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 integration/staging tree
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information, as well as an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/, or read the original whitepaper.
License
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Development Process
The master
branch is regularly built (see doc/build-*.md
for instructions) and tested, but it is not guaranteed to be
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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.
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Developers are strongly encouraged to write unit tests for new code, and to
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. Further details on running
and extending unit tests can be found in /src/test/README.md.
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