LCOV - code coverage report
Current view: top level - safekeeper/src - broker.rs (source / functions) Coverage Total Hit
Test: 53437f7e869ac68c86c7d3e4c20964c0156f158c.info Lines: 0.0 % 177 0
Test Date: 2024-09-20 16:14:12 Functions: 0.0 % 17 0

            Line data    Source code
       1              : //! Communication with the broker, providing safekeeper peers and pageserver coordination.
       2              : 
       3              : use anyhow::anyhow;
       4              : use anyhow::bail;
       5              : use anyhow::Context;
       6              : 
       7              : use anyhow::Error;
       8              : use anyhow::Result;
       9              : 
      10              : use storage_broker::parse_proto_ttid;
      11              : 
      12              : use storage_broker::proto::subscribe_safekeeper_info_request::SubscriptionKey as ProtoSubscriptionKey;
      13              : use storage_broker::proto::FilterTenantTimelineId;
      14              : use storage_broker::proto::MessageType;
      15              : use storage_broker::proto::SafekeeperDiscoveryResponse;
      16              : use storage_broker::proto::SubscribeByFilterRequest;
      17              : use storage_broker::proto::SubscribeSafekeeperInfoRequest;
      18              : use storage_broker::proto::TypeSubscription;
      19              : use storage_broker::proto::TypedMessage;
      20              : use storage_broker::Request;
      21              : 
      22              : use std::sync::atomic::AtomicU64;
      23              : use std::sync::Arc;
      24              : use std::time::Duration;
      25              : use std::time::Instant;
      26              : use std::time::UNIX_EPOCH;
      27              : use tokio::task::JoinHandle;
      28              : use tokio::time::sleep;
      29              : use tracing::*;
      30              : 
      31              : use crate::metrics::BROKER_ITERATION_TIMELINES;
      32              : use crate::metrics::BROKER_PULLED_UPDATES;
      33              : use crate::metrics::BROKER_PUSHED_UPDATES;
      34              : use crate::metrics::BROKER_PUSH_ALL_UPDATES_SECONDS;
      35              : use crate::GlobalTimelines;
      36              : use crate::SafeKeeperConf;
      37              : 
      38              : const RETRY_INTERVAL_MSEC: u64 = 1000;
      39              : const PUSH_INTERVAL_MSEC: u64 = 1000;
      40              : 
      41              : /// Push once in a while data about all active timelines to the broker.
      42            0 : async fn push_loop(conf: SafeKeeperConf) -> anyhow::Result<()> {
      43            0 :     if conf.disable_periodic_broker_push {
      44            0 :         info!("broker push_loop is disabled, doing nothing...");
      45            0 :         futures::future::pending::<()>().await; // sleep forever
      46            0 :         return Ok(());
      47            0 :     }
      48            0 : 
      49            0 :     let active_timelines_set = GlobalTimelines::get_global_broker_active_set();
      50              : 
      51            0 :     let mut client =
      52            0 :         storage_broker::connect(conf.broker_endpoint.clone(), conf.broker_keepalive_interval)?;
      53            0 :     let push_interval = Duration::from_millis(PUSH_INTERVAL_MSEC);
      54            0 : 
      55            0 :     let outbound = async_stream::stream! {
      56            0 :         loop {
      57            0 :             // Note: we lock runtime here and in timeline methods as GlobalTimelines
      58            0 :             // is under plain mutex. That's ok, all this code is not performance
      59            0 :             // sensitive and there is no risk of deadlock as we don't await while
      60            0 :             // lock is held.
