Off to Poland…

This week I will be speaking at the Polish Oracle User Group annual conference in Sopot, Poland. It looks like a beautiful location for what is a really fun conference. As well as being surrounded by some of the most knowledgeable and excellent technology speakers in the world, there’s also plenty of fun and dancing taking place.

If I am extremely unlucky, I’ll end up swimming in the Baltic Sea. If you are unlucky, you’ll see me swimming in the Baltic Sea. Where I am from in the England there is an expression “It’s Baltic”, which means it is very cold outside. Very cold. So it is because it’s cold, OK. 🙂logo

I hope I’ll see you in Poland – fantastic place to visit with lovely people.

And don’t forget the parties and the dancing. Oh yeah!

And don’t believe all you hear about the vodka and axes, it’s much worse than that!

 

 

Which Oracle Release are you using?

Post Date: August 2018!

Recently an awesome Oracle Guru friend of mine questioned someone who was installing 11.2.0.4 with the word “seriously”, which is think shows that Oracle staff sometimes don’t live in the same technological world as the rest of business.

My response was:

11.2.0.4 is normal. In the real world:

– large corps mostly use old versions
– consultants look at current versions
– Oracle staff look at unreleased versions

I have known instances of Oracle staff blogging about how a feature works when, in the officially released versions, it didn’t. It only worked that way in a version which was released some months later. There was no reference to the release and the fact that there was a significant functional change between releases (but I suppose that’s a blog and not “official” documentation – the official documentation said nothing at all about how that particular feature worked. Nothing! So thank you mystery blogger.)

Anyway, the point of this post was I then did a small twitter poll to my most excellent and cosy band of followers to see what Oracle releases people were using. I asked 2 questions (because twitter is limited) and here’s the results:

oracle_version_highest

So more people have some form of 12 in the DB, but only 7% have 18 in Production. This at a time when most Oracle staff are thinking about Oracle 20 and 21, as Oracle 19 is done and just awaiting release. Think about that, Oracle… Whenever I am at a presentation by an Oracle PM, I think “wow – I might be able to use those new features in 2-5 years”.

oracle_version_lowest

So very few people have 12.x as their lowest version (which would include 18 as that’s really 12.2.0.2) and MORE have 9, 8 or 7 as their major headache! Yes – there are more on 9, 8 and 7 than are using 18 in Production. Lets say that once more. There are more on 9, 8 and 7 than are using 18 in Production

So why upgrade? Very few databases take advantage of all of the latest sexy features. I suspect that many of the applications still being produced could run on Oracle 7.3.4. – more so as the proliferation of ORM’s like Hibernate has left a generation of developers with little appreciation of the database and how to take advantage of it**. So why upgrade? These days? Security. Patches. Support. Without those 3 things, you are living on hope, hope that nothing goes wrong as you’ll struggle to find anyone to fix it – including Oracle. Hoping that nobody tries to hack your 8.1.7 database as it’s a Swiss Cheese of vulnerabilities, like all 7, 8, 8i, 9i, 10G DB’s. Not that we hear about systems being compromised every day on the news.

Anecdote #1: By coincidence I was talking to a client at about the same time and whilst they are a mostly 12.1 shop, they still had an old 8i database hanging around… as usual it was going to  be “retired soon” (which in my experience means sometime in the next 15-20 years) and wasn’t worth the time and effort to be upgraded or even do a business case to upgrade it!

**Anecdote #2: At a client a few years ago, an excellent Java Developer asked me to put an index on a flag column. I pointed out that with only 3 values that an index wouldn’t help, and as this was OLTP a bitmap index wasn’t appropriate due to concurrency issues. He said that with 3 values indexed, his query would be 3 times faster! We sat down and I explained some database fundamentals to him, at which point he said “don’t put an index on there – that would be a stupid idea”. A few weeks later he came back over and asked about SQL queries “I’m trying to aggregate this data – can the database help?”. I spent 30 minutes showing him in-line views and windowing analytic functions and we wrote the code he needed for his output. “Wow! You have just saved me 3 days of Java coding…” – he was going to pull everything into Java and process it there, so as well as 3 days of coding, we also saved the SAN, the network and a whole bunch of CPU by dealing with data at the database layer – which is always the most efficient place to deal with it!

Running RAC in a Virtual Environment

I was in a discussion at an Oracle Meetup this week, and the subject of RAC in a virtualized environment – specifically Oracle Virtual Machine (OVM) – came up.
Here’s a couple of points which were discussed.

pingtarget

There was a lack of awareness of a common problem, which has a solution built-in to Oracle 12.1.0.2 Grid Infrastructure and later. In a virtualized environment, the network components are also virtualized. Sometimes, network failures on the host may not be raised up to the guests. As a result, the guest O/S commands can fail to detect the network failures and the Virtual NIC remains up. Grid Infrastructure (GI) will not perform a VIP fail-over as it can’t see the failure despite the network being unavailable.

