Eclipse zenoh

The Eclipse zenoh: Zero Overhead Pub/sub, Store/Query and Compute.

Eclipse zenoh /zeno/ unifies data in motion, data in-use, 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 for more detailed information.

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How to test it

For convenience, the zenoh router is pre-build and made available in a Docker image: https://hub.docker.com/r/eclipse/zenoh

Thus, run it just doing:

docker pull eclipse/zenoh:latest
docker run --init -p 7447:7447/tcp -p 7447:7447/udp -p 8000:8000/tcp eclipse/zenoh:latest

The ports used by zenoh are the following:

• 7447/tcp : the zenoh protocol via TCP
• 7447/udp : the zenoh scouting protocol using UDP multicast (for clients to automatically discover the router)
• 8000/tcp : the zenoh REST API

Then, you can test it using the zenoh API in your favorite language:

• Python using zenoh-python
• Java using zenoh-java
• Go using zenoh-go
• C using zenoh-c

Or with the REST API:

Examples of usage with the REST API

The complete Eclipse zenoh's key/value space is accessible through the REST API, using regular HTTP GET, PUT and DELETE methods. In those examples, we use the curl command line tool.

Managing the admin space

• Get info of the local zenoh router:

  curl http://localhost:8000/@/router/local
  

• Get the plugins of the local router (http and storages by default):

  curl 'http://localhost:8000/@/router/local/plugin/*'
  

• Get the backends of the local router (only memory by default):

  curl 'http://localhost:8000/@/router/local/**/backend/*'
  

• Get the storages of the local router (none by default):

  curl 'http://localhost:8000/@/router/local/**/storage/*'
  

• Add a memory storage on /zenoh/examples/**:

  curl -X PUT -d '{"selector":"/zenoh/examples/**"}' http://localhost:8000/@/router/local/plugin/storages/backend/memory/storage/my-storage
  

Put/Get into zenoh

Assuming the memory storage has been added, as described above, you can now:

• Put a key/value into zenoh:

curl -X PUT -d 'Hello World!' http://localhost:8000/zenoh/examples/test

• Retrieve the key/value:

curl http://localhost:8000/zenoh/examples/test

• Remove the key value

curl -X DELETE http://localhost:8000/zenoh/examples/test

Using an SQLite3 backend

• Add the SQLite3 backend using file /tmp/sqlite3-zenoh.db:

  curl -X PUT -d '{"lib":"sqlite3","url":"sqlite3:///tmp/sqlite3-zenoh.db"}' http://localhost:8000/@/router/local/plugin/storages/backend/sqlite3
  

• Add a storage using the SQLite3 backend on /zenoh/sql-examples/**.
  This storage will store everything in a table named 'example', and this table will be truncated when the storage is removed or when zenoh stops:

  curl -X PUT -d '{"selector":"/zenoh/sql-examples/**","table":"example","on_dispose":"Truncate"}' http://localhost:8000/@/router/local/plugin/storages/backend/sqlite3/storage/my-sql-storage
  

• Put different keys/values into the SQLite3 storage:

  curl -X PUT -d 'Value A' http://localhost:8000/zenoh/sql-examples/A
  curl -X PUT -d 'Value B' http://localhost:8000/zenoh/sql-examples/B
  curl -X PUT -d 'Value C' http://localhost:8000/zenoh/sql-examples/C
  

• Get all keys/values from the SQLite3 storage:

  curl 'http://localhost:8000/zenoh/sql-examples/**'
  

• Get all keys/values from the ALL storage:

  curl 'http://localhost:8000/zenoh/**'
  

Using an InfluxDB backend

• Add the InfluxDB backend (assuming InfluxDB runs locally, which is by default the case in the zenoh Docker image):

  curl -X PUT -d '{"lib":"influxdb","url":"http://localhost:8086"}' http://localhost:8000/@/router/local/plugin/storages/backend/influxdb
  

• Add a storage using the InfluxDB backend on /zenoh/ifx-examples/**.
  This storage will store everything in a databse named 'zenoh'. If it doesn't exists yet, zenoh creates it. It is configured to drop all series when the storage is removed or when zenoh stops:

  curl -X PUT -d '{"selector":"/zenoh/ifx-examples/**","db":"zenoh","on_dispose":"DropDB"}' http://localhost:8000/@/router/local/plugin/storages/backend/influxdb/storage/my-influxdb-storage
  

• Put different values for the same key into the InfluxDB storage:

  curl -X PUT -d '1' http://localhost:8000/zenoh/ifx-examples/A
  curl -X PUT -d '2' http://localhost:8000/zenoh/ifx-examples/A
  curl -X PUT -d '3' http://localhost:8000/zenoh/ifx-examples/A
  

• Get the latest value for this key:

  curl http://localhost:8000/zenoh/ifx-examples/A
  

• Get the complete serie of values for this key:

  curl 'http://localhost:8000/zenoh/ifx-examples/A?(stoptime=now())'
  

• Get the values put during the last minute:

  curl 'http://localhost:8000/zenoh/ifx-examples/A?(starttime=now()-1m)'
  

• Get the values put within the last 30 minutes, but not later than 10 minute ago:

  curl 'http://localhost:8000/zenoh/ifx-examples/A?(starttime=now()-30m;stoptime=now()-10m)'
  

Notice that zenoh supports the complete InfluxDB time syntax for the starttime and stoptime properties.