Previously Bitcoin would send 1/4 of transactions out to all peers
instantly. This causes high overhead because it makes >80% of
INVs size 1. Doing so harms privacy, because it limits the
amount of source obscurity a transaction can receive.
These randomized broadcasts also disobeyed transaction dependencies
and required use of the orphan pool. Because the orphan pool is
so small this leads to poor propagation for dependent transactions.
When the bypass wasn't in effect, transactions were sent in the
order they were received. This avoided creating orphans but
undermines privacy fairly significantly.
This commit:
Eliminates the bypass. The bypass is replaced by halving the
average delay for outbound peers.
Sorts candidate transactions for INV by their topological
depth then by their feerate (then hash); removing the
information leakage and providing priority service to
higher fee transactions.
Limits the amount of transactions sent in a single INV to
7tx/sec (and twice that for outbound); this limits the
harm of low fee transaction floods, gives faster relay
service to higher fee transactions. The 7 sounds lower
than it really is because received advertisements need
not be sent, and because the aggregate rate is multipled
by the number of peers.
- BIP9DeploymentInfo struct for static deployment info
- VersionBitsDeploymentInfo: Avoid C++11ism by commenting parameter names
- getblocktemplate: Make sure to set deployments in the version if it is LOCKED_IN
- In this commit, all rules are considered required for clients to support
As per meeting 2016-03-31
https://bitcoincore.org/en/meetings/2016/03/31/#bad-chain-alerts
The partition checker was producing huge number of false-positives
and was disabled in 0.12.1 on the understanding it would either be
fixed in 0.13 or removed entirely from master if not.
There was a previous assumption that blockindex would be quite small. With addressindex
and spentindex enabled the blockindex is much larger and the amount of cache allocated for
it should also increase. Furthermore, enabling compression should decrease the amount of
disk space required and less data to write/read. The default leveldb max_open_files is set to
1000, for the blockindex the default is set to 1000 with compression. The 64 value that is
current is kept for the utxo database and does not enable compression. Two additional options
are added here to be able to configure the values for leveldb and the block index:
- `-dbmaxopenfiles` A number of files for leveldb to keep open
- `-dbcompression` Boolean 0 or 1 to enable snappy leveldb compression
There was a bug where the spending address index could have the same key
as the receiving address index if the input and output indexes matched. This lead
to the output always overwriting the input index leading to incorrect balances
with missing spent amounts. This patch separates the two so that they have unique
keys so balances will be correctly calculated.
Now that #7804 fixed the timeout handling, reduce the block timeout from
20 minutes to 10 minutes. 20 minutes is overkill.
Conflicts:
src/main.h
Github-Pull: #7832
Rebased-From: 62b9a557fc
Currently, we're keeping a timeout for each requested block, starting
from when it is requested, with a correction factor for the number of
blocks in the queue.
That's unnecessarily complicated and inaccurate.
As peers process block requests in order, we can make the timeout for each
block start counting only when all previous ones have been received, and
have a correction based on the number of peers, rather than the total number
of blocks.
Conflicts:
src/main.cpp
src/main.h
Self check after the last peer is removed
Github-Pull: #7804
Rebased-From: 2d1d6581ec0e24bbf679
