b73d331937
The default max file size for LevelDB is 2 MiB, which results in the LevelDB compaction code generating ~4 disk cache flushes per second when syncing with the Bitcoin network. These disk cache flushes are triggered by fdatasync() syscall issued by the LevelDB compaction code when reaching the max file size. If the database is on a HDD this flush rate brings the whole system to a crawl. It also results in very slow throughput since 2 MiB * 4 flushes per second is about 8 MiB / second max throughput, while even an old HDD can pull 100 - 200 MiB / second streaming throughput. Increase the max file size for LevelDB to 32 MiB instead so the flush rate drops significantly and the system no longer gets so sluggish. The new max file size value chosen is a compromise between the one that works best for HDD and SSD performance, as determined by benchmarks done by various people. |
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|---|---|---|
| .github | ||
| .tx | ||
| ci | ||
| cmake | ||
| contrib | ||
| depends | ||
| doc | ||
| share | ||
| src | ||
| test | ||
| .cirrus.yml | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .python-version | ||
| .style.yapf | ||
| CMakeLists.txt | ||
| CMakePresets.json | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| INSTALL.md | ||
| libbitcoinkernel.pc.in | ||
| README.md | ||
| SECURITY.md | ||
| vcpkg.json | ||
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
What is Bitcoin Core?
Bitcoin Core connects to the Bitcoin peer-to-peer network to download and fully validate blocks and transactions. It also includes a wallet and graphical user interface, which can be optionally built.
Further information about Bitcoin Core is available in the doc folder.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled during the generation of the build system) with: ctest. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: build/test/functional/test_runner.py
(assuming build is your build directory).
The CI (Continuous Integration) systems make sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.