Release Notes for Bitcoin Cash Node version 22.2.0

Bitcoin Cash Node version 22.2.0 is now available from:

https://bitcoincashnode.org

Overview

This is a minor release of Bitcoin Cash Node that implements some interface enhancements and includes a number of other corrections and improvements.

Users who are running any of our previous releases are recommended to upgrade to v22.2.0 as part of regular maintenance.

Usage recommendations

Installing this version is optional, but we strongly recommend that users of 22.1.0 upgrade to this release for the corrections, performance improvements and post-upgrade checkpoints contained in it.

Network changes

Policy has been changed to enforce standard transactions on testnet4. This is to have a test network that is close to mainnet.
If you wish to experiment with non-standard transactions, please use testnet3 or scalenet.

This release reduces the interval between INV announcements (and introduces a new command-line configurable option, -txbroadcastinterval, with millisecond resolution. The default value is set to 500 ms for incoming connections (and half that for outgoing) instead of 5 seconds incoming (2 sec outgoing).

The rate at which new INV messages are broadcast has important implications for scalability.

In order to mitigate spam attacks, the node will limit the rate at which new transaction invs are broadcast to each peer. The default is to limit this to 7 tx/sec per MB of excessive block size. That is, with a 32 MB blocksize limit, no more than 224 tx INVs are allowed
to be broadcast each second. The broadcast rate limit is adjustable through the -txbroadcastrate configuration option.

Change of -maxmempool default value

The default value for -maxmempool has been changed to 10 times the excessiveblocksize, i.e. 320 MB on mainet and 2560 MB on scalenet. If your node does not have sufficient free memory to accommodate such a maxmempool setting when running on scalenet, we recommend to upgrade your memory capacity or override this default.

Added functionality

Configurable transaction broadcast interval and rate

Two new configuration have been added which control the INV broadcast interval and rate, with millisecond resolution.

These options have important impact on user experience and scalability, and have been configured with settings that improve on the previous conditions.

For more information on these impact of these options, please refer to the detailed description in:

https://gitlab.com/bitcoin-cash-node/bitcoin-cash-node/-/merge_requests/746

Thread names in logs

Log lines can be prefixed with the name of the thread that caused the log. To enable this behavior, use-logthreadnames=1.

Deprecated functionality

The getnetworkhashps RPC has an option to calculate average hashrate "since last difficulty change". This option works incorrectly, assuming that difficulty changes every 2016 blocks. The option is considered irrelevant with the per-block DAA adjustments introduced in 2017 and is scheduled for removal in a future release.

Removed functionality

No functionality is removed in this release.

New RPC methods

No new RPC methods are added in this release,

Low-level RPC changes

The getblockstats RPC is faster for fee calculation by using BlockUndo data. Also, -txindex is no longer required and getblockstats works for all non-pruned blocks.

A discrepancy was noticed in the argument and result value names of getexcessiveblock and setexcessiveblock RPC calls between the interface documentation, actual required argument names, error message and name of returned result. A two-step procedure will be followed to correct this.

1. In this release, the RPC help and error messages for the setexcessiveblock command have been corrected to maxBlockSize to align the name of the argument, previously blockSize, with the name required when the "named argument" form of the call is used.

2. In a future release, the parameter name maxBlockSize introduced by this version will be renamed to 'excessiveBlockSize' in order to make it the same as the result value of the getexcessiveblock RPC call.

Regressions

Bitcoin Cash Node 22.2.0 does not introduce any known regressions compared to 22.1.0.

Known Issues

Some issues could not be closed in time for release, but we are tracking all of them on our GitLab repository.

• MacOS versions earlier than 10.12 are no longer supported. Additionally, Bitcoin Cash Node does not yet change appearance when macOS "dark mode" is activated.

• Windows users are recommended not to run multiple instances of bitcoin-qt or bitcoind on the same machine if the wallet feature is enabled. There is risk of data corruption if instances are configured to use the same wallet folder.

