Homework on Stale Blocks

Blockchain and Bitcoin 101
#2970

When two miners solve a block at the same time, all nodes in the network keep track of both, but consider the first they got notice of as the valid one. Miners keep mining as usual. When a new block is solved, the lucky miner will append it to the previous one he considered valid. Then he will broadcast that version of the chain to the rest of the nodes, who will know for certain then which previous block to keep and which to discard.

A stale or orphaned block is the one that got discarded after two blocks get mined at the same time and after the valid one is decided.

It is important to wait for more than one block to be confirmed when sending or receiving a transaction because maybe the block where your transaction is becomes a stale block. The more confirmations, the better, but usually 3 confirmations are more than enough.

1 Like
#2971

1 It will create two chains that will live separately
2 stale block is a dropped block from the network
3 when two miners mine valid block at the same time
4 to see if the block is not dropped and the transaction is send

1 Like
#2972
  1. they are both propagated. next solved block closest to the the miner in question gets added. network then confirms and the longest chain wins
    2.Stale block is a block that was “rejected” by the longest chain and goes in the mempool
    3.it decreases the chances of stale block creation
1 Like
#2973

1Both blocks will start being propagating through the network until 1 of the 2 blocks will be refused because it is no longer the longest chain.

2A block that was mined correctly but eventually was not on the longest chain.

3When some miners mine a block at the same time (only 1 block can win).

4When your transaction is part of a stale block, it gets moved back into the mempool so the confirmation will be 0 again.

1 Like
#2974

Both blocks circulate into the network and are received by the nodes closest to the miner and confirmed, meanwhile, more blocks are added to the confirmed blocks creating 2 chains. Eventually one chain outpaces the other in terms of new blocks added and this becomes the true chain. All blocks that were added to the other chain with the original competing block are dropped and all transactions are added back into the mempool.

A stale block is a block that was added to the chain where there were initially 2 blocks competing for verification. The stale block would be linked to the block that was verified after the first competing block thus invalidating all blocks linked to the losing block

Stale blocks occur when 2 blocks are sent to the various nodes simultaneously and there is delay in confirming one block over the other. When certain miners choose to mine the block that was verified after the first one, these blocks that are added to the delayed block are eventually invalidated

Because of simultaneous block verifications there is always the possibility of dual chain developments and the time delay allows for this the true sequence to emerge.

1 Like
#2975
  1. The chain forks. The longest blockchain will win. The short one will be dropped.
  2. A block that doesn’t get mined and gets put into mempool in favor of a longer chain.
  3. After a fork, the shorter chain that has been dropped, is called stale block.
  4. It is important to wait for 6 confirmations to be sure that the block is not dropped from the blockchain.
1 Like
#2976

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The two solved blocks propagate to the nodes closest to them and are confirmed on a number of those nodes, creating a split in the chain (two-headed chain). As the mining of the next block is begun and builds from the hash of one of the previous two solved blocks, that block will eventually be solved and confirmed, creating a longer chain on one head than the other. This longer chain will become the accepted chain and the second head of the split chain will be dropped (stale or orphaned block), sending the transactions that are no longer part of the actual chain back to the mempool.

  2. What is a stale block?
    A stale block is the discarded block in the example above.

  3. How do stale blocks occur?
    When the subsequent block on the other head of the chain is confirmed, the block head on the shortest split of the chain 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? To avoid the transaction ending up on a stale block and being returned to the mempool as unconfirmed.

1 Like
#2977
  1. The chain splits and both are correct.
  2. A Stale block is a block that is not being built on by the new blocks. Therefore it returns to the mempool.
  3. When other blocks outcompetes it.
  4. You can have a scenario where to different chains build new blocks and then you have to wait and see which one is more effective and choosen. The “losing” chains returns to the mempool
1 Like
#2978
  1. Both blocks are going into the network and the longer version of blockchain takes the place.
  2. Stale block is the one that was in blockchain at some time but was dropped because there was another longer version of blockchain
  3. Two miners solve blocks at the same time , both blocks get into the network, one is becoming longer and stays in the network the other one is being dropped. The dropped one is a stale block
  4. In case that transaction gets into the block of the Stale block , in that case it would be sent back to the mempool
1 Like
#2979

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    There are temporarily 2 branches of the blockchain.

  2. What is a stale block?
    The branch of the blockchain that gets discarded and placed back into the mempool.

  3. How do stale blocks occur?
    When the 2 different blocks are mined for the same block number and each one is legit. They essentially solved the puzzles at the same time.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    The blockchain that is the longest is the one that will be kept. The shorter blockchain will be disregarded. By waiting for additional blocks to be mined, then you are essentially verifying that your transaction is on the longest blockchain that will be kept.

