toxiproxy

by Shopify

Shopify / toxiproxy

:alarm_clock: :fire: A TCP proxy to simulate network and system conditions for chaos and resiliency ...

4.9K Stars 269 Forks Last release: almost 2 years ago (v2.1.4) MIT License 456 Commits 18 Releases

Available items

No Items, yet!

The developer of this repository has not created any items for sale yet. Need a bug fixed? Help with integration? A different license? Create a request here:

Toxiproxy

GitHub release Build Status IRC Channel

Toxiproxy is a framework for simulating network conditions. It's made specifically to work in testing, CI and development environments, supporting deterministic tampering with connections, but with support for randomized chaos and customization. Toxiproxy is the tool you need to prove with tests that your application doesn't have single points of failure. We've been successfully using it in all development and test environments at Shopify since October, 2014. See our blog post on resiliency for more information.

Toxiproxy usage consists of two parts. A TCP proxy written in Go (what this repository contains) and a client communicating with the proxy over HTTP. You configure your application to make all test connections go through Toxiproxy and can then manipulate their health via HTTP. See Usage below on how to set up your project.

For example, to add 1000ms of latency to the response of MySQL from the Ruby client:

Toxiproxy[:mysql_master].downstream(:latency, latency: 1000).apply do
  Shop.first # this takes at least 1s
end

To take down all Redis instances:

Toxiproxy[/redis/].down do
  Shop.first # this will throw an exception
end

While the examples in this README are currently in Ruby, there's nothing stopping you from creating a client in any other language (see Clients).

Table of Contents

  1. Why yet another chaotic TCP proxy?
  2. Clients
  3. Example
  4. Usage
    1. Installing
      1. Upgrading from 1.x
    2. Populating
    3. Using
  5. Toxics
    1. Latency
    2. Down
    3. Bandwidth
    4. Slow close
    5. Timeout
    6. Slicer
  6. HTTP API
    1. Proxy fields
    2. Toxic fields
    3. Endpoints
    4. Populating Proxies
  7. CLI example
  8. FAQ
  9. Development

Why yet another chaotic TCP proxy?

The existing ones we found didn't provide the kind of dynamic API we needed for integration and unit testing. Linux tools like

nc
and so on are not cross-platform and require root, which makes them problematic in test, development and CI environments.

Clients

Example

Let's walk through an example with a Rails application. Note that Toxiproxy is in no way tied to Ruby, it's just been our first use case. You can see the full example at sirupsen/toxiproxy-rails-example. To get started right away, jump down to Usage.

For our popular blog, for some reason we're storing the tags for our posts in Redis and the posts themselves in MySQL. We might have a

Post
class that includes some methods to manipulate tags in a Redis set:
class Post < ActiveRecord::Base
  # Return an Array of all the tags.
  def tags
    TagRedis.smembers(tag_key)
  end

Add a tag to the post.

def add_tag(tag) TagRedis.sadd(tag_key, tag) end

Remove a tag from the post.

def remove_tag(tag) TagRedis.srem(tag_key, tag) end

Return the key in Redis for the set of tags for the post.

def tag_key "post:tags:#{self.id}" end end

We've decided that erroring while writing to the tag data store (adding/removing) is OK. However, if the tag data store is down, we should be able to see the post with no tags. We could simply rescue the

Redis::CannotConnectError
around the
SMEMBERS
Redis call in the
tags
method. Let's use Toxiproxy to test that.

Since we've already installed Toxiproxy and it's running on our machine, we can skip to step 2. This is where we need to make sure Toxiproxy has a mapping for Redis tags. To

config/boot.rb
(before any connection is made) we add:
require 'toxiproxy'

Toxiproxy.populate([ { name: "toxiproxy_test_redis_tags", listen: "127.0.0.1:22222", upstream: "127.0.0.1:6379" } ])

Then in

config/environments/test.rb
we set the
TagRedis
to be a Redis client that connects to Redis through Toxiproxy by adding this line:
TagRedis = Redis.new(port: 22222)

All calls in the test environment now go through Toxiproxy. That means we can add a unit test where we simulate a failure:

test "should return empty array when tag redis is down when listing tags" do
  @post.add_tag "mammals"

Take down all Redises in Toxiproxy

Toxiproxy[/redis/].down do assert_equal [], @post.tags end end

The test fails with

Redis::CannotConnectError
. Perfect! Toxiproxy took down the Redis successfully for the duration of the closure. Let's fix the
tags
method to be resilient:
def tags
  TagRedis.smembers(tag_key)
rescue Redis::CannotConnectError
  []
end

The tests pass! We now have a unit test that proves fetching the tags when Redis is down returns an empty array, instead of throwing an exception. For full coverage you should also write an integration test that wraps fetching the entire blog post page when Redis is down.

