Goodbye UKCMG, Hello Poughkeepsie

(Originally posted 2008-05-20.)

I feel like I’m on “home turf” at UKCMG… My use of English can be looser 🙂 and it’s so nice to catch up customers with whom I’ve a long and (I hope) fruitful history. I did my (slightly updated) “Memory Matters” and “Much Ado About CPU” presentations – and I really do lose track of how much change there’s been in each of them (though it seems to me I fiddle with them A LOT. 🙂 Actually I sat in a couple of presentations from Glenn Anderson which I HAVE seen before and actually technical topics DO bear repetition. And Glenn did, in my opinion, a GREAT job of the two I saw: One on Websphere Application Server Performance and the other on Unix System Services Performance. (So much so that I’m making sure I read them on the plane(s) tomorrow.)

It was also nice to see an external view of DB2 Version 9.

I’m conscious it may be time to either radically shake up my existing presentations or to do some new ones. I’ve an idea for ONE, sort of inspired by Glenn’s presentations. The working title is “z/OS Application Zoo”. Kinda like the “Particle Zoo” to my perhaps unfocused mind.

And I think there was some value in my Twittering in the sessions. Folks, you can follow my (perhaps marginally useful) Twitterings under my handle: MartinPacker. And I hope some of YOU will sign up to Twitter. I know of at least one customer and two very respected DB2 pundits who have: Willie Favero and Craig Mullins. (And just today a very good friend of mine who left IBM last year signed up – so it’s a great informal way of staying in touch.)

So, onwards:

Tomorrow sees me fly to Poughkeepsie to work on a Redbook on Parallel Sysplex Performance. I hope to try some of the material out here (and to use Twitter to ask questions or toss out odd thoughts that might influence the course of the book).

And I’ve already forewarned many of my Poughkeepsie friends of my imminent arrival… So they can clear out of town. 🙂 Seriously, if there ARE things that need raising with developers in Poughkeepsie feel free to contact me. Face to face there is SO much better for such discussions. But TRY not to abuse the offer. 🙂

System z Technical Conference – Dresden

(Originally posted 2008-05-09.)

I’m going to try something different this year – and composing this using OpenOffice Writer on my new ASUS EEE PC while flying home is certainly different. But what’s new is not documenting all the bits and pieces I learnt. Instead I’m going to give some impressions:

  • On Monday afternoon we had an enforced evacuation from the conference centre and much of the environs – because of a World War II bomb (that the local paper said was dropped by the US Air Force.) I think everybody was forced to tour Dresden  – which is well worth visiting. It’s a great cultural city.
  • Next time I’m going to ditch the jacket as it made me think I had to drag my backpack on wheels one mile each way each day. Far better to carry it – except in San Antonio last year when it was far too hot and humid.
  • Next time I’m going to follow the conference instructions and book my hotel well in advance so I don’t have to do the long commute on foot each day. Yeah right. 🙂
  • Next time I’m going to be fit enough to go the distance. Yeah right. 🙂
  • It’s handy to sit in sessions you already know a fair amount about – to get you thinking. Example: Peter Enrico’s excellent presentation on WLM samples. (I think my code needs working on as a result of that.) 🙂
  • There is lots going on in the “Web 2.0 and z/OS” space. Thanks to Kevin Keller and Holger Wunderlich for that.
  • Perhaps I shouldn’t assume everyone knows what CFCC Dynamic Dispatch is. I got a question on that.
  • There might be “unintended consequences” in z10 HiperDispatch disabling IRD’s Logical CP Management. And there was a good question on that.
  • Colin Paice from Hursley really is a very good speaker.
  • Twitter is useful as a way of raising consciousness about conferences going on -and it’s also good at helping people find each other.
  • It was good to run into Aneel Lakhani in person. He’s in the category of “I don’t know precisely why I know him but I know him from BlogCentral and I’m glad I know him” people. (BlogCentral is IBM’s internal blogging site.)
  • To the customer who said she was doing a thesis on Web 2.0 yes we really do encourage all IBMers to dive head first into Web 2.0 and social networking in general. Yes, we have guidelines (which I contributed a little to) but nobody finds them restrictive. I wish more companies were like this.
  • It’s great to have a tour guide who grew up in this part of the world and who went to university in Dresden. Thanks Barbara!
  • My manager is following me on Twitter. But that knowledge doesnt seem to have inhibited me in the slightest. 🙂 I’m still goading him into (hopefully) joining me there.
  • I got a chance to forewarn lots of Poughkeepsie folks I’ll be in town in a couple of weeks. If they scarper, given this amount of notice, I will take it personally. 🙂
  • I found lots of customers considering doing Data Sharing at non-trivial distances. So the Redbook ought to reflect that.
  • People agreed with me that the CF Structure CPU support in CFLEVEL 15 and RMF will make life much easier for Parallel Sysplex customers.

