Have you ever been attacked by a goose?
Goose is a Rust load testing tool inspired by Locust. User behavior is defined with standard Rust code. Load tests are applications that have a dependency on the Goose library. Web requests are made with the Reqwest HTTP Client.
The in-line documentation offers much more detail about Goose specifics. For a general background to help you get started with Rust and Goose, read on.
Cargo is the Rust package manager. To create a new load test, use Cargo to create a new application (you can name your application anything, we've generically selected loadtest
):
$ cargo new loadtest
Created binary (application) `loadtest` package
$ cd loadtest/
This creates a new directory named loadtest/
containing loadtest/Cargo.toml
and loadtest/src/main.rs
. Start by editing Cargo.toml
adding Goose under the dependencies heading:
[dependencies]
goose = "^0.10"
At this point it's possible to compile all dependencies, though the resulting binary only displays "Hello, world!":
$ cargo run
Updating crates.io index
Downloaded goose v0.10.3
...
Compiling goose v0.10.3
Compiling loadtest v0.1.0 (/home/jandrews/devel/rust/loadtest)
Finished dev [unoptimized + debuginfo] target(s) in 52.97s
Running `target/debug/loadtest`
Hello, world!
To create an actual load test, you first have to add the following boilerplate to the top of src/main.rs
to make Goose's functionality available to your code:
use goose::prelude::*;
Then create a new load testing function. For our example we're simply going to load the front page of the website we're load-testing. Goose passes all load testing functions a pointer to a GooseUser object, which is used to track metrics and make web requests. Thanks to the Reqwest library, the Goose client manages things like cookies, headers, and sessions for you. Load testing functions must be declared async, which helps ensure that your simulated users don't become CPU-locked.
In load test functions you typically do not set the host, and instead configure the host at run time, so you can easily run your load test against different environments without recompiling. The following loadtest_index
function simply loads the front page of our web page:
async fn loadtest_index(user: &GooseUser) -> GooseTaskResult {
let _goose_metrics = user.get("/").await?;
Ok(())
}
The function is declared async
so that we don't block a CPU-core while loading web pages. All Goose load test functions are passed in a reference to a GooseUser
object, and return a GooseTaskResult
which is either an empty Ok(())
on success, or a GooseTaskError
on failure. We use the GooseUser
object to make requests, in this case we make a GET
request for the front page, /
. The .await
frees up the CPU-core while we wait for the web page to respond, and the tailing ?
passes up any unexpected errors that may be returned from this request. When the request completes, Goose returns metrics which we store in the _goose_metrics
variable. The variable is prefixed with an underscore (_
) to tell the compiler we are intentionally not using the results. Finally, after making a single successful request, we return Ok(())
to let Goose know this task function completed successfully.
We have to tell Goose about our new task function. Edit the main()
function, setting a return type and replacing the hello world text as follows:
fn main() -> Result<(), GooseError> {
GooseAttack::initialize()?
.register_taskset(taskset!("LoadtestTasks")
.register_task(task!(loadtest_index))
)
.execute()?
.print();
Ok(())
}
If you're new to Rust, main()
's return type of Result<(), GooseError>
may look strange. It essentially says that main
will return nothing (()
) on success, and will return a GooseError
on failure. This is helpful as several of GooseAttack
's methods can fail, returning an error. In our example, initialize()
and execute()
each may fail. The ?
that follows the method's name tells our program to exit and return an error on failure, otherwise continue on. The print()
method consumes the GooseMetrics
object returned by GooseAttack.execute()
and prints a summary if metrics are enabled. The final line, Ok(())
returns the empty result expected on success.
And that's it, you've created your first load test! Let's run it and see what happens.
