Pipeline 2016

Frances Buontempo from BuontempoConsulting

A write up of my notes: they may or may not make any sense.

Keynote: Jez Humble "What I Learned From Three Years Of Sciencing The Cr*p Out Of Continuous Delivery" or "All about SCIENCE"


Surveys are measures looking for latent constructs for feelings and similar - see psychometrics.
Surveys need a hypothesis to test and should be worded carefully.
Consider discriminant and convergent validity.
Test for false positives.

Consider the Westrum toypology.
With 6 axes (rows) scaled across three columns: pathological, bureaucratic, generative you can start spotting connections.

Power Oriented
Rule Oriented
Performance Oriented
Low cooperation
Modest cooperation
High cooperation
Messengers shot
Messengers neglected
Messengers trained
Responsibilities shirked
Narrow responsibilities
Risks are shared
Bridging discouraged
Bridging tolerated
Bridging encouraged
Failure leads to scapegoating
Failure leads to justice
Failure leads to inquiry
Novelty crushed
Novelty leads to problems
Novelty implemented

For example "Failure leads to" has three different options: scapegoating, justice or inquiry. Where does your org come out for each question? If they say "It's all Matt's fault" and sack Matt that won't avoid mistakes happening again. Blameless postmortems are important.
IT and aviation are both high-tempo, high consequence environments. They are adaptive complex systems: there is frequently not enough information to make a decision. Therefore reduce the consequences of things going wrong.
In general for surveys, use a Likert type scale - use clearly worded statements on a scale, allowing numerical analysis. See if your questions "load together" (or bucket). Maybe spotting what's gone wrong with some software buckets into notification from outside (customers etc) and notification from inside (alerts etc).
Consider CMV, CMB - common method variance or bias. Look for early versus late respondents.
See https://puppetlabs.com/2015-devops-report for the previous devops survey.
In fact take this year's https://puppetlabs.com/blog/2016-state-devops-survey-here

IT performance

How do you measure it? How do you predict it? It seems that "I am satisfied with my job" is the biggest predictor of organisational performance.
Does your company have a culture of "autonomy, mastery, purpose"? What motivates us? [See Pink]

How do we measure IT performance? Consider lead time, release frequency, time to restore, change failure rate...
Going faster doesn't mean you break things, it actually makes you *more* stable, if you look at the data [citation needed]
"Bi-modal IT" is wrong: watch out for Jez's upcoming blog about "fast doesn't compromise safety"

Do we still want to work in the dark-ages of manual config and no test automation?

We claim we are doing continuous integration (CI) by redefining CI. Do devs merge to trunk daily? Do you have tests? Do you fix the build if it goes red?

Aside: "Surveys are a powerful source of confirmation bias"

Question: Can we work together when things go wrong?

Do you have peer reviewed changes? (Mind you, change advisory boards)

Science again (well, stats)

SEM: structured equation modelling: use this to avoid spurious correlations.

Apparently 25% of people do TDD - it's the lost XP practice. TDD forces you to write code in testable ways: it's not about the tests.

How good are your tests? Consider mutation testing e.g. Ivan Moore's Jester

Change advisory boards don't work. They obviously impact throughput but have negligible impact on stability. Jez suggested the phrase "Risk management theatre".

Ian Watson and Chris Covell "Steps closer to awesome"

They work at Call Credit (used to be part of the Skipton building soc) and talked about how to change an organisation.

Their hypothesis: "You already have the people you need."
"Metal as a service" sneaked a mention, since some people were playing buzz-word bingo.
Question: what would make this org "nirvana"?
They started broadcasting good (and bad) things to change the culture. e.g. moving away from a fear of failure. Having shared objectives helped.

We are people, not resources. "Matrix management" (queue obvious slides)  - not a good thing. Be the "A" team instead. (Or the goonies).

The environment matters. They suggested blowing up a red balloon each time you are interrupted for 15 seconds or more, giving a visual aid of the distractions.

They mentioned "Death to manual deployments" being worth reading.

They said devs should never have access to prod.
You need centres of excellence: peer pressure helps.
They have new bottlenecks: "two speed IT" .... the security team should be enablers not the police.
They mentioned the "improvement kata"
They said you need your ducks in a straight line == a backlog of good stories.

Gary Frost "Financial Institutions Carry Too Much Risk, It’s Time To Embrace Continuous Delivery"

of 51zero.com
Sarbanes-Oxley (SOx) was introduced because of risk in finance. Has it worked? No.
It brought about a segregation of duties and lots of change control review. "runbooks" This is still high risk. There have been lots of breeches from IT departments e.g. Knight Capital, NatWest (3 times).
Why are we still failing, despite these "safety measures"?
We need fully automated testing including security and performance. We need micro-services (and containers), giving us isolation.
Aside; architecture diagrams...! Are they helpful? Are they even correct? Why not automatically generate these too so they are at least correct?

