Add maximal amount-of-transactions limit to checkblock/CVerifyDB #8138

1. 
   jonasschnelli commented at 3:00 pm on June 2, 2016: contributor

   Reduces checkblocks default to 144 blocks (MIN_BLOCKS_TO_KEEP / 2).

   Introduce -checkmaxtx with a default of 100'000 transaction to set a upper bound of amount of transaction to check during the CVerifyDB process.

   There is also a new constant MIN_BLOCK_TO_RESPECT_WITH_MAX_TX_CHECK which defines the minimum amount of blocks to check even if the -checkmaxtx check has been fulfilled.

2. Add maximal amount-of-transactions limit to checkblock/CVerifyDB 58af361855
3. jonasschnelli added the label Validation on Jun 2, 2016
4. 
   dcousens commented at 3:11 pm on June 2, 2016: contributor

   Perhaps we should also reduce the number 288. Maybe a limit specified in number of transactions is better?

   Or perhaps a limit specified in size on disk? Last 288MB as an example.

5. in src/main.cpp: in 58af361855

   3915@@ -3915,6 +3916,11 @@ bool CVerifyDB::VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview,
   3916         }
   3917         if (ShutdownRequested())
   3918             return true;
   3919+        nTxCheckLimitCurrent+=block.vtx.size();
   3920+        if (nTxCheckLimit > 0 && nTxCheckLimitCurrent >= nTxCheckLimit && chainActive.Height() - pindex->nHeight >= std::min(nCheckDepth, MIN_BLOCK_TO_RESPECT_WITH_MAX_TX_CHECK)) {
   

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   sipa commented at 11:30 pm on June 2, 2016:

   The std::min isn’t necessary, as chainActive.Height() - pindex->nHeight will never exceed nCheckDepth (we bail out of the loop before that can happen).
6. 
   kazcw commented at 10:04 pm on June 5, 2016: contributor

   The relationship between -checkblocks and -checkmaxtx is not clear from the help text. It looks like as implemented it will stop when either limit is reached, modulo the MIN_BLOCK_TO_RESPECT_WITH_MAX_TX_CHECK logic (i.e. they are both maxes). Unless there’s a particular benefit to the max-based interface, I think I would prefer if they were both mins, which would also obviate MIN_BLOCK_TO_RESPECT_WITH_MAX_TX_CHECK.
7. 
   sipa commented at 12:08 pm on August 25, 2016: member

   You could also just get rid of MIN_BLOCK_TO_RESPECT_WITH_MAX_TX_CHECK. The theoretical maximum number of transactions in a block is 16665 anyway, so 100000 transactions effectively already requires 7 blocks anyway. If someone wants to set a lower number of transactions, so bit it.

   That would simplify this PR, and have clearer semantics.

8. 
   sipa commented at 3:44 pm on August 31, 2016: member

   Closing this as superseded by #8611.
9. sipa closed this on Aug 31, 2016

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10. DrahtBot locked this on Sep 8, 2021

Contributors
jonasschnelli dcousens sipa kazcw

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Validation