Homework on Mempool - Questions

[Jmsn]

1 - The mempool is where the unconfirmed transactions wait to be included in a block by a miner.

2 - The mempool will grow bigger

3 - Miners mine for a fee, so they choose the transactions in the mempool with the highest fees first because they can include only a limited number of transactions in the block they are entitled to create, which is not necessarily equal to the number of transactions available in the mempool. So a bigger mempool implies longer waiting periods to get a transaction validated, unless you offer higher fees to get a transaction picked up quicker. The result is an increase in fees.

[tcoltman]

• What is the mempool?
  All unconfirmed transacitions for minors to add to the block
• What happens if the miners can’t keep up with the rate of the new transaction?
  mempool grows
• How does a growing mempool effect transaction fees?
  Mempool gets larger, confirm process needs longer, Miner always goes first for the highest transaction fee, so the Transaction fees will increase.

[nick_bell2017]

• Mempool is short for memory pool and is where all transactions that are valid are stored by nodes until they are picked up by a miner, add to a block and appended to the blockchain.
• If the miners cannot keep up with the amount of transactions the time it takes to confirm a transaction will increase, 1. because there are more transactions to confirm and 2. as the miners will be choosing transactions with higher fees.
• As above a larger memepool results in longer confirmation times and higher fees.

[David_Walsh]

@ivan

• What is the mempool?
• What happens if the miners can’t keep up with the rate of the new transaction?
• How does a growing mempool effect transaction fees?

1. Mempool is the data structure where unconfirmed transaction are put by nodes on the network.

2. They mempool will grow causing delays in transactions being confirmed. Transactions with the lowest fees might experience the longest delay.

3. A Growing mempool would put an upward pressure on the price of fees as there would be more demand for the limited space in the new blocks being mined.

[CocoaCrypto]

1- A mempool is a data structure that each node has, which stores unconfirmed transactions. Although the transactions all follow the protocol and make sense for the network of nodes, they just haven’t been sent to the blockchain to be confirmed yet. The mempool of each node may look different because information takes time to go through the entire network of nodes, therefore, a few of them might not have received the information (transaction) yet, thus resulting in differences in their mempools. Eventually all of the nodes will have the information in their mempools.

2- It would take longer for them to put this transaction into the blockchain.

3- All I can say here is that transactions are picked from the mempool according to how high their fees are, since miners are financially incentivized. Perhaps the more transactions that are waiting in the mempool, the more money the miners will collect.

[tanyiakandohla]

1 Mempool

This is the unconfirmed transactions held at a node awaiting a miner to confirm the transaction and add it through blockchain.

2 if miners can’t keep up with the Mempool
I would assume that the wallets would adjust transaction fees to cope with control flow and hash Difficulty/rate would be adjusted so that the mining rate or blockchain addition rate would be kept more or less consistent.

3 if the mempool grows then the most attractive transaction fees will be choosen. Therefore transaction fees would have to compete for miner validation and become more attractive or higher.

[AJade]

1. What is the mempool? The pool of unconfirmed transactions in the network.

2. What happens if the miners can’t keep up with the rate of the new transaction? The mempool builds up

3. How does a growing mempool effect transaction fees? It will increase fees overall and increase competition

[sweeesh]

1- The mempool is a growing list of unconfirmed transactions that a node believes makes sense.

2- When there are more transactions than blocks can be mined the mempool will grow in size and the fee per byte will increase.

3- A growing mempool will force people to outbid each other for the highest priority for transaction confirmation.

[Cryptojuice]

1. a list of all unconfirmed transactions
2. the Mempool gets bigger. The miners prioritize transactions with higher fees.
3. fees will go up

[Gemstar]

1. The mempool is a data structure containing a list of unconfirmed TXs that each node has. When these TXs are taken from mempool and put in the block by Miners, that TX removed from mempool decreases its size by each block produced in the chain at 10-min. intervals.

2. If miners can’t keep up with the rate of the new transaction, mempool (of unconfirmed TXs) grows till TXs are picked and put in the block by Miners.

3. A growing mempool increases transaction fees as Miners prioritize and handle transactions with highest fees first. Since Miners are concerned by how much satoshis they make for each block and how much space & byte the transaction will take from their block, they’ll take the TX that gives them more satoshis for the space it takes in the block.

