compaction-style setting is broken

[kamijin-fanta]

Bug Report

What version of TiKV are you using?

using tiup for deployment.

TiKV
Release Version:   5.2.1
Edition:           Community
Git Commit Hash:   2c99f317d4ba125b772a8b94a6c3c0eb9d07ac59
Git Commit Branch: heads/refs/tags/v5.2.1
UTC Build Time:    2021-09-08 02:32:36
Rust Version:      rustc 1.56.0-nightly (2faabf579 2021-07-27)
Enable Features:   jemalloc mem-profiling portable sse protobuf-codec test-engines-rocksdb cloud-aws cloud-gcp
Profile:           dist_release

What operating system and CPU are you using?

It seems to be a machine-independent bug.

Steps to reproduce

The server will not start if the following settings are made.

# tiup-topology.yaml
server_configs:
  # tidb:
  tikv:
    rocksdb:
      defaultcf:
        compaction-style: universal

# /opt/tidb/deploy/tikv-20160/conf/tikv.toml
[rocksdb]
[rocksdb.defaultcf]
compaction-style = "universal"

Error: init config failed: 192.168.50.3:20160: executor.ssh.execute_failed: Failed to execute command over SSH for '********@********:22' {ssh_stderr: thread 'main' panicked at 'invalid auto generated configuration file /opt/tidb/deploy/tikv-20160/conf/tikv.toml, err invalid type: string "level", expected valid DBCompactionStyle for key `rocksdb.defaultcf.compaction-style` at line 10 column 20', src/config.rs:2836:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
, ssh_stdout: , ssh_command: export LANG=C; PATH=$PATH:/bin:/sbin:/usr/bin:/usr/sbin /opt/tidb/deploy/tikv-20160/bin/tikv-server --config-check --config=/opt/tidb/deploy/tikv-20160/conf/tikv.toml --pd "" --data-dir "/opt/tidb/data/tikv-20160"}, cause: Process exited with status 101: check config failed

What did you expect?

The reference looks like a correct description.
https://docs.pingcap.com/tidb/stable/tikv-configuration-file#compaction-style

What did happened?

If specify compaction-style: 1, it appears to start successfully.

[tabokie]

/assign @yuqi1129

[ti-chi-bot]

@tabokie: GitHub didn't allow me to assign the following users: yuqi1129.

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In response to this:

/assign @yuqi1129

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[yuqi1129]

/assign @yuqi1129

[yuqi1129]

@tabokie I have test this configuration and it seems that only numeric is supported like compaction-pri. Sounds like we need to update user docs.

numeric_enum_mod! {compaction_style_serde DBCompactionStyle {
    Level = 0,
    Universal = 1,
}}

[tabokie]

@yuqi1129 I prefer to use descriptive words for these config items, just like blob-run-mode, grpc-compression-type, etc. So I think you should submit a code patch to make compaction-pri accept string literals.

As for compaction-pri, it is problematic too, but we probably shouldn't change it directly for backward compatibility.