No problem, let me send you a few GIOTA to play with. — G. Mandolfo

The Testnet: A Brief History

Unfortunately, those aren’t real IOTA. As some of you who follow Discord rather closely may know, the IOTA Foundation operates a separate Tangle we call simply “the testnet”. Indeed, the name is almost self-explanatory: it’s a version of the Tangle meant for testing — apps, new versions of IRI, bug fixes, and so on. Or at least, it was meant for those things. As the testnet became more widely used — by exchanges for on-boarding to IOTA, by the Data Marketplace, and by other participants and collaborators developing IOTA related software — it became less and less operationally tenable to break it on a whim.

In fact, the testnet has not lived up to the name at all in recent months — it’s more of a Mainnet Lite. Meanwhile, Mainnet has frequently been the site of much community testing, for new IRI-compatible node software, tip selection algorithms, and more. While this shows the awesome power of permissionless innovation, a better solution is needed.

Devnet, Spamnet, and More

For all of those reasons, we are ready to introduce the latest improvements! We’ve already started on some, and the rest will be happening soon:

The testnet will now be known as Devnet . Devnet will run the latest stable version of IRI, and allow developers to work on their apps without getting in their way — or costing them any real tokens.

. Devnet will run the latest stable version of IRI, and allow developers to work on their apps without getting in their way — or costing them any real tokens. We are introducing Spamnet , already live behind a convenient load balancer at nodes.spamnet.iota.org . You don’t need even need to run a node to participate on Spamnet, so go ahead and start spamming — MWM 14 , please! We are currently running 7 nodes behind the load balancer, and we will be able to add nodes as needed to see the network effects we are interested in. There’s also a visualizer and public dashboard to help with collecting stats and analyzing spam techniques.

, already live behind a convenient load balancer at . You don’t need even need to run a node to participate on Spamnet, so go ahead and start spamming — , please! We are currently running 7 nodes behind the load balancer, and we will be able to add nodes as needed to see the network effects we are interested in. There’s also a and public to help with collecting stats and analyzing spam techniques. At least two more testnets are coming soon: Canarynet and Testnet1 (leaving room for a Testnet2 as you can guess). Canarynet will be specifically for testing new versions of IRI before they hit the Mainnet, and the other testnets would be for… well, everything else! We’ll probably come up with some better names as they are released, but for now it’s enough to know that they are on the way.

All of these new Tangles will be hosted the same as Spamnet at iota.org, and come with their own visualizers and dashboards. In fact, separating out testnets for different purposes is nothing new — it’s fairly common practice in other DLT projects, and it’s about time we enable these networks for our own community!

Research Focus

We hope that these testnets will provide a better R&D experience for everyone — we will certainly be making good use of them ourselves! While simulations and local testing have worked in the past, they are far from ideal when we need concrete research results based on real-world data.

Importantly, in the coming weeks and months, by leveraging these public networks (and with your help in growing them!), we will now be able to test and validate significant improvements to the tip selection algorithm. First and foremost, we are looking at two of the more prominent network phenomena that have recurred regularly in recent months: blowballs and CTPS variance.

Blowballs occur when a large number of transactions reference a single specific transaction, which typically turns out to be a milestone. This prevents the Tangle from growing organically, by “trapping” incoming transactions inside of the blowball. [Image from IOTA StackExchange]

CTPS variance is the rate at which the ratio between confirmed transactions per second (CTPS) and overall TPS varies. The CTPS:TPS ratio should be more or less stable over time, not a wave pattern as seen in the above image.

Once these issues are better understood and the bugs worked out, we will be able to begin experimenting with higher TPS, to continue exploring the Tangle, and to keep pushing IRI to the limit.

Having this variety of large, public testnets will allow both the Foundation’s own R&D teams, as well as those of our developer community, to work and experiment in more realistic environments, to speed up the development workflow, and to help close the gap between a local development machine and the IOTA Mainnet.

Special thanks to the various dev teams responsible for organizing this effort.