diff --git a/Cargo.toml b/Cargo.toml
index c73533e..5f7b0ea 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,7 +22,7 @@ clap = { version = "4.3.11", features = ["std", "cargo", "wrap_help"] }
 rand = "0.8.5"
 toml = { version = "0.7.6", default-features = false, features = ["parse"] }
 rustc-hash = "1.1.0"
-serde = { version = "1.0.167", default-features = false, features = ["derive"] }
+serde = { version = "1.0.171", default-features = false, features = ["derive"] }
 bytes = "1.4.0"
 thiserror = "1.0.43"
 x509-parser = "0.15.0"
@@ -31,11 +31,12 @@ futures = { version = "0.3.28", features = ["alloc", "async-await"] }
 tokio = { version = "1.29.1", default-features = false, features = [
   "net",
   "rt-multi-thread",
-  "parking_lot",
   "time",
   "sync",
   "macros",
 ] }
+async-trait = "0.1.71"
+hot_reload = "0.1.2" # reloading certs
 
 # http and tls
 hyper = { version = "0.14.27", default-features = false, features = [
diff --git a/quinn b/quinn
index b30711f..e652b6d 160000
--- a/quinn
+++ b/quinn
@@ -1 +1 @@
-Subproject commit b30711f5595983989b60bbbad0ac3f067be7a596
+Subproject commit e652b6d999f053ffe21eeea247854882ae480281
diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index b7923c5..c8298c3 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -13,26 +13,10 @@ pub use self::{
   upstream::{ReverseProxy, Upstream, UpstreamGroup, UpstreamGroupBuilder},
   upstream_opts::UpstreamOption,
 };
-use crate::{
-  log::*,
-  utils::{BytesName, PathNameBytesExp, ServerNameBytesExp},
-};
+use crate::utils::{BytesName, PathNameBytesExp, ServerNameBytesExp};
 use derive_builder::Builder;
-use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
-use rustls::{OwnedTrustAnchor, RootCertStore};
-use std::{
-  borrow::Cow,
-  fs::File,
-  io::{self, BufReader, Cursor, Read},
-  path::PathBuf,
-  sync::Arc,
-};
-use tokio_rustls::rustls::{
-  server::ResolvesServerCertUsingSni,
-  sign::{any_supported_type, CertifiedKey},
-  Certificate, PrivateKey, ServerConfig,
-};
-use x509_parser::prelude::*;
+use rustc_hash::FxHashMap as HashMap;
+use std::{borrow::Cow, path::PathBuf};
 
 /// Struct serving information to route incoming connections, like server name to be handled and tls certs/keys settings.
 #[derive(Builder)]
@@ -79,264 +63,9 @@ fn opt_string_to_opt_pathbuf(input: &Option<String>) -> Option<PathBuf> {
   input.to_owned().as_ref().map(PathBuf::from)
 }
 