So, roll on UKCMG in only a few days time. When I won’t have to watch my language so carefully. 🙂

And my experience of composing this on the EEE is:

  • The machine is nice and small – so it doesn’t feel cramped on the tray table.
  • The keyboard will take some getting used to as it’s small (but the screen, though small, is just fine).
  • OpenOffice is a new package to me so I’m finding its quirks. (But I have to find them somehow anyway.) 🙂
  • OpenOffice’s “Export to HTML” seems to export in a fairly style-rich way when I’d rather have had minimalistic HTML. I expect I can easily fix that.
  • OpenOffice’s “Export to PDF” works really nicely (and quickly). I was only messing about when I tried it but I was impressed.

I really do like this EEE. It’s a cheap Linux machine that’s easy to do LAMP stuff on. (On the way to Dresden I learnt a bit of Ruby.) But this has been the first (and I think successful) test of using it to do real work. If you can call blogging real work. 🙂

And the motivation for trying out Linux and OpenOffice is because I expect to be using them on my main machine within the next month or two. I have to start on the learning curve somewhere (or at least some time).

And finally thanks to all the customers and fellow presenters who made this a great conference for me.

Misunderstood Coupling Facility Commands

(Originally posted 2008-05-03.)

I wonder how many of you recognise the terms “READ_COCLASS”, “WARM”, “RFCOM”,”WRITE_DATALIST” and “CASTOUT_DATALIST”.

Granted that in that list are two pairs of terms that I believe to be synonymous, but all five are relatively recent enhancements to Parallel Sysplex infrastructure that have a positive impact on DB2 Data Sharing performance (or at least the management of Performance).

As I mentioned in a previous post I’m going to Poughkeepsie soon to work on a Parallel Sysplex Performance Redbook – which will deal with topics such as “Data Sharing at a Distance” and “New Parallel Sysplex Technologies”. In preparation for this (not that I do much preparation for such things) I read through the various sections on Data Sharing Performance in the various DB2 Performance Topics Redbooks, starting at the beginning – with Version 4.

It might be significant that I don’t really understand these Coupling Facility commands. But then again it might not be… given that there are (without being self-deprecating) far better proponents of DB2 Data Sharing performance. In any case I feel the material that’s out there falls short in terms of describing when these commands are used and what benefit they bring (and what the downsides, if any, might be. So I hope to write some material in this area and ask (what I hope to be) searching questions of Development.

Now, these commands were first exploited by DB2 Versions 6 and 8. So the material might end up on the cutting-room floor. After all we’re all interested in System z10, CFLEVEL 15 and DB2 Version 9. Right? 🙂 What I’m hoping to do – in any case – is to share some of that material through this blog. If I succeed in doing that I hope you’ll help me by feeding back on the blog entries. Corrections, additional questions, etc.

And the fun really begins on May 22nd. Just after UKCMG.

System z Technical Conference – Dresden

(Originally posted 2008-05-03.)

Tomorrow I fly to Dresden for the annual European System z Technical Conference. It’s at just the time of year when I can decide in my head that Spring has sprung and that Summer won’t be long coming. 🙂

This is a great conference and I always enjoy attending it (and presenting at it). Talking of which, I have three sessions this year:

  • Much Ado About CPU which has a fair modicum of new stuff, including material on System z10.
  • Memory Matters in 2008 for which the updates are mainly in the System memory area, particularly the 1MB Pages support in System z10
  • DB2 Data Sharing Performance For Beginners which actually isn’t much changed. (As I will be spending late May and much of June in Poughkeepsie working on a Parallel Sysplex Performance Redbook maybe the next iteration will be substantially changed.)

