dash/doc/release-notes.md
Gregory Maxwell e440ac7ef3 Introduce assumevalid setting to skip presumed valid scripts.
This disentangles the script validation skipping from checkpoints.

A new option is introduced "assumevalid" which specifies a block whos
 ancestors we assume all have valid scriptsigs and so we do not check
 them when they are also burried under the best header by two weeks
 worth of work.

Unlike checkpoints this has no influence on consensus unless you set
 it to a block with an invalid history.  Because of this it can be
 easily be updated without risk of influencing the network consensus.

This results in a massive IBD speedup.

This approach was independently recommended by Peter Todd and Luke-Jr
 since POW based signature skipping (see PR#9180) does not have the
 verifiable properties of a specific hash and may create bad incentives.

The downside is that, like checkpoints, the defaults bitrot and older
 releases will sync slower.  On the plus side users can provide their
 own value here, and if they set it to something crazy all that will
 happen is more time will be spend validating signatures.

Checkblocks and checklevel are also moved to the hidden debug options:
 Especially now that checkblocks has a low default there is little need
 to change these settings, and users frequently misunderstand them as
 influencing security or IBD speed.  By hiding them we offset the
 space added by this new option.
2017-01-13 15:42:24 +00:00

139 lines
5.4 KiB
Markdown

(note: this is a temporary file, to be added-to by anybody, and moved to
release-notes at release time)
Bitcoin Core version *version* is now available from:
<https://bitcoin.org/bin/bitcoin-core-*version*/>
This is a new major version release, including new features, various bugfixes
and performance improvements, as well as updated translations.
Please report bugs using the issue tracker at github:
<https://github.com/bitcoin/bitcoin/issues>
To receive security and update notifications, please subscribe to:
<https://bitcoincore.org/en/list/announcements/join/>
Compatibility
==============
Microsoft ended support for Windows XP on [April 8th, 2014](https://www.microsoft.com/en-us/WindowsForBusiness/end-of-xp-support),
an OS initially released in 2001. This means that not even critical security
updates will be released anymore. Without security updates, using a bitcoin
wallet on a XP machine is irresponsible at least.
In addition to that, with 0.12.x there have been varied reports of Bitcoin Core
randomly crashing on Windows XP. It is [not clear](https://github.com/bitcoin/bitcoin/issues/7681#issuecomment-217439891)
what the source of these crashes is, but it is likely that upstream
libraries such as Qt are no longer being tested on XP.
We do not have time nor resources to provide support for an OS that is
end-of-life. From 0.13.0 on, Windows XP is no longer supported. Users are
suggested to upgrade to a newer version of Windows, or install an alternative OS
that is supported.
No attempt is made to prevent installing or running the software on Windows XP,
you can still do so at your own risk, but do not expect it to work: do not
report issues about Windows XP to the issue tracker.
Notable changes
===============
Low-level RPC changes
----------------------
- `importprunedfunds` only accepts two required arguments. Some versions accept
an optional third arg, which was always ignored. Make sure to never pass more
than two arguments.
Removal of Priority Estimation
-------------------------------
- Estimation of "priority" needed for a transaction to be included within a target
number of blocks has been removed. The rpc calls are deprecated and will either
return -1 or 1e24 appropriately. The format for `fee_estimates.dat` has also
changed to no longer save these priority estimates. It will automatically be
converted to the new format which is not readable by prior versions of the
software.
- The concept of "priority" transactions is planned to be removed in the next
major version. To prepare for this, the default for the rate limit of priority
transactions (`-limitfreerelay`) has been set to `0` kB/minute.
P2P connection management
--------------------------
- Peers manually added through the addnode option or addnode RPC now have their own
limit of eight connections which does not compete with other inbound or outbound
connection usage and is not subject to the maxconnections limitation.
- New connections to manually added peers are much faster.
Introduction of assumed-valid blocks
-------------------------------------
- A significant portion of the initial block download time is spent verifying
scripts/signatures. Although the verification must pass to ensure the security
of the system, no other result from this verification is needed: If the node
knew the history of a given block were valid it could skip checking scripts
for its ancestors.
- A new configuration option 'assumevalid' is provided to express this knowledge
to the software. Unlike the 'checkpoints' in the past this setting does not
force the use of a particular chain: chains that are consistent with it are
processed quicker, but other chains are still accepted if they'd otherwise
be chosen as best. Also unlike 'checkpoints' the user can configure which
block history is assumed true, this means that even outdated software can
sync more quickly if the setting is updated by the user.
- Because the validity of a chain history is a simple objective fact it is much
easier to review this setting. As a result the software ships with a default
value adjusted to match the current chain shortly before release. The use
of this default value can be disabled by setting -assumevalid=0
0.14.0 Change log
=================
Detailed release notes follow. This overview includes changes that affect
behavior, not code moves, refactors and string updates. For convenience in locating
the code changes and accompanying discussion, both the pull request and
git merge commit are mentioned.
### RPC and REST
UTXO set query (`GET /rest/getutxos/<checkmempool>/<txid>-<n>/<txid>-<n>/.../<txid>-<n>.<bin|hex|json>`) responses
were changed to return status code HTTP_BAD_REQUEST (400) instead of HTTP_INTERNAL_SERVER_ERROR (500) when requests
contain invalid parameters.
The first boolean argument to `getaddednodeinfo` has been removed. This is an incompatible change.
Call "getmininginfo" loses the "testnet" field in favor of the more generic "chain" (which has been present for years).
### Configuration and command-line options
### Block and transaction handling
### P2P protocol and network code
### Validation
### Build system
### Wallet
### GUI
### Tests
### Miscellaneous
Credits
=======
Thanks to everyone who directly contributed to this release:
As well as everyone that helped translating on [Transifex](https://www.transifex.com/projects/p/bitcoin/).