CICS TS 4.1 WLM performance demo

If you have any interest in CICSPlex SM Workload Management (WLM) on CICS you should go check out this new YouTube video now! I’ll leave the video description itself to explain the contents.

This nine minute demo by Dave Williams of CICS Development in Hursley, UK demonstrates some of the performance improvements made in CICS TS V4.1 when using the new Sysplex Optimized WLM function. Throughputs for similar workloads are compared between CICS TS V3.2 and CICS TS V4.1 with Sysplex Optimized WLM switched on and off.

Just to give a little extra background, Dave was the chief developer and does an excellent job here of clearly describing the new improvements.

A slight confession, I wrote the tool the video uses to analyse and chart the workloads. It is an internal IBM test tool, so you can’t get your hands on it, but if you would like to know more or you think it would be useful to you, let me know.

If you are interested in seeing more videos like this, direct from the development team, add a comment, with maybe a sentence or two about what you would like to hear about.

Notes

• For more details on Sysplex Optimized WLM see here.
• Dave used the term ‘Base table’ in the clip. A ‘Base Table’ is more commonly known as a Resource Table. The new table Dave referred to is WLMATARG.
• The tests performed here show an artificial workload running 10,000 transactions using the Distributed Routing mechanism. The results you achieve with your workloads in your environments may differ.

CICSPlex SM Web User Interface and Browser Tabs

Over on CICS-L is a recent post about the CICSPlex SM Web User Interface (WUI) and how confusing it is with its multiple windows and the experience you get trying to use it within a tabbed browser.

What I’m going to try and do in this post is to (hopefully) explain some of the reasons why the WUI behaves as it does.

History

Originally CICSPlex SM was never going to have a WUI at all. Circa CICSPlex SM 1.3 a GUI was being looked at. As this was the mid to late 1990’s the platform for this GUI was OS/2! Yes O.K. I’ll admit it, I am an OS/2 fanboy err old-bloke – I still use it every day (please don’t tell my manager), but this decision was nothing to do with me. Due to various issues, the OS/2 based GUI was never shipped and instead a Web Based Interface aka WUI was developed.

By the time the WUI was ready, it was shipped as a no-charge feature on CICSPlex SM 1.4 – An exclusive element of CICS TS 1.3.

The prereqs for the web browser were kept very low, e.g. HTML 3.2 with frames, tables and cookies. Talk to some web designers (or Chris) and they will probably give you a stern look for mentioning the frame or table words.

Questions

Why does the WUI open a new window on signon?

The WUI relies on every request from the web browser being sent back to the server. The WUI checks for this by using a sequence number in it’s interactions with the browser. If the sequence number is not what the WUI expects, you will receive a ‘Navigation error’ response in the WUI.

The easiest way to get one of these errors is to use a browser forward or back button. To discourage users from using these buttons, the signon process causes a new window to open, and on this request the WUI asks the browser not to include the browser navigation controls. Although this decision might be considered heresy today, and it does not stop users from using keyboard shortcuts, mouse operations, or putting the browser controls back, it was done to try and discourage users from using these controls.

So the reason the ‘Begin signon’ button opens a new window, is simply to get a window without browser navigation buttons. As this response to the original CICS-L question indicates, you can bypass the ‘Begin signon’ by tweaking the URL that you use. Note however although this works, it is not an intended ‘interface’, so it potentially could change in the future (not that I know of any plans to do so).

Why the strange tab behavior?

The WUI knows absolutely nothing about tabs. They weren’t around when the WUI was developed originally and no explicit support for tabs has ever been added to the WUI.

The only thing the WUI does when it opens a new window for Help or the InfoCenter is to use the target=’_blank’ HTML option on the anchor tag. How the browser interprets this in conjunction with the ‘Open in new Tab’ options you use to get it to go to a tab is completely up to the web browser.

Why do I get another ‘Begin Signon’ window?

So you already have a ‘Begin signon’ tab, why do you get another one if you refresh a WUI window after you have signed off? Well it is simply because you no longer have any valid credentials on the WUI server, so the WUI starts the signon dialog. The WUI has no idea of what windows/tabs your browser has open (once you have signed off).

