Homework on Stale Blocks

Blockchain and Bitcoin 101
#442

  1. For a small timeframe there are now two correct versions of the blockchain. Some nodes might have blockchain one and other nodes have blockchain two. The following added block decides which blockchain will “survive”. The decision is based on proof of work which means the longest blockchain will be taken in terms of difficulty.

  2. A stale block is a block which was mined successfully (valid transactions, hashes etc.) but in time of being mined there was a second valid mined block. The stale block is the block which is then removed, because the next block is appended not to the “stale block” but to the other one. The transactions of the stale block getting back to the mempool.

  3. Stale blocks occur when two miners solve a block at the same time.

  4. To avoid and minimalize stale blocks you should wait for more than one block because then it can be ensured that all nodes are synched and every node have the same version of the blockchain.

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#443

1.The chain splits.
Miner (A) with the longer chain.
Miner (B) shorter version of the block chain.
Eventually the version with the longer blockchain wins (A). The block of Miner (B) gets dropped to the mempool.
2. It is a valid block that got dropped from the blockchain to the mempool because there is another version of the chain, without this block, that is longer.
3. When miners 1 and 2 create each a valid block at the same time. The version of the miner (1) that gets the next block will have the longer blockchain. Therefor the block of the other miner (2) gets dropped (stale block).
4. To make sure that the block has propagated through the network.

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#444
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The chain splits, the longest chain wins and the network drops the shortest one.
  2. What is a stale block?
    The block of the shortest chain dropped by the network
  3. How do stale blocks occur?
    Due to two miners mining a block at the same time, but only one can be accepted on the network.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Best practice is to wait for six confirmations to see if that chain has been accepted by the network.
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#445

  1. When miners solve a block at the same time we end up with two different blocks at the same block height so there are two versions of truth. Which one becomes the final blockchain is dependent upon the block the next miner decides to use to mine the next block.

  2. A stale block is a block that was at the same block height as another block but was on the shorter chain at the end so is no longer part of the block chain.

  3. Stale blocks occur when two miners mine the same block height with two separate blocks. One of these blocks will end up on the longer block chain and thus be the correct block for that block height, the other will be deleted from the blockchain and be considered a stale block.

  4. It is important to wait until you have more than one block confirmed so that you know your transaction isn’t on a stale block that will be deleted from the blockchain.

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#446

  1. If two miners are to have solved a block simultaneously, both blocks will be propagated until a new block is solved. The chain with the most proof of work will be maintained, and the transactions from the other chain will re-enter the mempool.

  2. A stale block is a block that has been dropped from the chain once a longer chain is established.

  3. Stale blocks occur once a chain with more proof of work is established. Once a part of the blockchain, these blocks will be removed. This is why many transactions will wait for multiple confirmations to validate the transaction.

  4. Waiting for multiple confirmations allows transactions to be validated since a transaction can still be dropped if the block becomes a stale block. Ensuring 6 confirmations will provide a highly trusted chain should there be multiple cases of stale blocks consecutively, regardless how unlikely.

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#447
  1. At first both blocks will be added to the blockchain with a separate connection.
    2.-3. A stale block is a block which was produced nearly the same time as another block, but as the
    succeeding block from another node was faster linked to the other block all the data from the
    stale block returned to the mempool.
  2. As it is a network around the world it takes time for confirmation of the block to be integrated to
    the blockchain . if there are at least 6 confirmations the new block is a valid block.
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#448

Hi,
1, The blockchain and miners keeps goin on with next blocks until one branch is faster then the other. Then the longer will be “true” one.
2, Stale block is the slower “guy” per question 1
3, When 2 blocks are mined at the same time- it can hapen because blockchain is all over the world so it takes some time to get info to the whole world ( all nodes). But in the meantime blockchain/miners keeps going.
4, Because one block could be the stale block ( one where my transaction is saved)… When this stale block is dispanded my transaction will go back to mempool. This cant go forever so its save to wait for more blocks to be done, so we are sure that our transaction is truly finished.

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#449

Thanks Fabrice. I understand it. Not sure why I typed it that way… Thanks for the catch!!

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#450

It’s not necessarily about speed. If 2 miners mine at the same blockheight, you’ll end up with 2 valid versions of the blockchain. Then it depends on wich version the next miner mines a new block. Wich will make this version a longer blockchain than the other one

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#451

Ok, thanks

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Od: Fabrice Manzo via ToshiTimes Crypto Forum [email protected]

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Předmět: [ToshiTimes Crypto Forum] [Blockchain and Bitcoin 101] Homework on
Stale Blocks

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#452

  1. Initially a fork is formed and the blockchain has temporarily two versions based on the miners who solved the puzzle at the same time.

  2. Once the fork is formed immediately other miners start building new blocks on top of either the two miners. When one arm of the fork becomes longer then immediately the other block gets deleted and all its transactions return to the mempool and therefore its called a stale block.

  3. They occur when two miners solve the puzzle at the same time and the block that does not attach to the longest chain becomes obsolete.

  4. The general practice in Bitcoin is to wait for at least six confirmations just to make sure that no stale blocks still form part of an obsolete chain arm.

