Line data    Source code

       1              : //!
       2              : //!   WAL service listens for client connections and
       3              : //!   receive WAL from wal_proposer and send it to WAL receivers
       4              : //!
       5              : use anyhow::{Context, Result};
       6              : use postgres_backend::QueryError;
       7              : use std::{future, time::Duration};
       8              : use tokio::net::TcpStream;
       9              : use tokio_io_timeout::TimeoutReader;
      10              : use tracing::*;
      11              : use utils::{auth::Scope, measured_stream::MeasuredStream};
      12              : 
      13              : use crate::handler::SafekeeperPostgresHandler;
      14              : use crate::metrics::TrafficMetrics;
      15              : use crate::SafeKeeperConf;
      16              : use postgres_backend::{AuthType, PostgresBackend};
      17              : 
      18              : /// Accept incoming TCP connections and spawn them into a background thread.
      19              : /// allowed_auth_scope is either SafekeeperData (wide JWT tokens giving access
      20              : /// to any tenant are allowed) or Tenant (only tokens giving access to specific
      21              : /// tenant are allowed). Doesn't matter if auth is disabled in conf.
      22         1034 : pub async fn task_main(
      23         1034 :     conf: SafeKeeperConf,
      24         1034 :     pg_listener: std::net::TcpListener,
      25         1034 :     allowed_auth_scope: Scope,
      26         1034 : ) -> anyhow::Result<()> {
      27              :     // Tokio's from_std won't do this for us, per its comment.
      28         1034 :     pg_listener.set_nonblocking(true)?;
      29              : 
      30         1034 :     let listener = tokio::net::TcpListener::from_std(pg_listener)?;
      31         1034 :     let mut connection_count: ConnectionCount = 0;
      32              : 
      33              :     loop {
      34         4761 :         let (socket, peer_addr) = listener.accept().await.context("accept")?;
      35            0 :         debug!("accepted connection from {}", peer_addr);
      36         3727 :         let conf = conf.clone();
      37         3727 :         let conn_id = issue_connection_id(&mut connection_count);
      38         3727 : 
      39         3727 :         tokio::spawn(async move {
      40         3727 :             if let Err(err) = handle_socket(socket, conf, conn_id, allowed_auth_scope)
      41         3727 :                 .instrument(info_span!("", cid = %conn_id))
      42      7338733 :                 .await
      43              :             {
      44          487 :                 error!("connection handler exited: {}", err);
      45         2870 :             }
      46         3727 :         });
      47              :     }
      48            0 : }
      49              : 
      50              : /// This is run by `task_main` above, inside a background thread.
      51              : ///
      52         3727 : async fn handle_socket(
      53         3727 :     socket: TcpStream,
      54         3727 :     conf: SafeKeeperConf,
      55         3727 :     conn_id: ConnectionId,
      56         3727 :     allowed_auth_scope: Scope,
      57         3727 : ) -> Result<(), QueryError> {
      58         3727 :     socket.set_nodelay(true)?;
      59         3727 :     let peer_addr = socket.peer_addr()?;
      60              : 
      61              :     // Set timeout on reading from the socket. It prevents hanged up connection
      62              :     // if client suddenly disappears. Note that TCP_KEEPALIVE is not enabled by
      63              :     // default, and tokio doesn't provide ability to set it out of the box.
      64         3727 :     let mut socket = TimeoutReader::new(socket);
      65         3727 :     let wal_service_timeout = Duration::from_secs(60 * 10);
      66         3727 :     socket.set_timeout(Some(wal_service_timeout));
      67         3727 :     // pin! is here because TimeoutReader (due to storing sleep future inside)
      68         3727 :     // is not Unpin, and all pgbackend/framed/tokio dependencies require stream
      69         3727 :     // to be Unpin. Which is reasonable, as indeed something like TimeoutReader
      70         3727 :     // shouldn't be moved.
      71         3727 :     tokio::pin!(socket);
      72         3727 : 
      73         3727 :     let traffic_metrics = TrafficMetrics::new();
      74         3727 :     if let Some(current_az) = conf.availability_zone.as_deref() {
      75         3727 :         traffic_metrics.set_sk_az(current_az);
      76         3727 :     }
      77              : 
      78         3727 :     let socket = MeasuredStream::new(
      79         3727 :         socket,
      80      3228651 :         |cnt| {
      81      3228651 :             traffic_metrics.observe_read(cnt);
      82      3228651 :         },
      83      2967391 :         |cnt| {
      84      2967391 :             traffic_metrics.observe_write(cnt);
      85      2967391 :         },
      86         3727 :     );
      87              : 
      88         3727 :     let auth_key = match allowed_auth_scope {
      89         2943 :         Scope::Tenant => conf.pg_tenant_only_auth.clone(),
      90          784 :         _ => conf.pg_auth.clone(),
      91              :     };
      92         3727 :     let auth_type = match auth_key {
      93         3592 :         None => AuthType::Trust,
      94          135 :         Some(_) => AuthType::NeonJWT,
      95              :     };
      96         3727 :     let auth_pair = auth_key.map(|key| (allowed_auth_scope, key));
      97         3727 :     let mut conn_handler =
      98         3727 :         SafekeeperPostgresHandler::new(conf, conn_id, Some(traffic_metrics.clone()), auth_pair);
      99         3727 :     let pgbackend = PostgresBackend::new_from_io(socket, peer_addr, auth_type, None)?;
     100              :     // libpq protocol between safekeeper and walproposer / pageserver
     101              :     // We don't use shutdown.
     102         3727 :     pgbackend
     103         3727 :         .run(&mut conn_handler, future::pending::<()>)
     104      7338733 :         .await
     105         3357 : }
     106              : 
     107              : /// Unique WAL service connection ids are logged in spans for observability.
     108              : pub type ConnectionId = u32;
     109              : pub type ConnectionCount = u32;
     110              : 
     111         3727 : pub fn issue_connection_id(count: &mut ConnectionCount) -> ConnectionId {
     112         3727 :     *count = count.wrapping_add(1);
     113         3727 :     *count
     114         3727 : }