Homework on Stale Blocks

Blockchain and Bitcoin 101
#4696

  1. When two miners solve a block a the same time there will be 2 versions of the bitcoin network (considering that the block are valid). After an average of 10 minutes a new block will be mined and it will be linked to one of the previous blocks making this network longer than the other and as result this will be the chain that will hold the truth (more accurately after 6 blocks are mined).

  2. A stale block is a valid block that was mined but in a different chain that the longest one. All the transactions of this stable block will return to the mempool.

  3. A stale block occurs after 2 blocks are mined at the same time (chains A and B). If chain B proves to have more PoW than chain A after 6 blocks, then the block from chains A will lose it’s validation and transactions will return to the mempool.

  4. It’s important to guarantee that our transactions are in fact in the valid chain instead by accidentally be on an stale block.

1 Like
#4697
  1. What happens in the bitcoin network when two miners solve a block at the same time?

A: The blockchain forks with each solved block and the forked blockchain paths compete to become the longest chain and essentially the source of truth

  1. What is a stale block?

A: A stale block is valid mined block that is dropped from the blockchain

  1. How do stale blocks occur?

A: Sometimes blocks get mined at the same time and essentially both are considered valid at one point. Eventually one gets dropped and becomes stale because the other block beats them by belonging to a longer chain of mined blocks. Remember the longest chain always get’s chosen.

  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

A: Because it could be possible the block get’s dropped and becomes stale. So best practice is to wait for 6 confirmations of mined blocks

1 Like
#4698

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    When 2 blocks are competing at the same time. Whichever block solves and have the longest chain will get the reward. The other orphaned/stale block will be sent to the mempool.

  2. What is a stale block?
    A block that lost and is then sent back to the mempool due to shorter chain than the other block.

  3. How do stale blocks occur?
    When two miners are solving the same block at the same time, whichever loses becomes the stale block.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Best practice shows for 6 confirmations to confirm that your block was used rather than dropped.

1 Like
#4699
  1. When two miners solve a block at the same time, the blockchain forks. We have temporarily 2 versions of the registry.
  2. A stale block is a block that will be dropped of the blockchain and its transactions will get back to the mempool.
  3. This event arises when the block produced by an other miner at the same time has been appended to a longer version of the blockchain.
  4. We need to wait 6 confirmations because the block can be discarded and get back to the mempool.
1 Like
#4700

  1. When two miners solve a block at the same time, and they’re both valid, two seperate blocks are created, and both can be accepted by various nodes. After approximately 10 minutes pass, a miners creates a block on top of a block that’s longer(has more transaction data) and the other block gets dropped.

  2. A stale block is a block that is dropped after a miner chose a block that is a part of of the longer chain.

  3. Stale blocks occur when 2 blocks are created at the same time and after cca 10 mins pass miners choose the block with more transaction data(more complex block), so the block that hasn’t been chosen becomes a stale block.

  4. It’s important to wait for more than one black to be confirmed when sending or receiving a transaction to make sure that the block you’ve chosen isn’t a stale or orphan block.

1 Like
#4701

1. What happens in the blockchain network when two miners solve a block at the same time?
Both blocks are appended to the blockchain. One will become orphaned. The other block to which other blocks are appended faster, becomes the real blockchain.

2. What is a stale block?
A stale block is a legitimately mined block that has been discarded - back to the mempool.

3. How do stale blocks occur?
Stale blocks occur when more than one legitimate block is added to the blockchain. One of the added blocks becomes the real blockchain because further blocks are added to it. The other (stale) block is discarded because it is a shorter chain (less proof of work).

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
The more confirmations you have after your block (6 is recommended), the less likely it will be that your block will be discarded.

1 Like
#4702

  1. When two miners solve blocks at the same time both blocks are validated and propagated on the network until the next block is linked to one of these blocks and the other is rejected. The link of the subsequent block always decides which version of the chain becomes the truth.

