update buffer size (stellar#948)

cmd/soroban-rpc/internal/jsonrpc.go

@@ -25,6 +25,11 @@ import (
 	"github.com/stellar/soroban-tools/cmd/soroban-rpc/internal/transactions"
 )
 
+// maxHTTPRequestSize defines the largest request size that the http handler
+// would be willing to accept before dropping the request. The implementation
+// uses the default MaxBytesHandler to limit the request size.
+const maxHTTPRequestSize = 512 * 1024 // half a megabyte
+
 // Handler is the HTTP handler which serves the Soroban JSON RPC responses
 type Handler struct {
 	bridge jhttp.Bridge
@@ -275,8 +280,7 @@ func NewJSONRPCHandler(cfg *config.Config, params HandlerParams) Handler {
 		globalQueueRequestExecutionDurationLimitCounter,
 		params.Logger)
 
-	// Limit request sizes to 10MB
-	handler = http.MaxBytesHandler(handler, 1024*1024*10)
+	handler = http.MaxBytesHandler(handler, maxHTTPRequestSize)
 
 	corsMiddleware := cors.New(cors.Options{
 		AllowedOrigins: []string{"*"},