Peter made a huge contribution to rowing in our region as a competitor, coach, volunteer and supporter. His picture appears on many photos on the walls of the Durham ARC Boathouse spanning over many decades. He has been particularly effective in bringing newcomers into rowing.

In 2011 Peter was awarded the British Rowing Volunteer of the Year Award and this is a most fitting way to remember his contribution to our sport.

Update: British Rowing have an article on Peter and I’m told that there will be an article about Peter in the next edition of Rowing & Regatta magazine.

In the past week I have been looking to add SPF records for a few domains that send/receive mail via my hosting provider Mythic Beasts. I was concerned about ensuring that the SPF records stay in sync with any future server changes at Mythic Beasts. When asked the Mythic Beasts guys informed me that they hadn’t been asked about this before but they quickly got their thinking hats on and came up with an SPF record at _spf.mythic-beasts.com

richm@royalcounty:~$ host -t spf _spf.mythic-beasts.com
_spf.mythic-beasts.com has SPF record "v=spf1 ip4:93.93.130.6 ip4:93.93.131.52 ip4:93.93.131.30 ip4:93.93.131.127 ip4:93.93.130.44 ip6:2a00:1098:0:86:1000::10/127 -all"

Now all I need to do is to add a an SPF record that references _spf.mythic-beasts.com using an include: clause and it will automatically pick up the changes made by Mythic Beasts without me having to change anything.

richm@royalcounty:~$ host -t  spf oldelvet.org.uk
oldelvet.org.uk has SPF record “v=spf1 include:_spf.mythic-beasts.com -all”

It is possible to use multiple include: clauses in one SPF record so if you send mail from more than one hosting provider/ISP you can easily do that.

So far things seem to be working fairly well. I did spot one initial problem where we used include= instead of include: and this meant that the correct record was not included.

I also noticed that on my existing records I was using square braces around ip6 addresses.

ip6:[2a00:1098:0:80:1000:4:1010:1010]

I’m not sure where this came from but it did seem to work but does not look to be part of the standard. I’ve now removed that.

ip6:2a00:1098:0:80:1000:4:1010:1010

For now I have left the revised SPF records with short time-to-live (TTL) times so that I can make changes quickly if I spot any further problems.

That made me wonder if the imminent arrival of IPv6 enabled servers/sites could introduce a vulerability here because IPv6 often uses the MAC address to generate a unique link local (and in some cases global) IPv6 address.

Food for thought…

Some key points of the documentary include:

• The Sexton Beetles that burried a dead rat within a couple of hours to use as food/housing for their offspring.
• The single celled mould/jelly that was able to build a near optimal network of paths between sources of food placed in the environment. Good to see that this is being investigated by Computer Scientists to see what lessons can be learned for planning/problem solving applications.
• The Fly Trap where many of the flies in the environment had unexpectedly ended up in a bottle of wine.

Update: Photo galleries of the YNEPF event now published.

At the time we had heard nothing about the riots going on in London and certainly didn’t expect anything like that to be going on in Birmingham. I’m guessing we made it out of the city centre about 30 minutes before things started getting heated.

Specifically it turns out that two identical calls to format a date will return different output if a date including a timezone is parsed using the SimpleDateFormat instance inbetween the two calls.

The following JUnit tests pass

    public void testFormatAfterParse() throws Exception {
        Date aDate = new Date(1311033202747L);
        SimpleDateFormat sdf = new SimpleDateFormat(
                         "yyyy-MM-dd'T'HH:mm:ss.SSSZ", Locale.US);
        sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
        assertEquals("2011-07-18T23:53:22.747+0000",
                         sdf.format(aDate));
        assertEquals("2011-07-18T23:53:22.747+0000",
                        sdf.format(aDate));
    }

whereas if we parse a date between the two we get a test failure

    public void testFormatAfterParse() throws Exception {
        Date aDate = new Date(1311033202747L);
        SimpleDateFormat sdf = new SimpleDateFormat(
                         "yyyy-MM-dd'T'HH:mm:ss.SSSZ", Locale.US);
        sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
        assertEquals("2011-07-18T23:53:22.747+0000",
                         sdf.format(aDate));
        sdf.parse("2009-01-01T00:00:00.000+0200");         // fails on the next line
        assertEquals("2011-07-18T23:53:22.747+0000",
                         sdf.format(aDate));
    }

With the additional sdf.parse call the Junit test fails saying

    junit.framework.ComparisonFailure:
          expected:<...0...> but was:<...2...>

That is the timezone output said “+0200″ and not the expected “+0000″ output.

This problem seems to have been fixed in Android 2.3 there is a fleeting reference to it in Comment 21 of Android issue 8258 but I have not found an specific bug report for it yet.

After quite a bit of investigation we managed to identify the test case above but it was difficult to identify the exact scenario in our multi-threaded environment where SimpleDateFormat instances are used within a utility class that is called from many different contexts.

