diff --git a/build/gobind/monolith.go b/build/gobind/monolith.go
index 2ea09f636..59535c7b9 100644
--- a/build/gobind/monolith.go
+++ b/build/gobind/monolith.go
@@ -111,13 +111,12 @@ func (m *DendriteMonolith) Start() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 	federation := ygg.CreateFederationClient(base)
 
 	serverKeyAPI := &signing.YggdrasilKeys{}
 	keyRing := serverKeyAPI.KeyRing()
 	keyAPI := keyserver.NewInternalAPI(&base.Cfg.KeyServer, federation, base.KafkaProducer)
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, cfg.Derived.ApplicationServices, keyAPI)
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, cfg.Derived.ApplicationServices, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
 	rsAPI := roomserver.NewInternalAPI(
@@ -153,7 +152,6 @@ func (m *DendriteMonolith) Start() {
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,
-		DeviceDB:      deviceDB,
 		Client:        ygg.CreateClient(base),
 		FedClient:     federation,
 		KeyRing:       keyRing,
diff --git a/build/scripts/Complement.Dockerfile b/build/scripts/Complement.Dockerfile
index 6489c22e4..32c5234b1 100644
--- a/build/scripts/Complement.Dockerfile
+++ b/build/scripts/Complement.Dockerfile
@@ -1,5 +1,5 @@
 FROM golang:1.13-stretch as build
-RUN apt-get update && apt-get install sqlite3
+RUN apt-get update && apt-get install -y sqlite3
 WORKDIR /build
 
 # Utilise Docker caching when downloading dependencies, this stops us needlessly
diff --git a/clientapi/clientapi.go b/clientapi/clientapi.go
index 1a4307c18..fe6789fcb 100644
--- a/clientapi/clientapi.go
+++ b/clientapi/clientapi.go
@@ -30,7 +30,6 @@ import (
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -39,7 +38,6 @@ func AddPublicRoutes(
 	router *mux.Router,
 	cfg *config.ClientAPI,
 	producer sarama.SyncProducer,
-	deviceDB devices.Database,
 	accountsDB accounts.Database,
 	federation *gomatrixserverlib.FederationClient,
 	rsAPI roomserverAPI.RoomserverInternalAPI,
@@ -59,7 +57,7 @@ func AddPublicRoutes(
 
 	routing.Setup(
 		router, cfg, eduInputAPI, rsAPI, asAPI,
-		accountsDB, deviceDB, userAPI, federation,
+		accountsDB, userAPI, federation,
 		syncProducer, transactionsCache, fsAPI, stateAPI, keyAPI, extRoomsProvider,
 	)
 }
diff --git a/clientapi/routing/device.go b/clientapi/routing/device.go
index d0b3bdbe5..56886d57f 100644
--- a/clientapi/routing/device.go
+++ b/clientapi/routing/device.go
@@ -15,7 +15,6 @@
 package routing
 
 import (
-	"database/sql"
 	"encoding/json"
 	"io/ioutil"
 	"net/http"
@@ -23,7 +22,7 @@ import (
 	"github.com/matrix-org/dendrite/clientapi/auth"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/userapi/api"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
@@ -50,57 +49,56 @@ type devicesDeleteJSON struct {
 
 // GetDeviceByID handles /devices/{deviceID}
 func GetDeviceByID(
-	req *http.Request, deviceDB devices.Database, device *api.Device,
+	req *http.Request, userAPI userapi.UserInternalAPI, device *api.Device,
 	deviceID string,
 ) util.JSONResponse {
-	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
+	var queryRes userapi.QueryDevicesResponse
+	err := userAPI.QueryDevices(req.Context(), &userapi.QueryDevicesRequest{
+		UserID: device.UserID,
+	}, &queryRes)
 	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("gomatrixserverlib.SplitID failed")
+		util.GetLogger(req.Context()).WithError(err).Error("QueryDevices failed")
 		return jsonerror.InternalServerError()
 	}
-
-	ctx := req.Context()
-	dev, err := deviceDB.GetDeviceByID(ctx, localpart, deviceID)
-	if err == sql.ErrNoRows {
+	var targetDevice *userapi.Device
+	for _, device := range queryRes.Devices {
+		if device.ID == deviceID {
+			targetDevice = &device
+			break
+		}
+	}
+	if targetDevice == nil {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: jsonerror.NotFound("Unknown device"),
 		}
-	} else if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("deviceDB.GetDeviceByID failed")
-		return jsonerror.InternalServerError()
 	}
 
 	return util.JSONResponse{
 		Code: http.StatusOK,
 		JSON: deviceJSON{
-			DeviceID:    dev.ID,
-			DisplayName: dev.DisplayName,
+			DeviceID:    targetDevice.ID,
+			DisplayName: targetDevice.DisplayName,
 		},
 	}
 }
 
 // GetDevicesByLocalpart handles /devices
 func GetDevicesByLocalpart(
-	req *http.Request, deviceDB devices.Database, device *api.Device,
+	req *http.Request, userAPI userapi.UserInternalAPI, device *api.Device,
 ) util.JSONResponse {
-	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
+	var queryRes userapi.QueryDevicesResponse
+	err := userAPI.QueryDevices(req.Context(), &userapi.QueryDevicesRequest{
+		UserID: device.UserID,
+	}, &queryRes)
 	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("gomatrixserverlib.SplitID failed")
-		return jsonerror.InternalServerError()
-	}
-
-	ctx := req.Context()
-	deviceList, err := deviceDB.GetDevicesByLocalpart(ctx, localpart)
-
-	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("deviceDB.GetDevicesByLocalpart failed")
+		util.GetLogger(req.Context()).WithError(err).Error("QueryDevices failed")
 		return jsonerror.InternalServerError()
 	}
 
 	res := devicesJSON{}
 
-	for _, dev := range deviceList {
+	for _, dev := range queryRes.Devices {
 		res.Devices = append(res.Devices, deviceJSON{
 			DeviceID:    dev.ID,
 			DisplayName: dev.DisplayName,
diff --git a/clientapi/routing/joinroom.go b/clientapi/routing/joinroom.go
index 3c7421bb2..c10113574 100644
--- a/clientapi/routing/joinroom.go
+++ b/clientapi/routing/joinroom.go
@@ -41,6 +41,17 @@ func JoinRoomByIDOrAlias(
 	}
 	joinRes := roomserverAPI.PerformJoinResponse{}
 
+	// Check to see if any ?server_name= query parameters were
+	// given in the request.
+	if serverNames, ok := req.URL.Query()["server_name"]; ok {
+		for _, serverName := range serverNames {
+			joinReq.ServerNames = append(
+				joinReq.ServerNames,
+				gomatrixserverlib.ServerName(serverName),
+			)
+		}
+	}
+
 	// If content was provided in the request then include that
 	// in the request. It'll get used as a part of the membership
 	// event content.
diff --git a/clientapi/routing/logout.go b/clientapi/routing/logout.go
index 3ce47169e..cb300e9ff 100644
--- a/clientapi/routing/logout.go
+++ b/clientapi/routing/logout.go
@@ -19,23 +19,21 @@ import (
 
