feat!: move v1/prof API to debug/prof (#4810)

* feat!: move v1/prof to debug/prof

* docs: update readme

* docs: move prof docs to docs dir

* chore: update message

* feat!: remove v1/prof

* docs: update mem prof docs

docs/how-to/how-to-profile-cpu.md

@@ -0,0 +1,28 @@
+# Profiling CPU
+
+## Build GreptimeDB with `pprof` feature
+
+```bash
+cargo build --features=pprof
+```
+
+## HTTP API
+Sample at 99 Hertz, for 5 seconds, output report in [protobuf format](https://github.com/google/pprof/blob/master/proto/profile.proto).
+```bash
+curl -s '0:4000/debug/prof/cpu' > /tmp/pprof.out
+```
+
+Then you can use `pprof` command with the protobuf file.
+```bash
+go tool pprof -top /tmp/pprof.out
+```
+
+Sample at 99 Hertz, for 60 seconds, output report in flamegraph format.
+```bash
+curl -s '0:4000/debug/prof/cpu?seconds=60&output=flamegraph' > /tmp/pprof.svg
+```
+
+Sample at 49 Hertz, for 10 seconds, output report in text format.
+```bash
+curl -s '0:4000/debug/prof/cpu?seconds=10&frequency=49&output=text' > /tmp/pprof.txt
+```

docs/how-to/how-to-profile-memory.md

@@ -0,0 +1,53 @@
+# Profile memory usage of GreptimeDB
+
+This crate provides an easy approach to dump memory profiling info.
+
+## Prerequisites
+### jemalloc
+```bash
+# for macOS
+brew install jemalloc
+
+# for Ubuntu
+sudo apt install libjemalloc-dev
+```
+
+### [flamegraph](https://github.com/brendangregg/FlameGraph)
+
+```bash
+curl https://raw.githubusercontent.com/brendangregg/FlameGraph/master/flamegraph.pl > ./flamegraph.pl
+```
+
+### Build GreptimeDB with `mem-prof` feature.
+
+```bash
+cargo build --features=mem-prof
+```
+
+## Profiling
+
+Start GreptimeDB instance with environment variables:
+
+```bash
+MALLOC_CONF=prof:true,lg_prof_interval:28 ./target/debug/greptime standalone start
+```
+
+Dump memory profiling data through HTTP API:
+
+```bash
+curl localhost:4000/debug/prof/mem > greptime.hprof
+```
+
+You can periodically dump profiling data and compare them to find the delta memory usage.
+
+## Analyze profiling data with flamegraph
+
+To create flamegraph according to dumped profiling data:
+
+```bash
+sudo apt install -y libjemalloc-dev
+
+jeprof <path_to_greptime_binary> <profile_data> --collapse | ./flamegraph.pl > mem-prof.svg
+
+jeprof <path_to_greptime_binary> --base <baseline_prof> <profile_data> --collapse | ./flamegraph.pl > output.svg
+```