Homework on Mempool - Questions

Blockchain and Bitcoin 101
#1287

Correct!! Miners are also nodes, so they will have their own mempool. Just a minor clarification, as you mentioned node and miner separately…

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#1288

Hello Mauro,

I have a question regarding this mining sobject.There are many miners ,an done of them gets the reward and plus the tx fees.If this is the fastest

How come next time there is another miner who gets the reward?Is the second one and third one so forth,get the new rewards and creates the new block?

Thanks

Jak Aciman

globallyours

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#1289
  1. Mempool is a list of transactions waiting to be confirmed, and finally added to the block by miner.
  2. As block size is limited, miners will prioritize the transactions from mempool which are with highest fees, and put just them into a block. Lower fee transactions must wait longer to get into the block.
  3. I would say no effect. Fee is being determined by my own wallet, isn´t it? Growing mempool will effect into longer transaction time as far as I understand.
#1290

1.The mempool is a place that unconfirmed transactions wait for the miners to pick up and add to the next block.
2. The mempool grows larger and slower.
3. The miners take the transaction with the higher fee. That happens because of the competition of the miners to get to the transaction first

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#1291
  1. Mempool is where all broadcast transactions that are unconfirmed are stored
  2. the size of the mempool grows and transactions can take longer to get recorded on the block
    3.the fees goes up as there is increased competition to get on the block , transactions paying higher fees get picked up first
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#1292
  1. What is the mempool?
    Is the node’s holding area for all the pending transactios. Consist of uncomfirmed transactions.
  2. What happens if the miners can’t kept up with rate of the new transaction.
    The miners will choose the transactions with the highiest fees from the mempool to put in the main block.
  3. How does a growing mempool affect the transaction fee?
    When mempool size spikes it increase the transaction fees.
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#1293

You are right, you or your wallet can still determine the fees in the transaction, but if the mempool grows, and miners are choosing the ones with better fees, then if you keep sending transaction with the same fees as before, the confirmation time will be longer, or it might never be confirmed!

Hope this makes sense!

Felipe.

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#1294

  1. The mempool is where unconfirmed transactions are stored. Each node in the network has its own mempool.

  2. If the miners can’t keep up with the new transactions then the mempool will become crowded.

  3. As the mempool increases in size the fees will also increase because there will be a greater demand for transactions to be placed into the blockchain and miners always choose the transactions with the highest fees.

#1295

Answer:

  1. A Mempool is a computer space for holding unconfirmed transactions.

  2. The Mempool will just grow in size in the sense of more and more unconfirmed transactions are being pile up.

  3. When there is a growing mempool, miners can choose the largest byte size transaction to mine because the larger the size, the higher the transaction fees will be.

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#1296
  1. The mempool is a list of unconfirmed transactions. It is like a waiting-room where transactions that have been berified by a fullnode are stored until they are picked up by a miner for confirmation.
  2. If the miners can’t keep up then the mempool becomes too full and transaction processing time gets longer.
  3. Because of a backlog of unprocessed transactions, a growing memepool means higher transaction fees as you will have to offer more to get your transaction processed sooner.
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#1297

Each block has a new block reward + the transaction fees that were included in that block. So after 5 blocks we would have 31.25 new bitcoins created. (Current block reward is 6.25btc). The miner that solves the block the fastest is the one that gets the rewards. Once a new block has been found, the same process repeats over and over again. This creates the blockchain. :smiley:

#1298

Just because a transaction is larger it does not mean it will have a higher fee. In fact, I would say that a transaction with more inputs and outputs has a chance of giving less fees than the smaller ones. Let me explain:

Fees are set by the wallet using a unit of measurement called “satoshi per byte”. Satoshi per byte is the number that prioritizes transactions. If we have 2 transactions that have different sizes but both pay 2 satoshi per byte, they will have the same priority. But the larger transaction will still pay more in total fees. If a larger transaction wanted to match the same total fee as the smaller one, it would be have low priority… This is because we pay for each byte of information. If you are still confused why, please say so. We can take a look at a blockchain explorer for examples. :smiley:

#1299

Thanks Mauro,

I understood that.

What i dont understand is,if for example the first miner that solves the block fastest who gets the reward is like Ferrari.

Since Ferrari is the fastest how come it is not the same Ferrari who does not solve the next block and next block and the next block.

How come there are other miners who can pass Ferrari on the next race?

I am not sure if i explained myself correctly,i hope i did.

Thanks

Jak

globallyyours

1 Like
#1300

I understand you question now. This is because miners are “brute forcing” the nonce, in order to get the hash to be lower than the difficulty target. This means that they don’t have a destination like a car race. Its random. There is a chance that a miner with the lower hash rate finds the next block. But if you have more hash power, you are more likely to get the new block the fastest. But just because you have more hash power it will not guarantee a 100% success rate. I hope I made it a bit more clearer for you. :smiley:

#1301

Thank you Mauro for once again pointing out my misunderstanding on transaction fees. With the Satoshi/Byte explanation, it provides me a clear perspective on how a transaction is prioritize by miners. It took me a while to research on what it actually means, found the following while browsing through blockchain explorer and some other sites:

"Let us say a transaction pays 0.01 BTC for it to be included in the block. And another transaction pays 0.015 BTC. And they are 512 KB each. So the miner gets 0.01 + 0.015 = 0.025 BTC for mining this block.

Another case can be, 4 transactions pay 0.01 BTC each with the size of 256 KB (256 * 4 = 1MB), now the total fee for the block will go up to 0.04 BTC. So the miner will profit more by including these smaller 4 transaction to improve his mining fee."

Really appreciate your help and guidance in here ^^

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#1302

Exactly. The easiest way to choose which transactions are more profitable, is to look at their satoshi per byte. Your examples are good. Don’t forget that the miners also the the block reward, which is currently 6.25btc.

#1303

Thanks Mauro,

Now i understand better.

Jak

globallyyours

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#1304

  1. mempool is a list of unconfirmed transactions

  2. The mempool files up with pending transaction

  3. transaction fees go up

1 Like
#1305

No problem Jak. I am glad I was able to explain it to you. :smiley:

#1306

  1. When a wallet broadcasts a transaction, each node on the blockchain eventually receives these transactions and each node maintains a list of all transactions not yet confirmed. This list is called the MEMPOOL. Miners are incentivized to inquire/review these node mempools to consider whether to use them in constructing their next BLOCK based upon the sizes of the these unconfirmed transactions. Since miner’s fees are calculated on satoshi per byte, the size if bytes involved is important to miners. Once a transaction is included into a block and appended to the blockchain by a miner, it is considered “confirmed” and all such transactions will be removed from all node mempool lists at the next 10minute interval update.

  2. If the miner can’t keep up with the rate of a transaction being included into a Block and thus confirmed, he will lose the fee opportunity.

  3. A growing pool of unconfirmed transactions would give miners more to pick and choose from when constructing their Blocks to select those transactions with the largest amount of bytes since their fees are a function of satoshi per byte.