$ cargo run
Compiling loadtest v0.1.0 (/home/jandrews/devel/rust/loadtest)
Finished dev [unoptimized + debuginfo] target(s) in 3.56s
Running `target/debug/loadtest`
Error: InvalidOption { option: "--host", value: "", detail: "A host must be defined via the --host option, the GooseAttack.set_default() function, or the GooseTaskSet.set_host() function (no host defined for LoadtestTasks)." }
Goose is unable to run, as it hasn't been told the host you want to load test. So, let's try again, this time passing in the --host
flag. After running for a few seconds, we then press ctrl-c
to stop the load test:
$ cargo run -- --host http://local.dev/
Finished dev [unoptimized + debuginfo] target(s) in 0.07s
Running `target/debug/loadtest --host 'http://local.dev/'`
=== PER TASK METRICS ===
------------------------------------------------------------------------------
Name | # times run | # fails | task/s | fail/s
-----------------------------------------------------------------------------
1: LoadtestTasks |
1: | 2,240 | 0 (0%) | 280.0 | 0.000
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
1: LoadtestTasks |
1: | 15.54 | 6 | 136 | 14
=== PER REQUEST METRICS ===
------------------------------------------------------------------------------
Name | # reqs | # fails | req/s | fail/s
-----------------------------------------------------------------------------
GET / | 2,240 | 0 (0%) | 280.0 | 0.000
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
GET / | 15.30 | 6 | 135 | 14
All 8 users hatched, resetting metrics (disable with --no-reset-metrics).
^C06:03:25 [ WARN] caught ctrl-c, stopping...
=== PER TASK METRICS ===
------------------------------------------------------------------------------
Name | # times run | # fails | task/s | fail/s
-----------------------------------------------------------------------------
1: LoadtestTasks |
1: | 2,054 | 0 (0%) | 410.8 | 0.000
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
1: LoadtestTasks |
1: | 20.86 | 7 | 254 | 19
=== PER REQUEST METRICS ===
------------------------------------------------------------------------------
Name | # reqs | # fails | req/s | fail/s
-----------------------------------------------------------------------------
GET / | 2,054 | 0 (0%) | 410.8 | 0.000
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
GET / | 20.68 | 7 | 254 | 19
-------------------------------------------------------------------------------
Slowest page load within specified percentile of requests (in ms):
------------------------------------------------------------------------------
Name | 50% | 75% | 98% | 99% | 99.9% | 99.99%
-----------------------------------------------------------------------------
GET / | 19 | 21 | 53 | 69 | 250 | 250
By default, Goose will hatch 1 GooseUser per second, up to the number of CPU cores available on the server used for load testing. In the above example, the server has 8 CPU cores, so it took 8 seconds to hatch all users. After all users are hatched, Goose flushes all metrics collected during the hatching process so all subsequent metrics are taken with all users running. Before flushing the metrics, they are displayed to the console so the data is not lost.
The same metrics are displayed per-task and per-request. In our simple example, our single task only makes one request, so in this case both metrics show the same results.
The per-task metrics are displayed first, starting with the name of our Task Set, LoadtestTasks
. Individual tasks in the Task Set are then listed in the order they are defined in our load test. We did not name our task, so it simply shows up as 1:
. All defined tasks will be listed here, even if they did not run, so this can be useful to confirm everything in your load test is running as expected.
Next comes the per-request metrics. Our single task makes a GET
request for the /
path, so it shows up in the metrics as GET /
. Comparing the per-task metrics collected for 1:
to the per-request metrics collected for GET /
, you can see that they are the same.
There are two common tables found in each type of metrics. The first shows the total number of requests made (2,054), how many of those failed (0), the average number of requests per second (410.8), and the average number of failed requests per second (0).
The second table shows the average time required to load a page (20.68 milliseconds), the minimum time to load a page (7 ms), the maximum time to load a page (254 ms) and the median time to load a page (19 ms).
The per-request metrics include a third table, showing the slowest page load time for a range of percentiles. In our example, in the 50% fastest page loads, the slowest page loaded in 19 ms. In the 75% fastest page loads, the slowest page loaded in 21 ms, etc.
In real load tests, you'll most likely have multiple task sets each with multiple tasks, and Goose will show you metrics for each along with an aggregate of them all together.
Refer to the examples directory for more complicated and useful load test examples.
- Avoid
unwrap()
in your task functions -- Goose generates a lot of load, and this tends to trigger errors. Embrace Rust's warnings and properly handle all possible errors, this will save you time debugging later. - When running your load test for real, use the cargo
--release
flag to generate optimized code. This can generate considerably more load test traffic.
The -h
flag will show all run-time configuration options available to Goose load tests. For example, you can pass the -h
flag to the simple
example as follows, cargo run --example simple -- -h
:
Usage: target/debug/examples/simple [OPTIONS]
Options available when launching a Goose load test.
