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Connecting with the Aerospike Ruby Client API

Use the Aerospike Ruby Client object to connect to a cluster of Aerospike server nodes. First, instantiate a new Client object to specify the IP address and port of one or more cluster seed nodes. The client will discover the remaining cluster nodes automatically. It will periodically ping all nodes for cluster status in a background thread it creates.

The Client instance is thread-safe and can be used concurrently. Each get or set call is a non-blocking, asynchronous network call to the Aerospike database cluster. Connections are cached in a connection pool for each server node.

Setting Seed Nodes via Hosts String

Create a new Client object to specify the server connection using the IP address and port. The client makes initial contact to the specified server node, and then discovers all other cluster nodes.

The hosts string can contain a single address or a comma-separated list of node addresses. The port number is optional and defaults to 3000 if not specified.

client =",")

If no hosts string is passed in the Client initializer, the client will attempt to read the hosts from the AEROSPIKE_HOSTS environment variable.

Setting Multiple Seed Nodes via Host Array

Alternatively, instead of passing the list of seed nodes as a hosts string, the addresses of the seed nodes can be passed as an array of Host instances. To connect to any known cluster node, specify each node in the cluster when creating the Client object. The client iterates through the node array until successfully connecting to a node. It then discovers all other cluster nodes.

hosts = ["", 3000),"", 3000),"", 3000),

client =


Aerospike Enterprise Edition version 3.10 and later support IPv6. Please refer to the IPv6 Configuration section in the operations manual for how to configure your cluster to use IPv6. To connect to a cluster with the Ruby client using IPv6, specify the IPv6 address of one of more cluster nodes as the host seed address(es). Note that on the client side, when using IPv6 addresses in a hosts string, the IPv6 addresses must be enclosed in square brackets, e.g. [fde4:8dba:82e1::c4]:3000.

client ="[fde4:8dba:82e1::c4]:3000")

Setting the Client Policy

The client policy can be set in the client initializer. The policy controls parameters of the client's overall behavior like e.g. connectiton timeout limits. The client policy can also set default values for the client's read/write/query/scan policies. These policy values affect specific client commands. The defautl policy values can be overridden when a command is issued to the client.

policy = 1.0)
client ="", policy: policy)

result = client.get("test", "test", "demo"), nil, {timeout: 0.5})

TLS Encrypted Connections

Starting with Aerospike Enterprise Edition version 3.11, the server supports Transport Layer Security (TLS) encryption for secure connections between the clients and the cluster nodes. Please refer to the TLS Guide for more information on this feature.

To connect to Aerospike cluster using TLS, the client policy needs to be configured correctly by passing an ssl_options hash with one or more of the following properties:

  • ca_file - The path to a file containing a PEM-format CA certificate.
  • ca_path - The path to a directory containing CA certificates in PEM format. Files are looked up by subject's X509 name's hash value.
  • cert_file - The path to a file containing a PEM-format client certificate.
  • pkey_file - The path to a file containing a PEM-format private key for the client certificate.
  • pkey_pass - Optional password in case pkey_file is an encrypted PEM resource.

These parameters are used to setup an SSLContext. Alternatively, a pre-configured SSLContext can be passed using the context property of ssl_options. In this case, all other properties in ssl_options are ignored.

The Aerospike server typically listens on two separate ports for unencrypted and TLS-encrypted connections. When using TLS, ensure that the client's seed nodes are configured with the correct port number.

To facilitate verification of the server certificate, the client also needs to know the server's tls-name. The expected tls-name needs to be set in the seed node configuration. When using a hosts string (either passed via the Client constructor or the AEROSPIKE_HOSTS env variable) each seed node address needs to be specified as

<hostname or IP> [ ":" <tls-name> ] [ ":" <port> ]

If not specified, the tls-name defaults to the cluster name, if configured, or else the node's hostname.


Enabling TLS encryption by specifying the cert/private key file:

require 'aerospike'
include Aerospike

tls_options = {
ca_file = './tls/ca.cert.pem',
cert_file = './tls/client.cert.pem',
pkey_file = './tls/client.key.pem'
policy = tls_options)
seed = ''

client =, policy: policy)

Enabling TLS encryption by passing a pre-configured SSLContext:

require 'aerospike'
require 'openssl'

include Aerospike

context =
cert ='./tls/client.cert.pem'))
pkey ='./tls/client.key.pem'))
context.add_certificate(cert, pkey)
context.ciphers = [ ... ] # Customize the context

policy = { context: context })
seed = ''

client =, policy: policy)

Cleaning Up

When all transactions complete and the application is ready for a clean shutdown, call #close to free resources held by the Client object:


The Client object cannot be used after #close is called.