Accumulated changes for message queue (#6600)

* rename

* set agent address

* refactor

* add agent sub

* pub messages

* grpc new client

* can publish records via agent

* send init message with session id

* fmt

* check cancelled request while waiting

* use sessionId

* handle possible nil stream

* subscriber process messages

* separate debug port

* use atomic int64

* less logs

* minor

* skip io.EOF

* rename

* remove unused

* use saved offsets

* do not reuse session, since always session id is new after restart

remove last active ts from SessionEntry

* simplify printing

* purge unused

* just proxy the subscription, skipping the session step

* adjust offset types

* subscribe offset type and possible value

* start after the known tsns

* avoid wrongly set startPosition

* move

* remove

* refactor

* typo

* fix

* fix changed path

weed/mq/agent/agent_grpc_pub_session.go

@@ -7,13 +7,12 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/pb/mq_agent_pb"
 	"log/slog"
 	"math/rand/v2"
-	"time"
 )
 
 func (a *MessageQueueAgent) StartPublishSession(ctx context.Context, req *mq_agent_pb.StartPublishSessionRequest) (*mq_agent_pb.StartPublishSessionResponse, error) {
 	sessionId := rand.Int64()
 
-	topicPublisher := pub_client.NewTopicPublisher(
+	topicPublisher, err := pub_client.NewTopicPublisher(
 		&pub_client.PublisherConfiguration{
 			Topic:          topic.NewTopic(req.Topic.Namespace, req.Topic.Name),
 			PartitionCount: req.PartitionCount,
@@ -21,18 +20,11 @@ func (a *MessageQueueAgent) StartPublishSession(ctx context.Context, req *mq_age
 			PublisherName:  req.PublisherName,
 			RecordType:     req.RecordType,
 		})
+	if err != nil {
+		return nil, err
+	}
 
 	a.publishersLock.Lock()
-	// remove inactive publishers to avoid memory leak
-	for k, entry := range a.publishers {
-		if entry.lastActiveTsNs == 0 {
-			// this is an active session
-			continue
-		}
-		if time.Unix(0, entry.lastActiveTsNs).Add(10 * time.Hour).Before(time.Now()) {
-			delete(a.publishers, k)
-		}
-	}
 	a.publishers[SessionId(sessionId)] = &SessionEntry[*pub_client.TopicPublisher]{
 		entry: topicPublisher,
 	}