Optional arguments:
-h, --help Displays this help
-V, --version Prints version information
-l, --list Lists all tasks and exits
-H, --host HOST Defines host to load test (ie http://10.21.32.33)
-u, --users USERS Sets concurrent users (default: number of CPUs)
-r, --hatch-rate RATE Sets per-second user hatch rate (default: 1)
-t, --run-time TIME Stops after (30s, 20m, 3h, 1h30m, etc)
-g, --log-level Sets log level (-g, -gg, etc)
-L, --log-file NAME Enables log file and sets name
-v, --verbose Sets debug level (-v, -vv, etc)
Metrics:
--only-summary Only prints final summary metrics
--no-reset-metrics Doesn't reset metrics after all users have started
--no-metrics Doesn't track metrics
--no-task-metrics Doesn't track task metrics
-m, --metrics-file NAME Sets metrics log file name
--metrics-format FORMAT Sets metrics log format (csv, json, raw)
-d, --debug-file NAME Sets debug log file name
--debug-format FORMAT Sets debug log format (json, raw)
--status-codes Tracks additional status code metrics
Advanced:
--throttle-requests VALUE Sets maximum requests per second
--sticky-follow Follows base_url redirect with subsequent requests
Gaggle:
--manager Enables distributed load test Manager mode
--expect-workers VALUE Sets number of Workers to expect
--no-hash-check Tells Manager to ignore load test checksum
--manager-bind-host HOST Sets host Manager listens on (default: 0.0.0.0)
--manager-bind-port PORT Sets port Manager listens on (default: 5115)
--worker Enables distributed load test Worker mode
--manager-host HOST Sets host Worker connects to (default: 127.0.0.1)
--manager-port PORT Sets port Worker connects to (default: 5115)
The examples/simple.rs
example copies the simple load test documented on the locust.io web page, rewritten in Rust for Goose. It uses minimal advanced functionality, but demonstrates how to GET and POST pages. It defines a single Task Set which has the user log in and then load a couple of pages.
Goose can make use of all available CPU cores. By default, it will launch 1 user per core, and it can be configured to launch many more. The following was configured instead to launch 1,024 users. Each user randomly pauses 5 to 15 seconds after each task is loaded, so it's possible to spin up a large number of users. Here is a snapshot of top
when running this example on a 1-core VM with 10G of available RAM -- there were ample resources to launch considerably more "users", though ulimit
had to be resized:
top - 06:56:06 up 15 days, 3:13, 2 users, load average: 0.22, 0.10, 0.04
Tasks: 116 total, 3 running, 113 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.7 us, 0.7 sy, 0.0 ni, 96.7 id, 0.0 wa, 0.0 hi, 1.0 si, 0.0 st
MiB Mem : 9994.9 total, 7836.8 free, 1101.2 used, 1056.9 buff/cache
MiB Swap: 10237.0 total, 10237.0 free, 0.0 used. 8606.9 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1339 goose 20 0 1235480 758292 8984 R 3.0 7.4 0:06.56 simple
Here's the output of running the loadtest. The -v
flag sends INFO
and more critical messages to stdout (in addition to the log file). The -u1024
tells Goose to spin up 1,024 users. The -r32
option tells Goose to hatch 32 users per second. The -t10m
option tells Goose to run the load test for 10 minutes, or 600 seconds. The --status-codes
flag tells Goose to track metrics about HTTP status codes returned by the server, in addition to the default per-task and per-request metrics. The --no-reset-metrics
flag tells Goose to start tracking the 10m run-time from when the first user starts, instead of the default which is to flush all metrics and start timing after all users have started. And finally, the --only-summary
flag tells Goose to only display the final metrics after the load test finishes, otherwise it would display running metrics every 15 seconds for the duration of the test.
$ cargo run --release --example simple -- --host http://local.dev -v -u1024 -r32 -t10m --status-codes --no-reset-metrics --only-summary
Finished release [optimized] target(s) in 0.09s
Running `target/release/examples/simple --host 'http://local.dev' -v -u1024 -r32 -t10m --status-codes --no-reset-metrics --only-summary`
10:55:04 [ INFO] Output verbosity level: INFO
10:55:04 [ INFO] Logfile verbosity level: INFO
10:55:04 [ INFO] Writing to log file: goose.log
10:55:04 [ INFO] run_time = 600
10:55:04 [ INFO] global host configured: http://local.dev
10:55:04 [ INFO] initializing user states...
