fix(cache): reduce tx cache retention (#3299)

Author: julienrbrt

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changes
 
 - Optimization of mutex usage in cache for reaper [#3286](https://github.com/evstack/ev-node/pull/3286)
+- Reduce tx cache retention to avoid OOM under (really) heavy tx load [#3299](https://github.com/evstack/ev-node/pull/3299)
 
 ## v1.1.1
 

block/internal/cache/manager.go

@@ -25,23 +25,8 @@ const (
 	// DataDAIncludedPrefix is the store key prefix for data DA inclusion tracking.
 	DataDAIncludedPrefix = "cache/data-da-included/"
 
-	// DefaultTxCacheRetention is how long tx hashes stay in the
-	// seen-tx cache before CleanupOldTxs evicts them.
-	//
-	// HACK(fiber-throughput): dropped from 24h to 30s while we chase
-	// throughput, but the previous default was itself wrong: 24h is
-	// retention × tps in memory, so any rollup with meaningful TPS
-	// would OOM (we hit ~16 GB in under a minute at ~1.5M tx/s).
-	// What this should be properly:
-	//   - Bounded by entry count, not wall time. The dedup window
-	//     should be "the last N txs we saw", LRU-evicted, so cache
-	//     memory is fixed regardless of throughput.
-	//   - Or expressed in DA blocks: "drop hashes once their txs
-	//     would have been retried out of the mempool", which is a
-	//     property of mempool TTL × DA block time, not 24 hours.
-	//   - 30s is a fine measurement default and a reasonable upper
-	//     bound for pretty much any rollup; pick the right number
-	//     when the cache structure itself is reworked.
+	// DefaultTxCacheRetention is the default time to keep transaction hashes in cache.
+	// Keeping a too high value can lead to OOM during heavy transaction load.
 	DefaultTxCacheRetention = 30 * time.Second
 )
 

block/internal/reaping/reaper.go

@@ -24,18 +24,7 @@ const (
 
 	// CleanupInterval is how often the reaper sweeps expired hashes
 	// out of the seen-tx cache.
-	//
-	// HACK(fiber-throughput): dropped from 1h to 5s. The original
-	// 1h was effectively coupled to the previous 24h retention —
-	// sweeping every hour against a 24h window means a cache entry
-	// can outlive its retention by 1h, which is fine when retention
-	// is a day but completely breaks at 30s retention (entries
-	// would survive 12× past expiry). Whatever the right retention
-	// turns out to be (see DefaultTxCacheRetention's note in
-	// cache/manager.go), this value should be a small fraction of
-	// it — not a fixed time. Better to derive: e.g.
-	// retention/10 with a sane min/max.
-	CleanupInterval = 5 * time.Second
+	CleanupInterval = max(cache.DefaultTxCacheRetention/10, 5*time.Second)
 )
 
 // Reaper is responsible for periodically retrieving transactions from the executor,