Ethereum is an open-source blockchain-based software platform that supports thousands of decentralized apps (DApps) and its native cryptocurrency, Ether (ETH), which can be sent and received globally without the intervention of a third party.
Ethereum was created in 2013 by Russian-Canadian programmer Vitalik Buterin as a platform for self-executing, persistent, and immutable decentralized applications (DApps) with applications ranging from banking to gaming and art.
DApps are frequently referred to as smart contracts, which are Ethereum transaction protocols that perform particular functions and operations, like as transaction processing, automatically and in accordance with predefined conditions and agreements. Sending a transaction, canceling it, or resolving a pending Ethereum transaction are all steps that are required for smart contracts to execute properly.
What is an Ethereum transaction?
Transactions are account-to-account instructions that are cryptographically signed.
The Ethereum network supports two primary transaction types: contract deployment transactions, which are transactions that do not require a recipient, and ordinary transactions, which are the simplest sort of transaction used to send ETH between wallets.
A standard Ethereum transaction that is submitted includes the sender’s identity or the signature generated when the sender’s private key signs the transaction, confirming that the sender authorized the particular Ethereum transaction. A normal Ethereum transaction has a receiving address, an amount of ETH to transfer from sender to recipient, information on the Ethereum transaction fee, and an optional field for including arbitrary data.
Ethereum transactions must be mined in order to be valid, and the sender must pay a fee.
Ethereum miners validate authentic transactions in exchange for a reward for their contribution to the creation of new ETH. A transaction is considered validated when a miner solves a cryptographic (mathematical) puzzle. Ethereum, like Bitcoin (BTC), uses a proof-of-work (PoW) scheme to guard against cyber assaults by a single person or group.
The requirement that users pay a transaction fee when utilizing the blockchain safeguards the Ethereum network against careless or harmful computing processes, such as users flooding the blockchain with meaningless transactions.
Ethereum transaction lifecycle
An Ethereum transaction goes through a series of states, starting with the unknown state until it is confirmed in a block.
Unknown: The unknown state refers to a transaction that the network has not seen or processed.
Pending: When a transaction is in the pending state, it is waiting for miners to pick it up and process it which is called a pooled transaction, also said to be called the “mempool.” Because miners prioritize greater gas prices, transactions with lower gas values may languish in the pending stage for an extended period. The transactions with the lowest gas prices may never be picked up, leaving them “stuck” in the pending status eternally.
In block: When a miner successfully selects a transaction and mines it within a block, it advances to the in-block state. In-block transactions are called mined transactions. If the block is forked, a transaction in the block may return to the pending state. When a mined transaction (i.e., one in the in block state) is reversed by the network, it is known as a forked transaction.
Replaced: When either of the following circumstances occurs, a transaction can be moved from the pending to the replaced state:
- A new transaction with the same nonce from the same sender enters the in block state, or
- Another transaction with the same nonce and a 12% higher gas price enters the pending stage, this time from the same sender.
Ethereum Transaction confirmations
The number of confirmations for an Ethereum transaction is the number of blocks created since the first block containing this transaction.
A pending Ethereum transaction requires a certain amount of confirmations. The higher the gas fee, the more certain it is that the transaction was processed and recognized by the Ethereum network.
Recent blocks can be reorganized to create the illusion of a failed transaction. Even yet, the transaction remains legitimate if it is included in another block. With each succeeding mined block, the risk of reorganization reduces; that is, the more confirmations, the more immutable the transaction becomes.
Ethereum transaction confirmations
A transaction fee is a cost that users pay to block miners in exchange for their services. It is used to send a specific Ethereum transaction to the blockchain.
The Ethereum blockchain transaction fees are also referred to as gas fees, as they are related to gas, a pricing mechanism employed on the Ethereum network that refers to the computation required for a miner to process a transaction. The computing activities associated with a transaction are quantified in terms of the cost of gas.
On the other side, each unit of gas is assigned an ETH price. While the complexity of a transaction dictates the cost of gas, users can specify their own pricing and gas limit, or the maximum number of gas units utilized during the transaction.
What is a nonce?
A nonce is an acronym for „number used only once,“ and refers to the total number of confirmed transactions made from a certain Ethereum address.
Due to the fact that Ethereum wallets can broadcast numerous transactions from an account without significant delay, a nonce computation is considered an essential mechanism for determining which transaction is processed first. Typically, Ethereum wallet software maintain nonces on behalf of their users.
How to cancel an Ethereum transaction?
There are two primary ways to cancel a pending Ethereum transaction: in-application cancellation and custom nonce setting.
Typically, Ethereum transactions take hours or even days to complete when users submit with a low gas price. As a result, users frequently need to modify Ethereum transactions.
When resolving this issue, users must keep in mind that cancellation is possible only while the transaction is still pending on the network. They should begin by determining whether the transaction is still pending in a block explorer. Specifically, to paste the transaction hash, commonly known as an Ethereum transaction ID, and to ensure that even if a block explorer indicates that the transaction is „waiting,“ users can still attempt to cancel it.
The simplest method of canceling a stalled Ethereum transaction is by in-application cancellation, which requires users to exit the Ethereum wallet application, close their browser, reopen it, and log back in.
If these actions do not resolve the issue, the second method will be used.
Canceling a pending Ethereum transaction with a custom nonce requires the user to generate a 0 ETH transaction with a high gas price to their own address in order to avoid a previous transaction becoming stuck. Prior to sending this second transaction, users must take note of the nonce used by the initial pending transaction and then reuse that nonce.
If users have numerous pending Ethereum transactions, they should prioritize the oldest one or the one with the lowest nonce value.
How to speed up Ethereum transaction?
By providing gas to a delayed Ethereum transaction, users can accelerate it. This step may encourage Ethereum miners to prioritize the cryptocurrency.
If an Ethereum user sets a gas price that is too low, other users have the opportunity to outbid this first bid, and the transaction remains pending. When a transaction becomes stuck, the network delays confirmation of subsequent transactions from the same wallet address until the miner confirms the initial transaction.
In this case, users can either wait for the network to agree to perform the transaction at the specified price or resubmit the transaction with a higher gas tax.
By using the „speed up“ button in their Ethreum wallet, they should be able to expedite the transaction’s processing.
If the preceding procedure does not work, customers can access the advanced tab and manually adjust the gas price.
After all, users are recommended to examine the transaction’s hash on the blockchain explorer to see whether it was successfully executed.
They will need to wait a few minutes and refresh the page if the transaction does not appear instantly.
Can Ethereum transactions be reversed?
Ethereum wallets are unable to undo previously executed Ethereum transactions.
When Ethereum users transfer funds to the incorrect address or transmit the incorrect quantity of ETH, the transaction may be canceled while it is still pending. When a transaction is confirmed and shown as „Successful,“ it cannot be reversed because it has been added to the next block. Because the Ethereum blockchain is immutable, the data inserted into blocks is irreversible. With this in mind, it is critical to double-check the transaction details before pressing the send button.
Finally, it’s worth mentioning that some blockchain businesses have already devised techniques for reversing Ethereum transactions.