The Ethereum network is scheduled to undergo an upgrade at block number 9,069,000 on Saturday, December 7, 2019. Please ensure you upgrade your node before Sunday, December 1, 2019 to accommodate the variable block times.
For Istanbul node statistics and a countdown timer, visit https://ethernodes.org/istanbul. etherscan.io also provides a countdown timer at https://etherscan.io/block/countdown/9069000. Real-time monitoring of the network upgrade can be done at http://forkmon.ethdevops.io/.
Istanbul refers to the name of this network upgrade, with previous upgrades being named Costantinople, Spurious Dragon, and Byzantium.
If you are an Ethereum user or ether holder using exchanges like Coinbase, Kraken, or Binance, web wallet services like Metamask, MyCrypto, or MyEtherWallet, mobile wallet services like Coinbase Wallet, Status.im, or Trust Wallet, or hardware wallets like Ledger, Trezor, or KeepKey, you do not need to take any action unless instructed to do so by your exchange or wallet service.
For node operators or miners, it is necessary to download the latest version of your Ethereum client. Please note that Harmony (ethereumJ) is now a deprecated client and will not support Istanbul. Besu is a mainnet compatible Ethereum client written in Java.
Failure to participate in the upgrade as a miner or node operator using outdated Ethereum clients will result in syncing to the pre-fork blockchain, leaving you on an incompatible chain following the old rules and making it impossible to send ether or operate on the post-upgrade Ethereum network.
A network upgrade in Ethereum refers to a change in the underlying protocol, introducing new rules to enhance the system. Due to the decentralized nature of blockchain systems, network upgrades present challenges that require cooperation and communication with the community and developers of Ethereum clients to ensure a smooth transition.
During a network upgrade, once the community agrees on the changes to implement, protocol changes are integrated into Ethereum clients such as geth, Parity, and Nethermind. Activation of the protocol changes occurs at a specific block number. Nodes that have not been upgraded will be left on the old chain with the previous rules.
The changes implemented in Istanbul are defined using Ethereum Improvement Proposals (EIPs) which outline standards for the Ethereum platform, including core protocol specifications, client APIs, and contract standards. EIP-1679 catalogs the specific changes going into Istanbul. You can also refer to an article from the Ethereum Cat Herders for a summary of all changes and details on the extensive testing process.
Lastly, a big thank you to the Ethereum community and developers across all clients and platforms for their input, thoughts, and contributions.
DISCLAIMER: This is a highly technical and evolving space. If you choose to implement the recommendations in this post and continue to participate, please ensure you understand how it impacts you. Be aware that there are risks involved, including unexpected bugs. By choosing to implement these recommendations, you assume the risks of the consequences. This post and recommendations are not a sale and do not create any warranties regarding the Ethereum network or the Ethereum clients mentioned.