  2. A stale block is a block that’s been validated at the same time as another block and has propagated on the network but has later been rejected because the next block created was linked to the alternative block. The stale block’s transactions go back into the mempool.

  3. Stale blocks occur when two blocks are validated at exactly the same time and one is later rejected because the next block that is created is linked to the alternative block meaning the network chooses the longer chain with more proof of work.

  4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction because the block your transaction is in may be found to be a Stale Block and its transactions, including yours, may be put back in the mempool. Standard practice is to wait for 6 subsequent blocks to be produced for confirmation.

1 Like
#4703

  1. There becomes two versions of the blockchain that are equally valid. A new miner chooses which version to continue building on.

  2. A stale block is a block that is valid, but not part of the longest chain. It gets dropped and all transactions return to the mempool.

  3. Stale blocks occur when a new miner starts building on another valid block, thereby dropping the block that wasn’t chosen.

  4. It is important to ensure that the block does not become a stale block.

1 Like
#4704
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Answer: When miners solve a block at the same time, these two versions start being propagated into the network, with some nodes adding one block and others adding another (depending on the node proximity to each other). Therefore, at this point there are two versions of truth on the network

  1. What is a stale block?

Answer: Stale block is block that once was a part of the blockchain but had to be dropped, because another version of blockchain exists and it is longer.

  1. How do stale blocks occur?

Answer: stale blocks occur because there is a possibility that miners can mine a block at the same time. And the network has to wait a see which version of the blockchain becomes longer (which version is picked up by more nodes).

  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

Answer: It is important to wait because we want to make sure that the transaction was included in the block that wasn’t dropped by the network.

1 Like
#4705

  1. the first one of those 2 versions of the blockchain that gets another block appended to it becomes the Truth…the other block will become a Stale block or Orphaned block

  2. a block that was dropped from the chain

  3. if a longer version of the chain arrives and the block it has at that particular spot in the chain is different, then that block will become stale

  4. Because 2 miners could both have solved a block at the same time causing 2 versions of the thruth on the network until one of those 2 becomes longer. If you had a transaction in the chain which is then NOT used, then your transaction is NOT confirmed yet. Wait for 6 blocks as confirmation.

1 Like
#4706
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The network takes the longer block chain as it has more proof of work and the other mined block is ignored
  2. What is a stale block?
    A block which has been put back into the mempool after loosing to another block which had a longer chain
  3. How do stale blocks occur?
    When there are 2 blocks produced at the same time, the stale block is the loosing block vs the block with a longer chain
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    you need to wait for 6X confirmations to be sure the transaction was not dropped by the chain and is valid
1 Like
#4707

Homework on Stale Blocks:

  1. When two miners solve a block at the same time, the nodes closest to each miner’s residence will receive that specific block first. So if A and Z release blocks simultaneously, nodes B,C, and D will receive A’s block first. Whereas, W, X, and Y will receive Z’s block first.

  2. A stale block is a block that has been dropped from the blockchain. This is because there was another version of the blockchain that was longer and had more proof of work.

  3. Stale blocks occur when miners around the world simultaneously release blocks, creating two versions of the blockchain. One version of the blockchain will be dropped once it becomes shorter than the other blockchain, creating stale blocks.

  4. It is extremely important to wait for more than one block to be confirmed when sending or receiving transactions. This is to confirm the transaction being has not dropped from the blockchain.

1 Like
#4708
  1. What happens in the bitcoin network when two miners solve a block at the same time?

A// What would happen if 2 miners solve a block at the same time is that the one that is going to be attach to the blockchain is the larger.

  1. What is a stale block?

A// A stale block or an orphan block is a block that was one time on the blockchain but was droped because a larger block was upload.

  1. How do stale blocks occur?

A// Stale block occurs when 2 miners solve different blocks at the same time but only the largest is fork to the blockchain.

  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

A// Because if we wait to 6 confirmations to the block it would be more probable that it wouldnt be droped by another block coming.

2 Likes
#4709

  1. They both create their own version of the blockchain, but when the next miner comes in to solve his/her own block, then the longest chain gets validated. Other blocks will be stale or orphaned blocks.

