- A Terminal Total Difficulty (TTD) of 50000000000000000 was selected for the Ropsten merger.
- Stakeholders and node operators must manually replace the TTD in their execution and consensus layer clients before June 7, 2022.
- Proof-of-work testnets can have volatile hash rates and the exact timing of the merge on Ropsten is difficult to accurately predict. Assuming there are no unexpected hash rate fluctuations, we expect the merge to occur around June 8 and 9, 2022.
- Note that synchronizing a runtime layer client to Ropsten can take several hours or even days, and is required to browse The Merge.
Background
Earlier this week, the Ropsten testnet transitioned to proof-of-stake was announced. Due to hash rate instability on proof-of-work testnets, client builds supporting the upgrade were configured using an artificially high hash rate. Terminal Total Difficulty (TTD). This ensured that the merge could not be triggered before the Ropsten beacon chain was ready.
Yesterday, at the slot 24000the Bellatrix upgrade activated on the Ropsten beacon chain, priming the network to go through The Merge. A new TTD value of 50000000000000000 was chosen to trigger the transition.
Node operators and stakeholders must update this manually TTD value on their execution and consensus layer clients before the network reaches this total difficulty. The current total network difficulty is part of the block header and can be obtained by querying your node or visiting a block explorer.
Assuming there are no unexpected changes in the network hash rate, we expect this total difficulty value to be reached, and TTD to be exceeded, around June 8-9, 2022.
Ropsten Fusion Client Versions
To complete the full terminal difficulty replacement, node operators and stakers must be running the following client versions or newer versions. Note that the consensus and execution layer clients must be fully synchronized before merging, and the execution layer clients may take several hours or even days to do so.
Consensus layer
Execution layer
Canceling Full Terminal Difficulty
To activate The Merge at the right time, node operators and stakers must replace both their execution and consensus layer clients Terminal Total Difficulty (TTD) value to 50000000000000000.
Here are instructions for doing this with each client:
Execution layer
Bésu
- If you are using TOML configuration files, add the following line:
override-genesis-config=(“terminalTotalDifficulty=50000000000000000”) - Or, when starting the node using the CLI, add the following flag:
–override-genesis-config=”terminalTotalDifficulty=50000000000000000″
Erigon
- When starting the node using the CLI, add the following flag: –override.terminaltotaldifficulty=50000000000000000
Go Ethereum (geth)
- When starting the node using the CLI, add the following flag: –override.terminaltotaldifficulty 50000000000000000
Void Spirit
- When starting the node using the CLI, add the following flag: –Merge.TerminalTotalDifficulty 50000000000000000
- This can also be set in your customer’s account configuration file Or environment variablesby defining the TerminalTotalDifficulty value to 50000000000000000
Consensus layer
Lighthouse
- When starting the node using the CLI, add the following flag: –terminal-total-difficulty-override=50000000000000000
North Star
- When starting the node using the CLI, add the following flag: –terminal-total-difficulty-override 50000000000000000
- For more information, see this blog post.
Nimbus
- When starting the node using the CLI, add the following flag: –terminal-total-difficulty-override=50000000000000000
Prism
- When starting the node using the CLI, add the following flag: –terminal-total-difficulty-override 50000000000000000
- This can also be defined in the config.yaml file by updating the TOTAL_TERMINAL_DIFFICULTY value in your configuration directory and restarting your client.
Teku
- When starting the node using the CLI, add the following flag: –Xnetwork-total-terminal-difficulty-override=50000000000000000
FAQs
As a node operator or staker, what should I do?
As mentioned in the Ropsten merger announcementNode operators and stakeholders on Ropsten should update their execution and consensus layer clients to the versions listed above or the latest.
Once this is done, node operators and stakers must manually replace the Ropsten Terminal Total Difficulty (TTD) value on both their execution and consensus layer client using the commands listed above.
Finally, make sure your execution and consensus layer clients are fully in sync before The Merge. This may take up to several days for runtime layer clients.
As an application or tool developer, what should I do?
With The Merge going live on Ropsten, now is the time to ensure your product performs as intended during the proof-of-stake transition and in a post-merger context. As explained in a previous messageThe merger will only have a minimal impact on a subset of contracts deployed on Ethereum, none of which are expected to be broken. Additionally, the lion’s share of user API endpoints remains stable (unless you use specific proof-of-work methods such as eth_getWork).
That said, most applications on Ethereum involve much more than on-chain contracts. Now is the time to make sure your front-end code, tools, deployment pipeline, and other off-chain components work as expected. We strongly recommend that developers perform a full cycle of testing and deployment on Ropsten (or Oven) and report any issues with the tools or dependencies to the maintainers of those projects. If you are unsure where to open an issue, please use this repository.
As an Ethereum user or Ether holder, do I need to do anything?
No. The Ethereum mainnet is not affected by this testnet. Further announcements will be made on this blog ahead of the mainnet transition.
As a minor, do I have to do anything?
No. If you are mining on the Ethereum or Ropsten mainnet, you should be aware that each network will operate entirely under proof of stake after the merge. At this point, mining will no longer be possible on the network.
This is expected around June 8-9, 2022 on Ropsten and later this year for the Ethereum mainnet.
When to merge?
Since this article was published, the transition date for Proof of Stake on the Ethereum mainnet has been not been settled. Any source claiming otherwise is likely to be a scam. Updates will be posted on this blog. Please stay safe!
Assuming no issues are found with Ropsten, once client testing is complete, Ethereum’s other testnets will operate via The Merge. Once Goerli and Sepolia successfully transition and stabilize, a slot height will be chosen for the Bellatrix upgrade on the Beacon Chain and a terminal total difficulty value will be defined for the mainnet transition. Customers will then release versions enabling The Merge on mainnet. These will be announced on this blog and in other community publications. The image below illustrates this process:
Note that this assumes that each step goes as expected. If issues are detected at any point during the process or test coverage is deemed insufficient, these will be resolved before continuing with the deployment process.
Only then will it be possible to estimate the exact date of The Merge.
In other words, 🔜.