I’m also looking forward to a number of other sessions. No doubt I’ll get to say a few words in those as well. 🙂 In particular Kevin Keller’s session on “Web 2.0 and z/OS” has caught my fancy. (As you probably know I really do feel we in the mainframe community ought to pay attention to things like Web 2.0 and bid for z/OS to run the infrastructure.)

So I hope to see lots of you in Dresden.

My HackDay 5 Project – z/OS System Logger Analysis

(Originally posted 2008-04-27.)

As some of you will know IBM has a twice-yearly “HackDay” programming fest. And the latest – HackDay5 – was last Friday. Couched as a competition it isn’t really… It’s a heck of a sight more cooperative than that. (Else I wouldn’t have got involved.) I’ve participated in all five we’ve had over the past two years. And it’s been great fun. This time – for the second time – I’ve physically gone to Hursley to take part in the local event.

New for HackDay5 was the “zHackDay” initiative – which I take “responsibility” 🙂 for…

The idea was that mainframe-related hacks were labelled as such. Partly to goad mainframe folks into participating, and partly to point out to non-mainframers that we’re just as capable of doing fun hacks as everyone else.

So, was my project exciting?

Probably not – but then I wasn’t personally aiming to set the world alight. I’m more interested in getting useful stuff done that I wouldn’t ordinarily get around to. So my project is basically to map the SMF 88 System Logger records.

This has been done before – and indeed there’s a z/OS-supplied utility to report on System Logger from Type 88 data.

So why would I “reinvent the wheel”?

The main reason is that it allows me to put the data together with other things. Such as SMF 74 Subtype 4 Coupling Facility data. If a logstream uses a coupling facility structure the SMF 88 record tells you the structure’s name. (This is similar to a recent trick where the 74-2 XCF data tells you the structure name and my code looks up the 74-4 view of the structure.)

Actually I know relatively little about System Logger – but I’m learning fast. And that’s the other reason I did this hack… To enable me to learn.

Finally, if I discover something’s missing from the data I can use real customer situations to discuss with Development what’s needed.

So, how far did I actually get? I got the Type 88 Subtype 1 (Logstream Activity) data mapped and summarised at the (e.g.) hourly level. And some very simple reporting. I haven’t (yet) done the same for the Type 88 Subtype 11 (Coupling Facility Structure) data. But that should be easy and straightforward.

So, if you’re sending me data I’m going to be asking you to send me your Type 88 data as well. I hope you’ll find what I do with it to be useful.

Moron SPAM :-)

(Originally posted 2008-01-28.)

We’ve been issued new guidance:

  • Delete SPAM rather than mark it invisible.
  • Disallow posting comments after, say, 30 days.

The latter appears to work at the individual entry level. Three of my entries have become particularly troublesome (for some unknown reason). So I’ve set them to “no more comments”. If you find a comment of yours bounced then please do let me know. I’m sure we can fix it.

Deleting all the SPAM comments that have arrived so far for these three posts has been a right pain in the neck. I’m sure a little Firefox Extension programming could make it easier. 🙂

And now back to some real content. I hope.

ERBSCAN / ERBSHOW – A Parameter You Might Not Know

(Originally posted 2008-01-11.)

Very few people spend as much time as I do down in the guts of individual SMF records. But for those who do ERBSCAN / ERBSHOW is an invaluable tool…

  • ERBSCAN, issued in ISPF 3.4 against an SMF data set, presents you with a list of SMF records and some VERY high level information. Such as the date and time the record was cut, the SMF ID and the record type and subtype.
  • ERBSHOW nnnn, issued from the ERBSCAN record list, formats the record. For “non-RMF” records it basically formats the header and presents the record sections – with little additional information. With “RMF” records (equivalently those from BMC’s CMF) it does a fair amount more. This is because it knows the layouts of such records.