10:55:09 [ INFO] launching user 1 from WebsiteUser...
10:55:09 [ INFO] launching user 2 from WebsiteUser...
10:55:09 [ INFO] launching user 3 from WebsiteUser...
...
10:55:42 [ INFO] launching user 1022 from WebsiteUser...
10:55:42 [ INFO] launching user 1023 from WebsiteUser...
10:55:42 [ INFO] launching user 1024 from WebsiteUser...
10:55:42 [ INFO] launched 1024 users...
All 1024 users hatched.
11:05:09 [ INFO] stopping after 600 seconds...
11:05:09 [ INFO] waiting for users to exit
11:05:09 [ INFO] exiting user 879 from WebsiteUser...
11:05:09 [ INFO] exiting user 41 from WebsiteUser...
11:05:09 [ INFO] exiting user 438 from WebsiteUser...
...
11:05:10 [ INFO] exiting user 268 from WebsiteUser...
11:05:10 [ INFO] exiting user 864 from WebsiteUser...
11:05:10 [ INFO] exiting user 55 from WebsiteUser...
11:05:11 [ INFO] printing metrics after 601 seconds...
=== PER TASK METRICS ===
------------------------------------------------------------------------------
Name | # times run | # fails | task/s | fail/s
-----------------------------------------------------------------------------
1: WebsiteUser |
1: | 1,024 | 0 (0%) | 1.707 | 0.000
2: | 28,746 | 0 (0%) | 47.91 | 0.000
3: | 28,748 | 0 (0%) | 47.91 | 0.000
------------------------+----------------+----------------+--------+---------
Aggregated | 58,518 | 0 (0%) | 97.53 | 0.000
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
1: WebsiteUser |
1: | 5.995 | 5 | 37 | 6
2: | 0.428 | 0 | 17 | 0
3: | 0.360 | 0 | 37 | 0
------------------------+------------+------------+------------+-------------
Aggregated | 0.492 | 5 | 37 | 5
=== PER REQUEST METRICS ===
------------------------------------------------------------------------------
Name | # reqs | # fails | req/s | fail/s
-----------------------------------------------------------------------------
GET / | 28,746 | 0 (0%) | 47.91 | 0.000
GET /about/ | 28,748 | 0 (0%) | 47.91 | 0.000
POST /login | 1,024 | 0 (0%) | 1.707 | 0.000
------------------------+----------------+----------------+--------+---------
Aggregated | 58,518 | 29,772 (50.9%) | 97.53 | 49.62
-------------------------------------------------------------------------------
Name | Avg (ms) | Min | Max | Median
-----------------------------------------------------------------------------
GET / | 0.412 | 0 | 17 | 0
GET /about/ | 0.348 | 0 | 37 | 0
POST /login | 5.979 | 5 | 37 | 6
------------------------+------------+------------+------------+-------------
Aggregated | 0.478 | 5 | 37 | 5
-------------------------------------------------------------------------------
Slowest page load within specified percentile of requests (in ms):
------------------------------------------------------------------------------
Name | 50% | 75% | 98% | 99% | 99.9% | 99.99%
-----------------------------------------------------------------------------
GET / | 0 | 1 | 3 | 4 | 5 | 5
GET /about/ | 0 | 0 | 3 | 3 | 5 | 5
POST /login | 6 | 6 | 7 | 7 | 28 | 28
------------------------+--------+--------+--------+--------+--------+-------
Aggregated | 5 | 5 | 5 | 6 | 7 | 17
-------------------------------------------------------------------------------
Name | Status codes
-----------------------------------------------------------------------------
GET / | 28,746 [200]
GET /about/ | 28,748 [200]
POST /login | 1,024 [200]
-------------------------------------------------------------------------------
Aggregated | 58,518 [200]
All run-time options can be configured with custom defaults. For example, you may want to default to the the host name of your local development environment, only requiring that --host
be set when running against a production environment. Assuming your local development environment is at "http://local.dev/" you can do this as follows:
GooseAttack::initialize()?
.register_taskset(taskset!("LoadtestTasks")
.register_task(task!(loadtest_index))
)
.set_default(GooseDefault::Host, "http://local.dev/")?
.execute()?
