Add random jitter to cache

This will help smooth out some of the cyclical load
DreamExposure · Apr 7, 2024 · 84fa396 · 84fa396
1 parent bfdf9b2
commit 84fa396
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Showing 3 changed files with 7 additions and 4 deletions.
diff --git a/core/src/main/kotlin/org/dreamexposure/discal/core/cache/CacheRepository.kt b/core/src/main/kotlin/org/dreamexposure/discal/core/cache/CacheRepository.kt
@@ -2,10 +2,13 @@ package org.dreamexposure.discal.core.cache
 
 import discord4j.common.util.Snowflake
 import java.time.Duration
+import kotlin.random.Random
 
 interface CacheRepository<K, V> {
     val ttl: Duration
         get() = Duration.ofMinutes(60)
+    val ttlWithJitter: Duration
+        get() = ttl.plusSeconds(Random.Default.nextLong(-333,333))
 
     // Write
     suspend fun put(guildId: Snowflake? = null, key: K, value: V)

diff --git a/core/src/main/kotlin/org/dreamexposure/discal/core/cache/JdkCacheRepository.kt b/core/src/main/kotlin/org/dreamexposure/discal/core/cache/JdkCacheRepository.kt
@@ -19,14 +19,14 @@ class JdkCacheRepository<K : Any, V>(override val ttl: Duration) : CacheReposito
     override suspend fun put(guildId: Snowflake?, key: K, value: V) {
         val guildedMap = getGuildedCache(guildId)
 
-        guildedMap[key] = Pair(Instant.now().plus(ttl), value)
+        guildedMap[key] = Pair(Instant.now().plus(ttlWithJitter), value)
         cache[guildId] = guildedMap
     }
 
     override suspend fun putMany(guildId: Snowflake?, values: Map<K, V>) {
         val guildedMap = getGuildedCache(guildId)
 
-        guildedMap.putAll(values.mapValues { Pair(Instant.now().plus(ttl), it.value) })
+        guildedMap.putAll(values.mapValues { Pair(Instant.now().plus(ttlWithJitter), it.value) })
         cache[guildId] = guildedMap
     }
 

diff --git a/core/src/main/kotlin/org/dreamexposure/discal/core/cache/RedisStringCacheRepository.kt b/core/src/main/kotlin/org/dreamexposure/discal/core/cache/RedisStringCacheRepository.kt
@@ -25,12 +25,12 @@ class RedisStringCacheRepository<K, V>(
     }
 
     override suspend fun put(guildId: Snowflake?, key: K, value: V) {
-        valueOps.setAndAwait(formatKey(guildId, key), objectMapper.writeValueAsString(value), ttl)
+        valueOps.setAndAwait(formatKey(guildId, key), objectMapper.writeValueAsString(value), ttlWithJitter)
     }
 
     override suspend fun putMany(guildId: Snowflake?, values: Map<K, V>) {
         values.forEach { (key, value) ->
-            valueOps.setAndAwait(formatKey(guildId, key), objectMapper.writeValueAsString(value), ttl)
+            valueOps.setAndAwait(formatKey(guildId, key), objectMapper.writeValueAsString(value), ttlWithJitter)
         }
     }