Skip to content

demo

Directory actions

More options

Directory actions

More options

Latest commit

 

History

History

demo

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
mysql
mysql
 
 
README.md
README.md
 
 
docker-compose.yml
docker-compose.yml
 
 
init.sh
init.sh
 
 
mysql.json
mysql.json
 
 

README.md

[DRAFT]

DEMO

For the purpose of the demo we will ask you to launch a bunch of containers. The docker-compose command will help you to do that by launching:

Step 1/3: deploy

docker-compose up -d

Wait for initialization:

docker logs -ft init

Step 2/3: use it!

api="http://localhost:9000"

# create the first block (36 elements that were already in the MySQL database at launch)
curl -sS -XPOST "$api/blocks?pretty=true"

# create the second block, the number of element inserted in this block should be 0
curl -sS -XPOST "$api/blocks?pretty=true"

You have created the first 2 blocks in your blockchain.

If you modify something in your MySQL database, the change will be automatically captured and inserted into the precedence system. Start a MySQL client to make some changes.

docker exec -it mysql mysql -uroot -pdebezium inventory
INSERT INTO customers VALUES (default, "test", "test", "test");
DELETE FROM customers WHERE id=1005;
quit

You can compute a new block and check by yourself that the number of elements that have been inserted into this new block is the number of changes made on the MySQL database.

# create the third block, count should be 2
curl -sS -XPOST "$api/blocks?pretty=true"

You can retrieve the last version of the records pushed in the precedence system. The previous field contains the identifier of the last record of the chain at insertion time.

# get demo.inventory.customers.{"id":1005} corresponding to
# - "database.server.name": demo
# - database (from "database.whitelist"): inventory
# - table: customers
# - PK (JSON URL encoded): %7B%22id%22%3A1005%7D ({"id":1005})
curl -sS "$api/chains/demo.inventory.customers.%7B%22id%22%3A1005%7D?pretty=true"

The data isn't here because the last modification is a delete. We can retrieve the data on the previous record.

previous=$(curl -sS "$api/chains/demo.inventory.customers.%7B%22id%22%3A1005%7D" | sed -En 's/.*"previous":\["([^"]*).*/\1/p')
curl -sS "$api/records/$previous?data=true"

You can recreate some containers, wait for initialisation and verify by yourself that all is in the same state because we don't touch the containers which contains data.

docker rm -f init debezium precedence precedence-debezium
docker-compose up -d
# wait for initialisation
docker logs -ft init

# make a bloc
curl -sS -XPOST "$api/blocks?pretty=true"
# count should be 0 because there is nothing to do!
curl -sS "$api/chains/demo.inventory.customers.%7B%22id%22%3A1005%7D?pretty=true"
# still here!

Step 3/3: clean

To clean out the demo you just need to shutdown the containers.

docker-compose down

Tips

# connect you inside a container, precedence for example
docker exec -it precedence sh

# exec a precedence command
docker exec precedence precedence help

# list kafka topics
docker exec -it kafka bash -c '$KAFKA_HOME/bin/kafka-topics.sh --zookeeper zookeeper:2181 --list'

# watch Debezium kafka changes
docker exec kafka bash -c '$KAFKA_HOME/bin/kafka-console-consumer.sh \
    --bootstrap-server kafka:9093 \
    --property print.key=true \
    --property key.separator="         " \
    --whitelist "^demo\.inventory\..*" \
    --from-beginning'

# reset precedence-demo-inventory kafka offsets
application_id="precedence-demo-inventory"
whitelist='^demo\.inventory\..*'
docker exec -it kafka bash -c '$KAFKA_HOME/bin/kafka-streams-application-reset.sh \
    --application-id '"$application_id"' \
    --to-earliest \
    --input-topics $(echo $($KAFKA_HOME/bin/kafka-topics.sh \
        --zookeeper zookeeper:2181 \
        --list \
        | egrep "'"$whitelist"'") | tr "[:blank:]" ",")'