Satoshi client 0.8 released, scalability addressed

Posted on February 20, 2013


Word on the street is that the latest, 0.8-est release of the ‘official’ reference client is out, with some moves to start addressing the scalability of the Bitcoin transaction database, by the looks of it. Grab it here. Here’s the full info from the mailing list:

Bitcoin-Qt version 0.8.0 are now available from:

This is a major release designed to improve performance and handle the
increasing volume of transactions on the network.

Please report bugs using the issue tracker at github:

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).

The first time you run after the upgrade a re-indexing process will be
started that will take anywhere from 30 minutes to several hours,
depending on the speed of your machine.

Incompatible Changes

This release no longer maintains a full index of historical transaction ids
by default, so looking up an arbitrary transaction using the
RPC call will not work. If you need that functionality, you must run once
with -txindex=1 -reindex=1 to rebuild block-chain indices (see below for


Mac and Windows binaries are signed with certificates owned by the Bitcoin
Foundation, to be compatible with the new security features in OSX 10.8 and
Windows 8.

LevelDB, a fast, open-source, non-relational database from Google, is
now used to store transaction and block indices.  LevelDB works much better
on machines with slow I/O and is faster in general. Berkeley DB is now only
used for the wallet.dat file (public and private wallet keys and
relevant to you).

Pieter Wuille implemented many optimizations to the way transactions are
verified, so a running, synchronized node uses less working memory and does
much less I/O. He also implemented parallel signature checking, so if you
have a multi-CPU machine all CPUs will be used to verify transactions.

New Features

"Bloom filter" support in the network protocol for sending only relevant
transactions to
lightweight clients.

contrib/verifysfbinaries is a shell-script to verify that the binary
at sourceforge have not been tampered with. If you are able, you can help
everybody's downloads more secure by running this occasionally to check PGP
signatures against download file checksums.

contrib/spendfrom is a python-language command-line utility that
how to use the "raw transactions" JSON-RPC api to send coins received from
addresses (also known as "coin control").

New/changed settings (command-line or bitcoin.conf file)

dbcache : controls LevelDB memory usage.

par : controls how many threads to use to validate transactions. Defaults
to the number
of CPUs on your machine, use -par=1 to limit to a single CPU.

txindex : maintains an extra index of old, spent transaction ids so they
will be found
by the getrawtransaction JSON-RPC method.

reindex : rebuild block and transaction indices from the downloaded block

New JSON-RPC API Features

lockunspent / listlockunspent allow locking transaction outputs for a
period of time so
they will not be spent by other processes that might be accessing the same

addnode / getaddednodeinfo methods, to connect to specific peers without

importprivkey now takes an optional boolean parameter (default true) to
control whether
or not to rescan the blockchain for transactions after importing a new
private key.

Important Bug Fixes

Privacy leak: the position of the "change" output in most transactions was
not being
properly randomized, making network analysis of the transaction graph to
users' wallets easier.

Zero-confirmation transaction vulnerability: accepting zero-confirmation
(transactions that have not yet been included in a block) from somebody you
do not
trust is still not recommended, because there will always be ways for
attackers to
double-spend zero-confirmation transactions. However, this release includes
a bug
fix that makes it a little bit more difficult for attackers to double-spend
certain type ("lockTime in the future") of zero-confirmation transaction.

Dependency Changes

Qt 4.8.3 (compiling against older versions of Qt 4 should continue to work)

Thanks to everybody who contributed to this release:

Alexander Kjeldaas
Andrey Alekseenko
Arnav Singh
Christian von Roques
Eric Lombrozo
Forrest Voight
Gavin Andresen
Gregory Maxwell
Jeff Garzik
Luke Dashjr
Matt Corallo
Mike Cassano
Mike Hearn
Peter Todd
Philip Kaufmann
Pieter Wuille
Richard Schwab
Robert Backhaus
Rune K. Svendsen
Sergio Demian Lerner
Wladimir J. van der Laan
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