Demo: Db2 CDC to Elasticsearch #
1. Create docker-compose.yml
file using following contents:
version: '2.1'
services:
db2:
image: ruanhang/db2-cdc-demo:v1
privileged: true
ports:
- 50000:50000
environment:
- LICENSE=accept
- DB2INSTANCE=db2inst1
- DB2INST1_PASSWORD=admin
- DBNAME=testdb
- ARCHIVE_LOGS=true
elasticsearch:
image: elastic/elasticsearch:7.6.0
environment:
- cluster.name=docker-cluster
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
- discovery.type=single-node
ports:
- "9200:9200"
- "9300:9300"
ulimits:
memlock:
soft: -1
hard: -1
nofile:
soft: 65536
hard: 65536
kibana:
image: elastic/kibana:7.6.0
ports:
- "5601:5601"
volumes:
- /var/run/docker.sock:/var/run/docker.sock
The Docker Compose environment consists of the following containers:
- Db2: db2 server and a pre-populated
products
table in the databasetestdb
. - Elasticsearch: store the result of the
products
table. - Kibana: mainly used to visualize the data in Elasticsearch
To start all containers, run the following command in the directory that contains the docker-compose.yml file.
docker-compose up -d
This command automatically starts all the containers defined in the Docker Compose configuration in a detached mode. Run docker ps to check whether these containers are running properly. You can also visit http://localhost:5601/ to see if Kibana is running normally.
Don’t forget to run the following command to stop all containers after you finished the tutorial:
docker-compose down
2. Download following JAR package to <FLINK_HOME>/lib
Download links are available only for stable releases, SNAPSHOT dependencies need to be built based on master or release branches by yourself.
- flink-sql-connector-elasticsearch7-3.0.1-1.17.jar
- flink-sql-connector-db2-cdc-3.0-SNAPSHOT.jar
3. Launch a Flink cluster and start a Flink SQL CLI
Execute following SQL statements in the Flink SQL CLI:
-- Flink SQL
-- checkpoint every 3000 milliseconds
Flink SQL> SET execution.checkpointing.interval = 3s;
Flink SQL> CREATE TABLE products (
ID INT NOT NULL,
NAME STRING,
DESCRIPTION STRING,
WEIGHT DECIMAL(10,3),
PRIMARY KEY (ID) NOT ENFORCED
) WITH (
'connector' = 'db2-cdc',
'hostname' = 'localhost',
'port' = '50000',
'username' = 'db2inst1',
'password' = 'admin',
'database-name' = 'testdb',
'schema-name' = 'DB2INST1',
'table-name' = 'PRODUCTS'
);
Flink SQL> CREATE TABLE es_products (
ID INT NOT NULL,
NAME STRING,
DESCRIPTION STRING,
WEIGHT DECIMAL(10,3),
PRIMARY KEY (ID) NOT ENFORCED
) WITH (
'connector' = 'elasticsearch-7',
'hosts' = 'http://localhost:9200',
'index' = 'enriched_products_1'
);
Flink SQL> INSERT INTO es_products SELECT * FROM products;
4. Check result in Elasticsearch
Check the data has been written to Elasticsearch successfully, you can visit Kibana to see the data.
5. Make changes in Db2 and watch result in Elasticsearch
Enter Db2’s container to make some changes in Db2, then you can see the result in Elasticsearch will change after executing every SQL statement:
docker exec -it ${containerId} /bin/bash
su db2inst1
db2 connect to testdb
# enter db2 and execute sqls
db2
UPDATE DB2INST1.PRODUCTS SET DESCRIPTION='18oz carpenter hammer' WHERE ID=106;
INSERT INTO DB2INST1.PRODUCTS VALUES (default,'jacket','water resistent white wind breaker',0.2);
INSERT INTO DB2INST1.PRODUCTS VALUES (default,'scooter','Big 2-wheel scooter ',5.18);
DELETE FROM DB2INST1.PRODUCTS WHERE ID=111;