      61            0 :             let now = Instant::now();
      62            0 :             let all_tlis = active_timelines_set.get_all();
      63            0 :             let mut n_pushed_tlis = 0;
      64            0 :             for tli in &all_tlis {
      65            0 :                 let sk_info = tli.get_safekeeper_info(&conf).await;
      66            0 :                 yield sk_info;
      67            0 :                 BROKER_PUSHED_UPDATES.inc();
      68            0 :                 n_pushed_tlis += 1;
      69            0 :             }
      70            0 :             let elapsed = now.elapsed();
      71            0 : 
      72            0 :             BROKER_PUSH_ALL_UPDATES_SECONDS.observe(elapsed.as_secs_f64());
      73            0 :             BROKER_ITERATION_TIMELINES.observe(n_pushed_tlis as f64);
      74            0 : 
      75            0 :             if elapsed > push_interval / 2 {
      76            0 :                 info!("broker push is too long, pushed {} timeline updates to broker in {:?}", n_pushed_tlis, elapsed);
      77            0 :             }
      78            0 : 
      79            0 :             sleep(push_interval).await;
      80            0 :         }
      81            0 :     };
      82            0 :     client
      83            0 :         .publish_safekeeper_info(Request::new(outbound))
      84            0 :         .await?;
      85            0 :     Ok(())
      86            0 : }
      87              : 
      88              : /// Subscribe and fetch all the interesting data from the broker.
      89            0 : #[instrument(name = "broker_pull", skip_all)]
      90              : async fn pull_loop(conf: SafeKeeperConf, stats: Arc<BrokerStats>) -> Result<()> {
      91              :     let mut client = storage_broker::connect(conf.broker_endpoint, conf.broker_keepalive_interval)?;
      92              : 
      93              :     // TODO: subscribe only to local timelines instead of all
      94              :     let request = SubscribeSafekeeperInfoRequest {
      95              :         subscription_key: Some(ProtoSubscriptionKey::All(())),
      96              :     };
      97              : 
      98              :     let mut stream = client
      99              :         .subscribe_safekeeper_info(request)
     100              :         .await
     101              :         .context("subscribe_safekeper_info request failed")?
     102              :         .into_inner();
     103              : 
     104              :     let ok_counter = BROKER_PULLED_UPDATES.with_label_values(&["ok"]);
     105              :     let not_found = BROKER_PULLED_UPDATES.with_label_values(&["not_found"]);
     106              :     let err_counter = BROKER_PULLED_UPDATES.with_label_values(&["error"]);
     107              : 
     108              :     while let Some(msg) = stream.message().await? {
     109              :         stats.update_pulled();
     110              : 
     111              :         let proto_ttid = msg
     112              :             .tenant_timeline_id
     113              :             .as_ref()
     114            0 :             .ok_or_else(|| anyhow!("missing tenant_timeline_id"))?;
     115              :         let ttid = parse_proto_ttid(proto_ttid)?;
     116              :         if let Ok(tli) = GlobalTimelines::get(ttid) {
     117              :             // Note that we also receive *our own* info. That's
     118              :             // important, as it is used as an indication of live
     119              :             // connection to the broker.
     120              : 
     121              :             // note: there are blocking operations below, but it's considered fine for now
     122              :             let res = tli.record_safekeeper_info(msg).await;
     123              :             if res.is_ok() {
     124              :                 ok_counter.inc();
     125              :             } else {
     126              :                 err_counter.inc();
     127              :             }
     128              :             res?;
     129              :         } else {
     130              :             not_found.inc();
     131              :         }
     132              :     }
     133              :     bail!("end of stream");
     134              : }
     135              : 
     136              : /// Process incoming discover requests. This is done in a separate task to avoid
     137              : /// interfering with the normal pull/push loops.
     138            0 : async fn discover_loop(conf: SafeKeeperConf, stats: Arc<BrokerStats>) -> Result<()> {
     139            0 :     let mut client =
     140            0 :         storage_broker::connect(conf.broker_endpoint.clone(), conf.broker_keepalive_interval)?;
     141              : 
     142            0 :     let request = SubscribeByFilterRequest {
     143            0 :         types: vec![TypeSubscription {
     144            0 :             r#type: MessageType::SafekeeperDiscoveryRequest as i32,
     145            0 :         }],
     146            0 :         tenant_timeline_id: Some(FilterTenantTimelineId {
     147            0 :             enabled: false,
     148            0 :             tenant_timeline_id: None,
     149            0 :         }),
     150            0 :     };
     151              : 
     152            0 :     let mut stream = client
     153            0 :         .subscribe_by_filter(request)
     154            0 :         .await
     155            0 :         .context("subscribe_by_filter request failed")?