(Actually ERBSHOW knows about a few other record types.)

If, instead of typing “ERBSHOW nnnn” you type “ERBSHOW nnnn X” you get a better layout and more formatting…

Some key fields in the Product Section are translated.

SMF Type 70 Subtype 1 (CPU) records have two section types for PR/SM. One per LPAR (whether active or inactive) and one per logical engine. It’s a nuisance to work out which logical engine section belongs to which LPAR. The extra “X” parameter resequences things so that the logical engine sections for an LPAR immediately follow the section for the LPAR itself. Neat!

Thanks to Matthias Gubitz of RMF Development for sharing this with me. He mentioned it when I started going “wouldn’t it be nice if ERBSCAN and ERBSHOW…”

Actually, I took a look at the ERBSCAN / ERBSHOW code. They are a pair of REXX execs that sit in SYS1.SERBCLS. So I copied them into a CLIST library ahead of SYS1.SERBCLS for my TSO / ISPF userid. Then I started to fiddle with the code. It was VERY easy to understand it to the point where I could straightforwardly format an additional field in the record – the Sysplex name.

Modifying the code is, of course, completely unsupported. So I’m not sure I can recommend it. But I do hope to modify it some more – to make my job easier. And if I do I may try and give my changes back to RMF Development.

So, while I’m in the code, are there any enhancements to ERBSCAN / ERBSHOW that you would like to see? I can’t promise anything, of course. But I’m motivated to work on useful enhancements.

And, no, I don’t use ERBSCAN / ERBSHOW instead of serious performance analysis tools. But as the developer of some of these I often need to dump raw records, particularly if I’m trying to trouble shoot or extend our code to map additional fields. I appreciate not a lot of people are in this position. 🙂

An Unexpected Benefit of Pornospam

(Originally posted 2007-12-21.)

As I’ve mentioned before I’m using Roller’s “Referer URL” page – for my developerWorks blog – to analyse where my blog hits are coming from. (It’s an informal exercise because I can only really work with hits that involve a search engine of some sort – and some 80% of my hits are said to be “direct”.)

Recently I’ve had a rash of “pornospam” comments to my blog. (As previously noted I’ve a way of hiding these entries from you, dear reader.) This has, in turn, caused search engines to index my blog with various porno terms.

So far so bad. 🙂 But this does have a positive side effect…

It causes a whole bunch of search engines to show up on my radar that wouldn’t have before. For example today’s “new search engine” roster is:

So when “genuine” searches from these engines take people to my (or other developerWorks bloggers’) blogs my analysis code will recognise them.

I suppose there’s an analogy in terms of virology, along the lines of “what doesn’t kill you makes you stronger”. 🙂

So, thanks pornospammers! But don’t try too hard to help me out. 🙂

I’ve A Little Button To Banish SPAMmers

(Originally posted 2007-12-14.)

Occasionally you’ll (hopefully briefly) see SPAM comments on this blog. I’m grown up about this sort of thing and just remove the comments when I see them. I hope you’re grown up enough to cope with this irritating phenomenon as well.

But I’ve gotten fed up with having to mark these comments as SPAM. So I added some code to my Firefox extension to create a little button on my “Comment Management” page. Press this button and all the comments at the end of the list of comments for a blog entry get marked as SPAM. And hence disappear from under YOUR nose. 🙂

Of course I do get genuine comments. So there’s an easy mechanism to mark them as NOT SPAM. And I’ll use that. But there are MANY more SPAM comments than genuine ones. It just requires me to scan the list of comments once in a while and mark the genuine ones as not SPAM.

Unfortunately this is part of an IBM Internal Firefox extension – as MOST of its function is of little use to non-IBMers. But I might soon be getting to the point where I want to re-engineer to surface some stuff. In the meantime any other IBM with a developerWorks blog who happens to pass by should feel free to contact me to get a copy of “Commentator” as it’s called.

(As to the name “Commentator” it arose from the original function – more than 2 years ago – to spruce up Internal Blog COMMENTing by making it easy to add links and to do various text effects. It’s come a long way since then.)