.print();
Ok(())
The following defaults can be configured with a &str
:
- host:
GooseDefault::Host
- log file name:
GooseDefault::LogFile
- metrics log file name:
GooseDefault::MetricsFile
- metrics log file format:
GooseDefault::MetricsFormat
- debug log file name:
GooseDefault::DebugFile
- debug log file format:
GooseDefault::DebugFormat
- host to bind Manager to:
GooseDefault::ManagerBindHost
- host for Worker to connect to:
GooseDefault::ManagerHost
The following defaults can be configured with a usize
integer:
- total users to start:
GooseDefault::Users
- users to start per second:
GooseDefault::HatchRate
- number of seconds for test to run:
GooseDefault::RunTime
- log level:
GooseDefault::LogLevel
- verbosity:
GooseDefault::Verbose
- maximum requests per second:
GooseDefault::ThrottleRequests
- number of Workers to expect:
GooseDefault::ExpectWorkers
- port to bind Manager to:
GooseDefault::ManagerBindPort
- port for Worker to connect to:
GooseDefault::ManagerPort
The following defaults can be configured with a bool
:
- only print final summary metrics:
GooseDefault::OnlySummary
- do not reset metrics after all users start:
GooseDefault::NoResetMetrics
- do not track metrics:
GooseDefault::NoMetrics
- do not track task metrics:
GooseDefault::NoTaskMetrics
- track status codes:
GooseDefault::StatusCodes
- follow redirect of base_url:
GooseDefault::StickyFollow
- enable Manager mode:
GooseDefault::Manager
- ignore load test checksum:
GooseDefault::NoHashCheck
- enable Worker mode:
GooseDefault::Worker
For example, without any run-time options the following load test would automatically run against local.dev
, logging metrics to goose-metrics.log
and debug to goose-debug.log
. It will automatically launch 20 users in 4 seconds, and run the load test for 15 minutes. Metrics will only be displayed when the load test completes, and will include additional status code metrics. The order the defaults are set is not important.
GooseAttack::initialize()?
.register_taskset(taskset!("LoadtestTasks")
.register_task(task!(loadtest_index))
)
.set_default(GooseDefault::Host, "local.dev")?
.set_default(GooseDefault::MetricsFile, "goose-metrics.log")?
.set_default(GooseDefault::DebugFile, "goose-debug.log")?
.set_default(GooseDefault::Users, 20)?
.set_default(GooseDefault::HatchRate, 4)?
.set_default(GooseDefault::RunTime, 900)?
.set_default(GooseDefault::OnlySummary, true)?
.set_default(GooseDefault::StatusCodes, true)?
.execute()?
.print();
Ok(())
By default, Goose will generate as much load as it can. If this is not desirable, the throttle allows optionally limiting the maximum number of requests per second made during a load test. This can be helpful to ensure consistency when running a load test from multiple different servers with different available resources.
The throttle is specified as an integer. For example:
$ cargo run --example simple -- --host http://local.dev/ -u100 -r20 -v --throttle-requests 5
In this example, Goose will launch 100 GooseUser threads, but the throttle will prevent them from generating a combined total of more than 5 requests per second. The --throttle-requests
command line option imposes a maximum number of requests, not a minimum number of requests.
Goose can optionally log details about all load test requests to a file. To enable, add the --metrics-log-file=foo
command line option, where foo
is either a relative or absolute path of the log file to create. Any existing file that may already exist will be overwritten.
When operating in Gaggle-mode, the --metrics-log-file
option can only be enabled on the Worker processes, configuring Goose to spread out the overhead of writing logs.