1 Like
#2980

1.The block with the shortest chain will be removed and sent to the mempool
2. Block that was in a blockchain and got dropped because it didn’t have a long enough chain
3. When the chain isn’t long enough
4.You wait 6 confimations to make sure your block doesn’t get dropped

1 Like
#2981
  1. It starts to propagate to nodes. Then the new block is added to one of that blocks and creates longer blockchain. Longest blockchain is accepted so it becomes valid/true.
  2. Stale block is rejected block that previusly was fair and valid. The rejection is based on adding new blockchain to another valid block faster than adding new block to stale block.
  3. It occurs when 2 valid blocks are created at the same time. Further explanation above :wink:
  4. Its important to check if our transaction isnt put in stale block and first confirmed, but lately rejected due to longer valid blockchain without our transaction.
1 Like
#2982

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The miner that has the most difficult or longest blockchain will be accepted in the network. And the miner that doesn’t get accepted their nodes/block are called Stale Block or Orphan; in this case they are placed in the mempool.

  2. What is a stale block?
    Are also called Orphan. Their name are used interchangeably. These nodes are valid but has been drop because it’s not long enough in which case goes to mempool.

  3. How do stale blocks occur?
    The network accepts the longest blockchain or most difficult blockchain in which case stale blocks does not have in completing with another blockchain at the time.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because there is a chance that a stale block can occur.

1 Like
#2983
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Though multiple miners solve a block simultaneously, those blocks may contain different transactions, nonces, and so hashes. As such, both may be valid blocks, meaning different regions of network currently (temporarily) recognize different versions of the blockchain (or truth).

  1. What is a stale block?

A stale block is one that, though valid, is not part of the longest chain on the network and so has been dropped (and its constituent transactions returned to the mempool).

  1. How do stale blocks occur?

When the scenario described above occurs (ie, two competing blocks are solved and submitted to the network simultaneously), one of these blocks will ultimately win out, being adopted by the network at large, as that particular blockchain grows in length and difficulty. The competing block of the “losing” chain is no longer part of the official blockchain and is recognized as “stale.”

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

Waiting for multiple confirmations helps ensure transactions are properly included in the official chain and are not left in stale blocks.

1 Like
#2984

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    If there are multiple chains competing on the network, each one is referred to as a different version of truth.
    The version of truth that can get blocks appended to it quicker, thereby becoming longer, serves as the current best blockchain for Bitcoin. Both miners are now on the same page and mining continues on the longest chain, until another split on the network occurs

  2. What is a stale block?
    it’s a block that’s was in the blockchain once and been dropped because another version of the blockchain appeared and eliminate quickly after, for the reason that nodes that had added it to their variations of the chain ended up forking away to an extended, majority chain that does not come with it.

  3. How do stale blocks occur?
    When 2 miners have produced a valid block at the same time. There is always one version of truth, the longest chain will be chosen so one of the 2 blocks will be dropped at the end.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    [/quote]
    Just to make sure that the block which contains your TX is not dropped, TX will return to the mempool if one of the 2 blocks is removed in case of a chain split in 2

1 Like
#2985
  1. whichever block becomes the foundation for the longest chain is accepted, the other is dissolved and txns go back to the mempool
  2. a block that has been rejected by the network as it was on a shorter chain than a competing block
  3. Two blocks are appended at the same time, but the competitor becomes the foundation for a longer chain. the stale block is then rejected (within 10mins)
  4. To ensure your transaction is not with a stale block
1 Like
#2986

1.2. The chain will split temporarily into two valid ends but in the future only one of the previously solved two blocks gets added to the chain and the other becomes a stale (orphaned) block and its transactions get returned to the Mempool, because always the longest chain win.

3.The stale blocks occur when two miners mine a valid block approximately at the same time.

4.To avoid the double spending.

1 Like
#2987

What do you mean? If a stale block occurs you want to make sure your tx is not part of it. :slight_smile:

#2988
  1. A third one will give the solution when the new block he mined has to be appended to either of those two blockchains. The longer blockchain will be confirmed and the other one will be dropped back to the mempool.
  2. A stale block is a block that once was a part of a blockchain that was dropped back to the mempool.
  3. If two miners find a valid next block at the same time both proposed blocks are valid, but only one can be appended. The one that get accepted quicker by the nodes of the network creates the longest blockchain. The other one gets discarded and is dropped back to the mempool. The blocks of the discarded blockchain are called stale blocks.
  4. Because if we don’t there is a chance that our transaction ends up in a stale block, and therefore back to the mempool and not confirmed.
1 Like
#2989

Hello,

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Both miners propagate their respective blocks to the network. This causes the network to fork (two versions of the blockchain). Some nodes have version A and others have version B. Both blocks are completely valid. TXs are valid, the nonces are valid, etc.
  2. What is a stale block?
    It is a mined block that was dropped or rejected after a temporary fork situation in the blockchain has been resolved in favor of the chain with the highest PoW (longer chain).
  3. How do stale blocks occur?
    A stale block occurs in the rare case that two blocks are mined at the same time, both are then propagated to the network, and one of them will be used to continue the blockchain. The block that wasn’t appended to the blockchain, sooner or later, will be rejected and become a stale block.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    If your TX happens to be within a stale block, it will be sent back to the mempool to be mined again in a future block.

R

1 Like