Full example application is at sirupsen/toxiproxy-rails-example.

Usage

Configuring a project to use Toxiproxy consists of three steps:

  1. Installing Toxiproxy
  2. Populating Toxiproxy
  3. Using Toxiproxy

1. Installing Toxiproxy

Linux

See

Releases
for the latest binaries and system packages for your architecture.

Ubuntu

$ wget -O toxiproxy-2.1.4.deb https://github.com/Shopify/toxiproxy/releases/download/v2.1.4/toxiproxy_2.1.4_amd64.deb
$ sudo dpkg -i toxiproxy-2.1.4.deb
$ sudo service toxiproxy start

OS X

$ brew tap shopify/shopify
$ brew install toxiproxy

Windows

Toxiproxy for Windows is available for download at https://github.com/Shopify/toxiproxy/releases/download/v2.1.4/toxiproxy-server-windows-amd64.exe

Docker

Toxiproxy is available on Docker Hub.

$ docker pull shopify/toxiproxy
$ docker run -it shopify/toxiproxy

If using Toxiproxy from the host rather than other containers, enable host networking with

--net=host
.

Source

If you have Go installed, you can build Toxiproxy from source using the make file:

bash
$ make build
$ ./toxiproxy-server

Upgrading from Toxiproxy 1.x

In Toxiproxy 2.0 several changes were made to the API that make it incompatible with version 1.x. In order to use version 2.x of the Toxiproxy server, you will need to make sure your client library supports the same version. You can check which version of Toxiproxy you are running by looking at the

/version
endpoint.

See the documentation for your client library for specific library changes. Detailed changes for the Toxiproxy server can been found in CHANGELOG.md.

2. Populating Toxiproxy

When your application boots, it needs to make sure that Toxiproxy knows which endpoints to proxy where. The main parameters are: name, address for Toxiproxy to listen on and the address of the upstream.

Some client libraries have helpers for this task, which is essentially just making sure each proxy in a list is created. Example from the Ruby client:

# Make sure `shopify_test_redis_master` and `shopify_test_mysql_master` are
# present in Toxiproxy
Toxiproxy.populate([
  {
    name: "shopify_test_redis_master",
    listen: "127.0.0.1:22220",
    upstream: "127.0.0.1:6379"
  },
  {
    name: "shopify_test_mysql_master",
    listen: "127.0.0.1:24220",
    upstream: "127.0.0.1:3306"
  }
])

This code needs to run as early in boot as possible, before any code establishes a connection through Toxiproxy. Please check your client library for documentation on the population helpers.

Alternatively use the CLI to create proxies, e.g.:

toxiproxy-cli create shopify_test_redis_master -l localhost:26379 -u localhost:6379

We recommend a naming such as the above:

___
. This makes sure there are no clashes between applications using the same Toxiproxy.

For large application we recommend storing the Toxiproxy configurations in a separate configuration file. We use

config/toxiproxy.json
. This file can be passed to the server using the
-config
option, or loaded by the application to use with the
populate
function.

An example

config/toxiproxy.json
:
[
  {
    "name": "web_dev_frontend_1",
    "listen": "[::]:18080",
    "upstream": "webapp.domain:8080",
    "enabled": true
  },
  {
    "name": "web_dev_mysql_1",
    "listen": "[::]:13306",
    "upstream": "database.domain:3306",
    "enabled": true
  }
]

Use ports outside the ephemeral port range to avoid random port conflicts. It's

32,768
to
61,000
on Linux by default, see
/proc/sys/net/ipv4/ip_local_port_range
.

