Homework on Stale Blocks

Blockchain and Bitcoin 101
#2930

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Both blocks will be propagated in the network, which will cause a temporary fork. Whichever block happens to be built on next will remain in the blockchain, and the other will be dropped.

  2. What is a stale block?
    A stale block is a valid block that was in the blockchain, but which was dropped because a longer blockchain fork was created.

  3. How do stale blocks occur?
    Stale blocks come from temporary forks in the network, as described in the first question.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Waiting for several blocks to be mined minimizes the chances that a transaction is in a stale block.

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#2931

  1. The chain split in two valid chains and are sent to all the nodes.

  2. A stale block is the chain that didn’t get chosen by the next miners and so it becomes the shortest version of the truth in other word invalid.

  3. A stale block occur when two people solve a block at the same time but one of them is the one choosed to continue the chain and the one no chosen is the one call stale or orphan block.

  4. Because if our transaction was part of the stale block, it goes back to the mempool and so it’s a pending transaction still

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#2932
  1. When two miners solve a block at the same time, the chain upon which the next block is appended by a miner becomes the valid chain.
  2. A stale block is a block that is invalidated because it was mined at the same time as another block and the next block was appended to another chain.
  3. Stale blocks occur when two blocks get mined at the same time and one block’s chain gets appended to before the stale block’s chain.
  4. This drastically increases the likelihood that the block will not become stale.
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#2933
  1. Each block will remain until one of those chains are longer than the other. The block that is dropped will be disregarded and the transactions in the block will be returned to the mempool.
  2. A stale block is a block that was solved but was disregarded because it solved the nonce at the same time as another block and the the chain it created after its competing block was longer.
  3. Stale blocks occur when 2 blocks solve the same nonce at the relative same time and then one of the competing chains was confirmed with 6 blocks before the other. The losing chain contains the stale blocks.
  4. So that it gives enough time for the valid last block on the chain to be broadcasted worldwide as to reach all nodes.
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#2934
  1. the blocks get added as a fork until one block becomes the winner and continues the block chain.
  2. A stale block is the block that gets rejected from the chain and the TX’s returned to the mempool.
  3. Because of distance in the network and two separate miners solving two separate blocks at the same time creating two blocks.
  4. To see if it was a stale block or part of the on going blockchain and confirmed by the other nodes as part of the on going blockchain.
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#2935
  1. The blockchain becomes forked. One of the solved blocks will eventually be used in a subsequent block, and at that point in time the chain with the higher stake of work wins.
  2. A stale block is a forked block that was correct in all aspects, but wasn’t chosen as the longest chain, and was discarded.
  3. As a result of a fork, and then not achieving the longest chain, and being discarded.
  4. It is possible that any one transaction is included in a block that could become an orphan. With the addition of additional blocks, that scenario becomes exponentially less likely.
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#2936 
1.-The miner who has the longest chain will win. the block from the shorter chain will be sent  to the mempool.

2.-Block lost from a miner which could not continue due to the competition with another miner
3.- When 2 miners are in a competition for a block, the loser will have his transactions lost, it is called then stale blocks
4.- we wait for 6 confirmations to avoid blocks are lost from the chains

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#2937
  1. The blockchain network splits in two after that the network will choose the blockchain with most blocks and cancel the others
  2. An stale block is a correctly created block which has been deleted from the network
  3. It occur because all the node will choose the longest version of the blockchain.
  4. To be sure that your transaction was not insert in a stale block
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#2938

One of the two blocks wins and is getting approved and added to the chain.
2
Is a block that has been rejected and dropped.
3
When the block was valid but then it has been dropped because the chain continued with another block
4
is important because by that you are sure that your block hasnt been dropped from the chain

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#2939
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Both blocks get added to the blockchain however as there can be only one version of the truth whichever chain the next miner adds a block to becomes the true block chain as it is longer and the nodes in the network will accept the longer chain as truth.

  1. What is a stale block?

A stale block is when a block that was a valid and a part of the block chain gets dropped from the blockchain.

  1. How do stale blocks occur?

This happens when there are 2 valid chains on the network at the same time and one chain gets accepted throughout the network in favor of the other. The chain that didn’t get accepted has its block dropped and sent back to the mempool

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

This gives your transactions enough time to ensure it hasn’t been dropped from the blockchain

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#2940

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    When two blocks are added to the blockchain at once, it temporarily splits. As there can only be one true blockchain, the chain to have the next block added then becomes the true blockchain. The block from the other chain is then dropped and sent back to the mempool.

  2. What is a stale block?
    A stale block is a block that is dropped from the blockchain.

  3. How do stale blocks occur?
    Stale blocks occur when two blocks are added to the blockchain at the same time and one ends up being dropped.

  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 confirmations just in case the block becomes stale.

