Line data    Source code

       1              : use std::collections::HashMap;
       2              : use std::error::Error as _;
       3              : use std::time::Duration;
       4              : 
       5              : use http_utils::error::HttpErrorBody;
       6              : use hyper::Uri;
       7              : use pageserver_api::shard::TenantShardId;
       8              : use reqwest::{StatusCode, Url};
       9              : use serde::{Deserialize, Serialize};
      10              : use tokio_util::sync::CancellationToken;
      11              : use utils::backoff;
      12              : 
      13              : use crate::tenant_shard::ObservedState;
      14              : 
      15              : #[derive(Debug, Clone)]
      16              : pub(crate) struct PeerClient {
      17              :     uri: Uri,
      18              :     jwt: Option<String>,
      19              :     client: reqwest::Client,
      20              : }
      21              : 
      22              : #[derive(thiserror::Error, Debug)]
      23              : pub(crate) enum StorageControllerPeerError {
      24              :     #[error(
      25              :         "failed to deserialize error response with status code {0} at {1}: {2}{}",
      26            0 :         .2.source().map(|e| format!(": {e}")).unwrap_or_default()
      27              :     )]
      28              :     DeserializationError(StatusCode, Url, reqwest::Error),
      29              :     #[error("storage controller peer API error ({0}): {1}")]
      30              :     ApiError(StatusCode, String),
      31            0 :     #[error("failed to send HTTP request: {0}{}", .0.source().map(|e| format!(": {e}")).unwrap_or_default())]
      32              :     SendError(reqwest::Error),
      33              :     #[error("Cancelled")]
      34              :     Cancelled,
      35              : }
      36              : 
      37              : pub(crate) type Result<T> = std::result::Result<T, StorageControllerPeerError>;
      38              : 
      39              : pub(crate) trait ResponseErrorMessageExt: Sized {
      40              :     fn error_from_body(self) -> impl std::future::Future<Output = Result<Self>> + Send;
      41              : }
      42              : 
      43              : impl ResponseErrorMessageExt for reqwest::Response {
      44            0 :     async fn error_from_body(self) -> Result<Self> {
      45            0 :         let status = self.status();
      46            0 :         if !(status.is_client_error() || status.is_server_error()) {
      47            0 :             return Ok(self);
      48            0 :         }
      49            0 : 
      50            0 :         let url = self.url().to_owned();
      51            0 :         Err(match self.json::<HttpErrorBody>().await {
      52            0 :             Ok(HttpErrorBody { msg }) => StorageControllerPeerError::ApiError(status, msg),
      53            0 :             Err(err) => StorageControllerPeerError::DeserializationError(status, url, err),
      54              :         })
      55            0 :     }
      56              : }
      57              : 
      58            0 : #[derive(Serialize, Deserialize, Debug, Default)]
      59              : pub(crate) struct GlobalObservedState(pub(crate) HashMap<TenantShardId, ObservedState>);
      60              : 
      61              : impl PeerClient {
      62            0 :     pub(crate) fn new(uri: Uri, jwt: Option<String>) -> Self {
      63            0 :         Self {
      64            0 :             uri,
      65            0 :             jwt,
      66            0 :             client: reqwest::Client::new(),
      67            0 :         }
      68            0 :     }
      69              : 
      70            0 :     async fn request_step_down(&self) -> Result<GlobalObservedState> {
      71            0 :         let step_down_path = format!("{}control/v1/step_down", self.uri);
      72            0 :         let req = self.client.put(step_down_path);
      73            0 :         let req = if let Some(jwt) = &self.jwt {
      74            0 :             req.header(reqwest::header::AUTHORIZATION, format!("Bearer {jwt}"))
      75              :         } else {
      76            0 :             req
      77              :         };
      78              : 
      79            0 :         let req = req.timeout(Duration::from_secs(2));
      80              : 
      81            0 :         let res = req
      82            0 :             .send()
      83            0 :             .await
      84            0 :             .map_err(StorageControllerPeerError::SendError)?;
      85            0 :         let response = res.error_from_body().await?;
      86              : 
      87            0 :         let status = response.status();
      88            0 :         let url = response.url().to_owned();
      89            0 : 
      90            0 :         response
      91            0 :             .json()
      92            0 :             .await
      93            0 :             .map_err(|err| StorageControllerPeerError::DeserializationError(status, url, err))
      94            0 :     }
      95              : 
      96              :     /// Request the peer to step down and return its current observed state
      97              :     /// All errors are retried with exponential backoff for a maximum of 4 attempts.
      98              :     /// Assuming all retries are performed, the function times out after roughly 4 seconds.
      99            0 :     pub(crate) async fn step_down(
     100            0 :         &self,
     101            0 :         cancel: &CancellationToken,
     102            0 :     ) -> Result<GlobalObservedState> {
     103            0 :         backoff::retry(
     104            0 :             || self.request_step_down(),
     105            0 :             |_e| false,
     106            0 :             2,
     107            0 :             4,
     108            0 :             "Send step down request",
     109            0 :             cancel,
     110            0 :         )
     111            0 :         .await
     112            0 :         .ok_or_else(|| StorageControllerPeerError::Cancelled)
     113            0 :         .and_then(|x| x)
     114            0 :     }
     115              : }