YavaConf 2022¶

This is the demo part of my talk about ksqlDB at Ya!vaConf conference in Warsaw Poland, 28 September 2022.

Start Confluent Platform (No ksqlDB Yet)¶

./start-confluent.sh docker-compose.yml

CLI¶

SHOW TOPICS;

CREATE STREAM names (
  name STRING)
WITH (
  kafka_topic='names',
  partitions=1,
  value_format='kafka');

SELECT * FROM names;

SELECT * FROM names EMIT CHANGES;

KSQLShell

INSERT INTO names VALUES ('yavaconf');
INSERT INTO names VALUES ('java');

$ echo yavaconf | kcat -P -b :9092 -t names
$ echo java | kcat -P -b :9092 -t names

SHOW FUNCTIONS;

DESCRIBE FUNCTION ucase;

SELECT UCASE(name) upper FROM names;

CREATE STREAM uppers AS
  SELECT UCASE(name) upper
  FROM names;

SHOW QUERIES;

EXPLAIN CSAS_UPPERS_7;

REST API¶

ksqlDB uses Eclipse Vert.x to handle HTTP communication using REST endpoints.

http -b localhost:8088/info

http -b localhost:8088/healthcheck

http -b localhost:8088/status

http -b http://localhost:8088/ksql ksql="LIST STREAMS;"

Queries File and Headless Execution Mode¶

You can execute all the above KSQL statements (incl. queries) using a queries file. The idea is to git-control it.

./bin/ksql -f yavaconf.ksql

You can also execute ksqlDB server in headless execution mode.

(Re)Start Confluent Platform¶

This time we're going to use the entire Confluent Platform (incl. ksqlDB).

./start-confluent.sh docker-compose.yml

Dockerized ksqlDB CLI for Queries File¶

docker run \
  --network=confluent-platform_default \
  -it \
  -v $(pwd):/home/appuser \
  confluentinc/cp-ksqldb-cli http://ksqldb-server:8088 \
  -f yavaconf.ksql