-impl Backend {
-  pub fn read_certs_and_key(&self) -> io::Result<CertifiedKey> {
-    debug!("Read TLS server certificates and private key");
-    let (Some(certs_path), Some(certs_keys_path)) = (self.tls_cert_path.as_ref(), self.tls_cert_key_path.as_ref()) else {
-      return Err(io::Error::new(io::ErrorKind::Other, "Invalid certs and keys paths"));
-    };
-    let certs: Vec<_> = {
-      let certs_path_str = certs_path.display().to_string();
-      let mut reader = BufReader::new(File::open(certs_path).map_err(|e| {
-        io::Error::new(
-          e.kind(),
-          format!("Unable to load the certificates [{certs_path_str}]: {e}"),
-        )
-      })?);
-      rustls_pemfile::certs(&mut reader)
-        .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "Unable to parse the certificates"))?
-    }
-    .drain(..)
-    .map(Certificate)
-    .collect();
-    let certs_keys: Vec<_> = {
-      let certs_keys_path_str = certs_keys_path.display().to_string();
-      let encoded_keys = {
-        let mut encoded_keys = vec![];
-        File::open(certs_keys_path)
-          .map_err(|e| {
-            io::Error::new(
-              e.kind(),
-              format!("Unable to load the certificate keys [{certs_keys_path_str}]: {e}"),
-            )
-          })?
-          .read_to_end(&mut encoded_keys)?;
-        encoded_keys
-      };
-      let mut reader = Cursor::new(encoded_keys);
-      let pkcs8_keys = rustls_pemfile::pkcs8_private_keys(&mut reader).map_err(|_| {
-        io::Error::new(
-          io::ErrorKind::InvalidInput,
-          "Unable to parse the certificates private keys (PKCS8)",
-        )
-      })?;
-      reader.set_position(0);
-      let mut rsa_keys = rustls_pemfile::rsa_private_keys(&mut reader)?;
-      let mut keys = pkcs8_keys;
-      keys.append(&mut rsa_keys);
-      if keys.is_empty() {
-        return Err(io::Error::new(
-          io::ErrorKind::InvalidInput,
-          "No private keys found - Make sure that they are in PKCS#8/PEM format",
-        ));
-      }
-      keys.drain(..).map(PrivateKey).collect()
-    };
-    let signing_key = certs_keys
-      .iter()
-      .find_map(|k| {
-        if let Ok(sk) = any_supported_type(k) {
-          Some(sk)
-        } else {
-          None
-        }
-      })
-      .ok_or_else(|| {
-        io::Error::new(
-          io::ErrorKind::InvalidInput,
-          "Unable to find a valid certificate and key",
-        )
-      })?;
-    Ok(CertifiedKey::new(certs, signing_key))
-  }
-
-  fn read_client_ca_certs(&self) -> io::Result<(Vec<OwnedTrustAnchor>, HashSet<Vec<u8>>)> {
-    debug!("Read CA certificates for client authentication");
-    // Reads client certificate and returns client
-    let client_ca_cert_path = {
-      let Some(c) = self.client_ca_cert_path.as_ref() else {
-        return Err(io::Error::new(io::ErrorKind::Other, "Invalid certs and keys paths"));
-      };
-      c
-    };
-    let certs: Vec<_> = {
-      let certs_path_str = client_ca_cert_path.display().to_string();
-      let mut reader = BufReader::new(File::open(client_ca_cert_path).map_err(|e| {
-        io::Error::new(
-          e.kind(),
-          format!("Unable to load the client certificates [{certs_path_str}]: {e}"),
-        )
-      })?);
-      rustls_pemfile::certs(&mut reader)
-        .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "Unable to parse the client certificates"))?
-    }
-    .drain(..)
-    .map(Certificate)
-    .collect();
-
-    let owned_trust_anchors: Vec<_> = certs
-      .iter()
-      .map(|v| {
-        // let trust_anchor = tokio_rustls::webpki::TrustAnchor::try_from_cert_der(&v.0).unwrap();
-        let trust_anchor = webpki::TrustAnchor::try_from_cert_der(&v.0).unwrap();
-        rustls::OwnedTrustAnchor::from_subject_spki_name_constraints(
-          trust_anchor.subject,
-          trust_anchor.spki,
-          trust_anchor.name_constraints,
-        )
-      })
-      .collect();
-
-    // TODO: SKID is not used currently
-    let subject_key_identifiers: HashSet<_> = certs
-      .iter()
-      .filter_map(|v| {
-        // retrieve ca key id (subject key id)
-        let cert = parse_x509_certificate(&v.0).unwrap().1;
-        let subject_key_ids = cert
-          .iter_extensions()
-          .filter_map(|ext| match ext.parsed_extension() {
-            ParsedExtension::SubjectKeyIdentifier(skid) => Some(skid),
-            _ => None,
-          })
-          .collect::<Vec<_>>();
-        if !subject_key_ids.is_empty() {
-          Some(subject_key_ids[0].0.to_owned())
-        } else {
-          None
-        }
-      })
-      .collect();
-
-    Ok((owned_trust_anchors, subject_key_identifiers))
-  }
-}
-
+#[derive(Default)]
 /// HashMap and some meta information for multiple Backend structs.
 pub struct Backends {
   pub apps: HashMap<ServerNameBytesExp, Backend>, // hyper::uriで抜いたhostで引っ掛ける
   pub default_server_name_bytes: Option<ServerNameBytesExp>, // for plaintext http
 }
-
-pub type SniServerCryptoMap = HashMap<ServerNameBytesExp, Arc<ServerConfig>>;
-pub struct ServerCrypto {
-  // For Quic/HTTP3, only servers with no client authentication
-  pub inner_global_no_client_auth: Arc<ServerConfig>,
-  // For TLS over TCP/HTTP2 and 1.1, map of SNI to server_crypto for all given servers
-  pub inner_local_map: Arc<SniServerCryptoMap>,
-}
-
-impl Backends {
-  pub async fn generate_server_crypto(&self) -> Result<ServerCrypto, anyhow::Error> {
-    let mut resolver_global = ResolvesServerCertUsingSni::new();
-    let mut server_crypto_local_map: SniServerCryptoMap = HashMap::default();
-
-    for (server_name_bytes_exp, backend) in self.apps.iter() {
-      if backend.tls_cert_key_path.is_some() && backend.tls_cert_path.is_some() {
-        match backend.read_certs_and_key() {
-          Ok(certified_key) => {
-            let mut resolver_local = ResolvesServerCertUsingSni::new();
-            let mut client_ca_roots_local = RootCertStore::empty();
-
-            // add server certificate and key
-            if let Err(e) = resolver_local.add(backend.server_name.as_str(), certified_key.to_owned()) {
-              error!(
-                "{}: Failed to read some certificates and keys {}",
-                backend.server_name.as_str(),
-                e
-              )
-            }
-
-            if backend.client_ca_cert_path.is_none() {
-              // aggregated server config for no client auth server for http3
-              if let Err(e) = resolver_global.add(backend.server_name.as_str(), certified_key) {
-                error!(
-                  "{}: Failed to read some certificates and keys {}",
-                  backend.server_name.as_str(),
-                  e
-                )
-              }
-            } else {
-              // add client certificate if specified
-              match backend.read_client_ca_certs() {
-                Ok((owned_trust_anchors, _subject_key_ids)) => {
-                  client_ca_roots_local.add_server_trust_anchors(owned_trust_anchors.into_iter());
-                }
-                Err(e) => {
-                  warn!(
-                    "Failed to add client CA certificate for {}: {}",
-                    backend.server_name.as_str(),
-                    e
-                  );
-                }
-              }
-            }
-
-            let mut server_config_local = if client_ca_roots_local.is_empty() {
-              // with no client auth, enable http1.1 -- 3
-              #[cfg(not(feature = "http3"))]
-              {
-                ServerConfig::builder()
-                  .with_safe_defaults()
-                  .with_no_client_auth()
-                  .with_cert_resolver(Arc::new(resolver_local))
-              }
-              #[cfg(feature = "http3")]
-              {
-                let mut sc = ServerConfig::builder()
-                  .with_safe_defaults()
-                  .with_no_client_auth()
-                  .with_cert_resolver(Arc::new(resolver_local));
-                sc.alpn_protocols = vec![b"h3".to_vec(), b"hq-29".to_vec()]; // TODO: remove hq-29 later?
-                sc
-              }
-            } else {
-              // with client auth, enable only http1.1 and 2
-              // let client_certs_verifier = rustls::server::AllowAnyAnonymousOrAuthenticatedClient::new(client_ca_roots);
-              let client_certs_verifier = rustls::server::AllowAnyAuthenticatedClient::new(client_ca_roots_local);
-              ServerConfig::builder()
-                .with_safe_defaults()
-                .with_client_cert_verifier(Arc::new(client_certs_verifier))
-                .with_cert_resolver(Arc::new(resolver_local))
-            };
-            server_config_local.alpn_protocols.push(b"h2".to_vec());
-            server_config_local.alpn_protocols.push(b"http/1.1".to_vec());
-
-            server_crypto_local_map.insert(server_name_bytes_exp.to_owned(), Arc::new(server_config_local));
-          }
-          Err(e) => {
-            warn!("Failed to add certificate for {}: {}", backend.server_name.as_str(), e);
-          }
-        }
-      }
-    }
-    // debug!("Load certificate chain for {} server_name's", cnt);
-
-    //////////////
-    let mut server_crypto_global = ServerConfig::builder()
-      .with_safe_defaults()
-      .with_no_client_auth()
-      .with_cert_resolver(Arc::new(resolver_global));
-
-    //////////////////////////////
-
-    #[cfg(feature = "http3")]
-    {
-      server_crypto_global.alpn_protocols = vec![
-        b"h3".to_vec(),
-        b"hq-29".to_vec(), // TODO: remove later?
-        b"h2".to_vec(),
-        b"http/1.1".to_vec(),
-      ];
-    }
-    #[cfg(not(feature = "http3"))]
-    {
-      server_crypto_global.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
-    }
-
-    Ok(ServerCrypto {
-      inner_global_no_client_auth: Arc::new(server_crypto_global),
-      inner_local_map: Arc::new(server_crypto_local_map),
-    })
-  }
-}
diff --git a/src/cert_reader.rs b/src/cert_reader.rs
new file mode 100644
index 0000000..a52f2e2
--- /dev/null
+++ b/src/cert_reader.rs
@@ -0,0 +1,93 @@
+use crate::{log::*, proxy::CertsAndKeys};
+use rustls::{Certificate, PrivateKey};
+use std::{
+  fs::File,
+  io::{self, BufReader, Cursor, Read},
+  path::PathBuf,
+};
+
+/// Read certificates and private keys from file
+pub(crate) fn read_certs_and_keys(
+  cert_path: &PathBuf,
+  cert_key_path: &PathBuf,
+  client_ca_cert_path: Option<&PathBuf>,
+) -> Result<CertsAndKeys, io::Error> {
+  debug!("Read TLS server certificates and private key");
+
+  let certs: Vec<_> = {
+    let certs_path_str = cert_path.display().to_string();
+    let mut reader = BufReader::new(File::open(cert_path).map_err(|e| {
+      io::Error::new(
+        e.kind(),
+        format!("Unable to load the certificates [{certs_path_str}]: {e}"),
+      )
+    })?);
+    rustls_pemfile::certs(&mut reader)
+      .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "Unable to parse the certificates"))?
+  }
+  .drain(..)
+  .map(Certificate)
+  .collect();
+
+  let cert_keys: Vec<_> = {
+    let cert_key_path_str = cert_key_path.display().to_string();
+    let encoded_keys = {
+      let mut encoded_keys = vec![];
+      File::open(cert_key_path)
+        .map_err(|e| {
+          io::Error::new(
+            e.kind(),
+            format!("Unable to load the certificate keys [{cert_key_path_str}]: {e}"),
+          )
+        })?
+        .read_to_end(&mut encoded_keys)?;
+      encoded_keys
+    };
+    let mut reader = Cursor::new(encoded_keys);
+    let pkcs8_keys = rustls_pemfile::pkcs8_private_keys(&mut reader).map_err(|_| {
+      io::Error::new(
+        io::ErrorKind::InvalidInput,
+        "Unable to parse the certificates private keys (PKCS8)",
+      )
+    })?;
+    reader.set_position(0);
+    let mut rsa_keys = rustls_pemfile::rsa_private_keys(&mut reader)?;
+    let mut keys = pkcs8_keys;
+    keys.append(&mut rsa_keys);
+    if keys.is_empty() {
+      return Err(io::Error::new(
+        io::ErrorKind::InvalidInput,
+        "No private keys found - Make sure that they are in PKCS#8/PEM format",
+      ));
+    }
+    keys.drain(..).map(PrivateKey).collect()
+  };
+
+  let client_ca_certs = if let Some(path) = client_ca_cert_path {
+    debug!("Read CA certificates for client authentication");
+    // Reads client certificate and returns client
+    let certs: Vec<_> = {
+      let certs_path_str = path.display().to_string();
+      let mut reader = BufReader::new(File::open(path).map_err(|e| {
+        io::Error::new(
+          e.kind(),
+          format!("Unable to load the client certificates [{certs_path_str}]: {e}"),
+        )
+      })?);
+      rustls_pemfile::certs(&mut reader)
+        .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "Unable to parse the client certificates"))?
+    }
+    .drain(..)
+    .map(Certificate)
+    .collect();
+    Some(certs)
+  } else {
+    None
+  };
+
+  Ok(CertsAndKeys {
+    certs,
+    cert_keys,
+    client_ca_certs,
+  })
+}
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 6e8123c..54b2600 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -1,4 +1,4 @@
 mod parse;
 mod toml;
 
-pub use parse::parse_opts;
+pub use parse::build_globals;
diff --git a/src/config/parse.rs b/src/config/parse.rs
index 8e4ddf7..1593aba 100644
--- a/src/config/parse.rs
+++ b/src/config/parse.rs
@@ -1,17 +1,9 @@
-use super::toml::{ConfigToml, ReverseProxyOption};
-use crate::{
-  backend::{BackendBuilder, ReverseProxy, Upstream, UpstreamGroup, UpstreamGroupBuilder, UpstreamOption},
-  constants::*,
-  error::*,
-  globals::*,
-  log::*,
-  utils::{BytesName, PathNameBytesExp},
-};
+use super::toml::ConfigToml;
+use crate::{backend::Backends, error::*, globals::*, log::*, utils::BytesName};
 use clap::Arg;
-use rustc_hash::FxHashMap as HashMap;
-use std::net::SocketAddr;
+use tokio::runtime::Handle;
 
-pub fn parse_opts(globals: &mut Globals) -> std::result::Result<(), anyhow::Error> {
+pub fn build_globals(runtime_handle: Handle) -> std::result::Result<Globals, anyhow::Error> {
   let _ = include_str!("../../Cargo.toml");
   let options = clap::command!().arg(
     Arg::new("config_file")
@@ -22,6 +14,7 @@ pub fn parse_opts(globals: &mut Globals) -> std::result::Result<(), anyhow::Erro
   );
   let matches = options.get_matches();
 
+  ///////////////////////////////////
   let config = if let Some(config_file_path) = matches.get_one::<String>("config_file") {
     ConfigToml::new(config_file_path)?
   } else {
@@ -29,117 +22,67 @@ pub fn parse_opts(globals: &mut Globals) -> std::result::Result<(), anyhow::Erro
     ConfigToml::default()
   };
 
