syn2mas: better performance, output tweaks, tracing tweaks, access token fixes

crates/cli/src/commands/syn2mas.rs

@@ -80,6 +80,7 @@ enum Subcommand {
 const NUM_WRITER_CONNECTIONS: usize = 8;
 
 impl Options {
+    #[tracing::instrument("cli.syn2mas.run", skip_all)]
     #[allow(clippy::too_many_lines)]
     pub async fn run(self, figment: &Figment) -> anyhow::Result<ExitCode> {
         warn!(
@@ -173,14 +174,14 @@ impl Options {
 
         // Display errors and warnings
         if !check_errors.is_empty() {
-            eprintln!("===== Errors =====");
+            eprintln!("\n\n===== Errors =====");
             eprintln!("These issues prevent migrating from Synapse to MAS right now:\n");
             for error in &check_errors {
                 eprintln!("• {error}\n");
             }
         }
         if !check_warnings.is_empty() {
-            eprintln!("===== Warnings =====");
+            eprintln!("\n\n===== Warnings =====");
             eprintln!(
                 "These potential issues should be considered before migrating from Synapse to MAS right now:\n"
             );
@@ -220,6 +221,7 @@ impl Options {
 
                 // TODO how should we handle warnings at this stage?
 
+                // TODO this dry-run flag should be set to false in real circumstances !!!
                 let reader = SynapseReader::new(&mut syn_conn, true).await?;
                 let mut writer_mas_connections = Vec::with_capacity(NUM_WRITER_CONNECTIONS);
                 for _ in 0..NUM_WRITER_CONNECTIONS {
@@ -234,6 +236,7 @@ impl Options {
 
                 // TODO progress reporting
                 let mas_matrix = MatrixConfig::extract(figment)?;
+                eprintln!("\n\n"); // padding above progress bar
                 syn2mas::migrate(
                     reader,
                     writer,

crates/syn2mas/Cargo.toml

@@ -18,13 +18,16 @@ serde.workspace = true
 thiserror.workspace = true
 thiserror-ext.workspace = true
 tokio.workspace = true
+tokio-util.workspace = true
 sqlx.workspace = true
 chrono.workspace = true
 compact_str.workspace = true
 tracing.workspace = true
 futures-util = "0.3.31"
+rustc-hash = "2.1.1"
 
 rand.workspace = true
+rand_chacha = "0.3.1"
 uuid = "1.15.1"
 ulid = { workspace = true, features = ["uuid"] }
 

crates/syn2mas/src/lib.rs

@@ -8,6 +8,9 @@ mod synapse_reader;
 
 mod migration;
 
+type RandomState = rustc_hash::FxBuildHasher;
+type HashMap<K, V> = rustc_hash::FxHashMap<K, V>;
+
 pub use self::{
     mas_writer::{MasWriter, checks::mas_pre_migration_checks, locking::LockedMasDatabase},
     migration::migrate,

crates/syn2mas/src/mas_writer/checks.rs

@@ -10,6 +10,7 @@
 
 use thiserror::Error;
 use thiserror_ext::ContextInto;
+use tracing::Instrument as _;
 
 use super::{MAS_TABLES_AFFECTED_BY_MIGRATION, is_syn2mas_in_progress, locking::LockedMasDatabase};
 
@@ -46,7 +47,7 @@ pub enum Error {
 /// - If any MAS tables involved in the migration are not empty.
 /// - If we can't check whether syn2mas is already in progress on this database
 ///   or not.
-#[tracing::instrument(skip_all)]
+#[tracing::instrument(name = "syn2mas.mas_pre_migration_checks", skip_all)]
 pub async fn mas_pre_migration_checks(mas_connection: &mut LockedMasDatabase) -> Result<(), Error> {
     if is_syn2mas_in_progress(mas_connection.as_mut())
         .await
@@ -60,8 +61,11 @@ pub async fn mas_pre_migration_checks(mas_connection: &mut LockedMasDatabase) ->
     // empty database.
 
     for &table in MAS_TABLES_AFFECTED_BY_MIGRATION {
-        let row_present = sqlx::query(&format!("SELECT 1 AS dummy FROM {table} LIMIT 1"))
+        let query = format!("SELECT 1 AS dummy FROM {table} LIMIT 1");
+        let span = tracing::info_span!("db.query", db.query.text = query);
+        let row_present = sqlx::query(&query)
             .fetch_optional(mas_connection.as_mut())
+            .instrument(span)
             .await
             .into_maybe_not_mas(table)?
             .is_some();

crates/syn2mas/src/mas_writer/constraint_pausing.rs

@@ -3,8 +3,10 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Please see LICENSE in the repository root for full details.
 
