Register the collector

internal/sqlutil/sqlutil.go

@@ -6,6 +6,8 @@ import (
 	"regexp"
 
 	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/sirupsen/logrus"
 )
 
@@ -47,5 +49,7 @@ func Open(dbProperties *config.DatabaseOptions, writer Writer) (*sql.DB, error)
 		db.SetMaxIdleConns(dbProperties.MaxIdleConns())
 		db.SetConnMaxLifetime(dbProperties.ConnMaxLifetime())
 	}
+	collector := collectors.NewDBStatsCollector(db, fmt.Sprintf("dendrite_%s", dbProperties.Name))
+	prometheus.MustRegister(collector)
 	return db, nil
 }

setup/config/config_federationapi.go

@@ -40,6 +40,7 @@ func (c *FederationAPI) Defaults(opts DefaultOpts) {
 		c.InternalAPI.Listen = "http://localhost:7772"
 		c.InternalAPI.Connect = "http://localhost:7772"
 		c.ExternalAPI.Listen = "http://[::]:8072"
+		c.Database.Name = "federation_api"
 		c.Database.Defaults(10)
 	}
 	c.FederationMaxRetries = 16

setup/config/config_global.go

@@ -96,6 +96,7 @@ func (c *Global) Defaults(opts DefaultOpts) {
 	}
 	c.KeyValidityPeriod = time.Hour * 24 * 7
 	if opts.Monolithic {
+		c.DatabaseOptions.Name = "global"
 		c.DatabaseOptions.Defaults(90)
 	}
 	c.JetStream.Defaults(opts)
@@ -237,6 +238,8 @@ func (c *Sentry) Verify(configErrs *ConfigErrors, isMonolith bool) {
 }
 
 type DatabaseOptions struct {
+	// Which database is this? For use in prometheus collectors.
+	Name string `json:"-"`
 	// The connection string, file:filename.db or postgres://server....
 	ConnectionString DataSource `yaml:"connection_string"`
 	// Maximum open connections to the DB (0 = use default, negative means unlimited)

setup/config/config_keyserver.go

@@ -12,6 +12,7 @@ func (c *KeyServer) Defaults(opts DefaultOpts) {
 	if !opts.Monolithic {
 		c.InternalAPI.Listen = "http://localhost:7779"
 		c.InternalAPI.Connect = "http://localhost:7779"
+		c.Database.Name = "keyserver"
 		c.Database.Defaults(10)
 	}
 	if opts.Generate {

setup/config/config_mediaapi.go

@@ -43,6 +43,7 @@ func (c *MediaAPI) Defaults(opts DefaultOpts) {
 		c.InternalAPI.Listen = "http://localhost:7774"
 		c.InternalAPI.Connect = "http://localhost:7774"
 		c.ExternalAPI.Listen = "http://[::]:8074"
+		c.Database.Name = "media_api"
 		c.Database.Defaults(5)
 	}
 	c.MaxFileSizeBytes = DefaultMaxFileSizeBytes

setup/config/config_mscs.go

@@ -15,6 +15,7 @@ type MSCs struct {
 
 func (c *MSCs) Defaults(opts DefaultOpts) {
 	if !opts.Monolithic {
+		c.Database.Name = "mscs"
 		c.Database.Defaults(5)
 	}
 	if opts.Generate {

setup/config/config_roomserver.go

@@ -12,6 +12,7 @@ func (c *RoomServer) Defaults(opts DefaultOpts) {
 	if !opts.Monolithic {
 		c.InternalAPI.Listen = "http://localhost:7770"
 		c.InternalAPI.Connect = "http://localhost:7770"
+		c.Database.Name = "roomserver"
 		c.Database.Defaults(20)
 	}
 	if opts.Generate {

setup/config/config_syncapi.go

@@ -18,6 +18,7 @@ func (c *SyncAPI) Defaults(opts DefaultOpts) {
 		c.InternalAPI.Listen = "http://localhost:7773"
 		c.InternalAPI.Connect = "http://localhost:7773"
 		c.ExternalAPI.Listen = "http://localhost:8073"
+		c.Database.Name = "sync_api"
 		c.Database.Defaults(20)
 	}
 	c.Fulltext.Defaults(opts)

setup/config/config_userapi.go

@@ -27,6 +27,7 @@ func (c *UserAPI) Defaults(opts DefaultOpts) {
 	if !opts.Monolithic {
 		c.InternalAPI.Listen = "http://localhost:7781"
 		c.InternalAPI.Connect = "http://localhost:7781"
+		c.AccountDatabase.Name = "user_api"
 		c.AccountDatabase.Defaults(10)
 	}
 	c.BCryptCost = bcrypt.DefaultCost