Homework on Stale Blocks

Blockchain and Bitcoin 101
#2910
  1. There becomes 2 versions of truth, and whichever block the next miner is basing the next block on, will be put into the blockchain.
  2. A stale block is a block that contains valid transactions but did not make it to the blockchain
  3. Stale blocks occur when there 2 miners solve a block at the same time, and one block then makes it to the blockchain (when the miner of the next block mines the next block based on this block) and the other one gets “dropped” and becomes a stale block.
  4. It’s important to ensure the block in which our transaction is contained, will not get dropped.
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#2911 
What happens in the bitcoin network when two miners solve a block at the same time?

Two different blockchains are created (different versions of the truth). Then after that, a subsequent miner will ‘pick’ one of these two options (randomly) and the longest blockchain then becomes the true blockchain. The other one will drop the orphaned block.

What is a stale block?

It is the block that didn’t get picked (out of the two competing blocks / chains) by the subsequent miner.

How do stale blocks occur?

Because of timing issues. If two of the same blocks were produced by different miners, with the same data / version of the truth/ transactions were solved at the same time. And then when one of these becomes the longer chain, the other chain drops the last block, and that is how a stale block occurs.

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

To make sure that the block your transactions are in is not the one that gets dropped.

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#2912

The blocks don’t contain the same data but are different blocks that are both valid at the same height of the chain. :slight_smile:

#2913
  1. Both propagate their new version of the blockchain to other nodes. Only when there has been build more blocks on one of their versions, we can state who’s block was confirmed.
    The other one is a stale block.
  2. Mined block that is not part of the blockchain any more. Because an other version of the blockchain is longer.
  3. They occur when 2 or more miners come up with a block at the same time.
  4. So that you are sure that the transaction is not in a stale block. Otherwise it could still disappear from the blockchain.
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#2914

What happens in the bitcoin network when two miners solve a block at the same time?

Temporary fork created. The longest chain wins the block and the other block is considered stale/orphaned. Remaining transactions go back to the mempool.

What is a stale block?

Stale blocks are blocks that were invalidated because the blockchain it was linked to was unconfirmed.

How do stale blocks occur?

The block chain it was a part of was not confirmed and subsequently invalidated. These blocks are placed in the mempool.

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

You want to verify that the block is confirmed by the network.

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#2915

  1. The blockchains could split into 2 paths

  2. Stale blocks are blocks which were connected to the blockchain but got dropped afterwards

  3. When the blockchain splits into 2 paths and one of them will finally get accepted as the true chain, so the second chain and all the blocks already connected to it will be dropped and the blocks become stale blocks

4.If a split chain occurs, the probability that another 2 blocks will be generated 6 times at the same time and connected to the 2 chains is so low that only after 6 further connected blocks can be assured that there is no split chain which is later released from the blockchain and all transactions, including those already confirmed, are discarded

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#2916

The block that ultimately has the next block attached to it forming the longest chain will win the shorter one will be dropped

Stale Block is a bock that has been ejected from the network / chain

A stale block occurs when 2 nodes complete a block at the same time but one makes it to the chain faster

Confirmation prevents a double spend scenario

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#2917
  1. When the next block is produced, and links to one of these 2 previous blocks, that chain will become the longest. At that moment the other previous block will be removed, and the transactions in it will be returned to mempool.
  2. That is that block that will be removed.
  3. When 2 blocks have been simultaneously mined and 1 is chosen, the other becomes the stale one.
  4. To make sure your transaction wasn’t part of a stale block.
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#2918

  1. The two new blocks are propagated through the network. Nodes closer to Miner A will receive his version of the block, whilst nodes closer to Miner B will receiver his version. Botch blocks are valid, in that the transactions they contain are fine and the nonces are below target. The blockchain therefore forks out, with half the network containing one version of the truth whilst the other possesses the alternative version.

  2. A stale block was part of a version of the blockchain that had become split; it is one that subsequently got dropped due to another version surpassing it in length.

  3. Miner C has the same intention as Miners A and B: he wants to add his block to the chain. If he chooses to append the block to Miner A’s then Miner B’s block will become stale and vice-versa. A stale block is dependent on which of the previous ‘competing’ blocks is selected and added to.

  4. It is best practice to wait for 6 confirmations (or the creation of 6 new blocks) before you can be assured that your transaction is part of the longest blockchain and not discarded. If your transaction is part of a stale block it gets placed back into the mempool, and thus it would be wrong to say that it was confirmed.

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#2919

  1. The one with the longest chain will be the one that the blockchain will follow.

  2. It is the block that gets rejected because their is a chain that is longer and the transactions that is in that block will go back to the mempool.

  3. When their is a 2 chain created and the nodes are confused what to follow and when the time comes that the one chain gains more block than the other chain the longest chain will be the one that the nodes will follow.

