c276df775914e4e42993c76e172ef159e3b830d4 zmq: enable tcp keepalive (mruddy) Pull request description: This addresses https://github.com/bitcoin/bitcoin/issues/12754. These changes enable node operators to address the silent dropping (by network middle boxes) of long-lived low-activity ZMQ TCP connections via further operating system level TCP keepalive configuration. For example, ZMQ sockets that publish block hashes can be affected in this way due to the length of time it sometimes takes between finding blocks (e.g.- sometimes more than an hour). Prior to this patch, operating system level TCP keepalive configurations would not take effect since the SO_KEEPALIVE option was not enabled on the underlying socket. There are additional ZMQ socket options related to TCP keepalive that can be set. However, I decided not to implement those options in this changeset because doing so would require adding additional bitcoin node configuration options, and would not yield a better outcome. I preferred a small, easily reviewable patch that doesn't add a bunch of new config options, with the tradeoff that the fine tuning would have to be done via well-documented operating system specific configurations. I tested this patch by running a node with: `./src/qt/bitcoin-qt -regtest -txindex -datadir=/tmp/node -zmqpubhashblock=tcp://127.0.0.1:28332 &` and connecting to it with: `python3 ./contrib/zmq/zmq_sub.py` Without these changes, `ss -panto | grep 28332 | grep ESTAB | grep bitcoin` will report no keepalive timer information. With these changes, the output from the prior command will show keepalive timer information consistent with the configuration at the time of connection establishment, e.g.-: `timer:(keepalive,119min,0)`. I also tested with a non-TCP transport and did not witness any adverse effects: `./src/qt/bitcoin-qt -regtest -txindex -datadir=/tmp/node -zmqpubhashblock=ipc:///tmp/bitcoin.block &` ACKs for top commit: adamjonas: Just to summarize for those looking to review - as of c276df775914e4e42993c76e172ef159e3b830d4 there are 3 tACKs (n-thumann, Haaroon, and dlogemann), 1 "looks good to me" (laanwj) with no NACKs or any show-stopping concerns raised. jonasschnelli: utACK c276df775914e4e42993c76e172ef159e3b830d4 Tree-SHA512: b884c2c9814e97e666546a7188c48f9de9541499a11a934bd48dd16169a900c900fa519feb3b1cb7e9915fc7539aac2829c7806b5937b4e1409b4805f3ef6cd1
Bitcoin Core
Setup
Bitcoin Core is the original Bitcoin client and it builds the backbone of the network. It downloads and, by default, stores the entire history of Bitcoin transactions, which requires a few hundred gigabytes of disk space. Depending on the speed of your computer and network connection, the synchronization process can take anywhere from a few hours to a day or more.
To download Bitcoin Core, visit bitcoincore.org.
Running
The following are some helpful notes on how to run Bitcoin Core on your native platform.
Unix
Unpack the files into a directory and run:
bin/bitcoin-qt
(GUI) orbin/bitcoind
(headless)
Windows
Unpack the files into a directory, and then run bitcoin-qt.exe.
macOS
Drag Bitcoin Core to your applications folder, and then run Bitcoin Core.
Need Help?
- See the documentation at the Bitcoin Wiki for help and more information.
- Ask for help on #bitcoin on Freenode. If you don't have an IRC client, use webchat here.
- Ask for help on the BitcoinTalk forums, in the Technical Support board.
Building
The following are developer notes on how to build Bitcoin Core on your native platform. They are not complete guides, but include notes on the necessary libraries, compile flags, etc.
- Dependencies
- macOS Build Notes
- Unix Build Notes
- Windows Build Notes
- FreeBSD Build Notes
- OpenBSD Build Notes
- NetBSD Build Notes
- Gitian Building Guide (External Link)
Development
The Bitcoin repo's root README contains relevant information on the development process and automated testing.
- Developer Notes
- Productivity Notes
- Release Notes
- Release Process
- Source Code Documentation (External Link)
- Translation Process
- Translation Strings Policy
- JSON-RPC Interface
- Unauthenticated REST Interface
- Shared Libraries
- BIPS
- Dnsseed Policy
- Benchmarking
Resources
- Discuss on the BitcoinTalk forums, in the Development & Technical Discussion board.
- Discuss project-specific development on #bitcoin-core-dev on Freenode. If you don't have an IRC client, use webchat here.
- Discuss general Bitcoin development on #bitcoin-dev on Freenode. If you don't have an IRC client, use webchat here.
Miscellaneous
- Assets Attribution
- bitcoin.conf Configuration File
- Files
- Fuzz-testing
- Reduce Memory
- Reduce Traffic
- Tor Support
- Init Scripts (systemd/upstart/openrc)
- ZMQ
- PSBT support
License
Distributed under the MIT software license.