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/userapi/api"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
-	"github.com/matrix-org/gomatrixserverlib"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/util"
 )
 
 // Logout handles POST /logout
 func Logout(
-	req *http.Request, deviceDB devices.Database, device *api.Device,
+	req *http.Request, userAPI userapi.UserInternalAPI, device *api.Device,
 ) util.JSONResponse {
-	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
+	var performRes userapi.PerformDeviceDeletionResponse
+	err := userAPI.PerformDeviceDeletion(req.Context(), &userapi.PerformDeviceDeletionRequest{
+		UserID:    device.UserID,
+		DeviceIDs: []string{device.ID},
+	}, &performRes)
 	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("gomatrixserverlib.SplitID failed")
-		return jsonerror.InternalServerError()
-	}
-
-	if err := deviceDB.RemoveDevice(req.Context(), device.ID, localpart); err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("deviceDB.RemoveDevice failed")
+		util.GetLogger(req.Context()).WithError(err).Error("PerformDeviceDeletion failed")
 		return jsonerror.InternalServerError()
 	}
 
@@ -47,16 +45,15 @@ func Logout(
 
 // LogoutAll handles POST /logout/all
 func LogoutAll(
-	req *http.Request, deviceDB devices.Database, device *api.Device,
+	req *http.Request, userAPI userapi.UserInternalAPI, device *api.Device,
 ) util.JSONResponse {
-	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
+	var performRes userapi.PerformDeviceDeletionResponse
+	err := userAPI.PerformDeviceDeletion(req.Context(), &userapi.PerformDeviceDeletionRequest{
+		UserID:    device.UserID,
+		DeviceIDs: nil,
+	}, &performRes)
 	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("gomatrixserverlib.SplitID failed")
-		return jsonerror.InternalServerError()
-	}
-
-	if err := deviceDB.RemoveAllDevices(req.Context(), localpart); err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("deviceDB.RemoveAllDevices failed")
+		util.GetLogger(req.Context()).WithError(err).Error("PerformDeviceDeletion failed")
 		return jsonerror.InternalServerError()
 	}
 
diff --git a/clientapi/routing/routing.go b/clientapi/routing/routing.go
index 69c76cf93..3d4b99935 100644
--- a/clientapi/routing/routing.go
+++ b/clientapi/routing/routing.go
@@ -35,7 +35,6 @@ import (
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
@@ -52,7 +51,6 @@ func Setup(
 	rsAPI roomserverAPI.RoomserverInternalAPI,
 	asAPI appserviceAPI.AppServiceQueryAPI,
 	accountDB accounts.Database,
-	deviceDB devices.Database,
 	userAPI userapi.UserInternalAPI,
 	federation *gomatrixserverlib.FederationClient,
 	syncProducer *producers.SyncAPIProducer,
@@ -333,13 +331,13 @@ func Setup(
 
 	r0mux.Handle("/logout",
 		httputil.MakeAuthAPI("logout", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
-			return Logout(req, deviceDB, device)
+			return Logout(req, userAPI, device)
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	r0mux.Handle("/logout/all",
 		httputil.MakeAuthAPI("logout", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
-			return LogoutAll(req, deviceDB, device)
+			return LogoutAll(req, userAPI, device)
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 
@@ -643,7 +641,7 @@ func Setup(
 
 	r0mux.Handle("/devices",
 		httputil.MakeAuthAPI("get_devices", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
-			return GetDevicesByLocalpart(req, deviceDB, device)
+			return GetDevicesByLocalpart(req, userAPI, device)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
@@ -653,7 +651,7 @@ func Setup(
 			if err != nil {
 				return util.ErrorResponse(err)
 			}
-			return GetDeviceByID(req, deviceDB, device, vars["deviceID"])
+			return GetDeviceByID(req, userAPI, device, vars["deviceID"])
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
diff --git a/cmd/dendrite-client-api-server/main.go b/cmd/dendrite-client-api-server/main.go
index 4961b34e0..35dbb7745 100644
--- a/cmd/dendrite-client-api-server/main.go
+++ b/cmd/dendrite-client-api-server/main.go
@@ -27,7 +27,6 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 	federation := base.CreateFederationClient()
 
 	asQuery := base.AppserviceHTTPClient()
@@ -39,7 +38,7 @@ func main() {
 	keyAPI := base.KeyServerHTTPClient()
 
 	clientapi.AddPublicRoutes(
-		base.PublicClientAPIMux, &base.Cfg.ClientAPI, base.KafkaProducer, deviceDB, accountDB, federation,
+		base.PublicClientAPIMux, &base.Cfg.ClientAPI, base.KafkaProducer, accountDB, federation,
 		rsAPI, eduInputAPI, asQuery, stateAPI, transactions.New(), fsAPI, userAPI, keyAPI, nil,
 	)
 
diff --git a/cmd/dendrite-demo-libp2p/main.go b/cmd/dendrite-demo-libp2p/main.go
index 4934fe5f0..e2d23e895 100644
--- a/cmd/dendrite-demo-libp2p/main.go
+++ b/cmd/dendrite-demo-libp2p/main.go
@@ -140,10 +140,9 @@ func main() {
 	defer base.Base.Close() // nolint: errcheck
 
 	accountDB := base.Base.CreateAccountsDB()
-	deviceDB := base.Base.CreateDeviceDB()
 	federation := createFederationClient(base)
 	keyAPI := keyserver.NewInternalAPI(&base.Base.Cfg.KeyServer, federation, base.Base.KafkaProducer)
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, nil, keyAPI)
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, nil, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
 	serverKeyAPI := serverkeyapi.NewInternalAPI(
@@ -175,7 +174,6 @@ func main() {
 	monolith := setup.Monolith{
 		Config:        base.Base.Cfg,
 		AccountDB:     accountDB,
-		DeviceDB:      deviceDB,
 		Client:        createClient(base),
 		FedClient:     federation,
 		KeyRing:       keyRing,
diff --git a/cmd/dendrite-demo-yggdrasil/main.go b/cmd/dendrite-demo-yggdrasil/main.go
index e8745b3ec..26999ebed 100644
--- a/cmd/dendrite-demo-yggdrasil/main.go
+++ b/cmd/dendrite-demo-yggdrasil/main.go
@@ -94,14 +94,13 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 	federation := ygg.CreateFederationClient(base)
 
 	serverKeyAPI := &signing.YggdrasilKeys{}
 	keyRing := serverKeyAPI.KeyRing()
 