+use std::time::Instant;
+
 use sqlx::PgConnection;
-use tracing::debug;
+use tracing::{debug, info};
 
 use super::{Error, IntoDatabase};
 
@@ -109,15 +111,20 @@ pub async fn drop_index(conn: &mut PgConnection, index: &IndexDescription) -> Re
 /// Restores (recreates) a constraint.
 ///
 /// The constraint must not exist prior to this call.
+#[tracing::instrument(name = "syn2mas.restore_constraint", skip_all, fields(constraint.name = constraint.name))]
 pub async fn restore_constraint(
     conn: &mut PgConnection,
     constraint: &ConstraintDescription,
 ) -> Result<(), Error> {
+    let start = Instant::now();
+
     let ConstraintDescription {
         name,
         table_name,
         definition,
     } = &constraint;
+    info!("rebuilding constraint {name}");
+
     sqlx::query(&format!(
         "ALTER TABLE {table_name} ADD CONSTRAINT {name} {definition};"
     ))
@@ -127,13 +134,21 @@ pub async fn restore_constraint(
         format!("failed to recreate constraint {name} on {table_name} with {definition}")
     })?;
 
+    info!(
+        "constraint {name} rebuilt in {:.1}s",
+        Instant::now().duration_since(start).as_secs_f64()
+    );
+
     Ok(())
 }
 
 /// Restores (recreates) a index.
 ///
 /// The index must not exist prior to this call.
+#[tracing::instrument(name = "syn2mas.restore_index", skip_all, fields(index.name = index.name))]
 pub async fn restore_index(conn: &mut PgConnection, index: &IndexDescription) -> Result<(), Error> {
+    let start = Instant::now();
+
     let IndexDescription {
         name,
         table_name,
@@ -147,5 +162,10 @@ pub async fn restore_index(conn: &mut PgConnection, index: &IndexDescription) ->
             format!("failed to recreate index {name} on {table_name} with {definition}")
         })?;
 
+    info!(
+        "index {name} rebuilt in {:.1}s",
+        Instant::now().duration_since(start).as_secs_f64()
+    );
+
     Ok(())
 }

crates/syn2mas/src/mas_writer/mod.rs

@@ -7,15 +7,22 @@
 //!
 //! This module is responsible for writing new records to MAS' database.
 
-use std::{fmt::Display, net::IpAddr};
+use std::{
+    fmt::Display,
+    net::IpAddr,
+    sync::{
+        Arc,
+        atomic::{AtomicU32, Ordering},
+    },
+};
 
 use chrono::{DateTime, Utc};
 use futures_util::{FutureExt, TryStreamExt, future::BoxFuture};
 use sqlx::{Executor, PgConnection, query, query_as};
 use thiserror::Error;
 use thiserror_ext::{Construct, ContextInto};
 use tokio::sync::mpsc::{self, Receiver, Sender};
-use tracing::{Level, error, info, warn};
+use tracing::{Instrument, Level, error, info, warn};
 use uuid::{NonNilUuid, Uuid};
 
 use self::{
@@ -44,6 +51,9 @@ pub enum Error {
     #[error("inconsistent database: {0}")]
     Inconsistent(String),
 
+    #[error("bug in syn2mas: write buffers not finished")]
+    WriteBuffersNotFinished,
+
     #[error("{0}")]
     Multiple(MultipleErrors),
 }
@@ -109,18 +119,21 @@ impl WriterConnectionPool {
         match self.connection_rx.recv().await {
             Some(Ok(mut connection)) => {
                 let connection_tx = self.connection_tx.clone();
-                tokio::task::spawn(async move {
-                    let to_return = match task(&mut connection).await {
-                        Ok(()) => Ok(connection),
-                        Err(error) => {
-                            error!("error in writer: {error}");
-                            Err(error)
-                        }
-                    };
-                    // This should always succeed in sending unless we're already shutting
-                    // down for some other reason.
-                    let _: Result<_, _> = connection_tx.send(to_return).await;
-                });
+                tokio::task::spawn(
+                    async move {
+                        let to_return = match task(&mut connection).await {
+                            Ok(()) => Ok(connection),
+                            Err(error) => {
+                                error!("error in writer: {error}");
+                                Err(error)
+                            }
+                        };
+                        // This should always succeed in sending unless we're already shutting
+                        // down for some other reason.
+                        let _: Result<_, _> = connection_tx.send(to_return).await;
+                    }
+                    .instrument(tracing::debug_span!("spawn_with_connection")),
+                );
 