  2. & 3. When a block can not get enough confirmation from the other miners(participants) stale blocks get invalidated and tx’s get back to the mempool.

  3. Because the network always accepts the longest chain which has the most PoW. So more confirmations mean more PoW.

1 Like
#4710

  1. When two miners solve a block at the same time the one that gets picked up on and built on quicker will be the one that is added to the blockchain. The other will become a stale block.

  2. A stale block is a block that was validated, but got dropped from the blockchain because another block was chosen to be used first.

  3. These occur because there is competition to solve these blocks and often times they will compete until the very end to get confirmed on the blockchain.

  4. IT is important to wait because you need at least 6 confirmations before your block is confirmed on the network or else it could become stale or orphaned

1 Like
#4711
  1. When two miners solve a block at the same time, both miners propagate a new valid but different block to the nodes, generating a sort of blockchain split, i.e. the previous block has two sucessors. But the split blockchain is not propagated as such; each miner will propagate only its own version. The nodes reached will confirm this version, since at that point of time they are not aware that a different but valid new blockchain exists, which is simultaneously propagated among other nodes.
  2. A stale (or orphan) block has been validly mined and propagated among some nodes, but has meanwhile been removed since it is not part of the longest chain anymore.
  3. Stale blocks occur since it is possible that two or more miners successfully mine and propagate a new block shortly behind one another, so different versions of the blockchain are progagated and adapted by nodes. Since bitcoin is a global network, it always takes some time to transfer data between computers, resulting in communication delays and multiple valid versions of the chain. However, this is a temporary state since stale blocks will eventually be removed from the chain (since per defintion they are ultimately not part of the longest chain, which will always win).
  4. It is advised to wait 6 block confirmations since that means another 5 blocks have been mined, so chances are very high that my transaction is part of the block included in the longest chain. The goal is to avoid that my transaction is cancelled because it has ended up in a stale/orphan block.
1 Like
#4712

  1. if two miners. make a block at the same time and distribute their blocks out there will be two different chains. the chain that becomes the longest will overtake the smaller chain and become the true chain

  2. a block that was dropped from a shorter chain.

  3. when a shorter chain is taken over by the longer chain, all the
    blocks in shorter chain will be dropped and all transactions will be sent back to the mempool.

  4. to make sure the block that has your transaction isnt dropped.

1 Like
#4713

  1. When two miners solve a block at the same time, there are two versions of the blockchain that begin to spread across the network. At some point, the network needs to choose one of those versions to be the effective one.

  2. A stale block is a block that was confirmed by some miners but was later replaced by another block.

  3. A stale block occurs when there is more than one valid block in a chain and the network generates consensus that selects a different block to be the effective block leaving the other alternative block as stale and no longer valid.

  4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction because there is always the possibility that a transaction in a block could be stale and go back to the mempool.

1 Like
#4714
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    A: Which ever block is not part of the longest chain, it will be dropped and sent back to the mempool.
  2. What is a stale block?
    A: A stale block is one that was on the blockchain for a short period, but was later dropped as it was not part of the longest chain.
  3. How do stale blocks occur?
    A: When more than one miner has guessed a hash below the nounce and the block is then added to the chain at the same time as another block.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? To ensure that the block added will not be dropped at a later stage and is an officially confirmed block. and propagated through the entire network.
1 Like
#4715

  1. They produce 2 valid but different version of the blockchain as the nodes geographically closest to the miners will get their respective versions of the blockchain.

  2. A valid block that was added to a version of the blockchain at one point but then later dropped due that version of the blockchain becoming invalid.

  3. Another version of the blockchain gets picked up by a majority of the miners and consequently by the entire network, which invalidates all other blockchains. Any blocks part of those invalidated blockchain(s) then become stale. The transactions in the state block(s) then get returned to the mempool.

  4. To ensure that the block in which the transaction was included does not eventually become a stale block, hence the transaction returning to the mempool.

1 Like