-  // listen port and socket
-  globals.http_port = config.listen_port;
-  globals.https_port = config.listen_port_tls;
-  ensure!(
-    { globals.http_port.is_some() || globals.https_port.is_some() } && {
-      if let (Some(p), Some(t)) = (globals.http_port, globals.https_port) {
-        p != t
-      } else {
-        true
-      }
-    },
-    anyhow!("Wrong port spec.")
-  );
-  // NOTE: when [::]:xx is bound, both v4 and v6 listeners are enabled.
-  let listen_addresses: Vec<&str> = match config.listen_ipv6 {
-    Some(true) => {
-      info!("Listen both IPv4 and IPv6");
-      LISTEN_ADDRESSES_V6.to_vec()
-    }
-    Some(false) | None => {
-      info!("Listen IPv4");
-      LISTEN_ADDRESSES_V4.to_vec()
-    }
-  };
-  globals.listen_sockets = listen_addresses
-    .iter()
-    .flat_map(|x| {
-      let mut v: Vec<SocketAddr> = vec![];
-      if let Some(p) = globals.http_port {
-        v.push(format!("{x}:{p}").parse().unwrap());
-      }
-      if let Some(p) = globals.https_port {
-        v.push(format!("{x}:{p}").parse().unwrap());
-      }
-      v
-    })
-    .collect();
-  if globals.http_port.is_some() {
-    info!("Listen port: {}", globals.http_port.unwrap());
+  ///////////////////////////////////
+  // build proxy config
+  let proxy_config: ProxyConfig = (&config).try_into()?;
+  // For loggings
+  if proxy_config.listen_sockets.iter().any(|addr| addr.is_ipv6()) {
+    info!("Listen both IPv4 and IPv6")
+  } else {
+    info!("Listen IPv4")
   }
-  if globals.https_port.is_some() {
-    info!("Listen port: {} (for TLS)", globals.https_port.unwrap());
+  if proxy_config.http_port.is_some() {
+    info!("Listen port: {}", proxy_config.http_port.unwrap());
+  }
+  if proxy_config.https_port.is_some() {
+    info!("Listen port: {} (for TLS)", proxy_config.https_port.unwrap());
+  }
+  if proxy_config.http3 {
+    info!("Experimental HTTP/3.0 is enabled. Note it is still very unstable.");
+  }
+  if !proxy_config.sni_consistency {
+    info!("Ignore consistency between TLS SNI and Host header (or Request line). Note it violates RFC.");
   }
 
-  // max values
-  if let Some(c) = config.max_clients {
-    globals.max_clients = c as usize;
-  }
-  if let Some(c) = config.max_concurrent_streams {
-    globals.max_concurrent_streams = c;
-  }
+  ///////////////////////////////////
+  // backend_apps
+  let apps = config.apps.ok_or(anyhow!("Missing application spec"))?;
 
-  // backend apps
-  ensure!(config.apps.is_some(), "Missing application spec.");
-  let apps = config.apps.unwrap();
+  // assertions for all backend apps
   ensure!(!apps.0.is_empty(), "Wrong application spec.");
+  // if only https_port is specified, tls must be configured for all apps
+  if proxy_config.http_port.is_none() {
+    ensure!(
+      apps.0.iter().all(|(_, app)| app.tls.is_some()),
+      "Some apps serves only plaintext HTTP"
+    );
+  }
+  // https redirection can be configured if both ports are active
+  if !(proxy_config.https_port.is_some() && proxy_config.http_port.is_some()) {
+    ensure!(
+      apps.0.iter().all(|(_, app)| {
+        if let Some(tls) = app.tls.as_ref() {
+          tls.https_redirection.is_none()
+        } else {
+          true
+        }
+      }),
+      "https_redirection can be specified only when both http_port and https_port are specified"
+    );
+  }
 
-  // each app
+  // build backends
+  let mut backends = Backends::default();
   for (app_name, app) in apps.0.iter() {
-    ensure!(app.server_name.is_some(), "Missing server_name");
-    let server_name_string = app.server_name.as_ref().unwrap();
-    if globals.http_port.is_none() {
-      // if only https_port is specified, tls must be configured
-      ensure!(app.tls.is_some())
-    }
-
-    // backend builder
-    let mut backend_builder = BackendBuilder::default();
-    // reverse proxy settings
-    ensure!(app.reverse_proxy.is_some(), "Missing reverse_proxy");
-    let reverse_proxy = get_reverse_proxy(server_name_string, app.reverse_proxy.as_ref().unwrap())?;
-
-    backend_builder
-      .app_name(server_name_string)
-      .server_name(server_name_string)
-      .reverse_proxy(reverse_proxy);
-
-    // TLS settings and build backend instance
-    let backend = if app.tls.is_none() {
-      ensure!(globals.http_port.is_some(), "Required HTTP port");
-      backend_builder.build()?
-    } else {
-      let tls = app.tls.as_ref().unwrap();
-      ensure!(tls.tls_cert_key_path.is_some() && tls.tls_cert_path.is_some());
-
-      let https_redirection = if tls.https_redirection.is_none() {
-        Some(true) // Default true
-      } else {
-        ensure!(globals.https_port.is_some()); // only when both https ports are configured.
-        tls.https_redirection
-      };
-
-      backend_builder
-        .tls_cert_path(&tls.tls_cert_path)
-        .tls_cert_key_path(&tls.tls_cert_key_path)
-        .https_redirection(https_redirection)
-        .client_ca_cert_path(&tls.client_ca_cert_path)
-        .build()?
-    };
-
-    globals
-      .backends
-      .apps
-      .insert(server_name_string.to_server_name_vec(), backend);
+    let server_name_string = app.server_name.as_ref().ok_or(anyhow!("No server name"))?;
+    let backend = app.try_into()?;
+    backends.apps.insert(server_name_string.to_server_name_vec(), backend);
     info!("Registering application: {} ({})", app_name, server_name_string);
   }
 
   // default backend application for plaintext http requests
   if let Some(d) = config.default_app {
-    let d_sn: Vec<&str> = globals
-      .backends
+    let d_sn: Vec<&str> = backends
       .apps
       .iter()
       .filter(|(_k, v)| v.app_name == d)
@@ -150,86 +93,17 @@ pub fn parse_opts(globals: &mut Globals) -> std::result::Result<(), anyhow::Erro
         "Serving plaintext http for requests to unconfigured server_name by app {} (server_name: {}).",
         d, d_sn[0]
       );
-      globals.backends.default_server_name_bytes = Some(d_sn[0].to_server_name_vec());
+      backends.default_server_name_bytes = Some(d_sn[0].to_server_name_vec());
     }
   }
 
-  // experimental
-  if let Some(exp) = config.experimental {
-    #[cfg(feature = "http3")]
-    {
-      if let Some(h3option) = exp.h3 {
-        globals.http3 = true;
-        info!("Experimental HTTP/3.0 is enabled. Note it is still very unstable.");
-        if let Some(x) = h3option.alt_svc_max_age {
-          globals.h3_alt_svc_max_age = x;
-        }
-        if let Some(x) = h3option.request_max_body_size {
-          globals.h3_request_max_body_size = x;
-        }
-        if let Some(x) = h3option.max_concurrent_connections {
-          globals.h3_max_concurrent_connections = x;
-        }
-        if let Some(x) = h3option.max_concurrent_bidistream {
-          globals.h3_max_concurrent_bidistream = x.into();
-        }
-        if let Some(x) = h3option.max_concurrent_unistream {
-          globals.h3_max_concurrent_unistream = x.into();
-        }
-        if let Some(x) = h3option.max_idle_timeout {
-          if x == 0u64 {
-            globals.h3_max_idle_timeout = None;
-          } else {
-            globals.h3_max_idle_timeout =
-              Some(quinn::IdleTimeout::try_from(tokio::time::Duration::from_secs(x)).unwrap())
-          }
-        }
-      }
-    }
+  ///////////////////////////////////
+  let globals = Globals {
+    proxy_config,
+    backends,
+    request_count: Default::default(),
+    runtime_handle,
+  };
 
-    if let Some(b) = exp.ignore_sni_consistency {
-      globals.sni_consistency = !b;
-      if b {
-        info!("Ignore consistency between TLS SNI and Host header (or Request line). Note it violates RFC.");
-      }
-    }
-  }
-
-  Ok(())
-}
-
-fn get_reverse_proxy(
-  server_name_string: &str,
-  rp_settings: &[ReverseProxyOption],
-) -> std::result::Result<ReverseProxy, anyhow::Error> {
-  let mut upstream: HashMap<PathNameBytesExp, UpstreamGroup> = HashMap::default();
-
-  rp_settings.iter().for_each(|rpo| {
-    let upstream_vec: Vec<Upstream> = rpo.upstream.iter().map(|x| x.to_upstream().unwrap()).collect();
-    // let upstream_iter = rpo.upstream.iter().map(|x| x.to_upstream().unwrap());
-    // let lb_upstream_num = vec_upstream.len();
-    let elem = UpstreamGroupBuilder::default()
-      .upstream(&upstream_vec)
-      .path(&rpo.path)
-      .replace_path(&rpo.replace_path)
-      .lb(&rpo.load_balance, &upstream_vec, server_name_string, &rpo.path)
-      .opts(&rpo.upstream_options)
-      .build()
-      .unwrap();
-
-    upstream.insert(elem.path.clone(), elem);
-  });
-  ensure!(
-    rp_settings.iter().filter(|rpo| rpo.path.is_none()).count() < 2,
-    "Multiple default reverse proxy setting"
-  );
-  ensure!(
-    upstream
-      .iter()
-      .all(|(_, elem)| !(elem.opts.contains(&UpstreamOption::ConvertHttpsTo11)
-        && elem.opts.contains(&UpstreamOption::ConvertHttpsTo2))),
-    "either one of force_http11 or force_http2 can be enabled"
-  );
-
-  Ok(ReverseProxy { upstream })
+  Ok(globals)
 }
diff --git a/src/config/toml.rs b/src/config/toml.rs
index 6ce48b2..b883f6a 100644
--- a/src/config/toml.rs
+++ b/src/config/toml.rs
@@ -1,7 +1,13 @@
-use crate::{backend::Upstream, error::*};
+use crate::{
+  backend::{Backend, BackendBuilder, ReverseProxy, Upstream, UpstreamGroup, UpstreamGroupBuilder, UpstreamOption},
+  constants::*,
+  error::*,
+  globals::ProxyConfig,
+  utils::PathNameBytesExp,
+};
 use rustc_hash::FxHashMap as HashMap;
 use serde::Deserialize;
-use std::fs;
+use std::{fs, net::SocketAddr};
 