 	keyAPI := keyserver.NewInternalAPI(&base.Cfg.KeyServer, federation, base.KafkaProducer)
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, nil, keyAPI)
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, nil, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
 	rsComponent := roomserver.NewInternalAPI(
@@ -136,7 +135,6 @@ func main() {
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,
-		DeviceDB:      deviceDB,
 		Client:        ygg.CreateClient(base),
 		FedClient:     federation,
 		KeyRing:       keyRing,
diff --git a/cmd/dendrite-monolith-server/main.go b/cmd/dendrite-monolith-server/main.go
index e2d2de48c..815117463 100644
--- a/cmd/dendrite-monolith-server/main.go
+++ b/cmd/dendrite-monolith-server/main.go
@@ -69,7 +69,6 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 	federation := base.CreateFederationClient()
 
 	serverKeyAPI := serverkeyapi.NewInternalAPI(
@@ -110,7 +109,7 @@ func main() {
 	rsImpl.SetFederationSenderAPI(fsAPI)
 
 	keyAPI := keyserver.NewInternalAPI(&base.Cfg.KeyServer, fsAPI, base.KafkaProducer)
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, cfg.Derived.ApplicationServices, keyAPI)
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, cfg.Derived.ApplicationServices, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
 	eduInputAPI := eduserver.NewInternalAPI(
@@ -130,7 +129,6 @@ func main() {
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,
-		DeviceDB:      deviceDB,
 		Client:        gomatrixserverlib.NewClient(cfg.FederationSender.DisableTLSValidation),
 		FedClient:     federation,
 		KeyRing:       keyRing,
diff --git a/cmd/dendrite-user-api-server/main.go b/cmd/dendrite-user-api-server/main.go
index c21525e60..c8e2e2a37 100644
--- a/cmd/dendrite-user-api-server/main.go
+++ b/cmd/dendrite-user-api-server/main.go
@@ -25,9 +25,8 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, cfg.Derived.ApplicationServices, base.KeyServerHTTPClient())
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, cfg.Derived.ApplicationServices, base.KeyServerHTTPClient())
 
 	userapi.AddInternalRoutes(base.InternalAPIMux, userAPI)
 
diff --git a/cmd/dendritejs/main.go b/cmd/dendritejs/main.go
index ceb252d82..c95eb3fce 100644
--- a/cmd/dendritejs/main.go
+++ b/cmd/dendritejs/main.go
@@ -191,10 +191,9 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	accountDB := base.CreateAccountsDB()
-	deviceDB := base.CreateDeviceDB()
 	federation := createFederationClient(cfg, node)
 	keyAPI := keyserver.NewInternalAPI(&base.Cfg.KeyServer, federation, base.KafkaProducer)
-	userAPI := userapi.NewInternalAPI(accountDB, deviceDB, cfg.Global.ServerName, nil, keyAPI)
+	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, nil, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
 	fetcher := &libp2pKeyFetcher{}
@@ -218,7 +217,6 @@ func main() {
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,
-		DeviceDB:      deviceDB,
 		Client:        createClient(node),
 		FedClient:     federation,
 		KeyRing:       &keyRing,
diff --git a/dendrite-config.yaml b/dendrite-config.yaml
index e48035b58..23f142a83 100644
--- a/dendrite-config.yaml
+++ b/dendrite-config.yaml
@@ -302,6 +302,8 @@ user_api:
     conn_max_lifetime: -1
 
 # Configuration for Opentracing.
+# See https://github.com/matrix-org/dendrite/tree/master/docs/tracing for information on
+# how this works and how to set it up.
 tracing:
   enabled: false
   jaeger:
diff --git a/docs/tracing/jaeger.png b/docs/tracing/jaeger.png
new file mode 100644
index 000000000..8b1e61feb
Binary files /dev/null and b/docs/tracing/jaeger.png differ
diff --git a/docs/opentracing.md b/docs/tracing/opentracing.md
similarity index 100%
rename from docs/opentracing.md
rename to docs/tracing/opentracing.md
diff --git a/docs/tracing/setup.md b/docs/tracing/setup.md
new file mode 100644
index 000000000..2cab4d1ef
--- /dev/null
+++ b/docs/tracing/setup.md
@@ -0,0 +1,49 @@
+## OpenTracing Setup
+
+![Trace when sending an event into a room](/docs/tracing/jaeger.png)
+
+Dendrite uses [Jaeger](https://www.jaegertracing.io/) for tracing between microservices.
+Tracing shows the nesting of logical spans which provides visibility on how the microservices interact.
+This document explains how to set up Jaeger locally on a single machine.
+
+### Set up the Jaeger backend
+
+The [easiest way](https://www.jaegertracing.io/docs/1.18/getting-started/) is to use the all-in-one Docker image:
+```
+$ docker run -d --name jaeger \
+  -e COLLECTOR_ZIPKIN_HTTP_PORT=9411 \
+  -p 5775:5775/udp \
+  -p 6831:6831/udp \
+  -p 6832:6832/udp \
+  -p 5778:5778 \
+  -p 16686:16686 \
+  -p 14268:14268 \
+  -p 14250:14250 \
+  -p 9411:9411 \
+  jaegertracing/all-in-one:1.18
+```
+
+### Configuring Dendrite to talk to Jaeger
+
+Modify your config to look like: (this will send every single span to Jaeger which will be slow on large instances, but for local testing it's fine)
+```
+tracing:
+  enabled: true
+  jaeger:
+    serviceName: "dendrite"
+    disabled: false
+    rpc_metrics: true
+    tags: []
+    sampler:
+      type: const
+      param: 1
+```
+
+then run the monolith server with `--api true` to use polylith components which do tracing spans:
+```
+$ ./dendrite-monolith-server --tls-cert server.crt --tls-key server.key --config dendrite.yaml --api true
+```
+
+### Checking traces
+
+Visit http://localhost:16686 to see traces under `DendriteMonolith`.
diff --git a/federationsender/storage/shared/storage_edus.go b/federationsender/storage/shared/storage_edus.go
index 75a6dd51f..529b46aa9 100644
--- a/federationsender/storage/shared/storage_edus.go
+++ b/federationsender/storage/shared/storage_edus.go
@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -33,7 +32,7 @@ func (d *Database) AssociateEDUWithDestination(
 	serverName gomatrixserverlib.ServerName,
 	receipt *Receipt,
 ) error {
-	return sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		for _, nid := range receipt.nids {
 			if err := d.FederationSenderQueueEDUs.InsertQueueEDU(
 				ctx,        // context
@@ -60,7 +59,7 @@ func (d *Database) GetNextTransactionEDUs(
 	receipt *Receipt,
 	err error,
 ) {
-	err = sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		nids, err := d.FederationSenderQueueEDUs.SelectQueueEDUs(ctx, txn, serverName, limit)
 		if err != nil {
 			return fmt.Errorf("SelectQueueEDUs: %w", err)
@@ -99,7 +98,7 @@ func (d *Database) CleanEDUs(
 		return errors.New("expected receipt")
 	}
 
