associated.

  Best regards,

  — Tony Perera, Trinity Guard, a division of Fresche Solutions

  ---

  Hey, one and all:

  As the article states, exit points are an enhancement to cybersecurity on the …

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• Guru: The Finer Points of Exit Points

  June 27, 2022 Bruce Bading

  Many years ago, we received a call from an IBM i customer stating that all exit points were gone and the QAUDJRN and receivers were missing. Then the question, “Do you think we’ve been hacked?” Truth was, the exit points weren’t gone; the associated programs had been de-registered. Conclusion, they had most likely been compromised.

  The IBM i platform is a very securable system that can be secured (Secure vs Secured – What’s the difference?, WikiDiff), if you take steps to secure it.

  On the IBM i, a limited number of functions provide an exit so that your …

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• Guru: The CALL I’ve Been Waiting For

  June 20, 2022 Ted Holt

  Christmas came to my house early this year. May 3, to be exact. Boy! Was Santa Claus good to me! IBM gave me two presents! The first was a CL enhancement that I had desired for years. The second was an improvement that, to my delight, almost obsoletes a utility I wrote years ago. Both have to do with the CL CALL command.

  CALL is arguably the most used and most important command in CL, yet for all these years it has remained untouched. I’m glad that IBM has seen fit to devote time and resources to the enhancement of …

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• Guru: IBM i Experience Sharing Case 4 – Investigating Time-Sensitive Transaction Issues

  June 6, 2022 Satid Singkorapoom

  Among the central processing hardware resources in a computer system – CPU, GPU, memory, disk, PCI-Express I/O bus – disk has always been the slowest component. Even the latest flash disk or NVM-Express flash drive or card is slowest, but not by much. Back in the days of hard disk, disk I/O was the most popular cause of performance problems. From experience, I always looked at it first in my investigation.

  The modern SAN flash disk can still be the performance bottleneck when it is not deployed properly, as I shared in Guru: IBM i Experience Sharing, Case 3 – …

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• Guru: IBM i *USRPRF Security

  May 23, 2022 Bruce Bading

  IBM i has long enjoyed a reputation of being one of the most securable application servers in the industry. IBM i object encapsulation or object-oriented architecture achieves a level of technology integrity not found in file-based systems such as Unix, Linux, and Windows – as long as QSECUTY is set to 40 or 50.

  This advanced technology however does not exclude the IBM i from security risks if your development teams are not practicing (DevSecOps | CSRC (nist.gov)) and (Zero Trust Architecture | NIST).

  Let me remind what one of the lead signatories on the Agile …

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• Guru: IBM i Unauthenticated Access

  April 25, 2022 Bruce Bading

  One of the greatest threats to any network, host, or server is unauthenticated access where an attacker can gain local or remote access with no credentials that can lead to a Critical rating with the following descriptions (CVSS v3.1 User Guide (first.org).

  Confidentiality Impact Complete (There is total information disclosure, resulting in all system files being revealed.)

  Integrity Impact Complete (There is a total compromise of system integrity, and a complete loss of system protection resulting in the entire system being compromised.)

  Availability Impact Complete (There is a total shutdown of the affected resource. The attacker can render …

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• Guru: Debugging SQL Stored Procedures With ACS

  April 11, 2022 Mike Larsen

  I use Access Client Solutions (ACS) daily to help with different tasks. I’m usually running SQL scripts or working with the IFS, but recently I was asked if there was a way to debug SQL stored procedures using ACS. More specifically, they were looking for a way that a “non-IBM i” person can debug SQL stored procedures on IBM i.

  After browsing the various menus in Run SQL Scripts in ACS, I found a system debugger. I had seen the system debugger before, but never took the time to explore it further. With this new request in mind, I decided …

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• Guru: IBM i Experience Sharing, Case 3 – When Performance Issues Come From Without

  April 4, 2022 Satid Singkorapoom

  When I started my IT career 35 years ago, it was in the “centralized” universe that originated from the mainframe model. All core application codes ran in one — and only one — big iron that all users accessed with “dumb” terminals devoid of any GUI. Problem solving in AS/400 systems was frequently straightforward and not time consuming because most cases were anything but elusive.

  But the contemporary IT infrastructure universe has evolved into a big onion, with layers that we must peel while troubleshooting. I often find myself having to address a problem in multiple layers, and it no …

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