By default, logs are written in JSON Lines format. For example:
{"elapsed":30,"final_url":"http://local.dev/user/42","method":"POST","name":"/login","redirected":true,"response_time":220,"status_code":200,"success":true,"update":false,"url":"http://local.dev/login","user":0}
{"elapsed":251,"final_url":"http://local.dev/","method":"GET","name":"/","redirected":false,"response_time":3,"status_code":200,"success":true,"update":false,"url":"http://local.dev/","user":0}
{"elapsed":1027,"final_url":"http://local.dev/user/13","method":"POST","name":"/login","redirected":true,"response_time":266,"status_code":200,"success":true,"update":false,"url":"http://local.dev/login","user":1}
{"elapsed":1294,"final_url":"http://local.dev/","method":"GET","name":"/","redirected":false,"response_time":4,"status_code":200,"success":true,"update":false,"url":"http://local.dev/","user":1}
Logs include the entire GooseRawRequest
object as defined in src/goose.rs
, which are created on all requests. This object includes the following fields:
elapsed
: total milliseconds between when theGooseUser
thread started and this request was made;method
: the type of HTTP request made;name
: the name of the request;url
: the URL that was requested;final_url
: the URL that was returned (may be different if the request was redirected);redirected
: true or false if the request was redirected;response_time
: how many milliseconds the request took;status_code
: the HTTP response code returned for this request;success
: true or false if this was a successful request;update
: true or false if this is a recurrence of a previous log entry, but withsuccess
toggling betweentrue
andfalse
. This happens when a load test callsset_success()
on a request that Goose previously interpreted as a failure, orset_failure()
on a request previously interpreted as a success;user
: an integer value indicating whichGooseUser
thread made this request.
In the first line of the above example, GooseUser
thread 0 made a POST
request to /login
and was successfully redirected to /user/42
in 220 milliseconds. The second line is the same GooseUser
thread which then made a GET
request to /
in 3 milliseconds. The third and fourth lines are a second GooseUser
thread doing the same thing, first logging in and then loading the front page.
By default Goose logs metrics in JSON Lines format. The --metrics-log-format
option can be used to log in csv
, json
or raw
format. The raw
format is Rust's debug output of the entire GooseRawRequest
object.
For example, csv
output of the same requests logged above would look like:
elapsed,method,name,url,final_url,redirected,response_time,status_code,success,update,user
30,POST,"/login","http://local.dev/login","http://local.dev/user/42",true,30,200,true,false,0
251,GET,"/","http://local.dev/","http://local.dev/",false,3,200,true,false,0
1027,POST,"/login","http://local.dev/login","http://local.dev/user/13",true,266,200,true,false,1
1294,GET,"/","http://local.dev/","http://local.dev/",false,4,200,true,false,1
Goose can optionally log details about requests and responses for debug purposes. When writing a load test you must invoke client.log_debug(tag, Option<request>, Option<headers>, Option<body>)
where tag
is an arbitrary string to identify where in the load test and/or why debug is being written, request
is an optional reference to a GooseRawRequest
object, headers
are an optional reference to the HTTP headers returned by the server, and body
is an optionial reference to the web page body returned by the server.
For an example on how to correctly use client.log_debug()
, including how to obtain the response headers and body, see examples/drupal_loadtest
.
If the load test is run with the --debug-log-file=foo
command line option, where foo
is either a relative or an absolute path, Goose will log all debug generated by calls to client.log_debug()
to this file. For example:
{"body":"<!DOCTYPE html>\n<html>\n <head>\n <title>503 Backend fetch failed</title>\n </head>\n <body>\n <h1>Error 503 Backend fetch failed</h1>\n <p>Backend fetch failed</p>\n <h3>Guru Meditation:</h3>\n <p>XID: 923425</p>\n <hr>\n <p>Varnish cache server</p>\n </body>\n</html>\n","header":"{\"date\": \"Wed, 01 Jul 2020 10:27:31 GMT\", \"server\": \"Varnish\", \"content-type\": \"text/html; charset=utf-8\", \"retry-after\": \"5\", \"x-varnish\": \"923424\", \"age\": \"0\", \"via\": \"1.1 varnish (Varnish/6.1)\", \"x-varnish-cache\": \"MISS\", \"x-varnish-cookie\": \"SESSd7e04cba6a8ba148c966860632ef3636=hejsW1mQnnsHlua0AicCjEpUjnCRTkOLubwL33UJXRU\", \"content-length\": \"283\", \"connection\": \"keep-alive\"}","request":{"elapsed":4192,"final_url":"http://local.dev/node/3247","method":"GET","name":"(Auth) comment form","redirected":false,"response_time":8,"status_code":503,"success":false,"update":false,"url":"http://local.dev/node/3247","user":4},"tag":"post_comment: no form_build_id found on node/3247"}
If --debug-log-file=foo
is not specified at run time, nothing will be logged.
By default Goose writes debug logs in JSON Lines format. The --debug-log-format
option can be used to log in json
or raw
format. The raw
format is Rust's debug output of the entire GooseDebug
object.