Requirements are important

So none of this ‘fixes’ the weirdness, but I wasn’t trying to provide a fix, just explain why some of these things happen. Could the experience be better? Sure. If there are things that really bug you, get in those requirements, either via organisations such as SHARE, or talk to your IBM account team, who should be able to submit requirements on your behalf. Although it might be frustrating waiting for those requirements, if they aren’t on the potential ‘To-Do’ list within the Lab, that dramatically lowers the chances of getting things changed.

CICS Explorer: SM Perspective

The SM (System Management) perspective in CICS Explorer provides different capabilities depending on the connections you choose to configure and the CICS TS version that you have. This post attempts to describe some of the differences with the connections you can use.

6 reasons to start using CICSPlex SM today

Before I begin, I should inform you that I am super-biased. I’m a CICSPlex SM developer and have been since I joined IBM almost 3 years ago now.  However, I really think this is a superb product, that does a horrendously hard job.  I like to think of CICSPlex SM as something that does all the painful, boring work so you just don’t have to.  Now to me, that is pure value!  So let’s get to it..

If you have CICS regions to manage or even just monitor, CICSPlex SM provides an ideal environment for getting your job done.  With CICS TS 3.2 it now has a much improved installation that is integrated directly with CICS, so it has never been easier to try it out.  Better yet, you don’t have to convince anyone to “show you the money” as it is bundled right there alongside CICS.

So why use CICSPlex SM?  What makes it so great?  Well here are 6 things, that I think makes CICSPlex SM a must have!

Sharing CICSPlex SM WUI data repositories

The CICSPlex SM Web User Interface (WUI) requires a repository that is used to store CICSPlex SM view sets, menus, user group profiles, user favourites (I am in the UK so hopefully I can get away with the proper spelling) etc. As CICS is great at dealing with files, a KSDS called EYUWREP was chosen as this repository.

CICS has a number of different facilities that let you share files. For example function shipping, shared data tables and RLS. However a slight snag in the design of the WUI object service meant that it was not possible to use any of these facilities and maintain integrity of the EYUWREP file.

In a nutshell, the WUI object service may use multiple physical records in the EYUWREP file to represent one logical record, for example a view set may contain any number of views. It is the view set that is the ‘container’ for the views, so is saved and loaded as a single entity.

The WUI does have a locking service, but this were built on the assumption that each WUI server had its own unique EYUWREP file. So the locking service only provides for locks within a single WUI server. This is one of the reasons why it is documented that the EYUWREP file can NOT be shared between WUI servers.

Prior to CICSPlex SM V3R2M0, there were no checks on the EYUWREP file definition to ensure that it had not been changed to RLS or a remote file or a data table. We didn’t expect customers to change the IBM supplied definition, but some of them did anyway.

When these customers (with ‘modified’ EYUWREP file definitions) migrate to CICSPlex SM V3R2M0, then the WUI server will fail to initialise with message:

EYUVS0916E FILE EYUWREP has invalid value: YES for option: RLSACCESS

This message is issued in V3R2M0 because we made some changes to the way CICSPlex SM resource definitions are built. Bootstrap definitions are created during CICS startup, and then if the bootstraps are invoked, the remaining definitions are created on the fly. Because we acknowledged that some people change definitions, we allow user definitions, but we now check the definitions to make sure it is something vaguely close to the IBM supplied one. If not, the EYUVS0916E message is issued.

So even though you might have a ‘modified’ EYUWREP definition and the modification was for something that was documented as not being supported due to the risk of corrupting data, a change has recently been made to CICSPlex SM V3R2M0 by APAR PK61740.

The PTF for this APAR changes the WUI locking service so that it can provide protection for the logical EYUWREP records. This allows the EYUWREP to be shared within a sysplex between multiple WUI servers via RLS. Note that that we are only supporting RLS for the sharing, not function shipping, or shared data tables etc, just RLS.

So take a look at this APAR if you want to share WUI server data repositories. Please make sure you check out the hold info in the PTF cover letter for further details