     156            0 :         .into_inner();
     157            0 : 
     158            0 :     let discover_counter = BROKER_PULLED_UPDATES.with_label_values(&["discover"]);
     159              : 
     160            0 :     while let Some(typed_msg) = stream.message().await? {
     161            0 :         stats.update_pulled();
     162            0 : 
     163            0 :         match typed_msg.r#type() {
     164              :             MessageType::SafekeeperDiscoveryRequest => {
     165            0 :                 let msg = typed_msg
     166            0 :                     .safekeeper_discovery_request
     167            0 :                     .expect("proto type mismatch from broker message");
     168              : 
     169            0 :                 let proto_ttid = msg
     170            0 :                     .tenant_timeline_id
     171            0 :                     .as_ref()
     172            0 :                     .ok_or_else(|| anyhow!("missing tenant_timeline_id"))?;
     173            0 :                 let ttid = parse_proto_ttid(proto_ttid)?;
     174            0 :                 if let Ok(tli) = GlobalTimelines::get(ttid) {
     175              :                     // we received a discovery request for a timeline we know about
     176            0 :                     discover_counter.inc();
     177              : 
     178              :                     // create and reply with discovery response
     179            0 :                     let sk_info = tli.get_safekeeper_info(&conf).await;
     180            0 :                     let response = SafekeeperDiscoveryResponse {
     181            0 :                         safekeeper_id: sk_info.safekeeper_id,
     182            0 :                         tenant_timeline_id: sk_info.tenant_timeline_id,
     183            0 :                         commit_lsn: sk_info.commit_lsn,
     184            0 :                         safekeeper_connstr: sk_info.safekeeper_connstr,
     185            0 :                         availability_zone: sk_info.availability_zone,
     186            0 :                         standby_horizon: 0,
     187            0 :                     };
     188            0 : 
     189            0 :                     // note this is a blocking call
     190            0 :                     client
     191            0 :                         .publish_one(TypedMessage {
     192            0 :                             r#type: MessageType::SafekeeperDiscoveryResponse as i32,
     193            0 :                             safekeeper_timeline_info: None,
     194            0 :                             safekeeper_discovery_request: None,
     195            0 :                             safekeeper_discovery_response: Some(response),
     196            0 :                         })
     197            0 :                         .await?;
     198            0 :                 }
     199              :             }
     200              : 
     201              :             _ => {
     202            0 :                 warn!(
     203            0 :                     "unexpected message type i32 {}, {:?}",
     204            0 :                     typed_msg.r#type,
     205            0 :                     typed_msg.r#type()
     206              :                 );
     207              :             }
     208              :         }
     209              :     }
     210            0 :     bail!("end of stream");
     211            0 : }
     212              : 
     213            0 : pub async fn task_main(conf: SafeKeeperConf) -> anyhow::Result<()> {
     214            0 :     info!("started, broker endpoint {:?}", conf.broker_endpoint);
     215              : 
     216            0 :     let mut ticker = tokio::time::interval(Duration::from_millis(RETRY_INTERVAL_MSEC));
     217            0 :     let mut push_handle: Option<JoinHandle<Result<(), Error>>> = None;
     218            0 :     let mut pull_handle: Option<JoinHandle<Result<(), Error>>> = None;
     219            0 :     let mut discover_handle: Option<JoinHandle<Result<(), Error>>> = None;
     220            0 : 
     221            0 :     let stats = Arc::new(BrokerStats::new());
     222            0 :     let stats_task = task_stats(stats.clone());
     223            0 :     tokio::pin!(stats_task);
     224              : 
     225              :     // Selecting on JoinHandles requires some squats; is there a better way to
     226              :     // reap tasks individually?
     227              : 
     228              :     // Handling failures in task itself won't catch panic and in Tokio, task's
     229              :     // panic doesn't kill the whole executor, so it is better to do reaping
     230              :     // here.
     231              :     loop {
     232            0 :         tokio::select! {
     233            0 :                 res = async { push_handle.as_mut().unwrap().await }, if push_handle.is_some() => {
     234              :                     // was it panic or normal error?