3. Using Toxiproxy

To use Toxiproxy, you now need to configure your application to connect through Toxiproxy. Continuing with our example from step two, we can configure our Redis client to connect through Toxiproxy:

# old straight to redis
redis = Redis.new(port: 6380)

new through toxiproxy

redis = Redis.new(port: 22220)

Now you can tamper with it through the Toxiproxy API. In Ruby:

redis = Redis.new(port: 22220)

Toxiproxy[:shopify_test_redis_master].downstream(:latency, latency: 1000).apply do redis.get("test") # will take 1s end

Or via the CLI:

toxiproxy-cli toxic add shopify_test_redis_master -t latency -a latency=1000

Please consult your respective client library on usage.

Toxics

Toxics manipulate the pipe between the client and upstream. They can be added and removed from proxies using the HTTP api. Each toxic has its own parameters to change how it affects the proxy links.

For documentation on implementing custom toxics, see CREATING_TOXICS.md

latency

Add a delay to all data going through the proxy. The delay is equal to

latency
+/-
jitter
.

Attributes:

  • latency
    : time in milliseconds
  • jitter
    : time in milliseconds

down

Bringing a service down is not technically a toxic in the implementation of Toxiproxy. This is done by

POST
ing to
/proxies/{proxy}
and setting the
enabled
field to
false
.

bandwidth

Limit a connection to a maximum number of kilobytes per second.

Attributes:

  • rate
    : rate in KB/s

slow_close

Delay the TCP socket from closing until

delay
has elapsed.

Attributes:

  • delay
    : time in milliseconds

timeout

Stops all data from getting through, and closes the connection after

timeout
. If
timeout
is 0, the connection won't close, and data will be delayed until the toxic is removed.

Attributes:

  • timeout
    : time in milliseconds

slicer

Slices TCP data up into small bits, optionally adding a delay between each sliced "packet".

Attributes:

  • average_size
    : size in bytes of an average packet
  • size_variation
    : variation in bytes of an average packet (should be smaller than average_size)
  • delay
    : time in microseconds to delay each packet by

limit_data

Closes connection when transmitted data exceeded limit.

  • bytes
    : number of bytes it should transmit before connection is closed

HTTP API

All communication with the Toxiproxy daemon from the client happens through the HTTP interface, which is described here.

Toxiproxy listens for HTTP on port 8474.

Proxy fields:

  • name
    : proxy name (string)
  • listen
    : listen address (string)
  • upstream
    : proxy upstream address (string)
  • enabled
    : true/false (defaults to true on creation)

To change a proxy's name, it must be deleted and recreated.

Changing the

listen
or
upstream
fields will restart the proxy and drop any active connections.

If

listen
is specified with a port of 0, toxiproxy will pick an ephemeral port. The
listen
field in the response will be updated with the actual port.

If you change

enabled
to
false
, it will take down the proxy. You can switch it back to
true
to reenable it.

Toxic fields:

  • name
    : toxic name (string, defaults to
    _
    )
  • type
    : toxic type (string)
  • stream
    : link direction to affect (defaults to
    downstream
    )
  • toxicity
    : probability of the toxic being applied to a link (defaults to 1.0, 100%)
  • attributes
    : a map of toxic-specific attributes

See Toxics for toxic-specific attributes.

The

stream
direction must be either
upstream
or
downstream
.
upstream
applies the toxic on the
client -> server
connection, while
downstream
applies the toxic on the
server -> client
connection. This can be used to modify requests and responses separately.

Endpoints

All endpoints are JSON.

  • GET /proxies - List existing proxies and their toxics
  • POST /proxies - Create a new proxy
  • POST /populate - Create or replace a list of proxies
  • GET /proxies/{proxy} - Show the proxy with all its active toxics
  • POST /proxies/{proxy} - Update a proxy's fields
  • DELETE /proxies/{proxy} - Delete an existing proxy
  • GET /proxies/{proxy}/toxics - List active toxics
  • POST /proxies/{proxy}/toxics - Create a new toxic
  • GET /proxies/{proxy}/toxics/{toxic} - Get an active toxic's fields
  • POST /proxies/{proxy}/toxics/{toxic} - Update an active toxic
  • DELETE /proxies/{proxy}/toxics/{toxic} - Remove an active toxic
  • POST /reset - Enable all proxies and remove all active toxics
  • GET /version - Returns the server version number

Populating Proxies

Proxies can be added and configured in bulk using the

/populate
endpoint. This is done by passing an json array of proxies to toxiproxy. If a proxy with the same name already exists, it will be compared to the new proxy and replaced if the
upstream
and
listen
address don't match.

