add doc for optimization (#903)

Signed-off-by: cormick <[email protected]>

Author: CormickKneey

docs/Optimization.md

@@ -0,0 +1,96 @@
+# Performance Optimization Guidance
+
+> This is a reference benchmark process document designed to
+> assist in performance analysis and optimization for **client**.
+> This document provides as general a testing framework as possible,
+> allowing developers with needs to adjust it
+> according to their specific circumstances across various platform.
+
+## Flow
+
+![architecture](images/client_bencmark.png)
+
+## Preparation
+
+### 1. Set up Dragonfly cluster
+
+- Please refer to [official doc](https://d7y.io/docs/next/getting-started/installation/helm-charts/).
+
+### 2. Start a file server
+
+- start with docker:
+
+```bash
+export FILE_SERVER_PORT=12345
+docker run -d  --rm -p ${FILE_SERVER_PORT}:80 --name dragonfly-fs dragonflyoss/file-server:latest
+```
+
+- check
+
+```bash
+# return success if ready
+curl -s -o /dev/null \
+     -w "%{http_code}" \
+     http://localhost:12345/nano \
+| grep -q "200" \
+&& echo "Success" \
+|| echo "Failed"
+```
+
+- optional:
+
+> you can build your own image, take a reference from [**Dockerfile**](https://github.com/dragonflyoss/perf-tests/blob/main/tools/file-server/Dockerfile).
+
+### 3. Prepare related tools
+
+- Request Generator: [**oha**](https://github.com/hatoo/oha)
+
+```bash
+brew install oha
+```
+
+- Profiling: [**flamegraph**](https://github.com/flamegraph-rs/flamegraph)
+
+```bash
+cargo install flamegraph
+```
+
+### 4. start the target client
+
+- compile the target binary
+
+```bash
+cargo build --release   --bin dfdaemon
+```
+
+- connect to dragonfly cluster
+
+```bash
+# prepare client.yaml by yourself.
+./target/release/dfdaemon --config client.yaml -l info --verbose
+```
+
+## FlameGraph
+
+Now, let's start benchmark with the following params:
+
+- $FILE_SERVER_ADDRESS
+- $CLIENT_PROXY_ADDRESS
+
+### collect flamegraph
+
+- capture the flamegraph:
+
+```bash
+## stop after all requests done.
+sudo flamegraph -o my_flamegraph.svg --pid 3442
+```
+
+- make the request:
+
+```bash
+oha -c 1000 \
+    -n 100 \
+    --rand-regex-url $FILE_SERVER_ADDRESS/\(nano\|micro\|small\|medium\|large\) \
+    -x $CLIENT_PROXY_ADDRESS
+```