From 68bd8745ee70627878796ad7ada10344201bc3b7 Mon Sep 17 00:00:00 2001
From: Steven Landers <steven.landers@gmail.com>
Date: Mon, 29 Jan 2024 17:24:10 -0500
Subject: [PATCH] add logging for expired txs

---
 internal/mempool/mempool.go | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/internal/mempool/mempool.go b/internal/mempool/mempool.go
index 612a0bc48..820e46593 100644
--- a/internal/mempool/mempool.go
+++ b/internal/mempool/mempool.go
@@ -848,6 +848,7 @@ func (txmp *TxMempool) removeTx(wtx *WrappedTx, removeFromCache bool) {
 
 	// Remove the transaction from the gossip index and cleanup the linked-list
 	// element so it can be garbage collected.
+
 	txmp.gossipIndex.Remove(wtx.gossipEl)
 	wtx.gossipEl.DetachPrev()
 
@@ -856,6 +857,32 @@ func (txmp *TxMempool) removeTx(wtx *WrappedTx, removeFromCache bool) {
 	wtx.removeHandler(removeFromCache)
 }
 
+func (txmp *TxMempool) expire(blockHeight int64, wtx *WrappedTx) {
+	txmp.metrics.ExpiredTxs.Add(1)
+	txmp.logExpiredTx(blockHeight, wtx)
+	wtx.removeHandler(!txmp.config.KeepInvalidTxsInCache)
+}
+
+func (txmp *TxMempool) logExpiredTx(blockHeight int64, wtx *WrappedTx) {
+	// defensive check
+	if wtx == nil {
+		return
+	}
+
+	txmp.logger.Info(
+		"transaction expired",
+		"priority", wtx.priority,
+		"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
+		"address", wtx.evmAddress,
+		"evm", wtx.isEVM,
+		"nonce", wtx.evmNonce,
+		"height", blockHeight,
+		"tx_height", wtx.height,
+		"tx_timestamp", wtx.timestamp,
+		"age", time.Since(wtx.timestamp),
+	)
+}
+
 // purgeExpiredTxs removes all transactions that have exceeded their respective
 // height- and/or time-based TTLs from their respective indexes. Every expired
 // transaction will be removed from the mempool, but preserved in the cache (except for pending txs).
@@ -902,14 +929,12 @@ func (txmp *TxMempool) purgeExpiredTxs(blockHeight int64) {
 	}
 
 	for _, wtx := range expiredTxs {
-		txmp.metrics.ExpiredTxs.Add(1)
-		txmp.removeTx(wtx, !txmp.config.KeepInvalidTxsInCache)
+		txmp.expire(blockHeight, wtx)
 	}
 
 	// remove pending txs that have expired
 	txmp.pendingTxs.PurgeExpired(txmp.config.TTLNumBlocks, blockHeight, txmp.config.TTLDuration, now, func(wtx *WrappedTx) {
-		txmp.metrics.ExpiredTxs.Add(1)
-		wtx.removeHandler(!txmp.config.KeepInvalidTxsInCache)
+		txmp.expire(blockHeight, wtx)
 	})
 }