     235            0 :                     let err = match res {
     236            0 :                         Ok(res_internal) => res_internal.unwrap_err(),
     237            0 :                         Err(err_outer) => err_outer.into(),
     238              :                     };
     239            0 :                     warn!("push task failed: {:?}", err);
     240            0 :                     push_handle = None;
     241              :                 },
     242            0 :                 res = async { pull_handle.as_mut().unwrap().await }, if pull_handle.is_some() => {
     243              :                     // was it panic or normal error?
     244            0 :                     match res {
     245            0 :                         Ok(res_internal) => if let Err(err_inner) = res_internal {
     246            0 :                             warn!("pull task failed: {:?}", err_inner);
     247            0 :                         }
     248            0 :                         Err(err_outer) => { warn!("pull task panicked: {:?}", err_outer) }
     249              :                     };
     250            0 :                     pull_handle = None;
     251              :                 },
     252            0 :                 res = async { discover_handle.as_mut().unwrap().await }, if discover_handle.is_some() => {
     253              :                     // was it panic or normal error?
     254            0 :                     match res {
     255            0 :                         Ok(res_internal) => if let Err(err_inner) = res_internal {
     256            0 :                             warn!("discover task failed: {:?}", err_inner);
     257            0 :                         }
     258            0 :                         Err(err_outer) => { warn!("discover task panicked: {:?}", err_outer) }
     259              :                     };
     260            0 :                     discover_handle = None;
     261              :                 },
     262            0 :                 _ = ticker.tick() => {
     263            0 :                     if push_handle.is_none() {
     264            0 :                         push_handle = Some(tokio::spawn(push_loop(conf.clone())));
     265            0 :                     }
     266            0 :                     if pull_handle.is_none() {
     267            0 :                         pull_handle = Some(tokio::spawn(pull_loop(conf.clone(), stats.clone())));
     268            0 :                     }
     269            0 :                     if discover_handle.is_none() {
     270            0 :                         discover_handle = Some(tokio::spawn(discover_loop(conf.clone(), stats.clone())));
     271            0 :                     }
     272              :                 },
     273            0 :                 _ = &mut stats_task => {}
     274              :         }
     275              :     }
     276              : }
     277              : 
     278              : struct BrokerStats {
     279              :     /// Timestamp of the last received message from the broker.
     280              :     last_pulled_ts: AtomicU64,
     281              : }
     282              : 
     283              : impl BrokerStats {
     284            0 :     fn new() -> Self {
     285            0 :         BrokerStats {
     286            0 :             last_pulled_ts: AtomicU64::new(0),
     287            0 :         }
     288            0 :     }
     289              : 
     290            0 :     fn now_millis() -> u64 {
     291            0 :         std::time::SystemTime::now()
     292            0 :             .duration_since(UNIX_EPOCH)
     293            0 :             .expect("time is before epoch")
     294            0 :             .as_millis() as u64
     295            0 :     }
     296              : 
     297              :     /// Update last_pulled timestamp to current time.
     298            0 :     fn update_pulled(&self) {
     299            0 :         self.last_pulled_ts
     300            0 :             .store(Self::now_millis(), std::sync::atomic::Ordering::Relaxed);
     301            0 :     }
     302              : }
     303              : 
     304              : /// Periodically write to logs if there are issues with receiving data from the broker.
     305            0 : async fn task_stats(stats: Arc<BrokerStats>) {
     306            0 :     let warn_duration = Duration::from_secs(10);
     307            0 :     let mut ticker = tokio::time::interval(warn_duration);
     308              : 
     309              :     loop {
     310            0 :         tokio::select! {
     311            0 :             _ = ticker.tick() => {
     312            0 :                 let last_pulled = stats.last_pulled_ts.load(std::sync::atomic::Ordering::SeqCst);
     313            0 :                 if last_pulled == 0 {
     314              :                     // no broker updates yet
     315            0 :                     continue;
     316            0 :                 }
     317            0 : 
     318            0 :                 let now = BrokerStats::now_millis();
     319            0 :                 if now > last_pulled && now - last_pulled > warn_duration.as_millis() as u64 {
     320            0 :                     let ts = chrono::DateTime::from_timestamp_millis(last_pulled as i64).expect("invalid timestamp");
     321            0 :                     info!("no broker updates for some time, last update: {:?}", ts);
     322            0 :                 }
     323              :             }
     324              :         }
     325              :     }
     326              : }
        

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