• Some users have encountered unit tests failures when running in WSL environments (e.g. WSL/Ubuntu). At this time, WSL is not considered a supported environment for the software. This may change in future. The functional failure on WSL is tracked in Issue #33. It arises when competing node program instances are not prevented from opening the same wallet folder. Running multiple program instances with the same configured walletdir could potentially lead to data corruption. The failure has not been observed on other operating systems so far.

• doc/dependencies.md needs revision (Issue #65).

• test_bitcoin can collide with temporary files if used by more than one user on the same system simultaneously. (Issue #43)

• For users running from sources built with BerkeleyDB releases newer than the 5.3 which is used in this release, please take into consideration the database format compatibility issues described in Issue #34. When building from source it is recommended to use BerkeleyDB 5.3 as this avoids wallet database incompatibility issues with the official release.

• There is a documentation build bug that causes some ordered lists on docs.bitcoincashnode.org to be rendered incorrectly (Issue #141).

• The test_bitcoin-qt test executable fails on Linux Mint 20 (see Issue #144). This does not otherwise appear to impact the functioning of the BCHN software on that platform.

• An 'autotools' build (the old build method) fails on OSX when using Clang. (Issue #129)

• With a certain combination of build flags that included disabling the QR code library, a build failure was observed where an erroneous linking against the QR code library (not present) was attempted (Issue #138).

• The 'autotools' build is known to require some workarounds in order to use the 'fuzzing' build feature (Issue #127).

• Some functional tests are known to fail spuriously with varying probability. (see e.g. Issue #148, and a fuller listing in #162).

• Possible out-of-memory error when starting bitcoind with high excessiveblocksize value (Issue #156)

• There are obstacles building the current version on Ubuntu 16.04 (see #187). These are worked around by our packaging system, but users trying to build the software from scratch are advised to either upgrade to more recent Ubuntu, or retrofit the necessary toolchains and perform the same build steps for Xenial as registered in our packaging repository, or build in a VM using the gitian build instructions, or run our reproducible binary release builds.

• The getnetworkhashps RPC call is not adapted to per-block DAA (see #193). It has an option to calculate average hashrate "since last difficulty change" and wrongly assumes difficulty changes every 2016 blocks. This irrelevant option will likely be removed in the next release.

• A problem was observed on scalenet where nodes would sometimes hang for around 10 minutes, accepting RPC connections but not responding to them (see #210).

• arc lint will advise that some src/ files are in need of reformatting or contain errors. This is because code style checking is currently a work in progress while we adjust it to our own project requirements (see Issue #75). One file in doc also violates the lint tool (Issue #153), and a new script in test/benchmark/ likewise contains code that is flagged by the current linting configuration. There are also RPC parameter type inconsistencies that flag linting checks (see #182).

Changes since Bitcoin Cash Node 22.1.0

New documents

None.

Removed documents

None.

Notable commits grouped by functionality

Security or consensus relevant fixes

• ab6226a Add checkpoints for Axion activation on Bitcoin Cash
• 4ee1083 Activate Nov. 15 HF (axion) based on height on 3 of the 4 chains

Interfaces / RPC

• 6e398da RPC: Restore getblockheader to allow any chain, plus add test
• 4e65071 Update chainparams.cpp [Note: require standardness on testnet4]
• 5386f29 threads: prefix log messages with thread names
• 3de1fe8 threads: add thread names to deadlock debugging message
• 7b2dfa8 util: Make thread names shorter
• a88a043 [tx relay] Make INV broadcast interval and rate command-line options with ms resolution, default 500 ms and 7tx/MB/sec
• 2da86c6 Mining bugfix: Properly initialize g_best_block at startup

