dendrite/setup/jetstream/nats.go
Neil Alexander ad6b902b84
Refactor appservices component (#2687)
This PR refactors the app services component. It makes the following changes:

* Each appservice now gets its own NATS JetStream consumer
* The appservice database is now removed entirely, since we just use JetStream as a data source instead
* The entire component is now much simpler and we deleted lots of lines of code 💅

The result is that it should be much lighter and hopefully much more performant.
2022-09-01 09:20:40 +01:00

203 lines
6.7 KiB
Go

package jetstream
import (
"crypto/tls"
"fmt"
"reflect"
"strings"
"sync"
"time"
"github.com/getsentry/sentry-go"
"github.com/matrix-org/dendrite/setup/config"
"github.com/matrix-org/dendrite/setup/process"
"github.com/sirupsen/logrus"
natsserver "github.com/nats-io/nats-server/v2/server"
natsclient "github.com/nats-io/nats.go"
)
type NATSInstance struct {
*natsserver.Server
}
var natsLock sync.Mutex
func DeleteAllStreams(js natsclient.JetStreamContext, cfg *config.JetStream) {
for _, stream := range streams { // streams are defined in streams.go
name := cfg.Prefixed(stream.Name)
_ = js.DeleteStream(name)
}
}
func (s *NATSInstance) Prepare(process *process.ProcessContext, cfg *config.JetStream) (natsclient.JetStreamContext, *natsclient.Conn) {
natsLock.Lock()
defer natsLock.Unlock()
// check if we need an in-process NATS Server
if len(cfg.Addresses) != 0 {
return setupNATS(process, cfg, nil)
}
if s.Server == nil {
var err error
s.Server, err = natsserver.NewServer(&natsserver.Options{
ServerName: "monolith",
DontListen: true,
JetStream: true,
StoreDir: string(cfg.StoragePath),
NoSystemAccount: true,
MaxPayload: 16 * 1024 * 1024,
NoSigs: true,
NoLog: cfg.NoLog,
})
if err != nil {
panic(err)
}
s.ConfigureLogger()
go func() {
process.ComponentStarted()
s.Start()
}()
go func() {
<-process.WaitForShutdown()
s.Shutdown()
s.WaitForShutdown()
process.ComponentFinished()
}()
}
if !s.ReadyForConnections(time.Second * 10) {
logrus.Fatalln("NATS did not start in time")
}
nc, err := natsclient.Connect("", natsclient.InProcessServer(s))
if err != nil {
logrus.Fatalln("Failed to create NATS client")
}
return setupNATS(process, cfg, nc)
}
func setupNATS(process *process.ProcessContext, cfg *config.JetStream, nc *natsclient.Conn) (natsclient.JetStreamContext, *natsclient.Conn) {
if nc == nil {
var err error
opts := []natsclient.Option{}
if cfg.DisableTLSValidation {
opts = append(opts, natsclient.Secure(&tls.Config{
InsecureSkipVerify: true,
}))
}
nc, err = natsclient.Connect(strings.Join(cfg.Addresses, ","), opts...)
if err != nil {
logrus.WithError(err).Panic("Unable to connect to NATS")
return nil, nil
}
}
s, err := nc.JetStream()
if err != nil {
logrus.WithError(err).Panic("Unable to get JetStream context")
return nil, nil
}
for _, stream := range streams { // streams are defined in streams.go
name := cfg.Prefixed(stream.Name)
info, err := s.StreamInfo(name)
if err != nil && err != natsclient.ErrStreamNotFound {
logrus.WithError(err).Fatal("Unable to get stream info")
}
subjects := stream.Subjects
if len(subjects) == 0 {
// By default we want each stream to listen for the subjects
// that are either an exact match for the stream name, or where
// the first part of the subject is the stream name. ">" is a
// wildcard in NATS for one or more subject tokens. In the case
// that the stream is called "Foo", this will match any message
// with the subject "Foo", "Foo.Bar" or "Foo.Bar.Baz" etc.
subjects = []string{name, name + ".>"}
}
if info != nil {
switch {
case !reflect.DeepEqual(info.Config.Subjects, subjects):
fallthrough
case info.Config.Retention != stream.Retention:
fallthrough
case info.Config.Storage != stream.Storage:
if err = s.DeleteStream(name); err != nil {
logrus.WithError(err).Fatal("Unable to delete stream")
}
info = nil
}
}
if info == nil {
// If we're trying to keep everything in memory (e.g. unit tests)
// then overwrite the storage policy.
if cfg.InMemory {
stream.Storage = natsclient.MemoryStorage
}
// Namespace the streams without modifying the original streams
// array, otherwise we end up with namespaces on namespaces.
namespaced := *stream
namespaced.Name = name
namespaced.Subjects = subjects
if _, err = s.AddStream(&namespaced); err != nil {
logger := logrus.WithError(err).WithFields(logrus.Fields{
"stream": namespaced.Name,
"subjects": namespaced.Subjects,
})
// If the stream was supposed to be in-memory to begin with
// then an error here is fatal so we'll give up.
if namespaced.Storage == natsclient.MemoryStorage {
logger.WithError(err).Fatal("Unable to add in-memory stream")
}
// The stream was supposed to be on disk. Let's try starting
// Dendrite with the stream in-memory instead. That'll mean that
// we can't recover anything that was queued on the disk but we
// will still be able to start and run hopefully in the meantime.
logger.WithError(err).Error("Unable to add stream")
sentry.CaptureException(fmt.Errorf("Unable to add stream %q: %w", namespaced.Name, err))
namespaced.Storage = natsclient.MemoryStorage
if _, err = s.AddStream(&namespaced); err != nil {
// We tried to add the stream in-memory instead but something
// went wrong. That's an unrecoverable situation so we will
// give up at this point.
logger.WithError(err).Fatal("Unable to add in-memory stream")
}
if stream.Storage != namespaced.Storage {
// We've managed to add the stream in memory. What's on the
// disk will be left alone, but our ability to recover from a
// future crash will be limited. Yell about it.
sentry.CaptureException(fmt.Errorf("Stream %q is running in-memory; this may be due to data corruption in the JetStream storage directory, investigate as soon as possible", namespaced.Name))
logrus.Warn("Stream is running in-memory; this may be due to data corruption in the JetStream storage directory, investigate as soon as possible")
process.Degraded()
}
}
}
}
// Clean up old consumers so that interest-based consumers do the
// right thing.
for stream, consumers := range map[string][]string{
OutputClientData: {"SyncAPIClientAPIConsumer"},
OutputReceiptEvent: {"SyncAPIEDUServerReceiptConsumer", "FederationAPIEDUServerConsumer"},
OutputSendToDeviceEvent: {"SyncAPIEDUServerSendToDeviceConsumer", "FederationAPIEDUServerConsumer"},
OutputTypingEvent: {"SyncAPIEDUServerTypingConsumer", "FederationAPIEDUServerConsumer"},
OutputRoomEvent: {"AppserviceRoomserverConsumer"},
} {
streamName := cfg.Matrix.JetStream.Prefixed(stream)
for _, consumer := range consumers {
consumerName := cfg.Matrix.JetStream.Prefixed(consumer) + "Pull"
consumerInfo, err := s.ConsumerInfo(streamName, consumerName)
if err != nil || consumerInfo == nil {
continue
}
if err = s.DeleteConsumer(streamName, consumerName); err != nil {
logrus.WithError(err).Errorf("Unable to clean up old consumer %q for stream %q", consumer, stream)
}
}
}
return s, nc
}