To resolve this, Oracle has added an option of a “pingtarget” for each public network defined in GI. This will perform a keep-alive to a external device, usually something like the default gateway. This is just like the heartbeat on the cluster interconnect.

Before

srvctl config network

Network 1 exists

Subnet IPv4: 192.168.0.160/255.255.255.224/eth1, static
Subnet IPv6:
Ping Targets:
Network is enabled
Network is individually enabled on nodes:
Network is individually disabled on nodes:

The default gateway makes a good ping target. For this IP and subnet, it’s 192.168.0.161

srvctl modify network -k 1 -pingtarget 192.168.0.161

After

srvctl config network

Network 1 exists

Subnet IPv4: 192.168.0.160/255.255.255.224/eth1, static
Subnet IPv6:
Ping Targets: 192.168.0.161
Network is enabled
Network is individually enabled on nodes:
Network is individually disabled on nodes:

All safe!

Server Pools

A second item we discussed was the Server Pools in OVM. Each RAC guest should be on a different host, otherwise you have not eliminated that as a Single Point Of Failure. A second less obvious SPOF is the Server Pool disk.

A Server Pool is a filesystem LUN (and IP address prior to release 3.4) used to group a logical collection of servers with similar CPU models, within which we can create and migrate VM guests. For a RAC installation, each RAC node should be within a different server pool, as well as on different physical hardware.

ovs

In this image, RAC nodes within the same cluster should be created within each server pool. This configuration can safely support a 2 node cluster despite having 4 servers, with one node created in “OVS-Pool-2” on server “ovs02“. The second node should be in “OVS-Pool-1″ and can be on “ovs01“, “ovs11” or “ovs12“.

It is possible to live migrate guests between these 3 servers.

 

 

 

 

 

UKOUG Member Advocate: sorted!

I received an email from the UKOUG last week.

winners-picture

 

It turns out that I have won the vote to become the next Member Advocate for the UKOUG. I will (eventually) be joined on the board by Martin Widlake – who won the vote for the position of President Elect – a position whereby Martin will shadow the current UKOUG President before taking office on the Board. He has written about it here.

I would very much like to thank everyone who voted for me. I hope I can live up to your expectations. If you did not vote for me, that’s OK – I’ll represent you and your interests just the same as everybody else! Looks like I’m going to have to spend time getting up to speed with the Apps community, and re-acquainting myself with my old JDE friends.

Here’s to moving the User Group forward to meet the challenges of the changing face of our industry. See you all soon, and Cheers Everyone!

(sorry – would have posted this sooner but I was at the OUG Ireland User Group giving a couple of presentations and taking part in a Q&A panel about “18c and everything else!” – fantastic conference and lovely people there!)

 

 

UKOUG M.A. Voting Hots Up!

It’s getting hotter!

After many years volunteering at the UKOUG I am standing to be the Member Advocate at the UKOUG, representing the members on the board.

Do you think I will represent the membership well? Yes. VOTE FOR ME!

Oh, you must be the main UKOUG membership contact, or know who is, to vote.

giphy

One twist in the election is that Steve Davis has withdrawn from the vote due to business commitments, leaving a straightforward race between myself and Andy Nellis. That’s a shame as I think Steve would have made a good Member Advocate had he been voted in. Andy is unknown to me so I cannot comment on his suitability as a UKOUG volunteer or board member.

I’d really appreciate your vote – I know that many of you have voted for me already, but I want ALL of you to give me a strong mandate to improve the user group.

VOTE HERE

 

 

I want your vote!

Are you a member of the UKOUG? Read on…

ukoug_logo

I’m currently standing for the role of Member Advocate. But why?

I’ve been volunteering at the UKOUG for over 10 years, and speaking at the conferences and SIGs for the last 5 years or so.  I’ve been deputy chairing or chairing a SIG for all of this time and I’m currently the RAC SIG Chairperson. I’m also involved with our main conference, having helped on the organizing committees for several years, I organized the database stream for Tech16 and the entire content for Tech17. I enjoy giving back to the community and I think that by joining the board to serve as Member Advocate I will be able to further enhance the user group and the members experience. Your experience.

 

 

Feel free to tweet me, message me or comment if you have any questions!

Oh, and while you’re there, can you also vote for Martin Widlake to be President Elect. Nobody is running against him but the membership do need to confirm they are happy with his appointment. I’ve already voted for him!

ukoug-vote

twit1twit2twit3


OK, here’s a few testimonials from Twitter…I hope you will join the other UKOUG members in voting for me and Martin!twit4twit5

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.

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