The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
Zenoh (pronounce /zeno/) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks.
Check the website zenoh.io and the roadmap for more detailed information.
Zenoh is extremely easy to learn, the best place to master the fundamentals is our getting started guide.
To install the latest release of the Zenoh router (zenohd
) and its default plugins (REST API plugin and Storages Manager plugin) you can do as follows:
All release packages can be downloaded from:
Each subdirectory has the name of the Rust target. See the platforms each target corresponds to on https://doc.rust-lang.org/stable/rustc/platform-support.html
Choose your platform and download the .zip
file.
Unzip it where you want, and run the extracted zenohd
binary.
Add Eclipse Zenoh private repository to the sources list, and install the zenoh
package:
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" | sudo tee -a /etc/apt/sources.list.d/zenoh.list > /dev/null
sudo apt update
sudo apt install zenoh
Then you can start run zenohd
.
Tap our brew package repository and install the zenoh
formula:
brew tap eclipse-zenoh/homebrew-zenoh
brew install zenoh
Then you can start run zenohd
.
Warning
Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project.
Install Cargo and Rust. Zenoh can be successfully compiled with Rust stable (>= 1.71.0), so no special configuration is required from your side. If you already have the Rust toolchain installed, make sure it is up-to-date with:
$ rustup update
To build Zenoh, just type the following command after having followed the previous instructions:
$ cargo build --release --all-targets
Zenoh's router is built as target/release/zenohd
. All the examples are built into the target/release/examples
directory. They can all work in peer-to-peer, or interconnected via the zenoh router.
Peer-to-peer tests:
-
pub/sub
- run:
./target/release/examples/z_sub
- in another shell run:
./target/release/examples/z_put
- the subscriber should receive the publication.
- run:
-
get/queryable
- run:
./target/release/examples/z_queryable
- in another shell run:
./target/release/examples/z_get
- the queryable should display the log in its listener, and the get should receive the queryable result.
- run:
Routed tests:
Note
Windows users: to properly execute the commands below in PowerShell you need to escape "
characters as \"
.
-
put/store/get
- run the Zenoh router with a memory storage:
./target/release/zenohd --cfg='plugins/storage_manager/storages/demo:{key_expr:"demo/example/**",volume:"memory"}'
- in another shell run:
./target/release/examples/z_put
- then run
./target/release/examples/z_get
- the get should receive the stored publication.
- run the Zenoh router with a memory storage:
-
REST API using
curl
tool- run the Zenoh router with a memory storage:
./target/release/zenohd --cfg='plugins/storage_manager/storages/demo:{key_expr:"demo/example/**",volume:"memory"}'
- in another shell, do a publication via the REST API:
curl -X PUT -d '"Hello World!"' http://localhost:8000/demo/example/test
- get it back via the REST API:
curl http://localhost:8000/demo/example/test
- run the Zenoh router with a memory storage:
-
router admin space via the REST API
- run the Zenoh router with permission to perform config changes via the admin space, and with a memory storage:
./target/release/zenohd --adminspace-permissions=rw --cfg='plugins/storage_manager/storages/demo:{key_expr:"demo/example/**",volume:"memory"}'
- in another shell, get info of the zenoh router via the zenoh admin space:
curl http://localhost:8000/@/router/local
- get the volumes of the router (only memory by default):
curl 'http://localhost:8000/@/router/local/**/volumes/*'
- get the storages of the local router (the memory storage configured at startup on '/demo/example/**' should be present):
curl 'http://localhost:8000/@/router/local/**/storages/*'
- add another memory storage on
/demo/mystore/**
:curl -X PUT -H 'content-type:application/json' -d '{"key_expr":"demo/mystore/**","volume":"memory"}' http://localhost:8000/@/router/local/config/plugins/storage_manager/storages/mystore
- check it has been created:
curl 'http://localhost:8000/@/router/local/**/storages/*'
- run the Zenoh router with permission to perform config changes via the admin space, and with a memory storage:
Configuration options:
A Zenoh configuration file can be provided via CLI to all Zenoh examples and the Zenoh router.
-c, --config <FILE>
: a JSON5 configuration file. DEFAULT_CONFIG.json5 shows the schema of this file and the available options.