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#453

1 it creates 2 different blockchains (both valid) and then depending on who solves the next block first and whose blockchain is longer and with higher difficulty , that would be the accepted one for all the nodes and the other block will get dropped from the blockhain (that is the stale block 2 and 3 ) as the network always goes for the longest and more difficult blockchain
4 because your transaction can get dropped if it ends up in the stale block
( 6 confirmations is the best )

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#454
  1. What happens in the bitcoin network when two miners solve a block at the same time?/ The one in the longest block chain will win and transactions from the other will go into the mempool.
  2. What is a stale block? The stale block is the one which has been put into the mempool.
  3. How do stale blocks occur? After a folk the block with the shortest chain is the stale block which joins the mempool
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? It is important to wait for a recommended 6 confirmations to avoid a stale block occurring
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#455
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  • The chain will temporarily split until one branch is longer than the other, longest chain wins and the transactions in the blocks on the shorter chain return to the mempool.
  1. What is a stale block?
  • A stale block is a block that finds itself on the shortest of two or more competing chains of valid blocks produced at the same time and is discarded due to being outpaced.
  1. How do stale blocks occur?
  • Stale blocks occur when two or more miners produce a valid block at the same time, eventually one of the branches will be longer than the other, the shorter branch’s blocks will fall away and the transactions be considered stale and returned to the mempool.
  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
  • In order to minimise the risk of stale blocks nullifying your transaction.
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#456
  1. Both blocks are propagated through the network and picked up by different nodes, essentially creating two versions of the blockchain. Newly mined blocks are then added to these two chains until one chain prevails with the most blocks and is accepted by the network as the source of truth. The transactions in the blockchain which is rejected are returned to the mempool.
  2. A block which is mined at at the same time as another block, however, is part of the chain that is rejected by the network.
  3. When two or more miners mine a block at the same time.
  4. In case the block your transactions are in becomes a stale/orphan block, resulting in your transactions being returned to the mempool.
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#457

Homework on Stale Blocks

  1. What happens in the bitcoin network when two miners solve a block at the same time?
  2. What is a stale block?
  3. How do stale blocks occur?
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

1-The chain splits, so there´s two chains at the same time competing to be recorded as the one with more PoW.

2- Is a block that was part of the blockchain but get discarded when other chain get recorded.

3- Different nodes get blocks at the same time so there´s multiple versions of the blockchain, when one of them probes to be the most secure, get´s recorded, discarting the blocks on the other chain.

4- Because blocks could be rejected as part of the chain, based on the PoW that was required to mine and not the quantity of blocks.

Tarea sobre Bloques Viciados

  1. Qué pasa en la red de bitcoin cuando dos mineros encuentran la solución a un bloque al mismo tiempo?
  2. Qué es un bloque viciado?
  3. Cómo llegan a existir los bloques viciados?
  4. Porqué es importante esperar más de un bloque confirmado cuando envías o recibes transacciones?

1- La cadena de divide y en este momento existen dos al mismo tiempo compitiendo por ser registradas en la cadena de bloques como la que más prueba de trabajo a realiazado.

2- Es un bloque que formó parte de la cadena de bloques pero fue descartado al ser otra la cadena que fue registrada.

3- Distintos nodos que se desconocen entre sí obtienen la respuesta a un bloque al mismo, provocando que existan dos versiones de la cadena de bloques al mismo tiempo, la que pruebe ser más segura será registrada descartando a la otra.

4- Pues los bloques podrían ser rechazados conforme avanza otra cadena con más prueba de trabajo.

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#458
  1. The network can fork temporarily until decision can be made what will win to get on the ‘most true’ chain (with bigger PoW “longest” chain).
  2. A stale block is the “loser” block on previous point.
  3. When node decides to adopt a “new block” in the ‘most true’ chain (with bigger PoW “longest” chain) then all blocks that do not belong to this ‘most true’ chain are discarded and all included transactions that are not already in the ‘most true’ chain blocks are reinserted back into the mempool.
  4. It is important to wait more than one confirmation to have higher probability that ‘our’ transactions in concern are not unset from “confirmed with 1” to ‘unconfirmed’/‘pending confirmation’ sent to the mempool again due to a temporary mining fork like this one described causing the block to become stale.
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#459
  1. If two bitcoin miners solve a block at the same time then the miner with more node
    connections to the bitcoin network will be accepted ,transactions from the losing block
    will be put back in the mempool.

2.Stale blocks are blocks that were overridden by a longer block chain.

3 Stale blocks occur when two miners solve the same block at the same time and results
in a fork in the chain which is longer.
4. 6 confirmations are recommended to avoid a stale block.

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#460

1
Temporarily there will be 2 versions of the bc. The longest bc longer than 6 blocks will be considered the valid one and the transactions appended in old bc from the moment of the diversification will be rejected in the mempool.

2
Stale (aka orphan) blocks are teporary block not valid.

3
A stale block was linked in the bc from the moment of the diversification but as only one version of the bc must propagate on the Internet, it was abandoned and no more consider valid by all nodes.

4
Because the same block number can be created (nearly in the same moment) and the transaction can be confirmed by the miner possibly propagating a stale block. The bc will resolve the duality of the bc after very few blocks but to be safe 6 confirmations are waited to accept the transaction.

#461

1 - After to miners solve a block at the same time, both blocks will start being distributed to all nodes. Then miners will keep working on either of the 2 new blocks and eventually after one chain becomes longer, the other blocks will be dropped back in the mempool.

2 - A stale (orphaned) block is a block that did not have a continuation in the blockchain. The block was mined simultaneously with another block hat managed to get further in the chain.

3 - It is important so that more nodes can have the right version of the blockchain and we prevent from having different version of the blockchain

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