Driver setup

The driver can be configured and instantiated using com.arangodb.ArangoDB.Builder:

ArangoDB arangoDB = new ArangoDB.Builder()
        // ...
        .build();

To customize the configuration properties can be set programmatically in the builder:

ArangoDB arangoDB = new ArangoDB.Builder()
        .host("127.0.0.1",8529)
        // ...
        .build();

or providing an implementation of com.arangodb.config.ArangoConfigProperties to the builder:

ArangoConfigProperties props = ...
ArangoDB arangoDB = new ArangoDB.Builder()
        .loadProperties(props)
        // ...
        .build();

Implementations of com.arangodb.config.ArangoConfigProperties could supply configuration properties coming from different sources, eg. system properties, remote stores, frameworks integrations, etc. An implementation for loading properties from local files is provided by ArangoConfigProperties.fromFile() and its overloaded variants.

To read config properties prefixed with arangodb from arangodb.properties file (as in version 6):

// ## src/main/resources/arangodb.properties
// arangodb.hosts=172.28.0.1:8529
// arangodb.password=test
// ...

ArangoConfigProperties props = ArangoConfigProperties.fromFile();

To read config properties from arangodb-with-prefix.properties file, where the config properties are prefixed with adb:

// ## src/main/resources/arangodb-with-prefix.properties
// adb.hosts=172.28.0.1:8529
// adb.password=test
// ...

ArangoConfigProperties props = ArangoConfigProperties.fromFile("arangodb-with-prefix.properties", "adb");

Here are examples to integrate configuration properties from different sources:

• Eclipse MicroProfile Config
• Micronaut Configuration

Configuration

ArangoDB.Builder has the following configuration methods:

• host(String, int): adds a host (hostname and port) to connect to, multiple hosts can be added
• protocol(Protocol): communication protocol, possible values are: VST, HTTP_JSON, HTTP_VPACK, HTTP2_JSON, HTTP2_VPACK, (default: HTTP2_JSON)
• timeout(Integer): connection and request timeout (ms), (default 0, no timeout)
• user(String): username for authentication, (default: root)
• password(String): password for authentication
• jwt(String): JWT for authentication
• useSsl(Boolean): use SSL connection, (default: false)
• sslContext(SSLContext): SSL context
• verifyHost(Boolean): enable hostname verification, (HTTP only, default: true)
• chunkSize(Integer): VST chunk size in bytes, (default: 30000)
• maxConnections(Integer): max number of connections per host, (default: 1 VST, 1 HTTP/2, 20 HTTP/1.1)
• connectionTtl(Long): max lifetime of a connection (ms), (default: no ttl)
• keepAliveInterval(Integer): VST keep-alive interval (s), (default: no keep-alive probes will be sent)
• acquireHostList(Boolean): acquire the list of available hosts, (default: false)
• acquireHostListInterval(Integer): acquireHostList interval (ms), (default: 3_600_000, 1 hour)
• loadBalancingStrategy(LoadBalancingStrategy): load balancing strategy, possible values are: NONE, ROUND_ROBIN, ONE_RANDOM, (default: NONE)
• responseQueueTimeSamples(Integer): amount of samples kept for queue time metrics, (default: 10)
• serde(ArangoSerde): serde to serialize and deserialize user-data

Config File Properties

ArangoConfigProperties.fromFile() reads config properties prefixed with arangodb from arangodb.properties file (as in version 6). Different prefix and file name can be specified using its overloaded variants.

The properties read are:

• hosts: comma-separated list of <hostname>:<port> entries
• protocol: VST, HTTP_JSON, HTTP_VPACK, HTTP2_JSON or HTTP2_VPACK
• timeout
• user
• password
• jwt
• useSsl
• verifyHost
• chunkSize
• maxConnections
• connectionTtl
• keepAliveInterval
• acquireHostList
• acquireHostListInterval
• loadBalancingStrategy: NONE, ROUND_ROBIN or ONE_RANDOM
• responseQueueTimeSamples

SSL

To use SSL, you have to set the configuration useSsl to true and set a SSLContext (see example code).

ArangoDB arangoDB = new ArangoDB.Builder()
  .useSsl(true)
  .sslContext(sc)
  .build();

Connection Pooling

The driver keeps a pool of connections for each host, the max amount of connections is configurable.

Connections are released after the configured connection time-to-live (ArangoDB.Builder.connectionTtl(Long)) or when the driver is shut down:

arangoDB.shutdown();

Thread Safety

The driver can be used concurrently by multiple threads. All the following classes are thread safe:

• com.arangodb.ArangoDB
• com.arangodb.ArangoDatabase
• com.arangodb.ArangoCollection
• com.arangodb.ArangoGraph
• com.arangodb.ArangoVertexCollection
• com.arangodb.ArangoEdgeCollection
• com.arangodb.ArangoView
• com.arangodb.ArangoSearch

Any other class should not be considered thread safe. In particular classes representing request options (package com.arangodb.model) and response entities (package com.arangodb.entity) are not thread safe.

Fallback hosts

The driver supports configuring multiple hosts. The first host is used to open a connection to. When this host is not reachable the next host from the list is used. To use this feature just call the method host(String, int) multiple times.

ArangoDB arangoDB = new ArangoDB.Builder()
  .host("host1", 8529)
  .host("host2", 8529)
  .build();

The driver is also able to acquire a list of known hosts in a cluster. For this the driver has to be able to successfully open a connection to at least one host to get the list of hosts. Then it can use this list when fallback is needed. To enable this feature:

ArangoDB arangoDB = new ArangoDB.Builder()
  .acquireHostList(true)
  .build();

Load Balancing

The driver supports load balancing for cluster setups in two different ways.

The first one is a round robin load balancing where the driver iterates through a list of known hosts and performs every request on a different host than the request before.

ArangoDB arangoDB = new ArangoDB.Builder()
  .loadBalancingStrategy(LoadBalancingStrategy.ROUND_ROBIN)
  .build();

The second load balancing strategy picks a random host from host list (configured or acquired) and sticks to it as long as the connection is open.

ArangoDB arangoDB = new ArangoDB.Builder()
  .loadBalancingStrategy(LoadBalancingStrategy.ONE_RANDOM)
  .build();

Active Failover

In case of an Active Failover deployment the driver should be configured in the following way:

• the load balancing strategy must be either set to LoadBalancingStrategy.NONE (default)
• acquireHostList should be set to true

ArangoDB arangoDB = new ArangoDB.Builder()
  .loadBalancingStrategy(LoadBalancingStrategy.NONE)
  .acquireHostList(true)
  .build();

Connection time to live

The driver supports setting a TTL (time to life) for connections:

ArangoDB arango = new ArangoDB.Builder()
  .connectionTtl(5 * 60 * 1000) // ms
  .build();

In this example all connections will be closed/reopened after 5 minutes.

If not set or set to null (default), no automatic connection closure will be performed.

VST Keep-Alive

The driver supports setting keep-alive interval (in seconds) for VST connections. If set, every VST connection will perform a no-op request at the specified intervals, to avoid to be closed due to inactivity by the server (or by the external environment, e.g. firewall, intermediate routers, operating system, … ).

ArangoDB arangoDB = new ArangoDB.Builder()
        .keepAliveInterval(1_800) // 30 minutes
        .build();

If not set or set to null (default), no keep-alive probes will be sent.