Goose also supports distributed load testing. A Gaggle is one Goose process running in Manager mode, and 1 or more Goose processes running in Worker mode. The Manager coordinates starting and stopping the Workers, and collects aggregated metrics. Gaggle support is a cargo feature that must be enabled at compile-time as documented below. To launch a Gaggle, you must copy your load test application to all servers from which you wish to generate load.
It is strongly recommended that the same load test application be copied to all servers involved in a Gaggle. By default, Goose will verify that the load test is identical by comparing a hash of all load test rules. Telling it to skip this check can cause the load test to panic (for example, if a Worker defines a different number of tasks or task sets than the Manager).
Gaggle support is a compile-time Cargo feature that must be enabled. Goose uses the nng
library to manage network connections, and compiling nng
requires that cmake
be available.
The gaggle
feature can be enabled from the command line by adding --features gaggle
to your cargo command.
When writing load test applications, you can default to compiling in the Gaggle feature in the dependencies
section of your Cargo.toml
, for example:
[dependencies]
goose = { version = "^0.10", features = ["gaggle"] }
To launch a Gaggle, you first must start a Goose application in Manager mode. All configuration happens in the Manager. To start, add the --manager
flag and the --expect-workers
flag, the latter necessary to tell the Manager process how many Worker processes it will be coordinating. For example:
cargo run --features gaggle --example simple -- --manager --expect-workers 2 --host http://local.dev/ -v
This configures a Goose Manager to listen on all interfaces on the default port (0.0.0.0:5115) for 2 Goose Worker processes.
At this time, a Goose process can be either a Manager or a Worker, not both. Therefor, it usually makes sense to launch your first Worker on the same server that the Manager is running on. If not otherwise configured, a Goose Worker will try to connect to the Manager on the localhost. This can be done as follows:
cargo run --features gaggle --example simple -- --worker -v
In our above example, we expected 2 Workers. The second Goose process should be started on a different server. This will require telling it the host where the Goose Manager process is running. For example:
cargo run --example simple -- --worker --manager-host 192.168.1.55 -v
Once all expected Workers are running, the distributed load test will automatically start. We set the -v
flag so Goose provides verbose output indicating what is happening. In our example, the load test will run until it is canceled. You can cancel the Manager or either of the Worker processes, and the test will stop on all servers.
--manager
: starts a Goose process in Manager mode. There currently can only be one Manager per Gaggle.--worker
: starts a Goose process in Worker mode. How many Workers are in a given Gaggle is defined by the--expect-workers
option, documented below.--no-hash-check
: tells Goose to ignore if the load test application doesn't match between Worker(s) and the Manager. This is not recommended, and can cause the application to panic.
The --no-metrics
, --only-summary
, --no-reset-metrics
, --status-codes
, and --no-hash-check
flags must be set on the Manager. Workers inherit these flags from the Manager
--manager-bind-host <manager-bind-host>
: configures the host that the Manager listens on. By default Goose will listen on all interfaces, or0.0.0.0
.--manager-bind-port <manager-bind-port>
: configures the port that the Manager listens on. By default Goose will listen on port5115
.--manager-host <manager-host>
: configures the host that the Worker will talk to the Manager on. By default, a Goose Worker will connect to the localhost, or127.0.0.1
. In a distributed load test, this must be set to the IP of the Goose Manager.--manager-port <manager-port>
: configures the port that a Worker will talk to the Manager on. By default, a Goose Worker will connect to port5115
.
The --users
, --hatch-rate
, --host
, and --run-time
options must be set on the Manager. Workers inherit these options from the Manager.
The --throttle-requests
option must be configured on each Worker, and can be set to a different value on each Worker if desired.
Goose uses nng
to send network messages between the Manager and all Workers. Serde and Serde CBOR are used to serialize messages into Concise Binary Object Representation.
Workers initiate all network connections, and push metrics to the Manager process.
By default Reqwest (and therefore Goose) uses the system-native transport layer security to make HTTPS requests. This means schannel
on Windows, Security-Framework
on macOS, and OpenSSL
on Linux. If you'd prefer to use a pure Rust TLS implementation, disable default features and enable rustls
in Cargo.toml
as follows:
[dependencies]
goose = { version = "^0.10", default-features = false, features = ["rustls"] }