When each line of code is written it is surrounded by a sea of context: who in the community this is for, what problem we’re trying to solve, what technical assumptions we’re making, what we already tried but didn’t work, how much coffee we’ve had today. All of these have an effect on the software we write.
By the time the next person looks at that code, some of that context will have evaporated.
It turns out that one of the things that is really difficult at Crossref is checking whether a set of Crossref credentials has permission to act on a specific DOI prefix. This is the result of many legacy systems storing various mappings in various different software components, from our Content System through to our CRM. To this end, I wrote a basic application, credcheck, that will allow you to test a Crossref credential against an API.
Subject classifications have been available via the REST API for many years but have not been complete or reliable from the start and will soon be deprecated.
The subject metadata element was born out of a Labs experiment intended to enrich the metadata returned via Crossref Metadata Search with All Subject Journal Classification codes from Scopus. This feature was developed when the REST API was still fairly new, and we now recognize that the initial implementation worked its way into the service prematurely.
Crossref and DOAJ share the aim to encourage the dissemination and use of scholarly research using online technologies and to work with and through regional and international networks, partners, and user communities for the achievement of their aims to build local institutional capacity and sustainability. Both organisations agreed to work together in 2021 in a variety of ways, but primarily to ‘encourage the dissemination and use of scholarly research using online technologies, and regional and international networks, partners and communities, helping to build local institutional capacity and sustainability around the world.
We believe in Persistent Identifiers. We believe in defence in depth. Today we’re excited to announce an upgrade to our data resilience strategy.
Defence in depth means layers of security and resilience, and that means layers of backups. For some years now, our last line of defence has been a reliable, tried-and-tested technology. One that’s been around for a while. Yes, I’m talking about the humble 5¼ inch floppy disk.
This may come as surprise to some. When things go well, you’re probably never aware of them. In day to day use, the only time a typical Crossref user sees a floppy disk is when they click ‘save’ (yes, some journals still require submissions in Microsoft Word).
History
But why?
Let me take you back to the early days of Crossref. The technology scene was different. This data was too important to trust to new and unproven technologies like Zip disks, CD-Rs or USB Thumb Drives. So we started with punched cards.
Punched cards are reliable and durable as long as you don’t fold, spindle or mutilate them. But even in 2001 we knew that punched cards’ days were numbered. The capacity of 80 characters kept DOIs short. Translating DOIs into EBCDIC made ASCII a challenge, let alone SICIs. We kept a close eye on the nascent Unicode.
Breathing Room
In 2017 the change of DOI display guidelines from http://dx.doi.org to https://doi.org shortened each DOI by 2 characters, buying us some time. But eventually we knew we had to upgrade to something more modern.
So we migrated to 5¼ inch floppy disks.
At 640 KB per disk these were a huge improvement. We could fit around 20,000 DOIs on one floppy. Today we only need around 10,000 floppy disks to store all of our DOIs (not the metadata, just the DOIs). Surprisingly this only takes about 20 metres of shelf space to store.
The move to working-from-home brought an unexpected benefit. Staff mail floppy disks to each other and keep them in constant rotation, which produces a distributed fault tolerant system.
Persistence Means Change
But it can’t last forever. DOIs registration shows no sign of slowing down. It’s clear we need a new, compact storage medium. So, after months of research, we’ve invested in new equipment.
Today we announce our migration to 3½ inch floppies.
If it goes to plan you won’t even notice the change.