 #[derive(Deserialize, Debug, Default)]
 pub struct ConfigToml {
@@ -65,25 +71,196 @@ pub struct UpstreamParams {
   pub location: String,
   pub tls: Option<bool>,
 }
-impl UpstreamParams {
-  pub fn to_upstream(&self) -> Result<Upstream> {
-    let mut scheme = "http";
-    if let Some(t) = self.tls {
-      if t {
-        scheme = "https";
+
+impl TryInto<ProxyConfig> for &ConfigToml {
+  type Error = anyhow::Error;
+
+  fn try_into(self) -> std::result::Result<ProxyConfig, Self::Error> {
+    let mut proxy_config = ProxyConfig {
+      // listen port and socket
+      http_port: self.listen_port,
+      https_port: self.listen_port_tls,
+      ..Default::default()
+    };
+    ensure!(
+      proxy_config.http_port.is_some() || proxy_config.https_port.is_some(),
+      anyhow!("Either/Both of http_port or https_port must be specified")
+    );
+    if proxy_config.http_port.is_some() && proxy_config.https_port.is_some() {
+      ensure!(
+        proxy_config.http_port.unwrap() != proxy_config.https_port.unwrap(),
+        anyhow!("http_port and https_port must be different")
+      );
+    }
+
+    // NOTE: when [::]:xx is bound, both v4 and v6 listeners are enabled.
+    let listen_addresses: Vec<&str> = if let Some(true) = self.listen_ipv6 {
+      LISTEN_ADDRESSES_V6.to_vec()
+    } else {
+      LISTEN_ADDRESSES_V4.to_vec()
+    };
+    proxy_config.listen_sockets = listen_addresses
+      .iter()
+      .flat_map(|addr| {
+        let mut v: Vec<SocketAddr> = vec![];
+        if let Some(port) = proxy_config.http_port {
+          v.push(format!("{addr}:{port}").parse().unwrap());
+        }
+        if let Some(port) = proxy_config.https_port {
+          v.push(format!("{addr}:{port}").parse().unwrap());
+        }
+        v
+      })
+      .collect();
+
+    // max values
+    if let Some(c) = self.max_clients {
+      proxy_config.max_clients = c as usize;
+    }
+    if let Some(c) = self.max_concurrent_streams {
+      proxy_config.max_concurrent_streams = c;
+    }
+
+    // experimental
+    if let Some(exp) = &self.experimental {
+      #[cfg(feature = "http3")]
+      {
+        if let Some(h3option) = &exp.h3 {
+          proxy_config.http3 = true;
+          if let Some(x) = h3option.alt_svc_max_age {
+            proxy_config.h3_alt_svc_max_age = x;
+          }
+          if let Some(x) = h3option.request_max_body_size {
+            proxy_config.h3_request_max_body_size = x;
+          }
+          if let Some(x) = h3option.max_concurrent_connections {
+            proxy_config.h3_max_concurrent_connections = x;
+          }
+          if let Some(x) = h3option.max_concurrent_bidistream {
+            proxy_config.h3_max_concurrent_bidistream = x.into();
+          }
+          if let Some(x) = h3option.max_concurrent_unistream {
+            proxy_config.h3_max_concurrent_unistream = x.into();
+          }
+          if let Some(x) = h3option.max_idle_timeout {
+            if x == 0u64 {
+              proxy_config.h3_max_idle_timeout = None;
+            } else {
+              proxy_config.h3_max_idle_timeout =
+                Some(quinn::IdleTimeout::try_from(tokio::time::Duration::from_secs(x)).unwrap())
+            }
+          }
+        }
+      }
+
+      if let Some(ignore) = exp.ignore_sni_consistency {
+        proxy_config.sni_consistency = !ignore;
       }
     }
+
+    Ok(proxy_config)
+  }
+}
+
+impl ConfigToml {
+  pub fn new(config_file: &str) -> std::result::Result<Self, RpxyError> {
+    let config_str = fs::read_to_string(config_file).map_err(RpxyError::Io)?;
+
+    toml::from_str(&config_str).map_err(RpxyError::TomlDe)
+  }
+}
+
+impl TryInto<Backend> for &Application {
+  type Error = anyhow::Error;
+
+  fn try_into(self) -> std::result::Result<Backend, Self::Error> {
+    let server_name_string = self.server_name.as_ref().ok_or(anyhow!("Missing server_name"))?;
+
+    // backend builder
+    let mut backend_builder = BackendBuilder::default();
+    // reverse proxy settings
+    let reverse_proxy = self.try_into()?;
+
+    backend_builder
+      .app_name(server_name_string)
+      .server_name(server_name_string)
+      .reverse_proxy(reverse_proxy);
+
+    // TLS settings and build backend instance
+    let backend = if self.tls.is_none() {
+      backend_builder.build()?
+    } else {
+      let tls = self.tls.as_ref().unwrap();
+      ensure!(tls.tls_cert_key_path.is_some() && tls.tls_cert_path.is_some());
+
+      let https_redirection = if tls.https_redirection.is_none() {
+        Some(true) // Default true
+      } else {
+        tls.https_redirection
+      };
+
+      backend_builder
+        .tls_cert_path(&tls.tls_cert_path)
+        .tls_cert_key_path(&tls.tls_cert_key_path)
+        .https_redirection(https_redirection)
+        .client_ca_cert_path(&tls.client_ca_cert_path)
+        .build()?
+    };
+    Ok(backend)
+  }
+}
+
+impl TryInto<ReverseProxy> for &Application {
+  type Error = anyhow::Error;
+
+  fn try_into(self) -> std::result::Result<ReverseProxy, Self::Error> {
+    let server_name_string = self.server_name.as_ref().ok_or(anyhow!("Missing server_name"))?;
+    let rp_settings = self.reverse_proxy.as_ref().ok_or(anyhow!("Missing reverse_proxy"))?;
+
+    let mut upstream: HashMap<PathNameBytesExp, UpstreamGroup> = HashMap::default();
+
+    rp_settings.iter().for_each(|rpo| {
+      let upstream_vec: Vec<Upstream> = rpo.upstream.iter().map(|x| x.try_into().unwrap()).collect();
+      // let upstream_iter = rpo.upstream.iter().map(|x| x.to_upstream().unwrap());
+      // let lb_upstream_num = vec_upstream.len();
+      let elem = UpstreamGroupBuilder::default()
+        .upstream(&upstream_vec)
+        .path(&rpo.path)
+        .replace_path(&rpo.replace_path)
+        .lb(&rpo.load_balance, &upstream_vec, server_name_string, &rpo.path)
+        .opts(&rpo.upstream_options)
+        .build()
+        .unwrap();
+
+      upstream.insert(elem.path.clone(), elem);
+    });
+    ensure!(
+      rp_settings.iter().filter(|rpo| rpo.path.is_none()).count() < 2,
+      "Multiple default reverse proxy setting"
+    );
+    ensure!(
+      upstream
+        .iter()
+        .all(|(_, elem)| !(elem.opts.contains(&UpstreamOption::ConvertHttpsTo11)
+          && elem.opts.contains(&UpstreamOption::ConvertHttpsTo2))),
+      "either one of force_http11 or force_http2 can be enabled"
+    );
+
+    Ok(ReverseProxy { upstream })
+  }
+}
+
+impl TryInto<Upstream> for &UpstreamParams {
+  type Error = RpxyError;
+
+  fn try_into(self) -> std::result::Result<Upstream, Self::Error> {
+    let scheme = match self.tls {
+      Some(true) => "https",
+      _ => "http",
+    };
     let location = format!("{}://{}", scheme, self.location);
     Ok(Upstream {
       uri: location.parse::<hyper::Uri>().map_err(|e| anyhow!("{}", e))?,
     })
   }
 }
-
-impl ConfigToml {
-  pub fn new(config_file: &str) -> std::result::Result<Self, anyhow::Error> {
-    let config_str = fs::read_to_string(config_file).context("Failed to read config file")?;
-
-    toml::from_str(&config_str).context("Failed to parse toml config")
-  }
-}
diff --git a/src/constants.rs b/src/constants.rs
index a29be29..2ed14d1 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -8,6 +8,7 @@ pub const TLS_HANDSHAKE_TIMEOUT_SEC: u64 = 15; // default as with firefox browse
 pub const MAX_CLIENTS: usize = 512;
 pub const MAX_CONCURRENT_STREAMS: u32 = 64;
 pub const CERTS_WATCH_DELAY_SECS: u32 = 60;
+pub const LOAD_CERTS_ONLY_WHEN_UPDATED: bool = true;
 
