Creating a Redis Enterprise Software (RS) database
You can create as many databases as you wish in the cluster, so long as you do not exceed the available memory or the number of shards you purchased with your subscription.
There are two types of Redis databases that can be created in RS.
- Traditional Redis databases that are sharded and distributed across a single RS cluster. The detailed instructions are covered below.
- Conflict-Free Replicated Database (CRDB) which is used to create a Geo-Distributed Active-Active Redis database.
To create a new database in the UI:
- On the Databases page, click the + (plus) sign below the table.
The buttons of the various database types that can be created will appear.
Note: If no databases exist, the new database buttons are displayed upon entering the page.
- Select the type of database to create: a Redis database or a Memcached database.
If the nodes in your cluster are Flash-enabled, you can opt to select “Runs on” as either RAM or Flash. For additional details, refer to Redis on Flash.
Select your “Deployment” as Single Region or Geo-Distributed. For more information on Geo-distributed, refer to Conflict-free geo-Replicated Databases (CRDB).
- Enter a name for the database.
The database name must comply with the following rules:
- Length: up to 63 characters.
- Characters: only letters, digits and hyphen (‘-‘) are allowed.
- Start with a letter and end with a letter or digit.
Note: The database name is case-insensitive, i.e. uppercase and lowercase letter are treated exactly the same.
- Set the memory limit of the database. The application displays the total amount of memory available in the cluster. For relevant considerations, refer to Database memory limit.
Note: If you create a Redis Flash or a Memcached Flash database, you also have to set the RAM-to-Flash ratio for this database. Minimum RAM portion is 10%, and maximum RAM portion is 50%. For additional details, refer to Redis Enterprise Flash.
Note: The name and the memory limit are the only mandatory parameters.
- Specify whether to enable replication. For a full explanation, refer to Database replication.
Note: Enabling replication affects the total database size, as explained in Database memory limit.
- If the cluster is configured to support rack-zone awareness, once you enable replication you can also choose whether to enable rack-zone awareness for the database. For additional details, refer to Rack-zone awareness.
- Specify whether to enable data persistence, and if so, what type to employ. For a full explanation, refer to Database persistence.
- Next, you can specify security settings:
- If you are creating a Redis database, enter a Redis password.
- If you are creating a Memcached database, enter a username and password for SASL Authentication.
- If you would like to define the port number that will be part of the endpoint used to connect to the database, you can insert it in the endpoint port number field. If you do not define it the system will allocate a randomly selected free port.
Note: Defining the port number during database creation is a one-time operation; the number cannot be changed at a later stage. For additional details, refer to Machine ports configuration.
- Select whether to enable database clustering. If you enable clustering, select the number of database shards. For a Redis database, select also the hashing policy. For additional details, refer to Database clustering.
- Set the data eviction policy (for additional details, refer to Database eviction policy). This policy is applied when the total size of the database reaches its memory limit.
- If you would like the database to be a replica of one or more databases, you can define the source databases with which this database will synchronize on an ongoing basis. For additional details, refer to Replica of.
- If you would like to encrypt the connection to the database endpoint with SSL encryption, you have to enter the contents of the client certificate to the SSL client authentication field. For additional details, refer to Securing client connection with SSL.
- Specify whether to perform a periodic back up of the database. For additional details, refer to Database backup. If you specify periodic backup, set the interval and specify the backup location parameters, as appropriate.
- Configure database alerts. For additional details, refer to Database alerts.
- Click Activate.
Simple Connectivity Test
Once the database is created, you can find the endpoint and port for the database in the web UI on the configuration page of each database. It is listed under the “Endpoint” property
There are a few simple ways to check connectivity to your database:
- Using a simple application
Testing Database Connectivity with Telnet
As a quick smoke test, telnet to your endpoint and port for the database you wish to test. Then do the redis PING command.
Using the URL based connection method, you should see something like this:
$ telnet redis-19836.c9.us-east-1-2.ec2.cloud.redislabs.com 19836 Trying 18.104.22.168… Connected to redis-19836.c9.us-east-1-2.ec2.cloud.redislabs.com. Escape character is '^]'. AUTH my_redis_password PING +PONG
Testing Database Connectivity with redis-cli
You can find redis-cli utility on each node in Redis Enterprise Software cluster with the rest of the utilities. For information about directory locations please refer to the installation page.
Using the URL based connection method, you can provide the database endpoint URL and port number as follows:
$ redis-cli -h redis-19836.c9.us-east-1-2.ec2.cloud.redislabs.com -p 19836 -a astrongpassword redis-19836.c9.us-east-1-2.ec2.cloud.redislabs.com:19836> PING PONG
Testing Database Connectivity with Simple Application
You can also use a simple application to test connectivity to your database. The following section details a simple IP based connection approach with a python app using the discovery service that is compliant with Redis Sentinel API. In the IP based connection method, you do not need to remember the port number for the database but simply remember the database name. In this method, we simply use the discovery service that listens on port 8001 on all nodes of the cluster to discover the endpoint for the database named “db1”
from redis.sentinel import Sentinel # with IP based connections, a list of known node IP addresses is constructed # to allow connection even if any one of the nodes in the list is unavailable. sentinel_list = [ (10.0.0.44', 8001), ('10.0.0.45', 8001), ('10.0.0.45', 8001) ] # change this to the db name you want to connect db_name = 'db1' sentinel = Sentinel(sentinel_list, socket_timeout=0.1) r = sentinel.master_for(db_name, socket_timeout=0.1) # set key "foo" to value "bar" print r.set('foo', 'bar') # set value for key "foo" print r.get('foo')
In the URL based connection method, you do need to provide the endpoint and the port number remember the port number for the database you like to connect to.
import redis # the URL provided to redis. Redis method comes from the database configuration # property called "Endpoint". The endpoint URL generated by the database is a # combination of the cluster name (FQDN) and database port number. r = redis.Redis( host='redis-19836.c9.us-east-1-2.ec2.cloud.redislabs.com', port=19836) # set key "foo" to value “bar” print(r.set('foo', 'bar')) # set value for key "foo" print(r.get('foo'))