KILL! KILL! KILL! (of Unix processes)

The start of this isn’t my post – I got it from here: but I wanted to reblog/repost and enhance it because as far as I can tell, 99% of all known DBA’s only use kill -9 to remove unhappy processes.


Original Post:

Useless Use of Kill -9 form letter

No no no.  Don't use kill -9.

It doesn't give the process a chance to cleanly:

1) shut down socket connections

2) clean up temp files

3) inform its children that it is going away

4) reset its terminal characteristics

and so on and so on and so on.

Generally, send 15, and wait a second or two, and if that doesn't
work, send 2, and if that doesn't work, send 1.  If that doesn't,
REMOVE THE BINARY because the program is badly behaved!**

Don't use kill -9.  Don't bring out the combine harvester just to tidy
up the flower pot.

**don’t remove your Oracle or any other binaries please.


 

I hope you found that useful. I know I did. But what do the numbers mean? Well, they are increasingly violent ways to ask the program to stop itself. The command kill -9 isn’t asking the program to stop, it’s asking the O/S to stop running the program now, regardless of what it’s doing.

Run order of kills:

kill -15 : this is the equivalent of kill -sigterm and it the default. The program should terminate after it has finished what it is doing.

kill -2 : this is the equivalent of kill -sigint and is the same as pressing CTRL+C. This should mean “stop what you’re doing” — and it may or may not kill the program.

kill -1 : this is the equivalent of kill -sighup and tells the program that the user has disconnected. (e.g. SSH session or terminal window was closed). It usually results in a graceful shutdown of the program.

The executing program needs to be coded to recognise these kill signals, and all good software will spot them.

The other fun kill command is kill -sigstop. This can’t be blocked (like -9) as it’s an O/S level command too, but freezes the program execution like pressing CTRL+Z. You can continue the program execution later using kill -sigcont.

Oracle ACE Director

I was at UKOUG Tech17 this week in my capacity at both Speaker and Tech Lead (organizing and selecting the agenda, drinks, parties, etc – although the heavy lifting is done by the @UKOUG office)

There was rather a nice surprise waiting for me. Jennifer from the Oracle ACE Program upgraded my Oracle ACE to Oracle ACE Director.

ACED_blk

This is a wonderful honour and reflects the many many days dedicated each year to the Oracle community through presenting at conferences around the world, helping on forums, writing magazine articles, arranging SIG’s and meetups, as well as the aforementioned Tech Lead at #UKOUG_TECH17 

Thank you Oracle ACE Program!

 

As for Tech17? Here’s a few images of this year’s event!

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UKOUG Tech17 Dec 3rd-6th

I love the UKOUG Tech conferences, but then I’m biased. It was the first conference I spoke at a few years ago, but I’ve been going to see UKOUG events since the mid 1990’s. At my first event there was a DBA talk about VLDB – the database was 40GB and growing at 1GB per month. We were all amazed at the huge size of the database!

This year I was the lead putting together Tech17; want to know what it’s all about?
Watch this short video

and look at the agenda here – 3 days of excellent technical content, plus SuperSunday!

Hope to see you there!

UKOUG Northern Technology Summit

northerntech17-com-600x110-cfp-v1

Here at the UKOUG, we’ve just announced that we will be holding a 1-day UKOUG Northern Technology Summit in the North of England on 18th April 2018.

It will be in Leeds, at the Park Plaza!

This is a 5-stream 1 day event, with around 30 talks! We’d call it a conference – it’s bigger than some European national conferences! – but we don’t want to have any confusion with our sexy flagship conference, UKOUG Tech17 (or, indeed Tech18 in Liverpool!)

The Call For Papers is now Open, and we are looking for talks in relation to Database, RAC, Cloud, Apex, Development and Engineered Systems. A full list can be found on the CfP page, linked here.

Tweet about it with the hashtag #UKOUG_ntech

HrOUG – The Croatian Conference

Arriving on Tuesday afternoon, directly from the Slovenia Conference and it’s straight into the 3rd Autumn conference! Conveniently, Slovenia and Croatia are timed together and are held within a little over 1 hours drive (plus a 15 minute boat ride!) apart. Well done on that one guys!IMG_1892

A quiet beer as many speakers and delegates wait at the docks for the boat to arrive, and I seem to be timing these sunsets well!IMG_1795

Wednesday was a day off, so Tuesday night allowed me to let my hair down a little and have a drink until late into the night. Wedneday, and the organizer, Davor, had arranged for all of the Oracle ACEs and Oakies to go on a tour of nearby Pula followed by some Go Karting. Great fun! I knew nothing of Pula so I was rather surprised to discover a huge Amphitheatre there!

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The talks, on Thursday and Friday, were a repeat of the talks in Slovenia about Histograms and Plan Stability.  A great conference in a truely excellent location – having the conference on an island gives it the same magic as the OUGN conference: you can’t just wander off, we are all there together and that really adds to the conference.

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Rovinj with Andrew!

As a added bonus, one of my friends happened to be in the nearby town of Rovinj on the Friiday afternoon, which meant a serendipidous meet-up for lunch.

Overall a wonderful pair of conferences which felt as much a holiday as work, although I think I need a holiday to recover from them.

SiOUG – The Slovenian Conference

So October came around and it was time for my second and third conferences of the autumn season.  I had been kindly select to do 2 talks at this Slovenian User Group, but a last-minute problem with another speaker meant I found myself giving 3 talks in 2 days. Excellent fun!IMG_1728

 

I arrived in lovely Portoroz just as the sun was setting, with what seemed like most of Slovenia leaving the coast on the final hot Sunday of the year, just in time for a huge and wonderful dinner with all of the other speakers.

Day 1 was a whirlwind of talks, food and presenting  much of what I know about Histograms and Chocolate, washed down with a local craft ale – Thank You HumanFish Brewery! Yum!

A party at the end of day 1, with a generous consumption of wine and Craft Ale – all consumed with the lovely friendly and fun Slovenians at the conference – y’all know who you are! – meant that Day 2 held some trepidation…. would I wake up in time!

Day 2 saw me giving 2 more talks, about Optimizer Plan Stability, and also about DataGuard, in front of an interested and good sized audience before hopping into my car and driving down to Croatia to give 2 talks in a somewhat more leisurely 3 days. Tomorrow is a day off! Holiday!

UKOUG RAC SIG, September 27th

There’s a UKOUG RAC SIG on the 27th of September in London.

There a range of great speakers talking about topics from the new RAC Domain Clusters, 12.2 Upgrading, Patching Exadata, and much more.

It’ll be great, it’s true! See you there…

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