## Bolt.Sips

Neo4j driver for Elixir wrapped around the Bolt protocol.

![Build Status](
[![Deps Status](](


## Disclaimer

`Bolt.Sips` is currently on `0.3.x` beta releases but considered **stable** starting from version: `0.1.6`. Please check the issues tracker for more information and outstanding issues. Also, please note the following **breaking change**: `Elixir 1.4 is now required`.

## 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, "~> 0.3"}]

#### 2. Ensure bolt_sips is started before your application:

def application do
  [applications: [:bolt_sips], mod: {Bolt.Sips.Application, []}]

You can also specify custom configuration settings in you app's mix config file. These may overwrite your config file:

def application do
  [extra_applications: [:logger], mod: 
    {Bolt.Sips.Application, [url: 'localhost', pool_size: 15]}

#### (Optional) 3. Use [etls]( TCP/TLS layer:

`Bolt.Sips` is working **very well** with [etls](, for encrypted communications; the preferred method. However, many users complained about the difficulty they encountered while building this dependency on some systems; especially on Windows. To use **etls**, you must define the environment variable: `BOLT_WITH_ETLS`, and compile the project again. If the `BOLT_WITH_ETLS` is not defined, then `Bolt.Sips` will use the standard Erlang [`:ssl` module](, for the SSL/TLS protocol; this is the default behavior, starting with this version.

Therefore, if you want the **much** faster ssl/tls support offered by ETLS, then use this: `export BOLT_WITH_ETLS=true` on Linux/OSX, for example. [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 [](, configuring the driver is a matter of a simple copy and paste:

config :bolt_sips, Bolt,
  url: "bolt://",
  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 existing pool management, of course. Example

config :bolt_sips, Bolt,
  url: "bolt://",
  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> {:ok, pid} = Bolt.Sips.start_link(url: "localhost")
{:ok, #PID<0.181.0>}

iex> conn = Bolt.Sips.conn

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 AS name") |>["name"]))


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 LIMIT 5"

Output sample:

    "MATCH (people:Person) RETURN 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: [mschae/boltex](

### 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

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.