Previously addnodes were in competition with outbound connections
for access to the eight outbound slots.
One result of this is that frequently a node with several addnode
configured peers would end up connected to none of them, because
while the addnode loop was in its two minute sleep the automatic
connection logic would fill any free slots with random peers.
This is particularly unwelcome to users trying to maintain links
to specific nodes for fast block relay or purposes.
Another result is that a group of nine or more nodes which are
have addnode configured towards each other can become partitioned
from the public network.
This commit introduces a new limit of eight connections just for
addnode peers which is not subject to any of the other connection
limitations (including maxconnections).
The choice of eight is sufficient so that under no condition would
a user find themselves connected to fewer addnoded peers than
previously. It is also low enough that users who are confused
about the significance of more connections and have gotten too
copy-and-paste happy will not consume more than twice the slot
usage of a typical user.
Any additional load on the network resulting from this will likely
be offset by a reduction in users applying even more wasteful
workaround for the prior behavior.
The retry delays are reduced to avoid nodes sitting around without
their added peers up, but are still sufficient to prevent overly
aggressive repeated connections. The reduced delays also make
the system much more responsive to the addnode RPC.
Ban-disconnects are also exempted for peers added via addnode since
the outbound addnode logic ignores bans. Previously it would ban
an addnode then immediately reconnect to it.
A minor change was also made to CSemaphoreGrant so that it is
possible to re-acquire via an object whos grant was moved.
Performing signing in the inner loop has terrible performance
when many passes through are needed to complete the selection.
Signing before the algorithm is complete also gets in the way
of correctly setting the fee (e.g. preventing over-payment when
the fee required goes down on the final selection.)
Use of the dummy might overpay on the signatures by a couple bytes
in uncommon cases where the signatures' DER encoding is smaller
than the dummy: Who cares?
Make a more conservative notion of whether the node is caught up to the rest of the network and only count transactions as fee estimation data points if the node is caught up.
All decisions about whether the transactions are valid data points are made at the time the transaction arrives. Updating on blocks all the time will now cause stale fee estimates to decay quickly when we restart a node.
Fee estimation can just check its own mapMemPoolTxs to determine the same information. Note that now fee estimation for block processing must happen before those transactions are removed, but this shoudl be a speedup.
This was an oversight, where blocks and mempool tracking were ignored during IBD, but transactions that arrived during IBD but were included in blocks after IBD were not ignored.
Once priority estimation was removed, not all transactions in the mempool are tracked in the fee estimation mempool tracking. So there is no error if a transaction is not found for removal.
We were marking coins FRESH before being sure they were not overwriting dirty undo data. This condition was never reached in existing code because undo data was always flushed before UpdateCoins was called with new transactions, but could have been exposed in an otherwise safe refactor.
Clarify in the comments the assumptions made in ModifyNewCoins.
Add ability to undo transactions to UpdateCoins unit test.
Thanks to Russ Yanofsky for suggestion on how to make logic clearer and fixing up the ccoins_modify_new test cases.
- Drop the interruption point directly after the pnode allocation. This would
be leaky if hit.
- Rearrange thread creation so that the socket handler comes first
Jeremy Rubin