  4. In case a stale block occur in the blockchain.

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#2920
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The block in the longest chain will win and the other one will be dropped. The transactions in the stale block will be send back to the mempool.
  2. What is a stale block?
    A stale block is a block that’s been started on but not made it to the blockchain.
  3. How do stale blocks occur?
    When two blocks get produced at the same time and only one can win.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To ensure that youre block get used and not dropped from the blockchain.
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#2921
  1. What happens in the bitcoin network when two miners solve a block at the same time? Answer: they propagate the blocks to the network, and the nodes closest to them get to connect it to their blockchain. This creates two versions of the blockchain. Subsequent block additions will create a situation where one chain becomes longer than the other.
  2. What is a stale block? Answer: A stale block is a block or are blocks that have been dropped because a longer version of the blockchain has been detected in the network.
  3. How do stale blocks occur? Answer: When two miners mine at the same time and propagate their blocks to the network, two parallel versions of the blockchain exist. Eventually one version outpaces the other. The longer chain is accepted by the network. The other version is dropped. Those blocks (of the dropped version) from the point of divergence are the stale blocks.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? Answer: We wait for more than one block to avoid being on the “shorter” chain, and the transaction being invalidated.
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#2922
  1. What happens in the bitcoin network when two miners solve a block at the same time? The longest blockchain will be selected and the other will become stale and drop out.
  2. What is a stale block? The looser.
  3. How do stale blocks occur? When more than one block in under contention. Only one winner and the others are stale or orphaned.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? It gives the global network time to sync.
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#2923
  1. Both blocks will be considered ‘the last block solved’ by different group of nodes until another miner will add his block on one of these groups. In this way there will be a longer chain (most Pow) which will be finally accepted by all the groups.
  2. A stale Block is a block that is no longer part of the current best blockchain because it was overridden by a longer chain.
  3. Stale blocks occur when two versions of the blockchain run for several blocks but the first longest chain will be added to the blockchain. All blocks of the shorter chain will become stale blocks and are returned to the mempool.
  4. Is good to wait for more than 1 block to be confirmed. Actually 6 confirmations is a norm where we can be sure that no reorganization can happen and your transaction is forever on the blockchain.
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#2924
  1. Different nodes will have two different ‘truths’ until anther block is added to one of the truths. Once this happens this chain is the longest in the blockchain and becomes the dominant chain to build on and continue the blockchain.
  2. The block that become irrelevant from the process above is thus called a stale block. It had relevance for a short time until blocks were added to the other block that was created around the same time.
  3. Stale blocks are the blocks that are left over from a section of chain where two blocks were added at the same time. One chain continued to add blocks to its chain faster than the other one so the shorter blockchain became irrelevant. Those blocks and their transactions weren’t included in the blockchain.
  4. As different nodes verify and synchronize the blockchain around the world, blocks may become added to blockchain. However, their segment may become irrelevant if another block was created at the same time and has outpaced for the number of blocks on the chain. It takes time for this process to happen, so best practice is to wait for six blocks to be added. This allows the network time to come to an agreement and for any stale blocks to be dropped.
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#2925

  • What happens in the bitcoin network when two miners solve a block at the same time?
    When two miners solve a block at the same time, the block with the most amount of transactions will be selected as the next block.

  • What is a stale block?
    A stale block is a block that was once on the network but was removed due to a larger block being accepted into the network instead of it.

  • How do stale blocks occur?
    Stale blocks occur when two miners solve a block at the same time, and the shorter block is rejected, which ultimately lands back into the mempool.

  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    It ensures that your transaction will be included in the correct version of the blockchain just incase an instance occurs where block are solved at the same time.

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#2926

1.- Both blocks start broadcasted in the network

2.- Is when a valid block are discarded

3.- When two valid blocks star broadcasted in the newtwok. But when the next block is mined, the past block that he use will be the correct one. So the other will be discarded

4.- Avoid stale blocks

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#2927

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    the longer chain is accepted and the other block’s transaction is returned to the Mempool

  2. What is a stale block?
    A block that was beat out by a faster, longer one and is now being discarded with its transactions returned to the mempool

  3. How do stale blocks occur?
    When two or more nodes create new blocks to append to the chain, but only one is fully accepted. The others -the shorter or less difficult ones - become stale blocks

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To ensure that your transaction actually makes it onto the block after multiple confirmations, and doesn’t just get lost in a stale block

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#2928
  1. Two versions of the blockchain are created and broadcasted to the network.
  2. A block that was once included in a blockchain version that was later discontinued as more blocks were mined on another blockchain version.
  3. Stale blocks occur when two or more versions of the blockchain are propagated. Only the longest will end up being valid and all the blocks of the shorter versions will become stale.
  4. To make sure that you transaction is in the longest chain and in consequence enters the definitive version of the Blockchain.
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#2929

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Then for some time there are two chains, after the blocks are propagated to the whole network and the new blocks will be produced, the blockchain will approve the longest chain.

  2. What is a stale block?
    It is a block that was a part of the alternate chain of the blockchain but unfortunately became invalid, after the approval of the second chain to be single valid chain

  3. How do stale blocks occur?
    They occur when two or more versions of the blockchain are temporarily propagated through the network. Only the longest chain will last eventually. The shorter chain will become stale.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because after several new blocks we can be sure that most likely this blockchain is the longest, no stale block will occur and our transaction will be final.

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