 // #[cfg(feature = "http3")]
 // pub const H3_RESPONSE_BUF_SIZE: usize = 65_536; // 64KB
diff --git a/src/error.rs b/src/error.rs
index 3fb3474..18b4307 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -29,6 +29,9 @@ pub enum RpxyError {
   #[error("I/O Error")]
   Io(#[from] io::Error),
 
+  #[error("Toml Deserialization Error")]
+  TomlDe(#[from] toml::de::Error),
+
   #[cfg(feature = "http3")]
   #[error("Quic Connection Error")]
   QuicConn(#[from] quinn::ConnectionError),
diff --git a/src/globals.rs b/src/globals.rs
index 0bd06a6..64f9d8d 100644
--- a/src/globals.rs
+++ b/src/globals.rs
@@ -1,4 +1,4 @@
-use crate::backend::Backends;
+use crate::{backend::Backends, constants::*};
 use std::net::SocketAddr;
 use std::sync::{
   atomic::{AtomicUsize, Ordering},
@@ -6,25 +6,38 @@ use std::sync::{
 };
 use tokio::time::Duration;
 
+/// Global object containing proxy configurations and shared object like counters.
+/// But note that in Globals, we do not have Mutex and RwLock. It is indeed, the context shared among async tasks.
 pub struct Globals {
-  pub listen_sockets: Vec<SocketAddr>,
-  pub http_port: Option<u16>,
-  pub https_port: Option<u16>,
+  /// Configuration parameters for proxy transport and request handlers
+  pub proxy_config: ProxyConfig, // TODO: proxy configはarcに包んでこいつだけ使いまわせばいいように変えていく。backendsも？
 
-  pub proxy_timeout: Duration,
-  pub upstream_timeout: Duration,
-
-  pub max_clients: usize,
-  pub request_count: RequestCount,
-  pub max_concurrent_streams: u32,
-  pub keepalive: bool,
-
-  pub runtime_handle: tokio::runtime::Handle,
+  /// Backend application objects to which http request handler forward incoming requests
   pub backends: Backends,
 
-  // experimentals
-  pub sni_consistency: bool,
+  /// Shared context - Counter for serving requests
+  pub request_count: RequestCount,
 
+  /// Shared context - Async task runtime handler
+  pub runtime_handle: tokio::runtime::Handle,
+}
+
+/// Configuration parameters for proxy transport and request handlers
+pub struct ProxyConfig {
+  pub listen_sockets: Vec<SocketAddr>, // when instantiate server
+  pub http_port: Option<u16>,          // when instantiate server
+  pub https_port: Option<u16>,         // when instantiate server
+
+  pub proxy_timeout: Duration,    // when serving requests at Proxy
+  pub upstream_timeout: Duration, // when serving requests at Handler
+
+  pub max_clients: usize,          // when serving requests
+  pub max_concurrent_streams: u32, // when instantiate server
+  pub keepalive: bool,             // when instantiate server
+
+  // experimentals
+  pub sni_consistency: bool, // Handler
+  // All need to make packet acceptor
   #[cfg(feature = "http3")]
   pub http3: bool,
   #[cfg(feature = "http3")]
@@ -41,7 +54,43 @@ pub struct Globals {
   pub h3_max_idle_timeout: Option<quinn::IdleTimeout>,
 }
 
+impl Default for ProxyConfig {
+  fn default() -> Self {
+    Self {
+      listen_sockets: Vec::new(),
+      http_port: None,
+      https_port: None,
+
+      // TODO: Reconsider each timeout values
+      proxy_timeout: Duration::from_secs(PROXY_TIMEOUT_SEC),
+      upstream_timeout: Duration::from_secs(UPSTREAM_TIMEOUT_SEC),
+
+      max_clients: MAX_CLIENTS,
+      max_concurrent_streams: MAX_CONCURRENT_STREAMS,
+      keepalive: true,
+
+      sni_consistency: true,
+
+      #[cfg(feature = "http3")]
+      http3: false,
+      #[cfg(feature = "http3")]
+      h3_alt_svc_max_age: H3::ALT_SVC_MAX_AGE,
+      #[cfg(feature = "http3")]
+      h3_request_max_body_size: H3::REQUEST_MAX_BODY_SIZE,
+      #[cfg(feature = "http3")]
+      h3_max_concurrent_connections: H3::MAX_CONCURRENT_CONNECTIONS,
+      #[cfg(feature = "http3")]
+      h3_max_concurrent_bidistream: H3::MAX_CONCURRENT_BIDISTREAM.into(),
+      #[cfg(feature = "http3")]
+      h3_max_concurrent_unistream: H3::MAX_CONCURRENT_UNISTREAM.into(),
+      #[cfg(feature = "http3")]
+      h3_max_idle_timeout: Some(quinn::IdleTimeout::try_from(Duration::from_secs(H3::MAX_IDLE_TIMEOUT)).unwrap()),
+    }
+  }
+}
+
 #[derive(Debug, Clone, Default)]
+/// Counter for serving requests
 pub struct RequestCount(Arc<AtomicUsize>);
 
 impl RequestCount {
diff --git a/src/handler/handler_main.rs b/src/handler/handler_main.rs
index a73dcbc..d2a47be 100644
--- a/src/handler/handler_main.rs
+++ b/src/handler/handler_main.rs
@@ -56,7 +56,7 @@ where
     };
     // check consistency of between TLS SNI and HOST/Request URI Line.
     #[allow(clippy::collapsible_if)]
-    if tls_enabled && self.globals.sni_consistency {
+    if tls_enabled && self.globals.proxy_config.sni_consistency {
       if server_name != tls_server_name.unwrap_or_default() {
         return self.return_with_error_log(StatusCode::MISDIRECTED_REQUEST, &mut log_data);
       }
@@ -75,7 +75,7 @@ where
     if !tls_enabled && backend.https_redirection.unwrap_or(false) {
       debug!("Redirect to secure connection: {}", &backend.server_name);
       log_data.status_code(&StatusCode::PERMANENT_REDIRECT).output();
-      return secure_redirection(&backend.server_name, self.globals.https_port, &req);
+      return secure_redirection(&backend.server_name, self.globals.proxy_config.https_port, &req);
     }
 
     // Find reverse proxy for given path and choose one of upstream host
@@ -112,7 +112,7 @@ where
 
     // Forward request to
     let mut res_backend = {
-      match timeout(self.globals.upstream_timeout, self.forwarder.request(req)).await {
+      match timeout(self.globals.proxy_config.upstream_timeout, self.forwarder.request(req)).await {
         Err(_) => {
           return self.return_with_error_log(StatusCode::GATEWAY_TIMEOUT, &mut log_data);
         }
@@ -207,14 +207,14 @@ where
     #[cfg(feature = "http3")]
     {
       // TODO: Workaround for avoid h3 for client authentication
-      if self.globals.http3 && chosen_backend.client_ca_cert_path.is_none() {
-        if let Some(port) = self.globals.https_port {
+      if self.globals.proxy_config.http3 && chosen_backend.client_ca_cert_path.is_none() {
+        if let Some(port) = self.globals.proxy_config.https_port {
           add_header_entry_overwrite_if_exist(
             headers,
             header::ALT_SVC.as_str(),
             format!(
               "h3=\":{}\"; ma={}, h3-29=\":{}\"; ma={}",
-              port, self.globals.h3_alt_svc_max_age, port, self.globals.h3_alt_svc_max_age
+              port, self.globals.proxy_config.h3_alt_svc_max_age, port, self.globals.proxy_config.h3_alt_svc_max_age
             ),
           )?;
         }
@@ -225,7 +225,7 @@ where
     }
     #[cfg(not(feature = "http3"))]
     {
-      if let Some(port) = self.globals.https_port {
+      if let Some(port) = self.globals.proxy_config.https_port {
         headers.remove(header::ALT_SVC.as_str());
       }
     }
diff --git a/src/main.rs b/src/main.rs
index ea60fa7..ea47e57 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@ use tikv_jemallocator::Jemalloc;
 static GLOBAL: Jemalloc = Jemalloc;
 
 mod backend;
+mod cert_reader;
 mod config;
 mod constants;
 mod error;
@@ -16,22 +17,12 @@ mod proxy;
 mod utils;
 
 use crate::{
-  backend::{Backend, Backends},
-  config::parse_opts,
-  constants::*,
-  error::*,
-  globals::*,
-  handler::HttpMessageHandlerBuilder,
-  log::*,
-  proxy::ProxyBuilder,
-  utils::ServerNameBytesExp,
+  config::build_globals, error::*, globals::*, handler::HttpMessageHandlerBuilder, log::*, proxy::ProxyBuilder,
 };
 use futures::future::select_all;
 use hyper::Client;
 // use hyper_trust_dns::TrustDnsResolver;
-use rustc_hash::FxHashMap as HashMap;
 use std::sync::Arc;
-use tokio::time::Duration;
 
 fn main() {
   init_logger();
@@ -42,52 +33,17 @@ fn main() {
   let runtime = runtime_builder.build().unwrap();
 