What are the blockers? Silos. Move to collaborative environments.

Look out for new FinTech disruption (start-ups I presume)

Gustavo Elias "How To Deal With A Hot Potato"

He was landed with legacy code that was deeply flawed, had multiple responsibilities and high maintenance costs. In fact he calculated these costs and told management, For example, with downtime for deployment and 40 minutes to restarted calculate the cost at over £500 per day per dev.
How to change this?
  • Re-architect
  • Reach zero downtime
  • Detach from the old release cycle
Re-architect with micro-services and the strangle-vine pattern.
Reach zero downtime with a canary release and blue/green deployment. You need business onside for the extra hardware.
Old release cycle: bamboo plan - but this needs new machines.
In the end, be proud.

Pete Marshall "Achieving Continuous Delivery In A Legacy Environment"

The tech architect at Planday (a shift work app)
C.D. in a legacy environment: and not "chaotic delivery".
Ask the question: "What are you business goals?"
They had DNS load balancing, "interesting stand-ups" (nobody cared), no monitoring.
He started a tech radar: goals to get people on board.
He used a corp screensaver to communicate the pipeline vision.
How easy is your code to build? Do you know what's actually in prod? Can you find the delta?
He changed nant to msbuild.
He became a test mentor, having half hour sessions to increase test coverage.
They had estimation sessions and planning sessions.
Teams started to release on their own schedule with minimal disruption to others. 
Logging, monitoring and alerting helped: look for patterns in the logs. n.b. loggly (though cloud based with no instance in Europe so might be slow)
He mentioned feature toggles (I wondered how he implemented these: please not boolean flags in a database, but enough of my pain), though watch out - you can still get surprises.
He used the strangle pattern.
Don't do loads of things: do a couple of things you can actually measure.
Ask yourself "What's the risk of failure?"

Sally Goble "What do you do if you don't do testing?"

From QA at The Guardian
They previously has a two-week release cycle, with a staging environment and lots of manual testing.
They deployed at 8am on a Wednesday. A big news day delayed the release cycle by a week. 
They couldn't roll back.
They moved to automated tests - perhaps selenium. They were mainly comparing pixels.
Then they threw them out.
So, what does QA do if it doesn't do testing? They now make sure they are "not wrong long." i.e. they can fix things quickly.
They have feature switching, canary releases and monitoring (but avoid noise).
They are not a testing department but a quality department. They can concentrate on other things - like less data so apps don't blow out users' data plans or similar.

Steve Elliott "Measure everything, not just production"

Laterooms: something about badgers.
Tools: log aggregation: elastic stack. Metrics: kibana, grafana. Alerting: icinga(2) [like nagios only prettier]
Previously dev/test was slow, had no investment. They had flaky tests and it was difficult to spot trends.
They moved to instrumentation and tooling in dev.
"Measure ALL the things"
Be aware that dashboard fatigue is a thing.
He pointed us at github
Have lots of metrics but don't used them to be Orwellian. Have data-driven retrospectives. (I once made a graph of who was asking who for code review to reveal cliques in our team - data makes a difference! And pictures more so.) He mentioned that you need to make space for feelings in the retrospectives too.
He suggested mixing up the format to keep retrospectives fresh: consider using http://plans-for-retrospectives.com/index.html

He said he was running sentiment analysis on the tweets he got during his talk. 

He mentioned that Devops Manchester is always looking for speakers.


I'm so glad I went. It's useful to see people talking about their successes (and failures) and to reflect on common themes. "People not resources" struck a deep note for me. I am always inspired when I see people trying to make things better, no matter how hard.
I loved the brief mention of stats in the keynote. The main themes were, of course, about measuring and automating. I will spend time thinking about what else I can measure and how to do stats and present them to non-statisticians in a clear way.
Never under-estimate the power of saying "Prove it" when someone makes a claim.

CentOS setup on VirtualBox

Tim Pizey from Tim Pizey

Once you have Networking working there is still a long way to go.

yum groupinstall "Development Tools"
yum install kernel-devel
yum install kde-workspace
yum group install "X Window System"
yum groupinstall "Fonts"
yum install gdm

Now we can login without a GUI but startx when one is needed.

Installing Guest Additions

The guest Centos is a stock distribution, you have to tell it that it is inside VirtualBox.