See other examples of Zenoh usage in examples/
Note
Zenoh Runtime Configuration: Starting from version 0.11.0-rc, Zenoh allows for configuring the number of worker threads and other advanced options of the runtime. For guidance on utilizing it, please refer to the doc.
zenohd
accepts the following arguments:
-
--adminspace-permissions <[r|w|rw|none]>
: Configure the read and/or write permissions on the admin space. Default is read only. -
-c, --config <FILE>
: a JSON5 configuration file. DEFAULT_CONFIG.json5 shows the schema of this file. All properties of this configuration are optional, so you may not need such a large configuration for your use-case. -
--cfg [<KEY>:<VALUE>]...
: allows you to change specific parts of the configuration right after it has been constructed. VALUE must be a valid JSON5 value, and key must be a path through the configuration file, where each element is separated by a/
. When inserting in parts of the config that are arrays, you may use indexes, or may use--cfg
passed values will always override any previously existing value for their key in the configuration. -
-l, --listen <ENDPOINT>...
: An endpoint on which this router will listen for incoming sessions. Repeat this option to open several listeners. By default,tcp/[::]:7447
is used. The following endpoints are currently supported: -
-e, --connect <ENDPOINT>...
: An endpoint this router will try to connect to. Repeat this option to connect to several peers or routers. -
--no-multicast-scouting
: By default zenohd replies to multicast scouting messages for being discovered by peers and clients. This option disables this feature. -
-i, --id <hex_string>
: The identifier (as an hexadecimal string - e.g.: A0B23...) that zenohd must use. WARNING: this identifier must be unique in the system! If not set, a random unsigned 128bit integer will be used. -
--no-timestamp
: By default zenohd adds a HLC-generated Timestamp to each routed Data if there isn't already one. This option disables this feature. -
-P, --plugin [<PLUGIN_NAME> | <PLUGIN_NAME>:<LIBRARY_PATH>]...
: A plugin that must be loaded. Accepted values:- a plugin name; zenohd will search for a library named
libzenoh_plugin_<name>.so
on Unix,libzenoh_plugin_<PLUGIN_NAME>.dylib
on MacOS orzenoh_plugin_<PLUGIN_NAME>.dll
on Windows. "<PLUGIN_NAME>:<LIBRARY_PATH>"
; the plugin will be loaded from library file at<LIBRARY_PATH>
.
Repeat this option to load several plugins.
- a plugin name; zenohd will search for a library named
-
--plugin-search-dir <DIRECTORY>...
: A directory where to search for plugins libraries to load. Repeat this option to specify several search directories'. By default, the plugins libraries will be searched in:'/usr/local/lib:/usr/lib:~/.zenoh/lib:.'
-
--rest-http-port <rest-http-port>
: Configures the REST plugin's HTTP port. Accepted values:- a port number
- a string with format
<local_ip>:<port_number>
(to bind the HTTP server to a specific interface) "None"
to deactivate the REST plugin
If not specified, the REST plugin will be active on any interface (
[::]
) and port8000
.
Warning
The following documentation pertains to the v0.6 API, which comes many changes to the behaviour and configuration of Zenoh. To access the v0.5 version of the code and matching README, please go to the 0.5.0-beta.9 tagged version.
Warning
As Rust doesn't have a stable ABI, the plugins should be
built with the exact same Rust version than zenohd
, and using for zenoh
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between zenohd
and the library can lead to a "SIGSEV"
crash.
By default the Zenoh router is delivered or built with 2 plugins. These may be configured through a configuration file, or through individual changes to the configuration via the --cfg
CLI option or via zenoh puts on individual parts of the configuration.
Warning
Since v0.6
, zenohd
no longer loads every available plugin at startup. Instead, only configured plugins are loaded (after processing --cfg
and --plugin
options). Once zenohd
is running, plugins can be hot-loaded and, if they support it, reconfigured at runtime by editing their configuration through the adminspace.
Note that the REST plugin is added to the configuration by the default value of the --rest-http-port
CLI argument.
REST plugin (exposing a REST API): This plugin converts GET and PUT REST requests into Zenoh gets and puts respectively.
Storages plugin (managing backends and storages) This plugin allows you to easily define storages. These will store key-value pairs they subscribed to, and send the most recent ones when queried. Check out DEFAULT_CONFIG.json5 for info on how to configure them.
In case of troubles, please first check on this page if the trouble and cause are already known. Otherwise, you can ask a question on the zenoh Discord server, or create an issue.