[Fabrice]

@tanyiakandohla

if miners can’t keep up with the Mempool
I would assume that the wallets would adjust transaction fees to cope with control flow and hash Difficulty/rate would be adjusted so that the mining rate or blockchain addition rate would be kept more or less consistent.

It has nothing to do with the difficulty or hashrate. This is just about how hard it is to mine a valid block.
If miners can’t keep up means that there are more transactions coming into the mempool than miners can confirm on the blockchain. So the mempool will grow bigger in size. In these busy times the average fee to get your transaction confirmed fast Enough will increase because users are basically bidding for blockspace. If your transaction is not urgent (for example sending to your own address, you can still use a low fee. But then it can take days until it gets confirmed. Some wallets have the option RBF (replace by fee) so if your transaction doesn’t get confirmed in the timeframe you want, you can boost it with more fee.

[Fabrice]

@CocoaCrypto

All I can say here is that transactions are picked from the mempool according to how high their fees are, since miners are financially incentivized. Perhaps the more transactions that are waiting in the mempool, the more money the miners will collect.

Yes, miners will pick transactions from the mempool based on sats/byte. Off course they will pick transactions with highest sats/byte first. If a miner successfully mines a block he will get the block subsidy + all transaction fee’s in that block.

[Fabrice]

@RLion

May i ask a question about wallets ?

Is it so that ALWAYS ALL UTXO inputs are used to create a new transaction or only a few to have enough balance together to create the new transaction. Ivan explained that all inputs are used but that makes no sence if 1 UTXO has more than enough balance. Thanks

You only need to pick enough utxo’s to cover the amount. If you have an utxo that is big enough, then this 1 utxo is enough.

[RLion]

Thanks, that was not clear from the video for me.

RLion

[jwhite]

1. The mempool is the list of unconfirmed transactions each node has. Each node first validates the transaction you broadcast to make certain it’s following all of the rules. Then, it is added to the mempool with all other unconfirmed transactions.

2. The mempool grows which causes longer wait times for confirmations.

3. If the mempool grows in size and causes longer confirmation times, fees will rise. Miners are financially incentivised and choose/prioritize transactions will higher fees. If confirmation times are lengthened, people will have to pay more in fees to get their transactions chosen/prioritized.

[Duff]

1. What is the mempool?
Unconfirmed transactions waiting to be picked up by a miner to be put in a new block.
2. What happens if the miners can’t keep up with the rate of the new transaction?
Then the left over transactions get stuck in the mempool until they can be put in a new block.
3. How does a growing mempool effect transaction fees?
It increases the fee as miners will pick the transactions with the highest fees.

*One question, most phone wallets do not allow you to choose your fee rates, correct? If there are any, which ones do? Basically my understanding is desktop wallets like Electrum allow for you to choose the fee. Although its always best to check the latest on the mempool so your transaction does not get stuck.

[gllan005]

1. A copy of a list of unconfirmed transactions sent out to each node.
2. The meme pool will grow with new unconfirmed transactions and fee will increase.
3. Transaction fees increase as well as the competition to move you transaction on the next block.

[cryptomarls]

1. What is the mempool?
2. What happens if the miners can’t keep up with the rate of the new transaction?
3. How does a growing mempool effect transaction fees?

A1. The mempool is where unconfirmed transactions are held until the transaction is mined. every node including the miner has a mempool.

A2. The mempool just gets bigger in size.

A3. Transactions that are bigger in size (bytes) will cost more because it takes up more space on the block.

[Statch]

1. A Mempool is where all transactions are held waiting to be picked up and put into a block by miners.
2. If miners can’t keep up then a backlog will build up, transactions will take longer and transactions with higher fee’s will be put into the block first pushing up transaction fee’s.
3. a Larger mempool means there is more competition for transactions to be confirmed. Miners will always pick up transactions with the highest fee’s per byte pushing up the price.

[wafflemakr]

Hi there!! Yeah, some wallets don’t let you specify the fee, but some others, like mycelium, they do let you. Most user won’t be able to determine which is the best fee, so the wallet just put the one they think fits the most.

Hope that answers your question!

Felipe