-	return sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		if err := d.FederationSenderQueueEDUs.DeleteQueueEDUs(ctx, txn, serverName, receipt.nids); err != nil {
 			return err
 		}
diff --git a/federationsender/storage/shared/storage_pdus.go b/federationsender/storage/shared/storage_pdus.go
index 005889561..9ab0b094c 100644
--- a/federationsender/storage/shared/storage_pdus.go
+++ b/federationsender/storage/shared/storage_pdus.go
@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -34,7 +33,7 @@ func (d *Database) AssociatePDUWithDestination(
 	serverName gomatrixserverlib.ServerName,
 	receipt *Receipt,
 ) error {
-	return sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		for _, nid := range receipt.nids {
 			if err := d.FederationSenderQueuePDUs.InsertQueuePDU(
 				ctx,           // context
@@ -62,7 +61,12 @@ func (d *Database) GetNextTransactionPDUs(
 	receipt *Receipt,
 	err error,
 ) {
-	err = sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	// Strictly speaking this doesn't need to be using the writer
+	// since we are only performing selects, but since we don't have
+	// a guarantee of transactional isolation, it's actually useful
+	// to know in SQLite mode that nothing else is trying to modify
+	// the database.
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		transactionID, err = d.FederationSenderQueuePDUs.SelectQueuePDUNextTransactionID(ctx, txn, serverName)
 		if err != nil {
 			return fmt.Errorf("SelectQueuePDUNextTransactionID: %w", err)
@@ -111,7 +115,7 @@ func (d *Database) CleanPDUs(
 		return errors.New("expected receipt")
 	}
 
-	return sqlutil.WithTransaction(d.DB, func(txn *sql.Tx) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		if err := d.FederationSenderQueuePDUs.DeleteQueuePDUs(ctx, txn, serverName, receipt.nids); err != nil {
 			return err
 		}
diff --git a/internal/setup/base.go b/internal/setup/base.go
index fc4083115..7bf06e748 100644
--- a/internal/setup/base.go
+++ b/internal/setup/base.go
@@ -32,7 +32,6 @@ import (
 
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
 
 	"github.com/Shopify/sarama"
 	"github.com/gorilla/mux"
@@ -237,17 +236,6 @@ func (b *BaseDendrite) KeyServerHTTPClient() keyserverAPI.KeyInternalAPI {
 	return f
 }
 
-// CreateDeviceDB creates a new instance of the device database. Should only be
-// called once per component.
-func (b *BaseDendrite) CreateDeviceDB() devices.Database {
-	db, err := devices.NewDatabase(&b.Cfg.UserAPI.DeviceDatabase, b.Cfg.Global.ServerName)
-	if err != nil {
-		logrus.WithError(err).Panicf("failed to connect to devices db")
-	}
-
-	return db
-}
-
 // CreateAccountsDB creates a new instance of the accounts database. Should only
 // be called once per component.
 func (b *BaseDendrite) CreateAccountsDB() accounts.Database {
diff --git a/internal/setup/monolith.go b/internal/setup/monolith.go
index 5e6c8fcfc..f79ebae45 100644
--- a/internal/setup/monolith.go
+++ b/internal/setup/monolith.go
@@ -33,7 +33,6 @@ import (
 	"github.com/matrix-org/dendrite/syncapi"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -41,7 +40,6 @@ import (
 // all components of Dendrite, for use in monolith mode.
 type Monolith struct {
 	Config        *config.Dendrite
-	DeviceDB      devices.Database
 	AccountDB     accounts.Database
 	KeyRing       *gomatrixserverlib.KeyRing
 	Client        *gomatrixserverlib.Client
@@ -65,7 +63,7 @@ type Monolith struct {
 // AddAllPublicRoutes attaches all public paths to the given router
 func (m *Monolith) AddAllPublicRoutes(csMux, ssMux, keyMux, mediaMux *mux.Router) {
 	clientapi.AddPublicRoutes(
-		csMux, &m.Config.ClientAPI, m.KafkaProducer, m.DeviceDB, m.AccountDB,
+		csMux, &m.Config.ClientAPI, m.KafkaProducer, m.AccountDB,
 		m.FedClient, m.RoomserverAPI,
 		m.EDUInternalAPI, m.AppserviceAPI, m.StateAPI, transactions.New(),
 		m.FederationSenderAPI, m.UserAPI, m.KeyAPI, m.ExtPublicRoomsProvider,
diff --git a/keyserver/internal/device_list_update.go b/keyserver/internal/device_list_update.go
index 3fbf31f1e..4d1b1107c 100644
--- a/keyserver/internal/device_list_update.go
+++ b/keyserver/internal/device_list_update.go
@@ -341,8 +341,12 @@ func (u *DeviceListUpdater) processServer(serverName gomatrixserverlib.ServerNam
 		if err != nil {
 			logger.WithError(err).WithField("user_id", userID).Error("failed to query device keys for user")
 			fcerr, ok := err.(*fedsenderapi.FederationClientError)
-			if ok && fcerr.RetryAfter > 0 {
-				waitTime = fcerr.RetryAfter
+			if ok {
+				if fcerr.RetryAfter > 0 {
+					waitTime = fcerr.RetryAfter
+				} else if fcerr.Blacklisted {
+					waitTime = time.Hour * 8
+				}
 			}
 			hasFailures = true
 			continue
diff --git a/mediaapi/fileutils/fileutils.go b/mediaapi/fileutils/fileutils.go
index 39687b9d4..92ce64001 100644
--- a/mediaapi/fileutils/fileutils.go
+++ b/mediaapi/fileutils/fileutils.go
@@ -16,6 +16,7 @@ package fileutils
 
 import (
 	"bufio"
+	"context"
 	"crypto/sha256"
 	"encoding/base64"
 	"fmt"
@@ -27,6 +28,7 @@ import (
 
 	"github.com/matrix-org/dendrite/internal/config"
 	"github.com/matrix-org/dendrite/mediaapi/types"
+	"github.com/matrix-org/util"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -104,18 +106,31 @@ func RemoveDir(dir types.Path, logger *log.Entry) {
 	}
 }
 
-// WriteTempFile writes to a new temporary file
-func WriteTempFile(reqReader io.Reader, maxFileSizeBytes config.FileSizeBytes, absBasePath config.Path) (hash types.Base64Hash, size types.FileSizeBytes, path types.Path, err error) {
+// WriteTempFile writes to a new temporary file.
+// The file is deleted if there was an error while writing.
+func WriteTempFile(
+	ctx context.Context, reqReader io.Reader, maxFileSizeBytes config.FileSizeBytes, absBasePath config.Path,
+) (hash types.Base64Hash, size types.FileSizeBytes, path types.Path, err error) {
 	size = -1
-
+	logger := util.GetLogger(ctx)
 	tmpFileWriter, tmpFile, tmpDir, err := createTempFileWriter(absBasePath)
 	if err != nil {
 		return
 	}
-	defer (func() { err = tmpFile.Close() })()
+	defer func() {
+		err2 := tmpFile.Close()
+		if err == nil {
+			err = err2
+		}
+	}()
 
