Presenting at the UKOUG Conference

After reading Niall Litchfield’s insight into the selection process for this years annual UKOUG Conference, I was really quite downbeat and pessimistic about my chances of getting selected. 212 abstracts for just 64 slots seems like poor odds to me! I am sure the number of slots has been reduced, and for a now 5 day event 64 slots seems perhaps less than could be crammed in, though of course whether people would actually want to attend more presentations is another question!

I had seen via judging the abstracts that there were some really excellent abstracts in the topic area of ASM, all of which were from people I rated very highly indeed. In fact I was cursing myself for putting in such a lightweight abstract and was thinking I should have spent more time on it to make it sound more appealing. I was also starting to regret not having put in an abstract on dataguard.

Thankfully, I have received an email saying one of my abstracts has been accepted and they were asking me to roll my 3 abstracts (one on ZFS, one on ASM, and one comparing the two) into the one presentation. I have managed to get a 1 hour slot for this. The selected presentation is as follows:

What ASM & ZFS Can Do For You

Both ASM and ZFS combine the role of Volume Manager and File System. This presentation will provide an introduction to the workings of both, giving an insight into their history and an understanding of the mechanics of how each works. I will also give an understanding of the benefits and drawbacks of both file systems.

I must say I am delighted with this arrangement and I really would have been a bit gutted to have missed out on the opportunity to present at the conference.

Don’t worry if you have not heard about your abstract, as I believe the confirmation emails may be going out around the 25th of July, so you may still be in with a chance.

UKOUG DBMS SIG

A fantastically well attended SIG, the large room is packed and it’s at my favourite venue used by UKOUG, just a hop from the houses of parliament. In fact there were 125 registered attendees, which is roughly double the number of the last UNIX SIG event, held in the midlands.

However, I would say having so many Oracle employees presenting (4 out of the 6) is a real shame - perhaps there is a danger in evangelising the product too much rather than giving a more balanced view.

Of course, perhaps it needs more end users to volunteer to do the presenting.

Support Update - Phil Davies (Oracle)

ASM instance hang/ORA-2103 in DB instance. see Note: 468572.1. A few issues with 10.2.0.4 Enterprise Manager.

New Oracle clusterware process oprocd appears with 10.2.0.4. This might cause issues with certain Linux flavours and the hangcheck timer.

Making Life Easier with Grid Control - James Anthony (Oracle)

Came from a command line mindset, but grid control has caused him to become a convert to a more gui based approach. A reasonable minority of people in the audience using grid control. The base product is free, though the “good stuff” is a cost option via various optional “packs”. He has a slide with “Reduced Cost of Ownership”" Whenever I see this, I immediately translate this to the vendor has a product to sell that will cost you money.

Inventory management - reporting what versions of the oracle and O/S software the servers in your database constellation are running. Appealing to the larger companies to keep track of things. This is not just capable of reporting on Oracle DB, but other DB’s and app servers.

A tiny percentage of attendees have applied the April 2008 CPU - this is 3 months after it appeared. PCI DSS demands that relevant patches are installed within 1 month of becoming available. Though of course according to the register 88% of business are ignoring PCI DSS.

Patch advisory will show which patches are needing to be applied to which server software.

Best practice reporting/compliance - apparently over 220 best practice policies that you can automatically test against your various instances with grid control. Other useful feature is automating daily checks. Big push on security checking.

James is really selling this as a tool for reassuring management by pointing them to the varous graphs - heck they can even give you a compliance score - “this database is 89% compliant”!

Auditing & Tracking Changes, Comparing two systems.

Provisioning Pack and automating patch updates. Not one audience member is keen on automated patching of production systems, however I can see that if you had a large number of db servers going round each of them manually would be a full time and tedious job.

Not one audience member is using Oracle Unbreakable Linux.

Data Masking. Only a few DBAs are taking steps to mask production data in test database - the vast majority are not doing this. This can be automated with grid control - assuming you pay for the data masking pack - you pay on a per cpu basis for the machine you are doing the masking on. You can mask on 1 machine and then clone the masked data out to numerous test systems.

Claims masking is fast 120Million row table masked in 1.2 hours on 1 cpu system - of course this table could have few columns or lots of columns, but he has not said what quantity of data this represents.

Active Dataguard, Backup & Recovery - Mike Appleyard (Oracle)

A pre-sales presentation - though the presenter has worked in Oracle Support for 10 years or so. Really hammering home the fact that a standby database is often not providing a great ROI as it has a lot of spare CPU cycles apart from just apply redo data - oh this is where Active dataguard comes in, this is where the standby is open for read only operations but you can still run managed recovery on the standby so your queries are bang up-to-date in terms of the data they are seeing.

Block change tracking can be implemented on the standby facilitating faster RMAN incremental backups.

The big sell, is taking read only reports away from your primary and putting them on your standby you can shovel more transactions through your primary - so instead of paying for more cpu on your primary you can pay for an active dataguard license instead.

Mentions itunes using active dataguard - they used to use logical standby - they have many standby instances.

