<commit_before>Bitcoin Core version 0.11.0 is now available from:

  <https://bitcoin.org/bin/bitcoin-core-0.11.0/>

This is a new major version release, bringing both new features and
bug fixes.

Please report bugs using the issue tracker at github:

  <https://github.com/bitcoin/bitcoin/issues>

Upgrading and downgrading
=========================

How to Upgrade
--------------

If you are running an older version, shut it down. Wait until it has completely
shut down (which might take a few minutes for older versions), then run the
installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
bitcoind/bitcoin-qt (on Linux).

Downgrade warning
------------------

Because release 0.10.0 and later makes use of headers-first synchronization and
parallel block download (see further), the block files and databases are not
backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

* Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or
other programs. Reindexing using earlier versions will also not work
anymore as a result of this.

* The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support.

If you want to be able to downgrade smoothly, make a backup of your entire data
directory. Without this your node will need start syncing (or importing from
bootstrap.dat) anew afterwards. It is possible that the data from a completely
synchronised 0.10 node may be usable in older versions as-is, but this is not
supported and may break as soon as the older version attempts to reindex.

This does not affect wallet forward or backward compatibility. There are no
known problems when downgrading from 0.11.x to 0.10.x.

Notable changes
===============

Block file pruning
----------------------<commit_msg>doc: add important information about tx flood to release notes<commit_after>Bitcoin Core version 0.11.0 is now available from:

  <https://bitcoin.org/bin/bitcoin-core-0.11.0/>

This is a new major version release, bringing both new features and
bug fixes.

Please report bugs using the issue tracker at github:

  <https://github.com/bitcoin/bitcoin/issues>

Upgrading and downgrading
=========================

How to Upgrade
--------------

If you are running an older version, shut it down. Wait until it has completely
shut down (which might take a few minutes for older versions), then run the
installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
bitcoind/bitcoin-qt (on Linux).

Downgrade warning
------------------

Because release 0.10.0 and later makes use of headers-first synchronization and
parallel block download (see further), the block files and databases are not
backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

* Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or
other programs. Reindexing using earlier versions will also not work
anymore as a result of this.

* The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support.

If you want to be able to downgrade smoothly, make a backup of your entire data
directory. Without this your node will need start syncing (or importing from
bootstrap.dat) anew afterwards. It is possible that the data from a completely
synchronised 0.10 node may be usable in older versions as-is, but this is not
supported and may break as soon as the older version attempts to reindex.

This does not affect wallet forward or backward compatibility. There are no
known problems when downgrading from 0.11.x to 0.10.x.

Important information
======================

Transaction flooding
---------------------

At the time of this release, the P2P network is being flooded with low-fee
transactions. This causes a ballooning of the mempool size.

If this growth of the mempool causes problematic memory use on your node, it is
possible to change a few configuration options to work around this. The growth
of the mempool can be monitored with the RPC command `getmempoolinfo`.

One is to increase the minimum transaction relay fee `minrelaytxfee`, which
defaults to 0.00001. This will cause transactions with fewer BTC/kB fee to be
rejected, and thus fewer transactions entering the mempool.

The other is to restrict the relaying of free transactions with
`limitfreerelay`. This option sets the number of kB/minute at which
free transactions (with enough priority) will be accepted. It defaults to 15.
Reducing this number reduces the speed at which the mempool can grow due
to free transactions.

For example, add the following to `bitcoin.conf`:

    minrelaytxfee=0.00005 
    limitfreerelay=5

More robust solutions are being worked on for a follow-up release.

Notable changes
===============

Block file pruning
----------------------
{'fraction_non_alphanumeric': 0.08800482218203737, 'fraction_numerical': 0.01285915209965843, 'mean_word_length': 3.842412451361868, 'pattern_counts': {'":': 0, '<': 7, '<?xml version=': 0, '>': 7, 'https://': 4, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 2, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '6302838', 'n_tokens_mistral': 1312, 'n_tokens_neox': 1225, 'n_words': 716}