-	// The amount of data read is limited to maxFileSizeBytes. At this point, if there is more data it will be truncated.
-	limitedReader := io.LimitReader(reqReader, int64(maxFileSizeBytes))
+	// If the max_file_size_bytes configuration option is set to a positive
+	// number then limit the upload to that size. Otherwise, just read the
+	// whole file.
+	limitedReader := reqReader
+	if maxFileSizeBytes > 0 {
+		limitedReader = io.LimitReader(reqReader, int64(maxFileSizeBytes))
+	}
 	// Hash the file data. The hash will be returned. The hash is useful as a
 	// method of deduplicating files to save storage, as well as a way to conduct
 	// integrity checks on the file data in the repository.
@@ -123,11 +138,13 @@ func WriteTempFile(reqReader io.Reader, maxFileSizeBytes config.FileSizeBytes, a
 	teeReader := io.TeeReader(limitedReader, hasher)
 	bytesWritten, err := io.Copy(tmpFileWriter, teeReader)
 	if err != nil && err != io.EOF {
+		RemoveDir(tmpDir, logger)
 		return
 	}
 
 	err = tmpFileWriter.Flush()
 	if err != nil {
+		RemoveDir(tmpDir, logger)
 		return
 	}
 
diff --git a/mediaapi/routing/download.go b/mediaapi/routing/download.go
index e61fa82b0..be0419048 100644
--- a/mediaapi/routing/download.go
+++ b/mediaapi/routing/download.go
@@ -728,12 +728,11 @@ func (r *downloadRequest) fetchRemoteFile(
 	// method of deduplicating files to save storage, as well as a way to conduct
 	// integrity checks on the file data in the repository.
 	// Data is truncated to maxFileSizeBytes. Content-Length was reported as 0 < Content-Length <= maxFileSizeBytes so this is OK.
-	hash, bytesWritten, tmpDir, err := fileutils.WriteTempFile(resp.Body, maxFileSizeBytes, absBasePath)
+	hash, bytesWritten, tmpDir, err := fileutils.WriteTempFile(ctx, resp.Body, maxFileSizeBytes, absBasePath)
 	if err != nil {
 		r.Logger.WithError(err).WithFields(log.Fields{
 			"MaxFileSizeBytes": maxFileSizeBytes,
 		}).Warn("Error while downloading file from remote server")
-		fileutils.RemoveDir(tmpDir, r.Logger)
 		return "", false, errors.New("file could not be downloaded from remote server")
 	}
 
diff --git a/mediaapi/routing/routing.go b/mediaapi/routing/routing.go
index 75f195cd3..4b6d2fd75 100644
--- a/mediaapi/routing/routing.go
+++ b/mediaapi/routing/routing.go
@@ -53,8 +53,8 @@ func Setup(
 
 	uploadHandler := httputil.MakeAuthAPI(
 		"upload", userAPI,
-		func(req *http.Request, _ *userapi.Device) util.JSONResponse {
-			return Upload(req, cfg, db, activeThumbnailGeneration)
+		func(req *http.Request, dev *userapi.Device) util.JSONResponse {
+			return Upload(req, cfg, dev, db, activeThumbnailGeneration)
 		},
 	)
 