Make the additions visible to the guest:

In the "Devices" menu in the virtual machine's menu bar, VirtualBox has a handy menu item named "Insert Guest Additions CD image", which mounts the Guest Additions ISO file inside your virtual machine.

yum install dkms
mkdir -p /media/cdrom
# Note change from /dev/scd0 in CentOS6
mount /dev/sr0 /media/cdrom
sh /media/cdrom/VBoxLinuxAdditions.run

We are now able to move the mouse seamlessly between our guest and host and window systems understand each other.

Sharing files between the host and guest

In the host (Windows) create C:\vbshared and using the VirtualBox interface share this with the guest. In the guest:

mkdir /vbshared
mount -t vboxsf vbshared /vbshared

it will be visible as /vbshared/ from inside the guest.

Random Magic

Frances Buontempo from BuontempoConsulting

Have you ever written a unit test with magic numbers in and felt bad? For example, given a C++ class that simulates stock prices, Simulation, you would expect a starting price of zero to stay at zero. Let’s write a test for this using Catch 

TEST_CASE("simulation starting at 0 remains at 0", "[Property]")
    const double start_price = 0.0;
    const double drift       = 0.3;//or whatever
    const double volatility  = 0.2;//or whatever
    const double dt          = 0.1;//or whatever
    const unsigned int seed  = 1;  //or whatever
    Simulation price(start_price, drift, volatility, dt, seed);
    REQUIRE(price.update() == 0.0);

Oh dear; magic numbers. That sinking feeling when you don’t know or care what values some variables take. The comments hint at the unhappiness. You could write a few more tests cases with other numbers, or use a parameterised approach. Trying every possible double or int would be extreme, and make the unit tests slow. Unit tests should be fast, so we’d best not. We could try some random variables instead of the magic numbers. This might lead to cases that sometimes fail, and unit tests should provide repeatable results, so we’d best not.

Oh dear. If only we had some random magic to help. We need something that allows us to test that properties hold for a variety of cases. We don’t want to hand roll lots of ad-hoc test cases ourselves. If we generate random test cases we need the results to be clearly reported so we know what went wrong if something fails. We need property-based testing. Good news! Haskell got there long before us. 

QuickCheck â€œis a tool for testing Haskell programs automatically. The programmer provides a specification of the program, in the form of properties which functions should satisfy, and QuickCheck then tests that the properties hold in a large number of randomly generated cases.” [See the manual] You define a property, such as reversing a reversed list gives the original list

prop_RevRev xs = reverse (reverse xs) == xs
          where types = xs::[Int]

Then quickly check it holds for some randomly generated examples.

        Main> quickCheck prop_RevRev
        OK, passed 100 tests.

If a property doesn’t hold, quickCheck reports the case or “counter-example” for which it does not hold. Instead of my initial “example-based” test I can now test my property holds generally. Since the cases are randomly generated rather than exhaustive I may still miss problems, but look how much shorter the code was.

Wait a moment! I was trying to test some C++ and got distracted by Haskell. The good news is ports of QuickCheck exist for various languages. For example, F# has FSCheck  Python has Hypothesis  and, C++ being C++, has various versions. I have tried Legiasoft’s QuickCheck and showed my initial attempts at the #ACCU2015 conference.

A recent blog from Spotify drew my attention to RapidCheck. This claims to integrate with Boost test and Google Test/Mock though I haven't tried it yet. I wonder if I can make it play nicely with Catch. I will report back. Another interesting feature it supports is stateful based testing, based on Erlang’s port of QuickCheck. Since this started with Haskell, many frameworks need *pure* functions. Once in a while, some of us are not quite as pure as we'd like, so I can imagine this being very useful.

I hope this has sparked some excitement about new ways of testing your code. Next time someone asks “Unit tests or integration tests?” say “Yes, and also property-based tests”.

Current Software Development Pre-Requisites

Tim Pizey from Tim Pizey

When starting a new project or joining an existing one there are a number of tools and features which should be in place. I have ordered them in order both of importance and the order in which the global community learnt the painful lessons that none of these are optional.

This is based upon Project initiation - a recipe.

Short name

Google it, ensure it is available as a url, check twitter.


If there is no README create it now!

Source control

The only decision is public or private. It will be a git repo.

If any other SCM system is in place convert to git before doing anything else.

Decide on git usage strategy: git flow, release branches, developer forks with feature branches and merge to master.

Development machine

Do we really want to develop in Fortran under VMS? oh, OK.

Develop on the operating system you are deploying to. If you develop on OSX and deploy to debian it will bite you. Developing for Redhat using Windows should be made illegal.

Continuous Integration

Jenkins of course.

Track the code coverage, anything less than 100&percent; is not acceptable.