                 Ok(())
             }
@@ -188,12 +201,52 @@ impl WriterConnectionPool {
     }
 }
 
+/// Small utility to make sure `finish()` is called on all write buffers
+/// before committing to the database.
+#[derive(Default)]
+struct FinishChecker {
+    counter: Arc<AtomicU32>,
+}
+
+struct FinishCheckerHandle {
+    counter: Arc<AtomicU32>,
+}
+
+impl FinishChecker {
+    /// Acquire a new handle, for a task that should declare when it has
+    /// finished.
+    pub fn handle(&self) -> FinishCheckerHandle {
+        self.counter.fetch_add(1, Ordering::SeqCst);
+        FinishCheckerHandle {
+            counter: Arc::clone(&self.counter),
+        }
+    }
+
+    /// Check that all handles have been declared as finished.
+    pub fn check_all_finished(self) -> Result<(), Error> {
+        if self.counter.load(Ordering::SeqCst) == 0 {
+            Ok(())
+        } else {
+            Err(Error::WriteBuffersNotFinished)
+        }
+    }
+}
+
+impl FinishCheckerHandle {
+    /// Declare that the task this handle represents has been finished.
+    pub fn declare_finished(self) {
+        self.counter.fetch_sub(1, Ordering::SeqCst);
+    }
+}
+
 pub struct MasWriter {
     conn: LockedMasDatabase,
     writer_pool: WriterConnectionPool,
 
     indices_to_restore: Vec<IndexDescription>,
     constraints_to_restore: Vec<ConstraintDescription>,
+
+    write_buffer_finish_checker: FinishChecker,
 }
 
 pub struct MasNewUser {
@@ -336,7 +389,7 @@ impl MasWriter {
     ///
     /// - If the database connection experiences an error.
     #[allow(clippy::missing_panics_doc)] // not real
-    #[tracing::instrument(skip_all)]
+    #[tracing::instrument(name = "syn2mas.mas_writer.new", skip_all)]
     pub async fn new(
         mut conn: LockedMasDatabase,
         mut writer_connections: Vec<PgConnection>,
@@ -453,6 +506,7 @@ impl MasWriter {
             writer_pool: WriterConnectionPool::new(writer_connections),
             indices_to_restore,
             constraints_to_restore,
+            write_buffer_finish_checker: FinishChecker::default(),
         })
     }
 
@@ -520,6 +574,8 @@ impl MasWriter {
     /// - If the database connection experiences an error.
     #[tracing::instrument(skip_all)]
     pub async fn finish(mut self) -> Result<PgConnection, Error> {
+        self.write_buffer_finish_checker.check_all_finished()?;
+
         // Commit all writer transactions to the database.
         self.writer_pool
             .finish()
@@ -1033,28 +1089,24 @@ type WriteBufferFlusher<T> =
 
 /// A buffer for writing rows to the MAS database.
 /// Generic over the type of rows.
-///
-/// # Panics
-///
-/// Panics if dropped before `finish()` has been called.
 pub struct MasWriteBuffer<T> {
     rows: Vec<T>,
     flusher: WriteBufferFlusher<T>,
-    finished: bool,
+    finish_checker_handle: FinishCheckerHandle,
 }
 
 impl<T> MasWriteBuffer<T> {
-    pub fn new(flusher: WriteBufferFlusher<T>) -> Self {
+    pub fn new(writer: &MasWriter, flusher: WriteBufferFlusher<T>) -> Self {
         MasWriteBuffer {
             rows: Vec::with_capacity(WRITE_BUFFER_BATCH_SIZE),
             flusher,
-            finished: false,
+            finish_checker_handle: writer.write_buffer_finish_checker.handle(),
         }
     }
 
     pub async fn finish(mut self, writer: &mut MasWriter) -> Result<(), Error> {
-        self.finished = true;
         self.flush(writer).await?;
+        self.finish_checker_handle.declare_finished();
         Ok(())
     }
 
@@ -1077,12 +1129,6 @@ impl<T> MasWriteBuffer<T> {
     }
 }
 
-impl<T> Drop for MasWriteBuffer<T> {
-    fn drop(&mut self) {
-        assert!(self.finished, "MasWriteBuffer dropped but not finished!");
-    }
-}
-
 #[cfg(test)]
 mod test {
     use std::collections::{BTreeMap, BTreeSet};