   runtime.block_on(async {
-    let mut globals = Globals {
-      listen_sockets: Vec::new(),
-      http_port: None,
-      https_port: None,
-
-      // TODO: Reconsider each timeout values
-      proxy_timeout: Duration::from_secs(PROXY_TIMEOUT_SEC),
-      upstream_timeout: Duration::from_secs(UPSTREAM_TIMEOUT_SEC),
-
-      max_clients: MAX_CLIENTS,
-      request_count: Default::default(),
-      max_concurrent_streams: MAX_CONCURRENT_STREAMS,
-      keepalive: true,
-
-      runtime_handle: runtime.handle().clone(),
-      backends: Backends {
-        default_server_name_bytes: None,
-        apps: HashMap::<ServerNameBytesExp, Backend>::default(),
-      },
-
-      sni_consistency: true,
-
-      #[cfg(feature = "http3")]
-      http3: false,
-      #[cfg(feature = "http3")]
-      h3_alt_svc_max_age: H3::ALT_SVC_MAX_AGE,
-      #[cfg(feature = "http3")]
-      h3_request_max_body_size: H3::REQUEST_MAX_BODY_SIZE,
-      #[cfg(feature = "http3")]
-      h3_max_concurrent_connections: H3::MAX_CONCURRENT_CONNECTIONS,
-      #[cfg(feature = "http3")]
-      h3_max_concurrent_bidistream: H3::MAX_CONCURRENT_BIDISTREAM.into(),
-      #[cfg(feature = "http3")]
-      h3_max_concurrent_unistream: H3::MAX_CONCURRENT_UNISTREAM.into(),
-      #[cfg(feature = "http3")]
-      h3_max_idle_timeout: Some(quinn::IdleTimeout::try_from(Duration::from_secs(H3::MAX_IDLE_TIMEOUT)).unwrap()),
-    };
-
-    if let Err(e) = parse_opts(&mut globals) {
-      error!("Invalid configuration: {}", e);
-      std::process::exit(1);
+    let globals = match build_globals(runtime.handle().clone()) {
+      Ok(g) => g,
+      Err(e) => {
+        error!("Invalid configuration: {}", e);
+        std::process::exit(1);
+      }
     };
 
     entrypoint(Arc::new(globals)).await.unwrap()
   });
-  warn!("Exit the program");
+  warn!("rpxy exited!");
 }
 
 // entrypoint creates and spawns tasks of proxy services
@@ -105,10 +61,10 @@ async fn entrypoint(globals: Arc<Globals>) -> Result<()> {
     .globals(globals.clone())
     .build()?;
 
-  let addresses = globals.listen_sockets.clone();
+  let addresses = globals.proxy_config.listen_sockets.clone();
   let futures = select_all(addresses.into_iter().map(|addr| {
     let mut tls_enabled = false;
-    if let Some(https_port) = globals.https_port {
+    if let Some(https_port) = globals.proxy_config.https_port {
       tls_enabled = https_port == addr.port()
     }
 
diff --git a/src/proxy/crypto_service.rs b/src/proxy/crypto_service.rs
new file mode 100644
index 0000000..728a531
--- /dev/null
+++ b/src/proxy/crypto_service.rs
@@ -0,0 +1,253 @@
+use crate::{
+  cert_reader::read_certs_and_keys, // TODO: Trait defining read_certs_and_keys and add struct implementing the trait to backend when build backend
+  globals::Globals,
+  log::*,
+  utils::ServerNameBytesExp,
+};
+use async_trait::async_trait;
+use hot_reload::*;
+use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
+use rustls::{
+  server::ResolvesServerCertUsingSni,
+  sign::{any_supported_type, CertifiedKey},
+  Certificate, OwnedTrustAnchor, PrivateKey, RootCertStore, ServerConfig,
+};
+use std::{io, sync::Arc};
+use x509_parser::prelude::*;
+
+#[derive(Clone)]
+/// Reloader service for certificates and keys for TLS
+pub struct CryptoReloader {
+  globals: Arc<Globals>,
+}
+
+/// Certificates and private keys in rustls loaded from files
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct CertsAndKeys {
+  pub certs: Vec<Certificate>,
+  pub cert_keys: Vec<PrivateKey>,
+  pub client_ca_certs: Option<Vec<Certificate>>,
+}
+
+pub type SniServerCryptoMap = HashMap<ServerNameBytesExp, Arc<ServerConfig>>;
+pub struct ServerCrypto {
+  // For Quic/HTTP3, only servers with no client authentication
+  pub inner_global_no_client_auth: Arc<ServerConfig>,
+  // For TLS over TCP/HTTP2 and 1.1, map of SNI to server_crypto for all given servers
+  pub inner_local_map: Arc<SniServerCryptoMap>,
+}
+
+/// Reloader target for the certificate reloader service
+#[derive(Debug, PartialEq, Eq, Clone, Default)]
+pub struct ServerCryptoBase {
+  inner: HashMap<ServerNameBytesExp, CertsAndKeys>,
+}
+
+#[async_trait]
+impl Reload<ServerCryptoBase> for CryptoReloader {
+  type Source = Arc<Globals>;
+  async fn new(source: &Self::Source) -> Result<Self, ReloaderError<ServerCryptoBase>> {
+    Ok(Self {
+      globals: source.clone(),
+    })
+  }
+
+  async fn reload(&self) -> Result<Option<ServerCryptoBase>, ReloaderError<ServerCryptoBase>> {
+    let mut certs_and_keys_map = ServerCryptoBase::default();
+
+    for (server_name_bytes_exp, backend) in self.globals.backends.apps.iter() {
+      if backend.tls_cert_key_path.is_some() && backend.tls_cert_path.is_some() {
+        let tls_cert_key_path = backend.tls_cert_key_path.as_ref().unwrap();
+        let tls_cert_path = backend.tls_cert_path.as_ref().unwrap();
+        let tls_client_ca_cert_path = backend.client_ca_cert_path.as_ref();
+        let certs_and_keys = read_certs_and_keys(tls_cert_path, tls_cert_key_path, tls_client_ca_cert_path)
+          .map_err(|_e| ReloaderError::<ServerCryptoBase>::Reload("Failed to reload cert, key or ca cert"))?;
+
+        certs_and_keys_map
+          .inner
+          .insert(server_name_bytes_exp.to_owned(), certs_and_keys);
+      }
+    }
+
+    Ok(Some(certs_and_keys_map))
+  }
+}
+
+impl CertsAndKeys {
+  fn parse_server_certs_and_keys(&self) -> Result<CertifiedKey, anyhow::Error> {
+    // for (server_name_bytes_exp, certs_and_keys) in self.inner.iter() {
+    let signing_key = self
+      .cert_keys
+      .iter()
+      .find_map(|k| {
+        if let Ok(sk) = any_supported_type(k) {
+          Some(sk)
+        } else {
+          None
+        }
+      })
+      .ok_or_else(|| {
+        io::Error::new(
+          io::ErrorKind::InvalidInput,
+          "Unable to find a valid certificate and key",
+        )
+      })?;
+    Ok(CertifiedKey::new(self.certs.clone(), signing_key))
+  }
+
+  pub fn parse_client_ca_certs(&self) -> Result<(Vec<OwnedTrustAnchor>, HashSet<Vec<u8>>), anyhow::Error> {
+    let certs = self.client_ca_certs.as_ref().ok_or(anyhow::anyhow!("No client cert"))?;
+
+    let owned_trust_anchors: Vec<_> = certs
+      .iter()
+      .map(|v| {
+        // let trust_anchor = tokio_rustls::webpki::TrustAnchor::try_from_cert_der(&v.0).unwrap();
+        let trust_anchor = webpki::TrustAnchor::try_from_cert_der(&v.0).unwrap();
+        rustls::OwnedTrustAnchor::from_subject_spki_name_constraints(
+          trust_anchor.subject,
+          trust_anchor.spki,
+          trust_anchor.name_constraints,
+        )
+      })
+      .collect();
+
+    // TODO: SKID is not used currently
+    let subject_key_identifiers: HashSet<_> = certs
+      .iter()
+      .filter_map(|v| {
+        // retrieve ca key id (subject key id)
+        let cert = parse_x509_certificate(&v.0).unwrap().1;
+        let subject_key_ids = cert
+          .iter_extensions()
+          .filter_map(|ext| match ext.parsed_extension() {
+            ParsedExtension::SubjectKeyIdentifier(skid) => Some(skid),
+            _ => None,
+          })
+          .collect::<Vec<_>>();
+        if !subject_key_ids.is_empty() {
+          Some(subject_key_ids[0].0.to_owned())
+        } else {
+          None
+        }
+      })
+      .collect();
+
+    Ok((owned_trust_anchors, subject_key_identifiers))
+  }
+}
+
+impl TryInto<Arc<ServerCrypto>> for &ServerCryptoBase {
+  type Error = anyhow::Error;
+
+  fn try_into(self) -> Result<Arc<ServerCrypto>, Self::Error> {
+    let mut resolver_global = ResolvesServerCertUsingSni::new();
+    let mut server_crypto_local_map: SniServerCryptoMap = HashMap::default();
+
+    for (server_name_bytes_exp, certs_and_keys) in self.inner.iter() {
+      let server_name: String = server_name_bytes_exp.try_into()?;
+
+      // Parse server certificates and private keys
+      let Ok(certified_key): Result<CertifiedKey, _> = certs_and_keys.parse_server_certs_and_keys() else {
+        warn!("Failed to add certificate for {}", server_name);
+        continue;
+      };
+
+      let mut resolver_local = ResolvesServerCertUsingSni::new();
+      let mut client_ca_roots_local = RootCertStore::empty();
+
+      // add server certificate and key
+      if let Err(e) = resolver_local.add(server_name.as_str(), certified_key.to_owned()) {
+        error!(
+          "{}: Failed to read some certificates and keys {}",
+          server_name.as_str(),
+          e
+        )
+      }
+
+      // add client certificate if specified
+      if certs_and_keys.client_ca_certs.is_none() {
+        // aggregated server config for no client auth server for http3
+        if let Err(e) = resolver_global.add(server_name.as_str(), certified_key) {
+          error!(
+            "{}: Failed to read some certificates and keys {}",
+            server_name.as_str(),
+            e
+          )
+        }
+      } else {
+        // add client certificate if specified
+        match certs_and_keys.parse_client_ca_certs() {
+          Ok((owned_trust_anchors, _subject_key_ids)) => {
+            client_ca_roots_local.add_server_trust_anchors(owned_trust_anchors.into_iter());
+          }
+          Err(e) => {
+            warn!(
+              "Failed to add client CA certificate for {}: {}",
+              server_name.as_str(),
+              e
+            );
+          }
+        }
+      }
+
+      let mut server_config_local = if client_ca_roots_local.is_empty() {
+        // with no client auth, enable http1.1 -- 3
+        #[cfg(not(feature = "http3"))]
+        {
+          ServerConfig::builder()
+            .with_safe_defaults()
+            .with_no_client_auth()
+            .with_cert_resolver(Arc::new(resolver_local))
+        }
+        #[cfg(feature = "http3")]
+        {
+          let mut sc = ServerConfig::builder()
+            .with_safe_defaults()
+            .with_no_client_auth()
+            .with_cert_resolver(Arc::new(resolver_local));
+          sc.alpn_protocols = vec![b"h3".to_vec(), b"hq-29".to_vec()]; // TODO: remove hq-29 later?
+          sc
+        }
+      } else {
+        // with client auth, enable only http1.1 and 2
+        // let client_certs_verifier = rustls::server::AllowAnyAnonymousOrAuthenticatedClient::new(client_ca_roots);
+        let client_certs_verifier = rustls::server::AllowAnyAuthenticatedClient::new(client_ca_roots_local);
+        ServerConfig::builder()
+          .with_safe_defaults()
+          .with_client_cert_verifier(Arc::new(client_certs_verifier))
+          .with_cert_resolver(Arc::new(resolver_local))
+      };
+      server_config_local.alpn_protocols.push(b"h2".to_vec());
+      server_config_local.alpn_protocols.push(b"http/1.1".to_vec());
+
+      server_crypto_local_map.insert(server_name_bytes_exp.to_owned(), Arc::new(server_config_local));
+    }
+
+    //////////////
+    let mut server_crypto_global = ServerConfig::builder()
+      .with_safe_defaults()
+      .with_no_client_auth()
+      .with_cert_resolver(Arc::new(resolver_global));
+
+    //////////////////////////////
+
+    #[cfg(feature = "http3")]
+    {
+      server_crypto_global.alpn_protocols = vec![
+        b"h3".to_vec(),
+        b"hq-29".to_vec(), // TODO: remove later?
+        b"h2".to_vec(),
+        b"http/1.1".to_vec(),
+      ];
+    }
+    #[cfg(not(feature = "http3"))]
+    {
+      server_crypto_global.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
+    }
+
+    Ok(Arc::new(ServerCrypto {
+      inner_global_no_client_auth: Arc::new(server_crypto_global),
+      inner_local_map: Arc::new(server_crypto_local_map),
+    }))
+  }
+}
diff --git a/src/proxy/mod.rs b/src/proxy/mod.rs
index 04413f5..d8fdc83 100644
--- a/src/proxy/mod.rs
+++ b/src/proxy/mod.rs
@@ -1,7 +1,9 @@
+mod crypto_service;
 mod proxy_client_cert;
 #[cfg(feature = "http3")]
 mod proxy_h3;
 mod proxy_main;
 mod proxy_tls;
 