diff --git a/mediaapi/routing/upload.go b/mediaapi/routing/upload.go
index b74d17323..1724ad255 100644
--- a/mediaapi/routing/upload.go
+++ b/mediaapi/routing/upload.go
@@ -31,6 +31,7 @@ import (
 	"github.com/matrix-org/dendrite/mediaapi/storage"
 	"github.com/matrix-org/dendrite/mediaapi/thumbnailer"
 	"github.com/matrix-org/dendrite/mediaapi/types"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	log "github.com/sirupsen/logrus"
@@ -55,8 +56,8 @@ type uploadResponse struct {
 // This implementation supports a configurable maximum file size limit in bytes. If a user tries to upload more than this, they will receive an error that their upload is too large.
 // Uploaded files are processed piece-wise to avoid DoS attacks which would starve the server of memory.
 // TODO: We should time out requests if they have not received any data within a configured timeout period.
-func Upload(req *http.Request, cfg *config.MediaAPI, db storage.Database, activeThumbnailGeneration *types.ActiveThumbnailGeneration) util.JSONResponse {
-	r, resErr := parseAndValidateRequest(req, cfg)
+func Upload(req *http.Request, cfg *config.MediaAPI, dev *userapi.Device, db storage.Database, activeThumbnailGeneration *types.ActiveThumbnailGeneration) util.JSONResponse {
+	r, resErr := parseAndValidateRequest(req, cfg, dev)
 	if resErr != nil {
 		return *resErr
 	}
@@ -76,13 +77,14 @@ func Upload(req *http.Request, cfg *config.MediaAPI, db storage.Database, active
 // parseAndValidateRequest parses the incoming upload request to validate and extract
 // all the metadata about the media being uploaded.
 // Returns either an uploadRequest or an error formatted as a util.JSONResponse
-func parseAndValidateRequest(req *http.Request, cfg *config.MediaAPI) (*uploadRequest, *util.JSONResponse) {
+func parseAndValidateRequest(req *http.Request, cfg *config.MediaAPI, dev *userapi.Device) (*uploadRequest, *util.JSONResponse) {
 	r := &uploadRequest{
 		MediaMetadata: &types.MediaMetadata{
 			Origin:        cfg.Matrix.ServerName,
 			FileSizeBytes: types.FileSizeBytes(req.ContentLength),
 			ContentType:   types.ContentType(req.Header.Get("Content-Type")),
 			UploadName:    types.Filename(url.PathEscape(req.FormValue("filename"))),
+			UserID:        types.MatrixUserID(dev.UserID),
 		},
 		Logger: util.GetLogger(req.Context()).WithField("Origin", cfg.Matrix.ServerName),
 	}
@@ -138,12 +140,18 @@ func (r *uploadRequest) doUpload(
 	// method of deduplicating files to save storage, as well as a way to conduct
 	// integrity checks on the file data in the repository.
 	// Data is truncated to maxFileSizeBytes. Content-Length was reported as 0 < Content-Length <= maxFileSizeBytes so this is OK.
-	hash, bytesWritten, tmpDir, err := fileutils.WriteTempFile(reqReader, *cfg.MaxFileSizeBytes, cfg.AbsBasePath)
+	//
+	// TODO: This has a bad API shape where you either need to call:
+	//   fileutils.RemoveDir(tmpDir, r.Logger)
+	// or call:
+	//   r.storeFileAndMetadata(ctx, tmpDir, ...)
+	// before you return from doUpload else we will leak a temp file. We could make this nicer with a `WithTransaction` style of
+	// nested function to guarantee either storage or cleanup.
+	hash, bytesWritten, tmpDir, err := fileutils.WriteTempFile(ctx, reqReader, *cfg.MaxFileSizeBytes, cfg.AbsBasePath)
 	if err != nil {
 		r.Logger.WithError(err).WithFields(log.Fields{
 			"MaxFileSizeBytes": *cfg.MaxFileSizeBytes,
 		}).Warn("Error while transferring file")
-		fileutils.RemoveDir(tmpDir, r.Logger)
 		return &util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: jsonerror.Unknown("Failed to upload"),
@@ -157,11 +165,14 @@ func (r *uploadRequest) doUpload(
 		ctx, hash, r.MediaMetadata.Origin,
 	)
 	if err != nil {
+		fileutils.RemoveDir(tmpDir, r.Logger)
 		r.Logger.WithError(err).Error("Error querying the database by hash.")
 		resErr := jsonerror.InternalServerError()
 		return &resErr
 	}
 	if existingMetadata != nil {
+		// The file already exists, delete the uploaded temporary file.
+		defer fileutils.RemoveDir(tmpDir, r.Logger)
 		// The file already exists. Make a new media ID up for it.
 		mediaID, merr := r.generateMediaID(ctx, db)
 		if merr != nil {
@@ -181,15 +192,13 @@ func (r *uploadRequest) doUpload(
 			Base64Hash:        hash,
 			UserID:            r.MediaMetadata.UserID,
 		}
-
-		// Clean up the uploaded temporary file.
-		fileutils.RemoveDir(tmpDir, r.Logger)
 	} else {
 		// The file doesn't exist. Update the request metadata.
 		r.MediaMetadata.FileSizeBytes = bytesWritten
 		r.MediaMetadata.Base64Hash = hash
 		r.MediaMetadata.MediaID, err = r.generateMediaID(ctx, db)
 		if err != nil {
+			fileutils.RemoveDir(tmpDir, r.Logger)
 			r.Logger.WithError(err).Error("Failed to generate media ID for new upload")
 			resErr := jsonerror.InternalServerError()
 			return &resErr
diff --git a/roomserver/internal/perform_join.go b/roomserver/internal/perform_join.go
index b92a6663b..3b9b1b3ca 100644
--- a/roomserver/internal/perform_join.go
+++ b/roomserver/internal/perform_join.go
@@ -161,8 +161,9 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 	// where we might think we know about a room in the following
 	// section but don't know the latest state as all of our users
 	// have left.
+	serverInRoom, _ := r.isServerCurrentlyInRoom(ctx, r.ServerName, req.RoomIDOrAlias)
 	isInvitePending, inviteSender, _, err := r.isInvitePending(ctx, req.RoomIDOrAlias, req.UserID)
-	if err == nil && isInvitePending {
+	if err == nil && isInvitePending && !serverInRoom {
 		// Check if there's an invite pending.
 		_, inviterDomain, ierr := gomatrixserverlib.SplitID('@', inviteSender)
 		if ierr != nil {
diff --git a/syncapi/storage/shared/syncserver.go b/syncapi/storage/shared/syncserver.go
index 6f7efefb7..257abf080 100644
--- a/syncapi/storage/shared/syncserver.go
+++ b/syncapi/storage/shared/syncserver.go
@@ -468,7 +468,7 @@ func (d *Database) addPDUDeltaToResponse(
 	wantFullState bool,
 	res *types.Response,
 ) (joinedRoomIDs []string, err error) {
-	txn, err := d.DB.BeginTx(ctx, &txReadOnlySnapshot)
+	txn, err := d.DB.BeginTx(context.TODO(), &txReadOnlySnapshot) // TODO: check mattn/go-sqlite3#764
 	if err != nil {
 		return nil, err
 	}
@@ -594,20 +594,23 @@ func (d *Database) IncrementalSync(
 		joinedRoomIDs, err = d.addPDUDeltaToResponse(
 			ctx, device, r, numRecentEventsPerRoom, wantFullState, res,
 		)
+		if err != nil {
+			return nil, fmt.Errorf("d.addPDUDeltaToResponse: %w", err)
+		}
 	} else {
 		joinedRoomIDs, err = d.CurrentRoomState.SelectRoomIDsWithMembership(
 			ctx, nil, device.UserID, gomatrixserverlib.Join,
 		)
-	}
-	if err != nil {
-		return nil, err
+		if err != nil {
+			return nil, fmt.Errorf("d.CurrentRoomState.SelectRoomIDsWithMembership: %w", err)
+		}
 	}
 
 	err = d.addEDUDeltaToResponse(
 		fromPos, toPos, joinedRoomIDs, res,
 	)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("d.addEDUDeltaToResponse: %w", err)
 	}
 
 	return res, nil
@@ -649,7 +652,7 @@ func (d *Database) getResponseWithPDUsForCompleteSync(
 	// a consistent view of the database throughout. This includes extracting the sync position.
 	// This does have the unfortunate side-effect that all the matrixy logic resides in this function,
 	// but it's better to not hide the fact that this is being done in a transaction.
-	txn, err := d.DB.BeginTx(ctx, &txReadOnlySnapshot)
+	txn, err := d.DB.BeginTx(context.TODO(), &txReadOnlySnapshot) // TODO: check mattn/go-sqlite3#764
 	if err != nil {
 		return
 	}
@@ -736,7 +739,7 @@ func (d *Database) CompleteSync(
 		ctx, res, device.UserID, numRecentEventsPerRoom,
 	)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("d.getResponseWithPDUsForCompleteSync: %w", err)
 	}
 
 	// Use a zero value SyncPosition for fromPos so all EDU states are added.
@@ -744,7 +747,7 @@ func (d *Database) CompleteSync(
 		types.NewStreamToken(0, 0, nil), toPos, joinedRoomIDs, res,
 	)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("d.addEDUDeltaToResponse: %w", err)
 	}
 
 	return res, nil
@@ -770,7 +773,7 @@ func (d *Database) addInvitesToResponse(
 		ctx, txn, userID, r,
 	)
 	if err != nil {
-		return err
+		return fmt.Errorf("d.Invites.SelectInviteEventsInRange: %w", err)
 	}
 	for roomID, inviteEvent := range invites {
 		ir := types.NewInviteResponse(inviteEvent)
diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 12c597bbe..357df240e 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -18,6 +18,7 @@ package sync
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"time"
 
@@ -204,31 +205,34 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.Strea
 	// See if we have any new tasks to do for the send-to-device messaging.
 	events, updates, deletions, err := rp.db.SendToDeviceUpdatesForSync(req.ctx, req.device.UserID, req.device.ID, since)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("rp.db.SendToDeviceUpdatesForSync: %w", err)
 	}
 