Once identified the problem is simple to workaround in our application. We have just allocated two separate SimpleDateFormat instances (actually 2 per thread – more below) one for formatting and one for parsing. This stops parsing from affecting the format calls output.

Sharing SimpleDateFormat instances

You may ask why we are reusing SimpleDateFormat instances and hence falling over this problem. This is due to the cost involved in allocating a new instance. When we were using a new instance everytime we wanted to format/parse a date our tests took 12 minutes to complete. Changing to use a per-thread instance of SimpleDateFormat as shown below the test time was reduced by 9 minutes so it now completes in just 3 minutes.

Ok so we do a large number of date time operations in the tests but it really does show how much time the allocation of the object takes.

We use a ThreadLocal helper to allocate new SimpleDateFormat objects. Our original formatting code was

    public static String formatAsIso8601XmlLocal(Date datetime) {
        SimpleDateFormat sdf = new SimpleDateFormat(
                "yyyy-MM-dd'T'HH:mm:ss.SSSZ", Locale.US);
        sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
        return sdf.format(datetime);
    }

but with a simple use of ThreadLocal we can safely reuse instances in a thread-safe manner with minimal effort.

    /** Zulu timezone date/time format helper. */
    private static final ThreadLocal<SimpleDateFormat>
                             iso8601XmlZuluDateFormatHelper =
        new ThreadLocal<SimpleDateFormat>() {
            /* (non-Javadoc)
             * @see java.lang.ThreadLocal#initialValue()
             */
            @Override
            protected SimpleDateFormat initialValue() {
                // Note Locale.US is always available
                // and formats correctly for XML interchange
                SimpleDateFormat sdf = new SimpleDateFormat(
                       "yyyy-MM-dd'T'HH:mm:ss.SSSZ", Locale.US);
                sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
                return sdf;
            }
        };
    }

    public static String formatAsIso8601XmlLocal(Date datetime) {
        return iso8601XmlLocalDateFormatHelper.get()
                                          .format(datetime);
    }

The whole piece on the news seemed to be very biased and most of the talk was about how copying a CD/DVD onto your MP3 player was taking money out of the media moguls pockets. The presenters seemed to be taking the side of the media people and no-one on the show was thinking about things from the consumers point of view.

What the report says

I haven’t had time to look at the review in depth yet but Professor Hargreaves does seem to have done a good job of looking deeply into the issues and taking the technology into account too. Briefly the report concludes that with the rate of development of new technologies the UK must be prepared to react and change to encompass the changes.

Many of our existing laws are still firmly based around supporting 19th century technologies which in many ways are at least two generations of technology behind. For instance today the public wants to format shift their music to allow it to be listened to on a wide variety of devices. Our existing laws are still based around sheet music and concert hall performances. I remember as a child being told that

“Home taping is illegal and is killing music”

Well that was over 20 years ago and if anything music is more alive in 2011 than it ever was in the 80′s and the big music companies who are making the most noise are often reported as having record profits.

I heard a few expressions of surprise today that copying from CD to tape (or MP3 player) is technically illegal. I really think that a large portion of the British public are unaware of how anti-consumer our IP laws are in places.

Restricting Rights using Technology

The thing that grates on me most about the lobbyists attempts to keep things firmly embedded in the 19th century is the attempts to use digital technology to enforce rights.  We have some wonderful technologies that are designed to allow things to interoperate with each other and the content producers try to use technical barriers to limit this interoperability.

Ultimately my view is that most of these are futile and only serve to make life harder for the legitimate end user and to drive things into black markets. The technologies themselves often only offer protection for a few years until ways of circumventing them becomes commonplace.  Whether it be phones/gaming consoles that are locked down to stop people customising them or DVD/Blueray disks that are only supposed to be viewed in certain locations.

Worst of all IMHO is the current proposals to try to force ISPs to block illegal filesharing sites from their customers. Whilst I have a fair amount of sympathy with the content producers there is also a large amount of advertising that comes from the wider distribution channels that these sites bring. Not every “illegal” download would be turned into a “paying” download and in many ways the people who would pay will likely pay if offered legitimate downloads with value added features too.

Ultimately blocking the filesharing sites means taking the away the fundamental aspects of the internet and also forcing ISPs to spy on all of our surfing behaviour. It is almost like the phone companies being forced to listen to/record all of our phone conversations and for the postman to open/read all of our mail deliveries.

Even if that happens there are many ways in which the end-users can circumvent the ISPs monitoring. Sure they are less convenient but ultimately they are perfectly workable necessary.

Finding the right balance

The key taking things forward is finding the right balance. I’m all for content providers getting a fair price for what they provide. But they also have to adapt to the new technologies and embrace the new opportunities that it brings them.

Other reading

• The report itself
• Glyn Moody – Reviewing the UK Government Response to the Hargreaves Review
• Department for culture, media and sport – Next steps for implementation of the Digital Economy Act
• Light Blue Touchpaper – DCMS illustrates the key issue about blocking - explains why site blocking is doomed to failure.