+pub use crypto_service::CertsAndKeys;
 pub use proxy_main::{Proxy, ProxyBuilder, ProxyBuilderError};
diff --git a/src/proxy/proxy_client_cert.rs b/src/proxy/proxy_client_cert.rs
index adac4b7..dfba4ce 100644
--- a/src/proxy/proxy_client_cert.rs
+++ b/src/proxy/proxy_client_cert.rs
@@ -10,26 +10,18 @@ pub(super) fn check_client_authentication(
   client_certs: Option<&[Certificate]>,
   client_ca_keyids_set_for_sni: Option<&HashSet<Vec<u8>>>,
 ) -> std::result::Result<(), ClientCertsError> {
-  let client_ca_keyids_set = match client_ca_keyids_set_for_sni {
-    Some(c) => c,
-    None => {
-      // No client cert settings for given server name
-      return Ok(());
-    }
+  let Some(client_ca_keyids_set) = client_ca_keyids_set_for_sni else {
+    // No client cert settings for given server name
+    return Ok(());
   };
 
-  let client_certs = match client_certs {
-    Some(c) => {
-      debug!("Incoming TLS client is (temporarily) authenticated via client cert");
-      c
-    }
-    None => {
-      error!("Client certificate is needed for given server name");
-      return Err(ClientCertsError::ClientCertRequired(
-        "Client certificate is needed for given server name".to_string(),
-      ));
-    }
+  let Some(client_certs) = client_certs else {
+    error!("Client certificate is needed for given server name");
+    return Err(ClientCertsError::ClientCertRequired(
+      "Client certificate is needed for given server name".to_string(),
+    ));
   };
+  debug!("Incoming TLS client is (temporarily) authenticated via client cert");
 
   // Check client certificate key ids
   let mut client_certs_parsed_iter = client_certs.iter().filter_map(|d| parse_x509_certificate(&d.0).ok());
diff --git a/src/proxy/proxy_h3.rs b/src/proxy/proxy_h3.rs
index d5a6c88..12ebd7d 100644
--- a/src/proxy/proxy_h3.rs
+++ b/src/proxy/proxy_h3.rs
@@ -43,7 +43,7 @@ where
               // We consider the connection count separately from the stream count.
               // Max clients for h1/h2 = max 'stream' for h3.
               let request_count = self.globals.request_count.clone();
-              if request_count.increment() > self.globals.max_clients {
+              if request_count.increment() > self.globals.proxy_config.max_clients {
                 request_count.decrement();
                 h3_conn.shutdown(0).await?;
                 break;
@@ -54,7 +54,7 @@ where
               let tls_server_name_inner = tls_server_name.clone();
               self.globals.runtime_handle.spawn(async move {
                 if let Err(e) = timeout(
-                  self_inner.globals.proxy_timeout + Duration::from_secs(1), // timeout per stream are considered as same as one in http2
+                  self_inner.globals.proxy_config.proxy_timeout + Duration::from_secs(1), // timeout per stream are considered as same as one in http2
                   self_inner.stream_serve_h3(req, stream, client_addr, tls_server_name_inner),
                 )
                 .await
@@ -97,7 +97,7 @@ where
 
     // Buffering and sending body through channel for protocol conversion like h3 -> h2/http1.1
     // The underling buffering, i.e., buffer given by the API recv_data.await?, is handled by quinn.
-    let max_body_size = self.globals.h3_request_max_body_size;
+    let max_body_size = self.globals.proxy_config.h3_request_max_body_size;
     self.globals.runtime_handle.spawn(async move {
       let mut sender = body_sender;
       let mut size = 0usize;
diff --git a/src/proxy/proxy_main.rs b/src/proxy/proxy_main.rs
index 722ef3c..a0f9660 100644
--- a/src/proxy/proxy_main.rs
+++ b/src/proxy/proxy_main.rs
@@ -56,7 +56,7 @@ where
     I: AsyncRead + AsyncWrite + Send + Unpin + 'static,
   {
     let request_count = self.globals.request_count.clone();
-    if request_count.increment() > self.globals.max_clients {
+    if request_count.increment() > self.globals.proxy_config.max_clients {
       request_count.decrement();
       return;
     }
@@ -64,7 +64,7 @@ where
 
     self.globals.runtime_handle.clone().spawn(async move {
       timeout(
-        self.globals.proxy_timeout + Duration::from_secs(1),
+        self.globals.proxy_config.proxy_timeout + Duration::from_secs(1),
         server
           .serve_connection(
             stream,
@@ -103,8 +103,8 @@ where
 
   pub async fn start(self) -> Result<()> {
     let mut server = Http::new();
-    server.http1_keep_alive(self.globals.keepalive);
-    server.http2_max_concurrent_streams(self.globals.max_concurrent_streams);
+    server.http1_keep_alive(self.globals.proxy_config.keepalive);
+    server.http2_max_concurrent_streams(self.globals.proxy_config.max_concurrent_streams);
     server.pipeline_flush(true);
     let executor = LocalExecutor::new(self.globals.runtime_handle.clone());
     let server = server.with_executor(executor);
diff --git a/src/proxy/proxy_tls.rs b/src/proxy/proxy_tls.rs
index de18e0c..e01f9d3 100644
--- a/src/proxy/proxy_tls.rs
+++ b/src/proxy/proxy_tls.rs
@@ -1,11 +1,9 @@
-use super::proxy_main::{LocalExecutor, Proxy};
-use crate::{
-  backend::{ServerCrypto, SniServerCryptoMap},
-  constants::*,
-  error::*,
-  log::*,
-  utils::BytesName,
+use super::{
+  crypto_service::{CryptoReloader, ServerCrypto, ServerCryptoBase, SniServerCryptoMap},
+  proxy_main::{LocalExecutor, Proxy},
 };
+use crate::{constants::*, error::*, log::*, utils::BytesName};
+use hot_reload::{ReloaderReceiver, ReloaderService};
 use hyper::{client::connect::Connect, server::conn::Http};
 #[cfg(feature = "http3")]
 use quinn::{crypto::rustls::HandshakeData, Endpoint, ServerConfig as QuicServerConfig, TransportConfig};
@@ -14,34 +12,18 @@ use rustls::ServerConfig;
 use std::sync::Arc;
 use tokio::{
   net::TcpListener,
-  sync::watch,
-  time::{sleep, timeout, Duration},
+  time::{timeout, Duration},
 };
 
