Global database connection pool (for monolith mode) (#2411)

* Allow monolith components to share a single database pool

* Don't yell about missing connection strings

* Rename field

* Setup tweaks

* Fix panic

* Improve configuration checks

* Update config

* Fix lint errors

* Update comments

1 files changed, 10 insertions, 8 deletions

diff --git a/roomserver/storage/sqlite3/storage.go b/roomserver/storage/sqlite3/storage.go
index 325c253b..e6cf1a53 100644
--- a/roomserver/storage/sqlite3/storage.go
+++ b/roomserver/storage/sqlite3/storage.go
@@ -18,12 +18,14 @@ package sqlite3
 import (
 	"context"
 	"database/sql"
+	"fmt"
 
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/storage/sqlite3/deltas"
 	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/gomatrixserverlib"
 )
@@ -34,12 +36,12 @@ type Database struct {
 }
 
 // Open a sqlite database.
-func Open(dbProperties *config.DatabaseOptions, cache caching.RoomServerCaches) (*Database, error) {
+func Open(base *base.BaseDendrite, dbProperties *config.DatabaseOptions, cache caching.RoomServerCaches) (*Database, error) {
 	var d Database
-	var db *sql.DB
 	var err error
-	if db, err = sqlutil.Open(dbProperties); err != nil {
-		return nil, err
+	db, writer, err := base.DatabaseConnection(dbProperties, sqlutil.NewExclusiveWriter())
+	if err != nil {
+		return nil, fmt.Errorf("sqlutil.Open: %w", err)
 	}
 
 	//db.Exec("PRAGMA journal_mode=WAL;")
@@ -49,7 +51,7 @@ func Open(dbProperties *config.DatabaseOptions, cache caching.RoomServerCaches)
 	// cause the roomserver to be unresponsive to new events because something will
 	// acquire the global mutex and never unlock it because it is waiting for a connection
 	// which it will never obtain.
-	db.SetMaxOpenConns(20)
+	// db.SetMaxOpenConns(20)
 
 	// Create the tables.
 	if err := d.create(db); err != nil {
@@ -67,7 +69,7 @@ func Open(dbProperties *config.DatabaseOptions, cache caching.RoomServerCaches)
 
 	// Then prepare the statements. Now that the migrations have run, any columns referred
 	// to in the database code should now exist.
-	if err := d.prepare(db, cache); err != nil {
+	if err := d.prepare(db, writer, cache); err != nil {
 		return nil, err
 	}
 
@@ -118,7 +120,7 @@ func (d *Database) create(db *sql.DB) error {
 	return nil
 }
 
-func (d *Database) prepare(db *sql.DB, cache caching.RoomServerCaches) error {
+func (d *Database) prepare(db *sql.DB, writer sqlutil.Writer, cache caching.RoomServerCaches) error {
 	eventStateKeys, err := prepareEventStateKeysTable(db)
 	if err != nil {
 		return err
@@ -174,7 +176,7 @@ func (d *Database) prepare(db *sql.DB, cache caching.RoomServerCaches) error {
 	d.Database = shared.Database{
 		DB:                  db,
 		Cache:               cache,
-		Writer:              sqlutil.NewExclusiveWriter(),
+		Writer:              writer,
 		EventsTable:         events,
 		EventTypesTable:     eventTypes,
 		EventStateKeysTable: eventStateKeys,