 	// TODO: handle ignored users
 	if req.since == nil {
 		res, err = rp.db.CompleteSync(req.ctx, res, req.device, req.limit)
+		if err != nil {
+			return res, fmt.Errorf("rp.db.CompleteSync: %w", err)
+		}
 	} else {
 		res, err = rp.db.IncrementalSync(req.ctx, res, req.device, *req.since, latestPos, req.limit, req.wantFullState)
-	}
-	if err != nil {
-		return res, err
+		if err != nil {
+			return res, fmt.Errorf("rp.db.IncrementalSync: %w", err)
+		}
 	}
 
 	accountDataFilter := gomatrixserverlib.DefaultEventFilter() // TODO: use filter provided in req instead
 	res, err = rp.appendAccountData(res, req.device.UserID, req, latestPos.PDUPosition(), &accountDataFilter)
 	if err != nil {
-		return res, err
+		return res, fmt.Errorf("rp.appendAccountData: %w", err)
 	}
 	res, err = rp.appendDeviceLists(res, req.device.UserID, since, latestPos)
 	if err != nil {
-		return res, err
+		return res, fmt.Errorf("rp.appendDeviceLists: %w", err)
 	}
 	err = internal.DeviceOTKCounts(req.ctx, rp.keyAPI, req.device.UserID, req.device.ID, res)
 	if err != nil {
-		return res, err
+		return res, fmt.Errorf("internal.DeviceOTKCounts: %w", err)
 	}
 
 	// Before we return the sync response, make sure that we take action on
@@ -238,7 +242,7 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.Strea
 		// Handle the updates and deletions in the database.
 		err = rp.db.CleanSendToDeviceUpdates(context.Background(), updates, deletions, since)
 		if err != nil {
-			return res, err
+			return res, fmt.Errorf("rp.db.CleanSendToDeviceUpdates: %w", err)
 		}
 	}
 	if len(events) > 0 {
@@ -263,7 +267,7 @@ func (rp *RequestPool) appendDeviceLists(
 ) (*types.Response, error) {
 	_, err := internal.DeviceListCatchup(context.Background(), rp.keyAPI, rp.stateAPI, userID, data, since, to)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("internal.DeviceListCatchup: %w", err)
 	}
 
 	return data, nil
@@ -329,7 +333,7 @@ func (rp *RequestPool) appendAccountData(
 		req.ctx, userID, r, accountDataFilter,
 	)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("rp.db.GetAccountDataInRange: %w", err)
 	}
 
 	if len(dataTypes) == 0 {
diff --git a/userapi/api/api.go b/userapi/api/api.go
index 84338dbf2..e6d05c335 100644
--- a/userapi/api/api.go
+++ b/userapi/api/api.go
@@ -61,7 +61,7 @@ type PerformDeviceUpdateResponse struct {
 
 type PerformDeviceDeletionRequest struct {
 	UserID string
-	// The devices to delete
+	// The devices to delete. An empty slice means delete all devices.
 	DeviceIDs []string
 }
 
@@ -192,8 +192,7 @@ type Device struct {
 	// The unique ID of the session identified by the access token.
 	// Can be used as a secure substitution in places where data needs to be
 	// associated with access tokens.
-	SessionID int64
-	// TODO: display name, last used timestamp, keys, etc
+	SessionID   int64
 	DisplayName string
 }
 
diff --git a/userapi/internal/api.go b/userapi/internal/api.go
index 05cecc1bc..b97f148e0 100644
--- a/userapi/internal/api.go
+++ b/userapi/internal/api.go
@@ -123,12 +123,21 @@ func (a *UserInternalAPI) PerformDeviceDeletion(ctx context.Context, req *api.Pe
 	if domain != a.ServerName {
 		return fmt.Errorf("cannot PerformDeviceDeletion of remote users: got %s want %s", domain, a.ServerName)
 	}
-	err = a.DeviceDB.RemoveDevices(ctx, local, req.DeviceIDs)
+	deletedDeviceIDs := req.DeviceIDs
+	if len(req.DeviceIDs) == 0 {
+		var devices []api.Device
+		devices, err = a.DeviceDB.RemoveAllDevices(ctx, local)
+		for _, d := range devices {
+			deletedDeviceIDs = append(deletedDeviceIDs, d.ID)
+		}
+	} else {
+		err = a.DeviceDB.RemoveDevices(ctx, local, req.DeviceIDs)
+	}
 	if err != nil {
 		return err
 	}
 	// create empty device keys and upload them to delete what was once there and trigger device list changes
-	return a.deviceListUpdate(req.UserID, req.DeviceIDs)
+	return a.deviceListUpdate(req.UserID, deletedDeviceIDs)
 }
 
 func (a *UserInternalAPI) deviceListUpdate(userID string, deviceIDs []string) error {
diff --git a/userapi/storage/devices/interface.go b/userapi/storage/devices/interface.go
index 3c9ec934a..9b4261c9d 100644
--- a/userapi/storage/devices/interface.go
+++ b/userapi/storage/devices/interface.go
@@ -35,5 +35,6 @@ type Database interface {
 	UpdateDevice(ctx context.Context, localpart, deviceID string, displayName *string) error
 	RemoveDevice(ctx context.Context, deviceID, localpart string) error
 	RemoveDevices(ctx context.Context, localpart string, devices []string) error
-	RemoveAllDevices(ctx context.Context, localpart string) error
+	// RemoveAllDevices deleted all devices for this user. Returns the devices deleted.
+	RemoveAllDevices(ctx context.Context, localpart string) (devices []api.Device, err error)
 }
diff --git a/userapi/storage/devices/postgres/devices_table.go b/userapi/storage/devices/postgres/devices_table.go
index 03bf7c722..282466f8d 100644
--- a/userapi/storage/devices/postgres/devices_table.go
+++ b/userapi/storage/devices/postgres/devices_table.go
@@ -251,11 +251,10 @@ func (s *devicesStatements) selectDevicesByID(ctx context.Context, deviceIDs []s
 }
 
 func (s *devicesStatements) selectDevicesByLocalpart(
-	ctx context.Context, localpart string,
+	ctx context.Context, txn *sql.Tx, localpart string,
 ) ([]api.Device, error) {
 	devices := []api.Device{}
-
-	rows, err := s.selectDevicesByLocalpartStmt.QueryContext(ctx, localpart)
+	rows, err := sqlutil.TxStmt(txn, s.selectDevicesByLocalpartStmt).QueryContext(ctx, localpart)
 
 	if err != nil {
 		return devices, err
diff --git a/userapi/storage/devices/postgres/storage.go b/userapi/storage/devices/postgres/storage.go
index 4a7c7f975..04dae9864 100644
--- a/userapi/storage/devices/postgres/storage.go
+++ b/userapi/storage/devices/postgres/storage.go
@@ -68,7 +68,7 @@ func (d *Database) GetDeviceByID(
 func (d *Database) GetDevicesByLocalpart(
 	ctx context.Context, localpart string,
 ) ([]api.Device, error) {
-	return d.devices.selectDevicesByLocalpart(ctx, localpart)
+	return d.devices.selectDevicesByLocalpart(ctx, nil, localpart)
 }
 
