Homework on Mempool - Questions

Blockchain and Bitcoin 101
#1246

Hi @Boba-Kush
Your third answer is not exactly accurate. The increased fees will not speed up the mining process.
Setting up a higher fee will only guarantee that your transaction gets picked up by the miner faster than transactions with lower fees.

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#1247

  1. It’s a record of pending TXs (validated, yet unconfirmed) in the data structure of a node (a full node, miners included). The content of the mempool of a node will be propagated to their peers, meaning that all the mempools in the network are not synchronized, however an unconfirmed TX will eventually reach all mempool in the network. An unconfirmed TX will stay in a mempool waiting for a miner to choose to confirm it. Once confirmed, the TX will be removed from the mempool and eventually removed from the other mempools too, when the information reaches all the nodes. All miners have their own mempool, however they can query (other) nodes to share the TXs pending in their mempool.

  2. The mempool and the fee will increase, accordingly. And the TX speed will slow down accordingly. The slow speed can be bypassed if you are willing to pay the highest fee in the market in order to be prioritized by a miner.

  3. Since a block has a limited size of bytes and about 10 minutes to be produced, a miner can only fit so, so many TXs (bytes) in each block they produce. A growing mempool will spike the fee market competition. The confirmations never stop; however, some ‘clients’ will experience that their TX took forever to be confirmed. This is due to all TXs, with much higher fee, that were prioritized by the miners. The miners are incentivized to do so, since they get to keep the fee. Thus, selecting from the mempool the more profitable TXs, first. i.e. the TXs that will give them more sat/B (satoshi per byte), since the blocks will have ‘wasted’ free space too (due to its size limits vs TXs’ byte fit).

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#1248

1. What is the mempool?
The mempool is a data structure where unconfirmed transactions are stored.

2. What happens if the miners can’t keep up with the rate of the new transaction?
A queue of transactions will be formed

3. How does a growing mempool effect transaction fees?
Because miners choose the transactions with higher fees, you have to put higher fees to let your transaction skip the queue.

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#1249

Mempool

  1. What is the mempool?
    The mempool is where all of the transactions that have not been confirmed sit. The nodes each have a mempool themselves, showing the unconfirmed transactions, which are waiting to be picked up by miners.

  2. What happens if the miners can’t keep up with the rate of the new transaction?
    Miners have many transactions to choose from in the mempool. Sometimes, with high network usage, the miners are not able to keep up and pick up all ofthe transactions in the mempool. The more transactions that occur in the mempool, the larger the mempool becomes, which results in higher transaction fees when sending a transaction.

  3. How does a growing mempool effect transaction fees?
    When the mempool becomes larger is size, the transaction fees will rise. There is only a certain amount of transactions that miners can fit into a block, that they are creating. To have your transaction appended into a block at a faster rate, setting a higher fee, will result in miners picking up your transaction before other transactions. There is a financial incentive for miners, so typically the miners will choose the higher fees.

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#1250

Thanks for your support, appreciate that! Nope, it’s actually opposite - the more i study, the more I realise I know nothing :rofl: I’m currently stuck in javascript and need more material to practice to get the idea how this language works, thanks!

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#1251

Hi there!! What question are you answering here? What happens to tx fees when mempool grows?

#1252

Maybe not skip it, but to have better chances of getting your transaction confirmed!

#1253

  1. The mempool is where all unconfiremd transcations are collected by nodes on the network. The nodes are storing all these unconfirmed transactions for a miner to pick them up and verify them.

  2. If miners cannot keep up with the rate of transactions, there will be a queue and transactions fees will be higher. This is because if you want your transcation to be verified quicker that means that miners who ultimately will pick the transaction with the higher fee will pick you first.

  3. The bigger the mempool is the higher the transaction fees will be.

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#1254

The unconfirmed ones are waiting to be included in the new block

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#1256

I just meant to be funny!
But if I understood this correctly: miners prioritize transaction with higher fees so if you put the highest fee of all in your transaction you can be pretty sure that you practically “skip” the line, and your transaction be processed as soon as possible. (unless a lot of other transactions put a higher fee than yours)

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#1257

Hi Wafflemaker,

monetary motivation. Increased fees bring in more miners and node operators because of the increased profit motive.

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#1258

  1. The mempool is a node’s holding area for pending transactions waiting to be included into a block. It is a collection of unconfirmed transactions seen by the node, so that the node can choose which ones it wants to put into the block.

  2. The mempool grows in size when miners have difficulty keeping up with the rate of transactions.

  3. Transactions fees rise with the size of the mempool, because that is how transactions “compete” with each other to be put into the block first. Miners like to collect the most profit they can when creating a block. As an addendum to the question, when miners create a block they like to include as many bytes as possible while also choosing transactions with highest fees. The fewer the inputs/outputs there are in a transaction, the fewer the bytes involved and therefore more small transactions means more that can be included in the block. The most basic way fees are determined is satoshis per byte, but when the mempool increases in size the competition factor becomes more prevalent.

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#1259

:joy: Yeah, so you are correct, then! I bet there are some times when you really need to skip the whole line!

#1260

Correct!! Although, as you mention, they look for satoshis/byte, so a miner will like a transaction small in size but if the fees are very low, maybe they will leave this one for later.

Felipe.

#1261

Thanks! I should have been a little more specific, in that what matters most is getting the highest profit when creating the block. It can be a balancing act between the amount of bytes and the fees available.

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#1262

You are welcome!! You are doing great!

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#1263
  1. Data structure in nodes that has all the unconfirmed transactions waiting to be picked up by a miner
  2. The mempool increases in size
  3. Transaction fees will go up as people increase the incentive to miners for them to pick up their unconfirmed tx and add it to the next block
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#1264
  1. Mempool is a list of all unconfirmed transactions.
  2. The mempool will grow in size and transactions with higher fees are prioritized.
  3. A growing mempool will likely increase fees as people try to prioritize there transactions into the next block by paying more fees.
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#1265

Homework on Mempool:

  1. A Mempool is where unconfirmed transactions are stored until they are mined into a bock.
  2. The Mempool will grow, transaction time and fee’s increase.
  3. The miners will take the transactions with higher fee’s first forcing other transactions to increase there fee.
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#1266

1.- The mempool is a bag of transactions that gets filled to later on be taken by the miners so they can mine it and add it to the blockchain.

2.- There is congestion in the network and transactions may wait longer for confirmation.

3.- Fees may go up as the miners will prioritize transactions with higher fees.

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