Venice is an open-source framework that enables users to deploy and manage stream processing pipelines. Venice abstracts away much of the complexity of creating and managing a pipeline, allowing developers to focus on application code rather than infrastructure.
A demo of the pipeline in action: display topics, launch the KSQL CLI, create and show data streams, create connection to Venice Postgres database, view tables in Postgres
Venice’s main features are:
- An easy to use command-line interface for common development and pipeline management tasks
- A default pipeline to quickly support stream processing applications
- Simple configuration of new connections and components
- A web-based UI for monitoring the message brokers - easily see and create new topics, view messages
The Venice default pipeline consists of multiple components:
- Kafka brokers for logging events
- A Zookeeper instance for managing the cluster of Kafka brokers
- A Schema Registry for managing schemas
- ksqlDB servers for performing aggregations, filtration, transformations, and joins over real-time data
- Kafka Connect workers for moving data in and out of Kafka and simplifying the process of adding new sources and sinks
- A PostgreSQL data sink for storing or presenting the data in multiple formats
The components used in the pipeline are packaged in Docker containers, making them easy to build and deploy or swap for others to better meet your needs.
To learn why we chose these pieces, read our Case Study.
The full Venice architecture - the Venice CLI manages the pipeline and can be used to attach containers, such as a producer, or launch the CLI for ksqlDB or PostgreSQL.
Venice is designed for users who want to set up a streaming pipeline with minimal hassle.
Venice may be a good fit if:
- You want to try stream processing using a fault-tolerant log-based message broker (Kafka) and have your data output to a familiar PostgreSQL database.
- Most of the default settings would work for your use case.
Venice may not be a good fit if your use case is complex and would require substantial customization.
how to download and install Node.js and npm
Clone the repo, install packages, and create a symbolic link:
git clone git@github.com:venice-framework/venice-cli.git && cd venice-cli && npm install && sudo npm link
This allows you to use the CLI from any console interface. (It shouldn’t be limited to the venice-cli directory.)
Navigate to a repo containing a pipeline, or install a Venice default pipeline.
You can use the Venice pipeline with a PostgreSQL sink if you do not have a pipeline you want to test.
NOTE: The following command will clone a repo into the current working directory. If you want the repo to be cloned into another folder, navigate away from venice-cli now (e.g., cd ..)
venice install and select “venice - Base pipeline with a Postgres sink”
cd venice-postgres-sink
You can use your own or a Venice producer example.
Open the docker-compose.yml file in a text editor.
Uncomment the section for the producer so that producer aligns vertically with the other services.
If you want to use your own producer, package it in a container and have it use the environment variables BROKER, TOPIC_NAME, and SCHEMA_REGISTRY_URL. Then, swap out image: veniceframework/python-producer-test-key-string for the image you want to use.
Open the docker-compose.yml file in a text editor if it is not yet open.
insert inserts every row into the table.
upsert adds a new row if a row with the same key does not exist yet. If a row with the same key exists, that row is updated.
The PostgreSQL pipeline uses upsert by default.
Within the commands for the connector-init service, change upsert to insert if you want to use insert instead.
Save and close the file.
Open the .env file in a text editor.
If you are following along with the Venice producer and PostgreSQL pipeline, change the values for TOPIC_NAME to bus_locations and POSTGRES_DB to buses.
Save and close the file.
venice up
venice status or venice -st
To follow the logs of one or more components (press space bar to select before pressing enter/return)
venice logs
The output is piped to less, so you can navigate up and down through the logs using the arrow keys or j and k. Use the spacebar to scroll down by “page”, and press q to quit.
venice topics or venice -t
venice schemas | venice -s
venice connectors | venice -cvenice
This will download the KSQL CLI if you have not already used it. There will be a notable delay as it loads for the first time.
venice ksql
If you get an error message that Remote server at http://ksql-server:8088 does not appear to be a valid KSQL server, exit the KSQL CLI and try again.
Try these KSQL commands:
-
Show all topics. You should see
bus_locationsamong the list of topics.SHOW TOPICS; -
Print all data from the beginning.
PRINT bus_locations FROM BEGINNING; -
Follow any new input.
PRINT bus_locations;CTRL + Cto stop printing.
You can issue additional queries over the data such as aggregations and other transformations. See more KSQL commands in the KSQL documentation
CTRL+D to exit the KSQL console.
venice psql
If you are following along with the bus example, enter “venice_user” for the name of the PostgreSQL user, and “buses” for the name of the PostgreSQL database.
PostgreSQL commands:
Show all tables. You should see bus_locations.
\dt
Show the first ten rows.
SELECT * FROM bus_locations LIMIT 10;
Display a count of how many records there are in the table.
SELECT COUNT(*) FROM bus_locations;
CTRL + D to exit the PSQL console.
You can also use exit, quit, \q, or CTRL + C.
For a graphic interface for the Kafka cluster, navigate to localhost:9000 in your web browser.
Here you can view Kafka topics and consumer groups. You can examine individual messages to ensure they are being serialized and deserialized correctly. You can also verify message distribution among partitions to ensure balance.
venice down