Static Analysis

For legacy projects Sonar establishes a baseline, for new projects it holds the line throughout the projects life.

Continuous Deployment

The closer to Continuous Deployment the fewer platform types are needed.


Metrics enable blue green deployment and A/B testing.

Issue tracking and work planning

Just you: gitthub, team: Jira

Continuous Availability for a Jenkins Continuous Integration Service

Tim Pizey from Tim Pizey

When your CI server is becoming too big to fail

This post was written when I was responsible for a heavily used CI server, for a company which is no longer trading, so the tenses may be a mixed

Once an organisation starts to use Jenkins, and starts to buy into the Continuous Integration methodology, very quickly the Continuous Integration server becomes indispensable.

The Problem

The success of Jenkins is based upon its plugin based architecture. This has enabled Kohsuke Kawaguchi to keep tight control over the core whilst allowing others to contribute plugins. This has led to rapid growth of the community and a very low bar to contributing (there are currently over 1000 plugins).

Each plugin has the ability to bring your CI server to a halt. Whilst there is a Long Term Support version of Jenkins the plugins, which supply almost all of the functionality, do not have any enforced gate keeping.

Solution Elements

A completely resilient CI service is an expensive thing to achieve. The following elements must be applied baring in mind the proportion of the risk of failure they mitigate.

Split its jobs onto multiple CI servers

Use of personal Jenkins installations is recommended, but there is still a requirement for a single, central server.

This should be a last resort, splitting tasks out across slaves achieves many of the benefits without losing a single reporting point.

Split jobs out to SSH slaves
We had a misconfiguration of our ssh slaves such that they install the Jenkins package. The only use of the package is to ensure that the jenkins user is present, though tasks should not, ideally, be run as the jenkins user.

One disadvantage of using ssh slaves is that it requires copies of the ssh keys to be manually copied from the master server to the slaves.

Because jobs are initiated from master to the slave the master cannot be restarted during a job's execution (this is currently also true for JNLP slaves, but is not necessarily so).

The main disadvantage of ssh slaves is that by referencing real slaves they make the task of creating a staging server more complex, as a simple copy of the master would initiate jobs on the real slaves.

Split jobs out to JNLP slaves

Existing ssh slave jobs should be left unchanged until they can be replaced. This is a blocker on creating a staging CI server.

This is the recommended setup, which we used eventually for most jobs.

Minimise Shared Resources

Most of these problems can be overcome by spinning up a virtual machine for each job, from scratch, provisioned by puppet via vagrant.

In addition to sharing plugins, and hence sharing faulty plugins, another way in which jobs can adversely interact is by their use of shared resources(disk space, memory, cpus) and shared services(databases, message queues, mail servers, web application servers, caches and indexes).

Run the LTS version on production CI servers

Move to LTS at the earliest opportunity.

There are two plugin feeds, one for bleeding edge, the other for LTS.

Strategies for Plugin upgrade

Hope and trust

Up until our recent problem I would have said that the Jenkins community is pretty high quality, most plugins do not break your server, your ability to predict which ones will break your installation is small so brace yourself and be ready to fix and report any problems that there are. I have run three servers for five years and not previously had a problem.

Upgrade plugins one at a time, restart server between each one.

This seems reasonable, but at a release rate of 4.3 per day, seven days a week since 2011-02-21 even your subset of plugins are going to get updated quite frequently.

Use a staging CI server, if you can

If your CI server and its slaves are all setup using puppet, then you can clone it all, including repositories and services, so that any publishing acts do not have any impact on the real world, otherwise you will send emails and publish artefacts which interfere with your live system. Whilst we are using ssh slaves the staging server would either initiate jobs on real slaves or they too would need to be staged.

Use a partial staging CI server
Jobs which publish an artefact every time they are run cannot be re-run so are not suitable for running on a staging server.

You can prune your jobs down to those which are idempotent, ie those which do not publish and do not use ssh slaves, but the non-idempotent jobs cannot be re-run.

Control and monitor the addition of plugins

Users intending to install a plugin should ask on irc, giving the plugin url.

From the above it is clear that for a production CI server the addition of plugins is not risk or cost free.

Remove unused plugins, after consulting original installer

We still have a number of redundant plugins installed.

Plugins build up over time.

Monitor the logs

Currently there is no monitoring of the Jenkins log.

A log monitor which detects java exceptions might be used.

Backup the whole machine

Whilst the machine is backed up a fire drill is needed to prove that a state can be returned to.

Once a month restore from backup to a clean machine.

Store the configuration in Git

The configuration of Jenkins has been stored, and restored from.

This process is only one element of recreating a server. Once a month restore from git to a clean machine.