services/horizon: Remove Horizon Submission Queue

services/horizon/internal/httpx/server.go

@@ -15,7 +15,6 @@ import (
 	"github.com/stellar/go/services/horizon/internal/ledger"
 	hProblem "github.com/stellar/go/services/horizon/internal/render/problem"
 	"github.com/stellar/go/services/horizon/internal/render/sse"
-	"github.com/stellar/go/services/horizon/internal/txsub/sequence"
 	"github.com/stellar/go/support/db"
 	"github.com/stellar/go/support/log"
 	"github.com/stellar/go/support/render/problem"
@@ -49,7 +48,6 @@ func init() {
 	// register problems
 	problem.SetLogFilter(problem.LogUnknownErrors)
 	problem.RegisterError(sql.ErrNoRows, problem.NotFound)
-	problem.RegisterError(sequence.ErrNoMoreRoom, hProblem.ServerOverCapacity)
 	problem.RegisterError(db2.ErrInvalidCursor, problem.BadRequest)
 	problem.RegisterError(db2.ErrInvalidLimit, problem.BadRequest)
 	problem.RegisterError(db2.ErrInvalidOrder, problem.BadRequest)

services/horizon/internal/init.go

@@ -14,7 +14,6 @@ import (
 	"github.com/stellar/go/services/horizon/internal/paths"
 	"github.com/stellar/go/services/horizon/internal/simplepath"
 	"github.com/stellar/go/services/horizon/internal/txsub"
-	"github.com/stellar/go/services/horizon/internal/txsub/sequence"
 	"github.com/stellar/go/support/db"
 	"github.com/stellar/go/support/log"
 )
@@ -239,9 +238,8 @@ func initWebMetrics(app *App) {
 
 func initSubmissionSystem(app *App) {
 	app.submitter = &txsub.System{
-		Pending:         txsub.NewDefaultSubmissionList(),
-		Submitter:       txsub.NewDefaultSubmitter(http.DefaultClient, app.config.StellarCoreURL),
-		SubmissionQueue: sequence.NewManager(),
+		Pending:   txsub.NewDefaultSubmissionList(),
+		Submitter: txsub.NewDefaultSubmitter(http.DefaultClient, app.config.StellarCoreURL),
 		DB: func(ctx context.Context) txsub.HorizonDB {
 			return &history.Q{SessionInterface: app.HorizonSession()}
 		},