Probe/iX: An Online Advisor for 3000 Performance

Analysis tool trades overhead hit for plain-English reports on performance

Review by Shawn Gordon

Probe/iX is system performance monitoring software for the HP 3000. Not a glamorous or exciting category — rather like security — but a critical one for proper system performance. Through a standard, terminal-based interface, Probe makes use of various line drawing and enhancement escape sequences to present its data in a comprehensive fashion. Through function keys and keyboard short-cuts, you are able to quickly navigate through the product.

How does it work?

Probe/iX uses the AIF Measurement Interface (AIF:MI) to collect its system information (this is how everyone does it, other than the Shot Nugget program from Allegro). The program has a configurable scan rate which determines how often it collects the data to display. There is a conflict here: the longer you let it run, the more accurate trend information you get — but tests have shown that enabling the AIF:MI can consume between 10 and 40 percent of the CPU above and beyond the amount that it reports on itself.

Unfortunately, since you usually want to run a tool when the system is slow, to see what the problem is, you will only make the problem worse by looking. It’s probably the only way to find out what is going on. As I said, this is true of any tool that uses the AIF:MI; there is an expense associated with using it.

Features

Hopefully that talk about the overhead didn’t scare you off, because these are great tools. Probe/iX is broken down into the sections and sub-sections listed in Table 1.

Table 1

Global Information	I/O Information
Overview (see Figure 1)	Disc
CPU	Non-Disc
Waits	Disc Queue Lengths
Memory Manager	Printers
Memory Usage
Process	Database Information
Dispatch	Overview
	Users
Process Information
Overview (see Figure 2)	System Oriented
Response	Locked SIR/Semaphore
CPU	Response Distribution
Memory
I/O
Detail (see Figure 3)
Files
Workload CPU
Workload Memory
Workload I/O
Workload View

The Workload section of Probe/iX allows you to lump different users and processes into logical groups so that you can track, display and record performance information for that entity. So if you wanted to have data entry grouped together, you would just assign the user IDs or the program name to a workgroup. This is a very handy facility for tracking the impact that your different groups have. However, if you are using a 4GL, it’s not as useful, since everything is charged to the single 4GL program that is interpreting your code — but you can still make use of the user tracking.

The database information is very nice. It will instantly (or almost) display a list of all databases that are currently open. You can then select a database to see all the users that have it open, and with what process and mode.

There are function key options within most of the screens that give you access to other information, such as the Online Analyst seen in Figure 4. This gives a very “English” overview of what is going on with your system, and suggestions on how to improve it. I love this section.

Figure 4

08:25:37
————
Your CPU is 16.0% busy, which is HIGH for your system by 118%.
-Processes are Paused for I/O 576% longer than normal.
-System Processes are using 198% more CPU than normal.
-The Dispatcher is using 366% more CPU than normal.
—->The CPU Hog is PIN #159 who is using 8% of the CPU.
(#S45 SHAWN,MGR.SMGA running CI.PUB.SYS)
* * *
Your Memory Manager Activity is HIGH for your system.
The Memory Manager is using 879% more CPU than normal.
-The Mem Mgr is using 100% more CPU than normal fetching the operating
system.
-The Mem Mgr is using 779% more CPU than normal on swap operations.
-The Mem Mgr is doing 370% more Prefetches than normal.
-The Mem Mgr is doing 366% more Posts than normal.
-The Mem Mgr is doing 38% more Recover Overlay Candidates than normal.
-The Mem Mgr is doing 276% more Swap Operations than normal.
*** I noted higher-than-usual Recover-Overlay-Candidates, Swaps or IMI’s...
*** One or more of these over a sustained period is usually a sign
*** of a SERIOUS Memory Shortage problem!
—->The Memory Hog is PIN #2 who is using 41.65 megabytes of real memory.
(# 0 ,MANAGER.SYS running LOAD.PUB.SYS)
* * *
Average Disc I/O rate is 4.0/sec which is HIGH for your system by 96%.
Average Disc Queue Length is 0.3 which is LOW for your system.
I noted an Average Response Time of 0.87 seconds, compared to your normal
3.09.
Transactions are 434% higher than normal.
* * *
Switches to NM are 172.3/second, which is HIGH for your system by 44%.
Switches to CM are 39.3/second, which is HIGH for your system by 354%.
Current Process Stop Rate is 90.6/second, which is HIGH for your system by
348%.

Current Process Launch Rate is 44.9/second, which is HIGH for your system
by 356%.
Your Launches-to-Stops ratio is 0.5-to-1.

You can also change the priority of executing processes by either putting them into another queue or giving them a linear priority. If you take a look at the different examples, you will see just a small part of the wealth of information available to you.

Installation and Documentation

Installation is your standard restore, stream, put tape back in. Everything works without a hitch. The manual is a little over 140 pages and is very well written. There are some terrific sections at the back that go into serious detail about performance and how to tune a system. This includes such things as the most efficient types of counters in COBOL (or any language), how to declare and use integers, database design considerations, disc space usage and file spreading for performance, load management, memory management, CPU management, etc. This is really an excellent manual for both using Probe/iX and learning more about system management in general.

The TestDrive

I spent a little time loading up my poor 922 and testing Probe, then decided to give it a run at a client site that had many more people on it. I was able to use the displays to help them justify a memory upgrade using the Online Analyst. This provided them, essentially, with an unbiased opinion of the system, which is just the push that some people require.

Another nice feature of Probe/iX is that if you run it in a process-handling environment such as MPEX or QEdit, when you exit it will suspend itself instead of terminating. This is nice, because the program will start right up again without the wait time associated with its normal startup — and I believe it disables all the high overhead stuff when it suspends, such as the AIF:MI.

Basically, I just had fun running the product and shuffling processes around in the queues to increase system performance during some peak usage. We were able to identify a couple of real hog programs that we dedicated some resources to fixing as well.

Comparisons

The obvious comparisons are to Glance from HP and SOS from Lund Performance. Probe has been around longer than either of these products, although it seems to have gone into hibernation for the last five or six years. Probe is far superior to Glance, and is probably similar to SOS. Both Probe and SOS offer features that the other doesn’t, but they both include all the basics. I love the Online Analyst feature in Probe, which is even more English-like than the suggestions provided in SOS.

Conclusions

Using Probe again was like catching up with an old friend. I had first used Probe back on MPE/XL version 1.2, and it was my first experience with a third party tool designed to look at a system. Prior to that there were all the CSL versions of Overlord and its many offspring. I like Probe a lot, a whole lot. The product provides information that none of the competitors do, such as open databases and who’s got them open. It seems to be priced less than the competition as well. The interface is easy and the screens provide a wealth of information (you just have to understand what it’s telling you). The Online Advisor helps tremendously for people who either have trouble understanding the displays, or have trouble explaining it to someone else. You know, those discussions you have while buying hardware upgrades.

If you’re one of the few that hasn’t actually purchased an HP 3000 system performance monitoring tool, then add Probe/iX to the list of products to compare.

Shawn Gordon, whose S.M. Gordon & Associates firm supplies HP 3000 utilities, has worked with 3000s since 1983.