Add `db_spin` and refactor ChaosController

1 files changed, 41 insertions, 18 deletions

diff --git a/doc/development/chaos_endpoints.md b/doc/development/chaos_endpoints.md
index 403a5b21827..b3406275937 100644
--- a/doc/development/chaos_endpoints.md
+++ b/doc/development/chaos_endpoints.md
@@ -15,23 +15,19 @@ Currently, there are four endpoints for simulating the following conditions:
 
 ## Enabling chaos endpoints
 
-For obvious reasons, these endpoints are not enabled by default. They can be enabled by setting the `GITLAB_ENABLE_CHAOS_ENDPOINTS` environment variable to `1`.
-
-For example, if you're using the [GDK](https://gitlab.com/gitlab-org/gitlab-development-kit) this can be done with the following command:
-
-```bash
-GITLAB_ENABLE_CHAOS_ENDPOINTS=1 gdk run
-```
-
-## Securing the chaos endpoints
+For obvious reasons, these endpoints are not enabled by default on `production`.
+They are enabled by default on **development** environments.
 
 DANGER: **Danger:**
-It is highly recommended that you secure access to the chaos endpoints using a secret token. This is recommended when enabling these endpoints locally and essential when running in a staging or other shared environment. You should not enable them in production unless you absolutely know what you're doing.
+It is required that you secure access to the chaos endpoints using a secret token.
+You should not enable them in production unless you absolutely know what you're doing.
 
-A secret token can be set through the `GITLAB_CHAOS_SECRET` environment variable. For example, when using the [GDK](https://gitlab.com/gitlab-org/gitlab-development-kit) this can be done with the following command:
+A secret token can be set through the `GITLAB_CHAOS_SECRET` environment variable.
+For example, when using the [GDK](https://gitlab.com/gitlab-org/gitlab-development-kit)
+this can be done with the following command:
 
 ```bash
-GITLAB_ENABLE_CHAOS_ENDPOINTS=1 GITLAB_CHAOS_SECRET=secret gdk run
+GITLAB_CHAOS_SECRET=secret gdk run
 ```
 
 Replace `secret` with your own secret token.
@@ -56,10 +52,11 @@ GET /-/chaos/leakmem?memory_mb=1024&duration_s=50
 | Attribute    | Type    | Required | Description                                                                        |
 | ------------ | ------- | -------- | ---------------------------------------------------------------------------------- |
 | `memory_mb`  | integer | no       | How much memory, in MB, should be leaked. Defaults to 100MB.                       |
-| `duration_s` | integer | no       | Minimum duration, in seconds, that the memory should be retained. Defaults to 30s. |
+| `duration_s` | integer | no       | Minimum duration_s, in seconds, that the memory should be retained. Defaults to 30s. |
 
 ```bash
 curl http://localhost:3000/-/chaos/leakmem?memory_mb=1024&duration_s=10 --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/leakmem?memory_mb=1024&duration_s=10&token=secret
 ```
 
 ## CPU spin
@@ -70,23 +67,47 @@ Depending on your rack server setup, your request may timeout after a predermine
 If you're using Unicorn, this is done by killing the worker process.
 
 ```
-GET /-/chaos/cpuspin
-GET /-/chaos/cpuspin?duration_s=50
+GET /-/chaos/cpu_spin
+GET /-/chaos/cpu_spin?duration_s=50
+```
+
+| Attribute    | Type    | Required | Description                                                           |
+| ------------ | ------- | -------- | --------------------------------------------------------------------- |
+| `duration_s` | integer | no       | Duration, in seconds, that the core will be utilised. Defaults to 30s |
+
+```bash
+curl http://localhost:3000/-/chaos/cpu_spin?duration_s=60 --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/cpu_spin?duration_s=60&token=secret
+```
+
+## DB spin
+
+This endpoint attempts to fully utilise a single core, and interleave it with DB request, for the given period.
+This endpoint can be used to model yielding execution to another threads when running concurrently.
+
+Depending on your rack server setup, your request may timeout after a predermined period (normally 60 seconds).
+If you're using Unicorn, this is done by killing the worker process.
+
+```
+GET /-/chaos/db_spin
+GET /-/chaos/db_spin?duration_s=50
 ```
 
 | Attribute    | Type    | Required | Description                                                           |
 | ------------ | ------- | -------- | --------------------------------------------------------------------- |
+| `interval_s` | float   | no       | Interval, in seconds, for every DB request. Defaults to 1s            |
 | `duration_s` | integer | no       | Duration, in seconds, that the core will be utilised. Defaults to 30s |
 
 ```bash
-curl http://localhost:3000/-/chaos/cpuspin?duration_s=60 --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/db_spin?interval_s=1&duration_s=60 --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/db_spin?interval_s=1&duration_s=60&token=secret
 ```
 
 ## Sleep
 
-This endpoint is similar to the CPU Spin endpoint but simulates off-processor activity, such as network calls to backend services. It will sleep for a given duration.
+This endpoint is similar to the CPU Spin endpoint but simulates off-processor activity, such as network calls to backend services. It will sleep for a given duration_s.
 
-As with the CPU Spin endpoint, this may lead to your request timing out if duration exceeds the configured limit.
+As with the CPU Spin endpoint, this may lead to your request timing out if duration_s exceeds the configured limit.
 
 ```
 GET /-/chaos/sleep
@@ -99,6 +120,7 @@ GET /-/chaos/sleep?duration_s=50
 
 ```bash
 curl http://localhost:3000/-/chaos/sleep?duration_s=60 --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/sleep?duration_s=60&token=secret
 ```
 
 ## Kill
@@ -114,4 +136,5 @@ GET /-/chaos/kill
 
 ```bash
 curl http://localhost:3000/-/chaos/kill --header 'X-Chaos-Secret: secret'
+curl http://localhost:3000/-/chaos/kill?token=secret
 ```