Disable txpool if SequencerUrl is set

src/Nethermind/Nethermind.Optimism/Rpc/RegisterOptimismRpcModules.cs

@@ -54,6 +54,11 @@ protected override void RegisterEthRpcModule(IRpcModuleProvider rpcModuleProvide
             _logger.Warn($"SequencerUrl is not set. Nethermind will behave as a Sequencer");
         }
 
+        if (_config.SequencerUrl is not null)
+        {
+            _api.TxPool.Disable();
+        }
+
         BasicJsonRpcClient? sequencerJsonRpcClient = _config.SequencerUrl is null
             ? null
             : new(new Uri(_config.SequencerUrl), _api.EthereumJsonSerializer, _api.LogManager);

src/Nethermind/Nethermind.TxPool/ITxPool.cs

@@ -49,6 +49,8 @@ bool TryGetBlobAndProof(byte[] blobVersionedHash,
             [NotNullWhen(true)] out byte[]? blob,
             [NotNullWhen(true)] out byte[]? proof);
         UInt256 GetLatestPendingNonce(Address address);
+        void Disable();
+
         event EventHandler<TxEventArgs> NewDiscovered;
         event EventHandler<TxEventArgs> NewPending;
         event EventHandler<TxEventArgs> RemovedPending;

src/Nethermind/Nethermind.TxPool/NullTxPool.cs

@@ -73,6 +73,7 @@ public bool TryGetBlobAndProof(byte[] blobVersionedHash,
 
         public UInt256 GetLatestPendingNonce(Address address) => 0;
 
+        public void Disable() { }
 
         public event EventHandler<TxEventArgs> NewDiscovered
         {

src/Nethermind/Nethermind.TxPool/TxPool.cs

@@ -66,7 +66,7 @@ public class TxPool : ITxPool, IDisposable
         /// </summary>
         private ulong _txIndex;
 
-        private readonly ITimer? _timer;
+        private ITimer? _timer;
         private Transaction[]? _transactionSnapshot;
         private Transaction[]? _blobTransactionSnapshot;
         private long _lastBlockNumber = -1;
@@ -369,7 +369,7 @@ private bool RemoveIncludedTransaction(Transaction tx)
 
         public void AddPeer(ITxPoolPeer peer)
         {
-            if (_broadcaster.AddPeer(peer))
+            if (!_disabled && _broadcaster.AddPeer(peer))
             {
                 if (_logger.IsTrace) _logger.Trace($"Added a peer to TX pool: {peer}");
 
@@ -399,6 +399,8 @@ public void RemovePeer(PublicKey nodeId)
 
         public AcceptTxResult SubmitTx(Transaction tx, TxHandlingOptions handlingOptions)
         {
+            if (_disabled) return AcceptTxResult.AlreadyKnown;
+
             Metrics.PendingTransactionsReceived++;
 
             // assign a sequence number to transaction so we can order them by arrival times when
@@ -752,11 +754,21 @@ public UInt256 GetLatestPendingNonce(Address address)
 
         public void Dispose()
         {
-            _timer?.Dispose();
-            TxPoolHeadChanged -= _broadcaster.OnNewHead;
-            _broadcaster.Dispose();
-            _headInfo.HeadChanged -= OnHeadChange;
-            _headBlocksChannel.Writer.Complete();
+            if (!_disabled)
+            {
+                _timer?.Dispose();
+                TxPoolHeadChanged -= _broadcaster.OnNewHead;
+                _broadcaster.Dispose();
+                _headInfo.HeadChanged -= OnHeadChange;
+                _headBlocksChannel.Writer.Complete();
+            }
+        }
+
+        private bool _disabled = false;
+        void ITxPool.Disable()
+        {
+            Dispose();
+            _disabled = true;
         }
 
         /// <summary>