 func (d *Database) GetDevicesByID(ctx context.Context, deviceIDs []string) ([]api.Device, error) {
@@ -176,11 +176,16 @@ func (d *Database) RemoveDevices(
 // If something went wrong during the deletion, it will return the SQL error.
 func (d *Database) RemoveAllDevices(
 	ctx context.Context, localpart string,
-) error {
-	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+) (devices []api.Device, err error) {
+	err = sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+		devices, err = d.devices.selectDevicesByLocalpart(ctx, txn, localpart)
+		if err != nil {
+			return err
+		}
 		if err := d.devices.deleteDevicesByLocalpart(ctx, txn, localpart); err != sql.ErrNoRows {
 			return err
 		}
 		return nil
 	})
+	return
 }
diff --git a/userapi/storage/devices/sqlite3/devices_table.go b/userapi/storage/devices/sqlite3/devices_table.go
index c93e8b772..ecf43524a 100644
--- a/userapi/storage/devices/sqlite3/devices_table.go
+++ b/userapi/storage/devices/sqlite3/devices_table.go
@@ -231,11 +231,10 @@ func (s *devicesStatements) selectDeviceByID(
 }
 
 func (s *devicesStatements) selectDevicesByLocalpart(
-	ctx context.Context, localpart string,
+	ctx context.Context, txn *sql.Tx, localpart string,
 ) ([]api.Device, error) {
 	devices := []api.Device{}
-
-	rows, err := s.selectDevicesByLocalpartStmt.QueryContext(ctx, localpart)
+	rows, err := sqlutil.TxStmt(txn, s.selectDevicesByLocalpartStmt).QueryContext(ctx, localpart)
 
 	if err != nil {
 		return devices, err
diff --git a/userapi/storage/devices/sqlite3/storage.go b/userapi/storage/devices/sqlite3/storage.go
index 4f426c6ed..f775fb664 100644
--- a/userapi/storage/devices/sqlite3/storage.go
+++ b/userapi/storage/devices/sqlite3/storage.go
@@ -72,7 +72,7 @@ func (d *Database) GetDeviceByID(
 func (d *Database) GetDevicesByLocalpart(
 	ctx context.Context, localpart string,
 ) ([]api.Device, error) {
-	return d.devices.selectDevicesByLocalpart(ctx, localpart)
+	return d.devices.selectDevicesByLocalpart(ctx, nil, localpart)
 }
 
 func (d *Database) GetDevicesByID(ctx context.Context, deviceIDs []string) ([]api.Device, error) {
@@ -180,11 +180,16 @@ func (d *Database) RemoveDevices(
 // If something went wrong during the deletion, it will return the SQL error.
 func (d *Database) RemoveAllDevices(
 	ctx context.Context, localpart string,
-) error {
-	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
+) (devices []api.Device, err error) {
+	err = d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
+		devices, err = d.devices.selectDevicesByLocalpart(ctx, txn, localpart)
+		if err != nil {
+			return err
+		}
 		if err := d.devices.deleteDevicesByLocalpart(ctx, txn, localpart); err != sql.ErrNoRows {
 			return err
 		}
 		return nil
 	})
+	return
 }
diff --git a/userapi/userapi.go b/userapi/userapi.go
index c4ab90bac..132491429 100644
--- a/userapi/userapi.go
+++ b/userapi/userapi.go
@@ -23,7 +23,7 @@ import (
 	"github.com/matrix-org/dendrite/userapi/inthttp"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
 	"github.com/matrix-org/dendrite/userapi/storage/devices"
-	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 )
 
 // AddInternalRoutes registers HTTP handlers for the internal API. Invokes functions
@@ -34,13 +34,19 @@ func AddInternalRoutes(router *mux.Router, intAPI api.UserInternalAPI) {
 
 // NewInternalAPI returns a concerete implementation of the internal API. Callers
 // can call functions directly on the returned API or via an HTTP interface using AddInternalRoutes.
-func NewInternalAPI(accountDB accounts.Database, deviceDB devices.Database,
-	serverName gomatrixserverlib.ServerName, appServices []config.ApplicationService, keyAPI keyapi.KeyInternalAPI) api.UserInternalAPI {
+func NewInternalAPI(
+	accountDB accounts.Database, cfg *config.UserAPI, appServices []config.ApplicationService, keyAPI keyapi.KeyInternalAPI,
+) api.UserInternalAPI {
+
+	deviceDB, err := devices.NewDatabase(&cfg.DeviceDatabase, cfg.Matrix.ServerName)
+	if err != nil {
+		logrus.WithError(err).Panicf("failed to connect to device db")
+	}
 
 	return &internal.UserInternalAPI{
 		AccountDB:   accountDB,
 		DeviceDB:    deviceDB,
-		ServerName:  serverName,
+		ServerName:  cfg.Matrix.ServerName,
 		AppServices: appServices,
 		KeyAPI:      keyAPI,
 	}
diff --git a/userapi/userapi_test.go b/userapi/userapi_test.go
index 548148f27..3fc97d06a 100644
--- a/userapi/userapi_test.go
+++ b/userapi/userapi_test.go
@@ -15,7 +15,6 @@ import (
 	"github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/inthttp"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
-	"github.com/matrix-org/dendrite/userapi/storage/devices"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -23,27 +22,31 @@ const (
 	serverName = gomatrixserverlib.ServerName("example.com")
 )
 
-func MustMakeInternalAPI(t *testing.T) (api.UserInternalAPI, accounts.Database, devices.Database) {
+func MustMakeInternalAPI(t *testing.T) (api.UserInternalAPI, accounts.Database) {
 	accountDB, err := accounts.NewDatabase(&config.DatabaseOptions{
 		ConnectionString: "file::memory:",
 	}, serverName)
 	if err != nil {
 		t.Fatalf("failed to create account DB: %s", err)
 	}
-	deviceDB, err := devices.NewDatabase(&config.DatabaseOptions{
-		ConnectionString: "file::memory:",
-	}, serverName)
-	if err != nil {
-		t.Fatalf("failed to create device DB: %s", err)
+	cfg := &config.UserAPI{
+		DeviceDatabase: config.DatabaseOptions{
+			ConnectionString:   "file::memory:",
+			MaxOpenConnections: 1,
+			MaxIdleConnections: 1,
+		},
+		Matrix: &config.Global{
+			ServerName: serverName,
+		},
 	}
 
-	return userapi.NewInternalAPI(accountDB, deviceDB, serverName, nil, nil), accountDB, deviceDB
+	return userapi.NewInternalAPI(accountDB, cfg, nil, nil), accountDB
 }
 
 func TestQueryProfile(t *testing.T) {
 	aliceAvatarURL := "mxc://example.com/alice"
 	aliceDisplayName := "Alice"
-	userAPI, accountDB, _ := MustMakeInternalAPI(t)
+	userAPI, accountDB := MustMakeInternalAPI(t)
 	_, err := accountDB.CreateAccount(context.TODO(), "alice", "foobar", "")
 	if err != nil {
 		t.Fatalf("failed to make account: %s", err)