Peformance optimizations

• ff5364a Optimized Logger class to do less redundant copying
• 200c220 RPC: Significantly improve performance of getblockstats
• 3d917c5 RPC: Release lock earlier in getblock
• cb4091f Performance nits in signature handling (#117)
• 10fe8be RPC: Make getblockstats not require txindex, use undo file instead
• 1ee2631 FlatFileSeq: Move directory creation out of the read only path
• a188f9b Upgrade UniValue code in JSON-RPC server/client
• 13d28d3 Upgrade UniValue code in rpc/mining.cpp (#51)
• f08c7ae Upgrade UniValue code in rpc/blockchain.cpp (#51)
• eba4016 Upgrade UniValue code in rpc/net.cpp, rpc/misc.cpp, rpc/abc.cpp (#51)
• 1b2804d Upgrade UniValue code in rpc/rawtransaction.cpp (#51)
• c582717 Upgrade UniValue code in wallet/rpcwallet.cpp, wallet/rpcdump.cpp (#51)

GUI

• 0e2a4f2 [qa] Adjust sizes of testnet4 and scalenet blockchains

Code quality

• 86be8a2 Fix deprecated warnings in paymentserver.cpp
• 32be66f [trivial] Remove extraneous debug print in mininode.py on_version
• 14ea9c9 refactor: Make coinsel an enum class
• a6f2b5f [qa] Remove unused, commented out function 'GetPubKey'
• 71a6b50 [lint] align getexcessiveblock argument name to 'maxBlockSize'
• dc2dda0 Update ChainTxData
• 87bc68c Make UniValue accept any integer type
• 31c1f38 Consistently name the "excessive block size" concept + add a test

Documentation updates

• 244ccb5 fix link to source of disclosure policy
• a4e19b1 [doc] Add section on LFS in benchmark docs
• 63e46a4 mkdocs: consistent page names for release notes in navigation menu
• 1413810 [doc] Update test networks doc for Axion and v22.2.0 release changes
• 9a42efb mkdocs: Fix bullet list rendering
• 3966a24 [doc] Update known GitLab labels
• 11a38ce [doc] Fix the ordered list in CONTRIBUTING.md
• 03a75f8 [doc] Regenerate (update) the manpages and markdown docs for v22.2.0

Build / general

• a320927 Fix ODR violation leading to subtle build error on Fedora
• 75a2b79 threads: introduce util/threadnames, refactor thread naming
• 00c4784 Fix portability issue with pthreads
• 10cead4 Don't rename main thread at process level
• 028a2a1 Allow to extend and override the sanitizers options
• 393e46f Block storage: Fix OOM crash when block is larger than block file size
• 8af5ace Make -maxmempool default to 10x excessiveblocksize (e.g. 320 MB on mainet, 2560 MB on scalenet)

Build / Linux

No changes.

Build / Windows

No changes.

Build / MacOSX

• 7205d35 Fix for compile problem in rpc/mining.cpp on some platforms

Tests / test framework

• 82adea6 Fix ninja check failure on Arch Linux
• b7ce498 tests: add threadutil tests
• f22ed05 test: Disable mockforward scheduler unit test for now
• ce52577 Tests: fix for the infamous bchn-rpc-gbtl-bg-cleaner sometimes failing
• 4b6c954 Functional test for avg inv send interval
• a7f8f5e qa: Add wallet_encryption error tests
• 10eb3e7 Add .markdownlint.json
• c7ee4fa [qa] fix unreliable wallet_basic tests
• 3745f76 Improve functional test decodescript RPC
• c3d6d4c Functional tests: check for duplicate keys in JSON-RPC responses
• d930164 qa: Fix format of error message

Benchmarks

No changes.

Seeds / seeder software

• bba4243 [seeder] Modernize code
• 413e54f remove bitcoinabc.org seeders

Maintainer tools

• 2a9e6d6 [qa] Update make_seeds script and samples

Infrastructure

No changes.

Cleanup

• 4d6467c Update default assume valid and minimum chain work params after Axion activation

Continuous Integration (GitLab CI)

No changes.

Backports

• b8d9db8 Core: PR#18284: [backport] Work around negative nsecs bug in boost::wait_until
• e422356 Core: PR#15615: [backport] Add log output during initial header sync
• d21e79a Core: PR#14726: (partial) Use RPCHelpMan for most RPCs
• 430a311 Core: PR#18965: tests: implement base58_decode
• b7e0828 ABC: D5760: [DOC] Update the sanitizer documentation