Active dataguard is a cost option, it costs around 12.4% of an EE license. Hmm, another slide seems to contradict that pricing. Some real confusion out there around the licensing of the dataguard - quite a few questions being generated.

A huge percentage of the audience have a physical standby already.s

snapshot standby is basically opening a standby read-write and then flash it back to become a physical standby. This has become a less manual process with 11g. This is FREE, not a cost option.

He was somewhat skeptical (in terms of reliability) regarding rolling upgrade with a physical standby becoming a logical during the upgrade.

A slide regarding the performance of media recovery, claiming practically doubled number of MB/s that the same system can do going from 10gR2 to 11gR1 - that seems a big claim to make.

A Beginners Guide to Statspack (AWR) - Jonathan Lewis (Independent Consultant)

At last a non-oracle employee. What can you do with statspack:

routine checks for anomalies
Occasional health checks
diagnosing historic performance problems

statspack is not a response time tuning tool. it aggregates over sessions.

Interesting point about victims and culprits - is it my query that is at fault, or is my query just the victim of some other query hogging a lot of system resources? Explaining that competition for resources can be a big cause of increased response time, affecting both wait time & service time.

Advocating checking how various metrics are changing over time, so that any exception really stands out.

Pointed out some inconsistencies in the numbers that statspack reports and not to always cross-check the numbers.

Jonathan is talking about the wait time histograms available with 10g statspack (but I don’t see it in AWR). This shows the breakout from an average wait time - maybe you have some waits that are waiting a very long time that are hidden by the average.

Certification Exams - Joel Goodman (Oracle)

Joel helps write the Oracle University curriculum so has a somewhat vested interest in Oracle certification.

My take on certification is that it’s worthwhile to gain an understanding of features that you rarely encounter in your day to day DBA work, but just having certification without being backed up by practical experience it’s not that useful.

Best Practices for Gathering Oracle Database Statistics - Martin Widlake (ORA600 LTD)

Martin was talking a lot about the automated stats gathering job that is turned on by default in 10g. The idea of this job is to collect stats when the underlying tables have changed enough to have the stats marked as stale. Of course it may run at a very inconvenient time for your system and there is little information on what it is really doing.

I hope there are less Oracle employee presentations in future.

Comparing ASM with ZFS

Here is a copy of the document I produced for UKOUG delegates attending my presentation on Comparing ASM with ZFS document.

I’m also making available the slides I used, though be WARNED these are 25MB in total (for 22 slides) so think before downloading!

I think in the end I was more comfortable talking about ASM than I was on ZFS, and I did not really do the ZFS part justice. I’m not all that convinced that the actual talk works all that well. I ran over and even then did not cover everything about ZFS that I wanted to.

With that in mind, I have put in two other abstracts for the UKOUG Birmingham conference. I think splitting up the talk into two seperate talks is really the only way to tackle it. Maybe it was like comparing apples & oranges after all.

What ASM can do for you

This will give insight into how ASM works and an understanding of its features. You will gain an insight in the benefits and drawbacks of running a database on ASM. I will cover:

Introduction to ASM

disk discovery

diskgroups

extents

mirroring

rebalancing

metadata

myths

and for ZFS:

What ZFS can do for you

This would give insight into how ZFS works and an understanding of its features. You will gain an insight in the benefits and drawbacks of running a database on ZFS. I would aim to cover:

Introduction to ZFS

Data Integrity

Creating a pool

Snapshots & Cloning

Particularly with the ZFS talk I’d like to do a few demos so people can see just how easy administration with ZFS really is.

UKOUG UNIX SIG

I’m clearly doing something wrong. Doug Burns is off cruising down a Scandinavian fjord, while I’ll get to do Solihull! I’m afraid I thought the venue was quite poor, a bit of a pain to get to via train and boy was the lunch stingy!

Support Update: Phil Davies

Phil asked the audience how many were on 9i, and astonishingly 3/4 of the audience were on 9.2! This is completely and utterly at odds with the RAC SIG. I wonder if with RAC you have more incentive to upgrade, or perhaps it’s the case that most RAC installs are more recent, therefore the choice being 10gR2.

rman do or die Roland Brown and Emily Taylor

This was a real user experience story. It really reminded me how much I do not want to work in the public sector. They were using Veritas Netbackup for backing up their databases but they did not have the Netbackup Oracle agent. So as late as 2004/2005 they were backing up their databases by having Netbackup do a cold backup of their database files. They then had a nightmare trying to persuade their management to fork out for the database agents (total cost £20K), even though they were demanding 24×7 access to the databases! I also found it interesting the timeframe they stated that it took them to upgrade Netbackup to version 6, seems like they had as much hard a time at persuading all the interested parties (management, SA’s) to move to rman as they had actually with rman.

Lets get Virtual: Clayton Blake & Tom Dale

This was an amusing talk regarding using VMWARE at BERR. Again another presentation from the public sector, and again they had real hardware limitations so they chose to run several tiers of an application on the one box and use VMWARE to perform the virtualisation. They clearly had done the virtualisation quite well in terms of cloning from a “golden copy”. It seemed to make their deployment far more agile. This was quite an amusing talk and though the dolly the sheep metaphor for cloning is not new, the dolly with a red hat I found quite funny.

