sylph01 / bolt_sips

Neo4j driver for Elixir, wrapped around the Bolt protocol.

BoltSips

Neo4j driver for Elixir wrapped around the Bolt protocol.

Documentation: http://hexdocs.pm/bolt_sips/

Disclaimer

Bolt.Sips is currently on 0.x beta releases but it is heading towards a stable release. Please check the issues tracker for more information and outstanding issues.

Features

• It is using: Bolt. Neo4j's newest network protocol, designed for high-performance
• Supports transactions, simple and complex Cypher queries with or w/o parameters
• Connection pool implementation using: "A hunky Erlang worker pool factory", aka: Poolboy :)
• Supports Neo4j 3.0.x/3.1.x

Installation

Available in Hex, the package can be installed as:

1. Add bolt_sips to your list of dependencies in mix.exs:

def deps do
  [{:bolt_sips, "~> 0.1"}]
end

2. Ensure bolt_sips is started before your application:

def application do
  [applications: [:bolt_sips]]
end

3 Verify you have the dependencies required for building the etls TCP/TLS layer:

Bolt.Sips is using etls, for encrypted communications. etls is a NIF-based implementation of the whole TLS stack, built on top of Asio and BoringSSL. It manages its own native threads to asynchronously handle socket operations.

To successfully compile etls, you will need the following:

• cmake >= 3.1.0
• erlang >= 17.0
• g++ >= 4.9.0 (or clang)
• git
• perl
• golang
• make
• ninja-build
• openssl

Currently only TLSv1.2 is supported, and default BoringSSL cipher is used.

etls is very fast!

OTP version	transport	bandwidth
18.3	ssl	70 MB/s
19.0-rc1	ssl	111 MB/s
19.0-rc1	etls	833 MB/s

(data extracted from etls's own project page)

Usage

Edit your config/config.exs and set Bolt connection, for example:

config :bolt_sips, Bolt,
  hostname: 'localhost',
  # basic_auth: [username: "neo4j", password: "*********"],
  port: 7687,
  pool_size: 5,
  max_overflow: 1

A new parameter: url, can be used for reducing the verbosity of the config files; available starting with version 0.1.5. For example:

config :bolt_sips, Bolt,
  url: 'localhost:7687',
  pool_size: 5,
  max_overflow: 1

And if you are using any remote instances of hosted Neo4j servers, such as the ones available (also for free) at GrapheneDB.com, configuring the driver is a matter of a simple copy and paste:

config :bolt_sips, Bolt,
  url: "bolt://hobby-happyHoHoHo.dbs.graphenedb.com:24786",
  basic_auth: [username: "demo", password: "demo"]
  ssl: true

We’re also retrying sending the requests to the Neo4j server, with a linear backoff, and try them a couple of times before giving up - all these as part of the exiting pool management, of course. Example

config :bolt_sips, Bolt,
  url: "bolt://Bilbo:[email protected]:24786",
  ssl: true,
  timeout: 15_000,
  retry_linear_backoff: [delay: 150, factor: 2, tries: 3]

In the configuration above, the retry will linearly increase the delay from 150ms following a Fibonacci pattern, cap the delay at 15 seconds (the value defined by the :timeout parameter) and giving up after 3 attempts.

But you can reduce the configuration even further, and rely on the driver's default values. For example: given you're running a Neo4j server on your local machine and Bolt is enabled on 7687, this is the simplest configuration you need, in order to get you started:

config :bolt_sips, Bolt,
  url: "localhost:7687"

With a minimalist setup configured as above, and the Neo4j 3.x server running, you can connect to the server and run some queries using Elixir’s interactive shell (IEx). Example:

$ MIX_ENV=test iex -S mix
Erlang/OTP 19 [erts-8.2] [source] [64-bit] [smp: ....

Interactive Elixir (1.3.4) - press Ctrl+C to exit (type h() ENTER for help)

iex> conn = Bolt.Sips.conn
#Port<0.5312>

iex> Bolt.Sips.query!(conn, "CREATE (a:Person {name:'Bob'})")
%{stats: %{"labels-added" => 1, "nodes-created" => 1, "properties-set" => 1}, type: "w"}

iex> Bolt.Sips.query!(conn, "MATCH (a:Person {name: 'Bob'}) RETURN a.name AS name") |> Enum.map(&(&1["name"]))

["Bob"]

iex> Bolt.Sips.query!(conn, "MATCH (a:Person {name:'Bob'}) DELETE a")
%{stats: %{"nodes-deleted" => 1}, type: "w"}

Command line

Run simple Cypher commands from a mix task, for quick testing Cypher results or the connection with your server:

mix bolt.cypher "MATCH (people:Person) RETURN people.name LIMIT 5"

Output sample:

"MATCH (people:Person) RETURN people.name as name LIMIT 5"

[%{"name" => "Keanu Reeves"}, %{"name" => "Carrie-Anne Moss"},
 %{"name" => "Andy Wachowski"}, %{"name" => "Lana Wachowski"},
 %{"name" => "Joel Silver"}]

Available command line options:

• --host, -h - server host
• --port, -P - server port
• --username, -u - the user name (optional)
• --password, -p - password

Testing

Tests run against a running instance of Neo4J. Please verify that you do not store critical data on this server!

If you have docker available on your system, you can start an instance before running the test suite:

docker run --rm -p 7687:7687 -e 'NEO4J_AUTH=none' neo4j:3.0.6

mix test

Special thanks

• Michael Schaefermeyer (@mschae), for implementing the Bolt protocol in Elixir.

Bolt.Sips incorporates the Bolt protocol code originally created at mschae/boltex, for the low level communication with the Neo4j server.

Contributors

As reported by Github: contributions to master, excluding merge commits

Contributing

• Fork it
• Create your feature branch (git checkout -b my-new-feature)
• Test (mix test)
• Commit your changes (git commit -am 'Add some feature')
• Push to the branch (git push origin my-new-feature)
• Create new Pull Request

Author

Florin T.PATRASCU (@florin, on Twitter)

License

Copyright 2016-2017 Florin T.PATRASCU

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.