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#2941
  1. The new blocks are added to the blockchain and propagated throughout the network.
  2. A block that has been mined, added to the blockchain, but then rejected as there is another, longer version of the blockchain.
  3. Multiple blocks mined at the same time and broadcasted to the network to be added to the blockchain, the blocks rejected are called stale blocks and all tx will return to the mempool.
  4. 6 confirmations to be sure, because the block can be rejected and tx returned to the mempool.

Question: Can you cancel the tx while it is waiting in the mempool?for example after 1 confirmation tx goes back to the mempool, can you cancel it?

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#2942

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

Both block will be added to the chain. This will, for a moment, create the perception of two separate truths about the state of the whole chain. The next appended block will determine the continuation of the chain. Since the protocol will always use the longest chain this will lead to the unused block becoming stale.

2. What is a stale block?

A stale block is an valid appended block that is not part of the longest chain.

3. How do stale blocks occur?

Answered with question 1.

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

Depending on the achieved block time at the moment (although the goal is 10 min but this can vary) it is possible for more than one block to become stale.

But after enough other consequent block being added and confirmed it is less likely (and possible) for the transaction to be part of a possibly stale block.

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#2943

1. What happens in the bitcoin network when two miners solve a block at the same time?
Both blocks are propagated through the network. There are two versions of the blockchain temporarily until one of them become the longest chain. This new chain will then be propagated and accepted from the network.
2. What is a stale block?
It is a dropped block out of two or more parallel recently mined blocks.
3. How do stale blocks occur?
A part of the network already accepted the block “A” as a new mined block, whereas another part of the network accepted another block “B”. Meanwhile a new block was added to chain with block “B”, which is form now on the longest chain in the network. The longer chain will no be propagated and accepted by the network. All nodes which previously accepted block “A” will drop it.
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
There is the possibility that the transaction is included in a block which becomes a stale block. You have to wait for a few more blocks added to the chain, to be sure the block will not be dropped.

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#2944

  1. Both will add the block to the chain and propagate. Eventually one of the blocks will be on the longer chain. The other block will be removed and the transactions returned to the mempool.

  2. A stale block is a properly mined block that gets removed because it’s on the shorter chain.

  3. Stale block occur by chance.

  4. Wait for 6 confirmations to guarantee that the block with your transaction in it did not, by chance, get removed.

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#2945

  1. If two miners solve a block simultaneously, there is a split in the blockchain creating two valid blocks. Which ever of the two new blocks is solved first and continued as the new chain (or as many times as it takes for the whole network to be informed of the longer chain; usually 6 blocks if I’m understanding correctly) will be the true blockchain.

  2. A stale block is the block(s) which are on the shorter chain that does not get adopted by the network. All of the tx within these block(s) will be dropped & sent back to the mempool.

  3. Stale blocks will occur when the longer chain is officially chosen by all nodes in the network.

  4. It is important to wait for more than one block (6 is good) to be confirmed ahead of the one containing your transaction to allow for the whole network to weed out the longest PoW chain and drop stale blocks. If your transaction is dropped, it is important to be aware.

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#2946

  1. When two miners solve a block at the same time then the network will not have the time to propagate correctly and there will be two versions of the truth. This causes the shorter one to become dropped.

  2. Stale block is a block or blocks that have been dropped from the network.

  3. stale blocks occur when there is two miners that have been accepted around the same time thus causing them to be propagated at the same time and throwing off the network.

  4. This step is important because it is possible for your block to be a stale block. which means that it still has the potential of being sent back into the mempool.

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#2947
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    They both begin to propagate their block information through the network, starting with the nodes closest. Whichever block that has a new block created on it first is usually the block that stays and becomes accepted by the entire network because it is the chain with the most PoW.
  2. What is a stale block?
    A stale block is the block that is dropped in the above scenario. Another version of the truth has been accepted by the network and this block has been removed.
  3. How do stale blocks occur?
    They occur when more than one version of the truth begins to be passed through the network when multiple blocks have been successfully mined at the same time. The longest chain ends up being accepted and the block belonging to the shorter chain is not accepted. Generally there is a 6 block rule where after 6 new blocks have been added to the network it is safe to assume that is the truth the network has accepted.
  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 network has accepted that chain as the truth. If there are multiple chains being formed with different versions of the truth it is possible for that original block to be invalidated by the network and the other chain will be selected.
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#2948
  1. The miners might append their block to one of several existing blocks.
  2. It is a block that gets “dropped” and returned to the mempool as it was appended to the shortest block that got deleted after around 10 mins
  3. they occur when their blockchain gets dropped as it was too short
  4. it is important to wait because if the blockchain their in wins or gets accepted and not dropped
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#2949
  1. Creates two branches of the block
  2. It is a block that was honestly created but the branch that it belonged wasn’t the longest one
  3. Because it might happen that some blocks ahead or your block itself be annulated by longer branch in the blockchain
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