 impl<T> Proxy<T>
 where
   T: Connect + Clone + Sync + Send + 'static,
 {
-  async fn cert_service(&self, server_crypto_tx: watch::Sender<Option<Arc<ServerCrypto>>>) {
-    info!("Start cert watch service");
-    loop {
-      if let Ok(server_crypto) = self.globals.backends.generate_server_crypto().await {
-        if let Err(_e) = server_crypto_tx.send(Some(Arc::new(server_crypto))) {
-          error!("Failed to populate server crypto");
-          break;
-        }
-      } else {
-        error!("Failed to update certs");
-      }
-      sleep(Duration::from_secs(CERTS_WATCH_DELAY_SECS.into())).await;
-    }
-  }
-
   // TCP Listener Service, i.e., http/2 and http/1.1
   async fn listener_service(
     &self,
     server: Http<LocalExecutor>,
-    mut server_crypto_rx: watch::Receiver<Option<Arc<ServerCrypto>>>,
+    mut server_crypto_rx: ReloaderReceiver<ServerCryptoBase>,
   ) -> Result<()> {
     let tcp_listener = TcpListener::bind(&self.listening_on).await?;
     info!("Start TCP proxy serving with HTTPS request for configured host names");
@@ -105,9 +87,14 @@ where
         }
         _ = server_crypto_rx.changed() => {
           if server_crypto_rx.borrow().is_none() {
+            error!("Reloader is broken");
             break;
           }
-          let server_crypto = server_crypto_rx.borrow().clone().unwrap();
+          let cert_keys_map = server_crypto_rx.borrow().clone().unwrap();
+          let Some(server_crypto): Option<Arc<ServerCrypto>> = (&cert_keys_map).try_into().ok() else {
+            error!("Failed to update server crypto");
+            break;
+          };
           server_crypto_map = Some(server_crypto.inner_local_map.clone());
         }
         else => break
@@ -117,7 +104,7 @@ where
   }
 
   #[cfg(feature = "http3")]
-  async fn listener_service_h3(&self, mut server_crypto_rx: watch::Receiver<Option<Arc<ServerCrypto>>>) -> Result<()> {
+  async fn listener_service_h3(&self, mut server_crypto_rx: ReloaderReceiver<ServerCryptoBase>) -> Result<()> {
     info!("Start UDP proxy serving with HTTP/3 request for configured host names");
     // first set as null config server
     let rustls_server_config = ServerConfig::builder()
@@ -129,13 +116,13 @@ where
 
     let mut transport_config_quic = TransportConfig::default();
     transport_config_quic
-      .max_concurrent_bidi_streams(self.globals.h3_max_concurrent_bidistream)
-      .max_concurrent_uni_streams(self.globals.h3_max_concurrent_unistream)
-      .max_idle_timeout(self.globals.h3_max_idle_timeout);
+      .max_concurrent_bidi_streams(self.globals.proxy_config.h3_max_concurrent_bidistream)
+      .max_concurrent_uni_streams(self.globals.proxy_config.h3_max_concurrent_unistream)
+      .max_idle_timeout(self.globals.proxy_config.h3_max_idle_timeout);
 
     let mut server_config_h3 = QuicServerConfig::with_crypto(Arc::new(rustls_server_config));
     server_config_h3.transport = Arc::new(transport_config_quic);
-    server_config_h3.concurrent_connections(self.globals.h3_max_concurrent_connections);
+    server_config_h3.concurrent_connections(self.globals.proxy_config.h3_max_concurrent_connections);
     let endpoint = Endpoint::server(server_config_h3, self.listening_on)?;
 
     let mut server_crypto: Option<Arc<ServerCrypto>> = None;
@@ -146,29 +133,24 @@ where
             continue;
           }
           let mut conn: quinn::Connecting = new_conn.unwrap();
-          let hsd = match conn.handshake_data().await {
-            Ok(h) => h,
-            Err(_) => continue
+          let Ok(hsd) = conn.handshake_data().await else {
+            continue
           };
 
-          let hsd_downcast = match hsd.downcast::<HandshakeData>() {
-            Ok(d) => d,
-            Err(_) => continue
+          let Ok(hsd_downcast) = hsd.downcast::<HandshakeData>() else {
+            continue
           };
-          let new_server_name = match hsd_downcast.server_name {
-            Some(sn) => sn.to_server_name_vec(),
-            None => {
-              warn!("HTTP/3 no SNI is given");
-              continue;
-            }
+          let Some(new_server_name) = hsd_downcast.server_name else {
+            warn!("HTTP/3 no SNI is given");
+            continue;
           };
           debug!(
             "HTTP/3 connection incoming (SNI {:?})",
-            new_server_name.0
+            new_server_name
           );
           // TODO: server_nameをここで出してどんどん深く投げていくのは効率が悪い。connecting -> connectionsの後でいいのでは？
           // TODO: 通常のTLSと同じenumか何かにまとめたい
-          let fut = self.clone().connection_serve_h3(conn, new_server_name);
+          let fut = self.clone().connection_serve_h3(conn, new_server_name.to_server_name_vec());
           self.globals.runtime_handle.spawn(async move {
             // Timeout is based on underlying quic
             if let Err(e) = fut.await {
@@ -178,12 +160,18 @@ where
         }
         _ = server_crypto_rx.changed() => {
           if server_crypto_rx.borrow().is_none() {
+            error!("Reloader is broken");
             break;
           }
-          server_crypto = server_crypto_rx.borrow().clone();
-          if server_crypto.is_some(){
-            endpoint.set_server_config(Some(QuicServerConfig::with_crypto(server_crypto.clone().unwrap().inner_global_no_client_auth.clone())));
-          }
+          let cert_keys_map = server_crypto_rx.borrow().clone().unwrap();
+
+          server_crypto = (&cert_keys_map).try_into().ok();
+          let Some(inner) = server_crypto.clone() else {
+            error!("Failed to update server crypto for h3");
+            break;
+          };
+          endpoint.set_server_config(Some(QuicServerConfig::with_crypto(inner.clone().inner_global_no_client_auth.clone())));
+
         }
         else => break
       }
@@ -193,7 +181,14 @@ where
   }
 
   pub async fn start_with_tls(self, server: Http<LocalExecutor>) -> Result<()> {
-    let (tx, rx) = watch::channel::<Option<Arc<ServerCrypto>>>(None);
+    let (cert_reloader_service, cert_reloader_rx) = ReloaderService::<CryptoReloader, ServerCryptoBase>::new(
+      &self.globals.clone(),
+      CERTS_WATCH_DELAY_SECS,
+      !LOAD_CERTS_ONLY_WHEN_UPDATED,
+    )
+    .await
+    .map_err(|e| anyhow::anyhow!(e))?;
+
     #[cfg(not(feature = "http3"))]
     {
       tokio::select! {
@@ -212,15 +207,15 @@ where
     }
     #[cfg(feature = "http3")]
     {
-      if self.globals.http3 {
+      if self.globals.proxy_config.http3 {
         tokio::select! {
-          _= self.cert_service(tx) => {
+          _= cert_reloader_service.start() => {
             error!("Cert service for TLS exited");
           },
-          _ = self.listener_service(server, rx.clone()) => {
+          _ = self.listener_service(server, cert_reloader_rx.clone()) => {
             error!("TCP proxy service for TLS exited");
           },
-          _= self.listener_service_h3(rx) => {
+          _= self.listener_service_h3(cert_reloader_rx) => {
             error!("UDP proxy service for QUIC exited");
           },
           else => {
@@ -231,10 +226,10 @@ where
         Ok(())
       } else {
         tokio::select! {
-          _= self.cert_service(tx) => {
+          _= cert_reloader_service.start() => {
             error!("Cert service for TLS exited");
           },
-          _ = self.listener_service(server, rx) => {
+          _ = self.listener_service(server, cert_reloader_rx) => {
             error!("TCP proxy service for TLS exited");
           },
           else => {
diff --git a/src/utils/bytes_name.rs b/src/utils/bytes_name.rs
index 16ec7ab..a093c41 100644
--- a/src/utils/bytes_name.rs
+++ b/src/utils/bytes_name.rs
@@ -7,6 +7,13 @@ impl From<&[u8]> for ServerNameBytesExp {
     Self(b.to_ascii_lowercase())
   }
 }
+impl TryInto<String> for &ServerNameBytesExp {
+  type Error = anyhow::Error;
+  fn try_into(self) -> Result<String, Self::Error> {
+    let s = std::str::from_utf8(&self.0)?;
+    Ok(s.to_string())
+  }
+}
 
 /// Path name, like "/path/ok", represented in bytes-based struct
 /// for searching hashmap or key list by exact or longest-prefix matching