A

/populate
call can be included for example at application start to ensure all required proxies exist. It is safe to make this call several times, since proxies will be untouched as long as their fields are consistent with the new data.

CLI Example

$ toxiproxy-cli create redis -l localhost:26379 -u localhost:6379
Created new proxy redis
$ toxiproxy-cli list
Listen          Upstream        Name  Enabled Toxics
======================================================================
127.0.0.1:26379 localhost:6379  redis true    None

Hint: inspect toxics with toxiproxy-client inspect <proxyname>

$ redis-cli -p 26379
127.0.0.1:26379> SET omg pandas
OK
127.0.0.1:26379> GET omg
"pandas"
$ toxiproxy-cli toxic add redis -t latency -a latency=1000
Added downstream latency toxic 'latency_downstream' on proxy 'redis'
$ redis-cli -p 26379
127.0.0.1:26379> GET omg
"pandas"
(1.00s)
127.0.0.1:26379> DEL omg
(integer) 1
(1.00s)
$ toxiproxy-cli toxic remove redis -n latency_downstream
Removed toxic 'latency_downstream' on proxy 'redis'
$ redis-cli -p 26379
127.0.0.1:26379> GET omg
(nil)
$ toxiproxy-cli delete redis
Deleted proxy redis
$ redis-cli -p 26379
Could not connect to Redis at 127.0.0.1:26379: Connection refused

Frequently Asked Questions

How fast is Toxiproxy? The speed of Toxiproxy depends largely on your hardware, but you can expect a latency of < 100µs when no toxics are enabled. When running with

GOMAXPROCS=4
on a Macbook Pro we achieved ~1000MB/s throughput, and as high as 2400MB/s on a higher end desktop. Basically, you can expect Toxiproxy to move data around at least as fast the app you're testing.

Can Toxiproxy do randomized testing? Many of the available toxics can be configured to have randomness, such as

jitter
in the
latency
toxic. There is also a global
toxicity
parameter that specifies the percentage of connections a toxic will affect. This is most useful for things like the
timeout
toxic, which would allow X% of connections to timeout.

I am not seeing my Toxiproxy actions reflected for MySQL. MySQL will prefer the local Unix domain socket for some clients, no matter which port you pass it if the host is set to

localhost
. Configure your MySQL server to not create a socket, and use
127.0.0.1
as the host. Remember to remove the old socket after you restart the server.

Toxiproxy causes intermittent connection failures. Use ports outside the ephemeral port range to avoid random port conflicts. It's

32,768
to
61,000
on Linux by default, see
/proc/sys/net/ipv4/ip_local_port_range
.

Should I run a Toxiproxy for each application? No, we recommend using the same Toxiproxy for all applications. To distinguish between services we recommend naming your proxies with the scheme:

___
. For example,
shopify_test_redis_master
or
shopify_development_mysql_1
.

Development

  • make
    . Build a toxiproxy development binary for the current platform.
  • make all
    . Build Toxiproxy binaries and packages for all platforms. Requires to have Go compiled with cross compilation enabled on Linux and Darwin (amd64) as well as
    fpm
    in your
    $PATH
    to build the Debian package.
  • make test
    . Run the Toxiproxy tests.
  • make darwin
    . Build binary for Darwin.
  • make linux
    . Build binary for Linux.
  • make windows
    . Build binary for Windows.

Release

  1. Ensure this release has run internally for
    Shopify/shopify
    for at least a day which is the best fuzzy test for robustness we have.
  2. Update
    CHANGELOG.md
  3. Bump
    VERSION
  4. Change versions in
    README.md
  5. Commit
  6. Tag
  7. make release
    to create binaries, packages and push new Docker image
  8. Create Github draft release against new tag and upload binaries and Debian package
  9. Bump version for Homebrew

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.