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Diffstat (limited to 'doc/zmq.md')
| -rw-r--r-- | doc/zmq.md | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/doc/zmq.md b/doc/zmq.md index 3a1194de1c..835dea23f2 100644 --- a/doc/zmq.md +++ b/doc/zmq.md @@ -1,6 +1,6 @@ # Block and Transaction Broadcasting with ZeroMQ -[ZeroMQ](http://zeromq.org/) is a lightweight wrapper around TCP +[ZeroMQ](https://zeromq.org/) is a lightweight wrapper around TCP connections, inter-process communication, and shared-memory, providing various message-oriented semantics such as publish/subscribe, request/reply, and push/pull. @@ -39,8 +39,9 @@ For version information, see [dependencies.md](dependencies.md). Typically, it is packaged by distributions as something like *libzmq3-dev*. The C++ wrapper for ZeroMQ is *not* needed. -In order to run the example Python client scripts in contrib/ one must -also install *python3-zmq*, though this is not necessary for daemon +In order to run the example Python client scripts in the `contrib/zmq/` +directory, one must also install [PyZMQ](https://github.com/zeromq/pyzmq) +(generally with `pip install pyzmq`), though this is not necessary for daemon operation. ## Enabling @@ -98,6 +99,20 @@ ZMQ_SUBSCRIBE option set to one or either of these prefixes (for instance, just `hash`); without doing so will result in no messages arriving. Please see [`contrib/zmq/zmq_sub.py`](/contrib/zmq/zmq_sub.py) for a working example. +The ZMQ_PUB socket's ZMQ_TCP_KEEPALIVE option is enabled. This means that +the underlying SO_KEEPALIVE option is enabled when using a TCP transport. +The effective TCP keepalive values are managed through the underlying +operating system configuration and must be configured prior to connection establishment. + +For example, when running on GNU/Linux, one might use the following +to lower the keepalive setting to 10 minutes: + +sudo sysctl -w net.ipv4.tcp_keepalive_time=600 + +Setting the keepalive values appropriately for your operating environment may +improve connectivity in situations where long-lived connections are silently +dropped by network middle boxes. + ## Remarks From the perspective of bitcoind, the ZeroMQ socket is write-only; PUB |