fix lint

docs/performance.md

@@ -5,7 +5,7 @@ However, it is possible to substantially improve performance using an appropriat
 
 ## Number of Threads and Workers
 
-By default, FrankenPHP starts 2 times more threads and workers (in worker mode) than the available numbers of CPU.
+By default, FrankenPHP starts 2 times more threads than the available numbers of CPU.
 
 The appropriate values depend heavily on how your application is written, what it does and your hardware.
 We strongly recommend changing these values.
@@ -16,6 +16,22 @@ To find the right values, it's best to run load tests simulating real traffic.
 To configure the number of threads, use the `num_threads` option of the `php_server` and `php` directives.
 To change the number of workers, use the `num` option of the `worker` section of the `frankenphp` directive.
 
+### Rule of Thumb—Threads
+
+A good starting point is to set the number of threads to the number of CPU cores * 2, however, this gets complicated
+when using orchestrations like Kubernetes or cgroups, in general.
+
+However, if your application is heavily I/O bound,
+you can usually increase the number of threads to a much higher number, assuming you have enough memory.
+This will largely depend on your application and the hardware/orchestration system you are running on.
+You may need to experiment with different values to find the optimal number.
+
+#### Cores
+
+FrankenPHP is a multithreaded application,
+and as such,
+running it on less than 2 cores for production workloads is [not recommended](https://github.com/dunglas/frankenphp/discussions/941#discussioncomment-10195431).
+
 ## Worker Mode
 
 Enabling [the worker mode](worker.md) dramatically improves performance,
@@ -38,6 +54,13 @@ This can be achieved by using the Debian Docker images (the default) and [by com
 
 Alternatively, we provide static binaries compiled with [the mimalloc allocator](https://github.com/microsoft/mimalloc), which makes FrankenPHP+musl faster (but still slower than FrankenPHP+glibc).
 
+## Load Balancing
+
+It is recommended to use caddy to load balance between multiple instances of FrankenPHP to ensure high availability,
+performance and reliability.
+Nginx can also be used,
+but it is [not nearly as performant as Caddy](https://www.patrickdap.com/post/benchmarking-is-hard/) without professional tuning.
+
 ## Go Runtime Configuration
 
 FrankenPHP is written in Go.
@@ -52,6 +75,44 @@ set the `GOMEMLIMIT` environment variable to the available amount of memory.
 
 For more details, [the Go documentation page dedicated to this subject](https://pkg.go.dev/runtime#hdr-Environment_Variables) is a must-read to get the most out of the runtime.
 
+### Rule of Thumb—Memory
+
+When dealing with memory limits (such as in containers),
+this memory limit isn’t shared with the application and thus must be set manually; just like with any other workload.
+
+If you are using Kubernetes, it is usually recommended to set GOMEMLIMIT like so:
+
+```yaml
+env:
+- name: GOMEMLIMIT
+  valueFrom:
+    resourceFieldRef:
+      resource: limits.memory
+```
+
+However, PHP also uses memory separate from the go runtime using the `memory_limit` directive in `php.ini`.
+Thus, a balance is required between the Go runtime and the PHP runtime.
+
+If your application is using the entire available memory (i.e., no memory limit),
+then you can basically skip the remainder of this section,
+as the Go runtime will automatically adjust to the available memory.
+However, if you are using container memory limits,
+you will need to adjust the Go runtime memory limit to ensure you don’t crash from an out-of-memory error.
+
+A quick calculation you can use to determine the optimal memory limit for the Go runtime is:
+
+```pseudocode
+POD_MEMORY_LIMIT = (PHP_MAX_MEMORY * NUM_THREADS) + (NUM_CPU * 100MB)
+GOMEMLIMIT = (NUM_CPU * 1000000000)
+```
+
+The 100MB is an extremely conservative estimate of the memory
+required for the Go runtime to run FrankenPHP and terminate SSL.
+This value may need to be adjusted based on your specific application.
+
+Thus, if you have 16 threads on an 8-core machine with a 128mb memory limit for PHP,
+then you should allocate ~2.9GB to the container and set `GOMEMLIMIT` to 0.8GB (`8000000000`).
+
 ## `file_server`
 
 By default, the `php_server` directive automatically sets up a file server to