Ethereum Phase 3 Upgrade Progress: Construction of “Metropolis” is Halfway Completed, Ethereum Will Be More Useful

Ethereum has made it through its most difficult period and is heading toward the third of four planned development phases, further laying the foundation for the so-called “world computer.”

The next phase of ethereum’s development, called “Metropolis,” is a mix of various technical changes that may seem a bit confusing, but it will pave the way for future updates that will make ethereum even easier to use.

The upgrade is taking longer than expected, mainly because the Ethereum network suffered a DoS attack from an unknown attacker last year, which disrupted and destroyed transactions and projects being created on the Ethereum platform.

However, recent developer meeting minutes show that Ethereum upgrades are still ongoing, and some teams have almost completed the changes and are now preparing for testing.

Ethereum Foundation test engineer Dimitry Khokhlov told CoinDesk that development of the third phase is about halfway done.

So, what's next?

Improvement Proposal

First, developers need to finish coding these upgrades. Although this long-awaited release will not include major changes such as PoS or sharding, this phase incorporates about 10 Ethereum Improvement Proposals (EIPs).

All of these EIPs will reduce the amount of functionality hard-coded into Ethereum, paving the way for “abstraction.” The purpose of this, or the purpose of Ethereum itself, is to leave more room for application developers to make their own design decisions.

For example, EIP 86 allows users or application developers to protect account security as they wish.

A spokesperson for ethereum development startup Ethcore told CoinDesk that Parity — a popular ethereum client written in Rust — has implemented seven of the 10 EIPs but is currently awaiting clearer instructions as developers reach consensus on the changes that need to be implemented.

This approach of "rough consensus" is common in open source development.

The wait shouldn’t be long for Parity or Geth, as those projects are already resolved, but other projects using different programming languages ​​like Python and C++ may lag behind a bit.

Complex process

One tricky part is that all ethereum clients need to change in lockstep, regardless of the programming language they use.

The Ethereum Foundation’s Khokhlov has been using a tool called Hive to write tests to ensure not only that these clients can implement the changes correctly, but that all clients can reach consensus on the changes, because if all clients don’t follow the same rules, it could cause ethereum to accidentally split into multiple different networks (as happened last November).

As with previous development phases Frontier and Homestead, the switch to Metropolis requires a “hard fork” — meaning nodes or miners that fail to upgrade to the new blockchain will be left behind. Hard forks are controversial and are taken seriously because of the potential for an unexpected blockchain split.

However, given that this hard fork has long been part of Ethereum's technical development roadmap and was not a sudden decision, a split is unlikely to occur in traditional terms.

Still, these changes require extra caution, Khokhlov said:

“I’ve always had a hard time with the hard fork transition rules.”

In Khokhlov’s view, there are a lot of “ifs” around the corner when it comes to ensuring that users’ ether is safe in all circumstances.

For example, he must ensure that transactions on the new fork can only be used if the “gas limit” and transaction signatures are correct, and that opcodes that change from one fork to another do not disrupt the operation of the network.

“The more changes we make, the more checks the code needs, and the more logic that needs to be checked. But that doesn’t make the code clean.”

Many benefits

But when all the changes are complete, the Metropolis update could create better ethereum applications.

Stefan George, CTO of Ethereum prediction market Gnosis, told CoinDesk:

"Higher abstraction generally means higher flexibility."

For example, George said, this additional flexibility could allow recipients or middlemen to pay transaction fees rather than application users.

This could benefit users of Ethereum-based apps, such as a notebook. Normally, users would need to buy ETH to make changes, such as adding or deleting a note, but with the Metropolis upgrade, providers will be able to pay these fees, and users will be able to make changes without having to go through the extra step of buying ETH.

Ultimately, this will bring the Ethereum protocol closer to the traditional app store experience we are familiar with.

George said:

“I guess we’ll get more users using Ethereum services this way.”

George added that another change brought by Metropolis will also help solve some off-chain technologies, allowing data to remain on the main Ethereum blockchain, while improving performance and network scalability without compromising user security.

This adjustment will also once again give developers control over their app design.

As the Parity team put it:

“Metropolis is an important step that will improve the Ethereum protocol and enable some use cases that were not feasible before.”