Oracle ILM - Lilian Hobbs

Lilian used to be the product manager for ILM inside Oracle but has recently left Oracle to become independent. She obviously new her ILM and presented it well. The basic idea is not to delete old data but to move it to cheaper storage. The way the size of disks are going this is obviously becoming cheaper and cheaper. This was the first time I had heard of the concept of MAID (Massive Array of Idle Disks). The idea behind this being that you have a big cabinet of cheap disks but only have some spinning at a time and if you want to access data on a disk that is idle, you just have to wait a bit longer while the drive spins up. This is a clever idea for read only or archive data.

I could not help thinking that if you are storing these huge quantities of data that ZFS and disk scrubbing might really be of benefit.

11g partitioning new features: Joel Goodman

This was a fairly comprehensive look at partitioning and in particular new features available in 11g. I must confess I did not hear much of this of talk, even though I was in the room, as I was far to alarmed at my presentation which was after Joel’s.

Comparing ASM with ZFS: ME
It’s not fun being last presenter of the day. The audience had thinned quite substantially I thought, though I don’t think the events in the Midlands attract quite the same numbers anyway. This was the first presentation zen style presentation I had done and I must say I found it a little harder than a traditional bullet point presentation. Twice I completely forgot what I wanted to say, both times on ZFS content - I was a little disappointed I did not really get across all I wanted to regarding the design of ZFS. I thought the ASM content went much better. I also found people asking questions during the presentation really, really put me off my stride and I found it difficult to remember after answering the question exactly where I had got to.

It will be interesting seeing the feedback on this.

UKOUG RAC & HA SIG

Introduction

A rainy day london for the RAC & HA Sig.

First up as per usual was the survey of who is using what, Julian dyke

9.2 a few
10.1 a few
10.2 almost eveyone
11.1 two people in production

solaris on sparc around 10 a similiar number to AIX and 32 bit linux

The majority on linux x86-64. A little sprinkling of windows. No one on windows itanium. One person shouting out for VMS.

majority on 2 nodes. a few with 3, and a few with 4. A few with 3 One guy with 10 nodes and one with 12.

everyone on SAN hardly any with NAS.

Going on for 1/2 or more using ASM, a sprinkling on OCFS.

A good lot running physical standby with RAC and a surprising sprinkling using logical standby.

Only around 20% applying critical patch updates

Phil Davies Support Update

Interesting problem about IOT corruption when doing a 9i to 10g upgrade Metalink note: 471479.1.

Apparently Oracle developers now have to justify why a patch cannot be rolling.

Joel Goodman Managing Sequences in RAC

In some ways the name sequence is a misnomer as they are not actually guaranteed to be sequential, there may be gaps, they may even wrap around. They need not start with 1 or increment by 1.

Sequence cant be rolled back.

SQ Enqueue is used during cache replenishment.

gaps occur due to sql being rolled back (seuence number can’t be rolled back it’s an autonomous transaction to get the sequence number)
metadata ages out of row cache
instance shutdown.

In RAC there is the option of order or noorder. This controls the ordering of generated numbers. In increasing levels of performance:

nocache and order
nocache and noorder
cache and order
cache and noorder

With cache in RAC each instance caches it’s own set of numbers

Simon Haslam Fast Connection Failover

FCF basically means subscribers (app servers) get notified of events occuring on the db tier.

Possibility of using JDBC driver without an Oracle client with FCF.

Simon had a demo of a rac node failing and the app server still being used for queries without any intervention. JDBC driver has some methods that can be used with FCF.

Be interesting to see if this will work with tomcat, but as it’s at the jdbc level there is no reason it should not.

Mo Beik Sun & HA

This was a marketing talk, seems somewhat outdated, I’m sure there are lots of customers using Sun, Oracle Veritas, but really with 10g (&11) oracle are out to kill veritas anyway.

Claimed Oracle 11.2 was slated for end of year 2008. Hmm, is this going to be announced at Openworld?

He showed some graphs comparing ASM with SharedQFS, and as the number of nodes in a cluster increased (6, 7 & 8 nodes) SharedQFS seemed (in these sun tests) to actually outperform ASM. At lower number of nodes there was not really anything in it.

Harald Van Breederode Client Connectivity in a Dataguard Environment

how can one prevent clients from connecting to the wrong database in a dataguard environment?

Harald’s idea is using database services and after startup triggers to set services based on events happening on the database, e.g. if the database becomes read only, then a service is started that reflects this. It is now just a case of ensuring that clients connect to the appropriate service. This can be used in case of switchovers or failovers.

This was a really clever way of ensuring application connectivity in a dataguard environment.

Martin Bach Oracle RAC on Oracle VM

paravirtualisation vm’s do not (necessarily) simulate hardware
vm performance closer to physical hardware but requires kernel changes.

This seemed like a great way of having a play with RAC without having to have additional hardware.

Julian Dyke’s Tour

Julian has been presenting in the far east and Australasia. He has encountered quite a few CRS corruptions he emphasized how important it is to backup your OCR automatic backups.

In Summary

As usual highly worthwhile event.