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Before you can start using ScyllaDB Alternator, you will have to have an up and running a ScyllaDB cluster configured to expose the Alternator port. This section will guide you through the steps for setting up the cluster:
Download the latest stable ScyllaDB image for Docker, by running
docker pull scylladb/scylla:latest
To run this Docker image, follow the instructions in
https://hub.docker.com/r/scylladb/scylla/, but add to every docker run
command a -p 8000:8000
before the image name and
--alternator-port=8000 --alternator-write-isolation=always
at the end.
The “alternator-port” option specifies on which port Scylla will listen for
the (unencrypted) DynamoDB API, and the “alternator-write-isolation” chooses
whether or not Alternator will use LWT for every write.
For example,
docker run --name scylla -d -p 8000:8000 scylladb/scylla:latest --alternator-port=8000 --alternator-write-isolation=always
.
The --alternator-https-port=...
option can also be used to enable
Alternator on an encrypted (HTTPS) port. Note that in this case, the files
/etc/scylla/scylla.crt
and /etc/scylla/scylla.key
must be inserted into
the image, containing the SSL certificate and key to use.
Follow the instructions on the AWS github page
Enjoy your tic-tac-toe game :-)
Run the following commands on your machine, this will install boto3 python library which also contains drivers for DynamoDB:
sudo pip install --upgrade boto3
The following is a 3 scripts test that creates a table named usertable writes the famous hello world record to it, and then, reads it back.
Put the following create table example script in a python file and run it (changing local host to the address of your docker node if you are using docker):
import boto3
dynamodb = boto3.resource('dynamodb',endpoint_url='http://localhost:8000',
region_name='None', aws_access_key_id='None', aws_secret_access_key='None')
dynamodb.create_table(
AttributeDefinitions=[
{
'AttributeName': 'key',
'AttributeType': 'S'
},
],
BillingMode='PAY_PER_REQUEST',
TableName='usertable',
KeySchema=[
{
'AttributeName': 'key',
'KeyType': 'HASH'
},
])
Put the following write example script in a python file and run it (changing local host to the address of your docker node if you are using docker):
import boto3
dynamodb = boto3.resource('dynamodb',endpoint_url='http://localhost:8000',
region_name='None', aws_access_key_id='None', aws_secret_access_key='None')
dynamodb.batch_write_item(RequestItems={
'usertable': [
{
'PutRequest': {
'Item': {
'key': 'test', 'x' : {'hello': 'world'}
}
},
}
]
})
Put the following read example script in a python file and run it (changing local host to the address of your docker node if you are using docker):
import boto3
dynamodb = boto3.resource('dynamodb',endpoint_url='http://localhost:8000',
region_name='None', aws_access_key_id='None', aws_secret_access_key='None')
print(dynamodb.batch_get_item(RequestItems={
'usertable' : { 'Keys': [{ 'key': 'test' }] }
}))
You should see the record you inserted in step 2 along with some http info printed to screen.
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