Jitter-based cache expiration policy

prebid · Nov 16, 2023 · 87cc1fc · 87cc1fc
1 parent 5e4bb21
commit 87cc1fc
Show file tree

Hide file tree

Showing 6 changed files with 31 additions and 35 deletions.
diff --git a/...ver/activity/infrastructure/creator/privacy/uscustomlogic/USCustomLogicModuleCreator.java b/...ver/activity/infrastructure/creator/privacy/uscustomlogic/USCustomLogicModuleCreator.java
@@ -48,15 +48,15 @@ public USCustomLogicModuleCreator(USCustomLogicGppReaderFactory gppReaderFactory
                                       JsonLogic jsonLogic,
                                       Integer cacheTtl,
                                       Integer cacheSize,
-                                      int refreshPeriod,
+                                      int jitter,
                                       Metrics metrics) {
 
         this.gppReaderFactory = Objects.requireNonNull(gppReaderFactory);
         this.jsonLogic = Objects.requireNonNull(jsonLogic);
         this.metrics = Objects.requireNonNull(metrics);
 
         jsonLogicNodesCache = cacheTtl != null && cacheSize != null
-                ? SettingsCache.createCache(cacheTtl, cacheSize, refreshPeriod)
+                ? SettingsCache.createCache(cacheTtl, cacheSize, jitter)
                 : null;
     }
 

diff --git a/src/main/java/org/prebid/server/settings/CachingApplicationSettings.java b/src/main/java/org/prebid/server/settings/CachingApplicationSettings.java
@@ -49,16 +49,16 @@ public CachingApplicationSettings(ApplicationSettings delegate,
                                       Metrics metrics,
                                       int ttl,
                                       int size,
-                                      int refreshPeriod) {
+                                      int jitter) {
 
         if (ttl <= 0 || size <= 0) {
             throw new IllegalArgumentException("ttl and size must be positive");
         }
         this.delegate = Objects.requireNonNull(delegate);
-        this.accountCache = SettingsCache.createCache(ttl, size, refreshPeriod);
-        this.accountToErrorCache = SettingsCache.createCache(ttl, size, refreshPeriod);
-        this.adServerPublisherToErrorCache = SettingsCache.createCache(ttl, size, refreshPeriod);
-        this.categoryConfigCache = SettingsCache.createCache(ttl, size, refreshPeriod);
+        this.accountCache = SettingsCache.createCache(ttl, size, jitter);
+        this.accountToErrorCache = SettingsCache.createCache(ttl, size, jitter);
+        this.adServerPublisherToErrorCache = SettingsCache.createCache(ttl, size, jitter);
+        this.categoryConfigCache = SettingsCache.createCache(ttl, size, jitter);
         this.cache = Objects.requireNonNull(cache);
         this.ampCache = Objects.requireNonNull(ampCache);
         this.videoCache = Objects.requireNonNull(videoCache);

diff --git a/src/main/java/org/prebid/server/settings/SettingsCache.java b/src/main/java/org/prebid/server/settings/SettingsCache.java
@@ -1,16 +1,17 @@
 package org.prebid.server.settings;
 
+import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.Caffeine;
 import org.apache.commons.collections4.MapUtils;
 import org.apache.commons.lang3.ObjectUtils;
 import org.prebid.server.settings.model.StoredItem;
 
-import javax.validation.ValidationException;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -21,25 +22,25 @@ public class SettingsCache implements CacheNotificationListener {
     private final Map<String, Set<StoredItem>> requestCache;
     private final Map<String, Set<StoredItem>> impCache;
 
-    public SettingsCache(int ttl, int size, int refreshPeriod) {
+    public SettingsCache(int ttl, int size, int jitter) {
         if (ttl <= 0 || size <= 0) {
             throw new IllegalArgumentException("ttl and size must be positive");
         }
-        requestCache = createCache(ttl, size, refreshPeriod);
-        impCache = createCache(ttl, size, refreshPeriod);
+        requestCache = createCache(ttl, size, jitter);
+        impCache = createCache(ttl, size, jitter);
     }
 
-    public static <T> Map<String, T> createCache(int ttl, int size, int refreshPeriod) {
-        final Caffeine<Object, Object> caffeine = Caffeine.newBuilder().maximumSize(size);
-        if (refreshPeriod > 0 && refreshPeriod > ttl) {
-            throw new ValidationException("SettingsCache parameter \"refreshPeriod\" should be less than \"ttl\"");
-        }
-        if (refreshPeriod > 0) {
-            caffeine.refreshAfterWrite(ttl, TimeUnit.SECONDS).expireAfterWrite(ttl * 5L, TimeUnit.SECONDS);
-        } else {
-            caffeine.expireAfterWrite(ttl, TimeUnit.SECONDS);
-        }
-        return caffeine.<String, T>build().asMap();
+    public static <T> Map<String, T> createCache(int ttl, int size, int jitter) {
+        final Cache<String, T> cache = Caffeine.newBuilder()
+                .expireAfterWrite(ttl, TimeUnit.SECONDS)
+                .maximumSize(size)
+                .build();
+        cache.policy()
+                .expireAfterWrite()
+                .ifPresent(expiration -> expiration.setExpiresAfter(
+                        jitter != 0 ? ttl + ThreadLocalRandom.current().nextLong(jitter * -1, jitter) : ttl,
+                        TimeUnit.SECONDS));
+        return cache.asMap();
     }
 
     Map<String, Set<StoredItem>> getRequestCache() {

diff --git a/src/main/java/org/prebid/server/spring/config/ActivityInfrastructureConfiguration.java b/src/main/java/org/prebid/server/spring/config/ActivityInfrastructureConfiguration.java
@@ -53,11 +53,11 @@ USCustomLogicModuleCreator usCustomLogicModuleCreator(
                     JsonLogic jsonLogic,
                     @Value("${settings.in-memory-cache.ttl-seconds:#{null}}") Integer ttlSeconds,
                     @Value("${settings.in-memory-cache.cache-size:#{null}}") Integer cacheSize,
-                    @Value("${settings.in-memory-cache.refreshPeriod:0}") int refreshPeriod,
+                    @Value("${settings.in-memory-cache.cache-size:0}") int jitter,
                     Metrics metrics) {
 
                 return new USCustomLogicModuleCreator(
-                        gppReaderFactory, jsonLogic, ttlSeconds, cacheSize, refreshPeriod, metrics);
+                        gppReaderFactory, jsonLogic, ttlSeconds, cacheSize, jitter, metrics);
             }
         }
     }

diff --git a/src/main/java/org/prebid/server/spring/config/SettingsConfiguration.java b/src/main/java/org/prebid/server/spring/config/SettingsConfiguration.java
@@ -281,7 +281,7 @@ CachingApplicationSettings cachingApplicationSettings(
                     metrics,
                     cacheProperties.getTtlSeconds(),
                     cacheProperties.getCacheSize(),
-                    cacheProperties.getRefreshPeriod());
+                    cacheProperties.getJitter());
         }
     }
 
@@ -304,24 +304,21 @@ static class CacheConfiguration {
         @Qualifier("settingsCache")
         SettingsCache settingsCache(ApplicationSettingsCacheProperties cacheProperties) {
             return new SettingsCache(
-                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getRefreshPeriod()
-            );
+                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getJitter());
         }
 
         @Bean
         @Qualifier("ampSettingsCache")
         SettingsCache ampSettingsCache(ApplicationSettingsCacheProperties cacheProperties) {
             return new SettingsCache(
-                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getRefreshPeriod()
-            );
+                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getJitter());
         }
 
         @Bean
         @Qualifier("videoSettingCache")
         SettingsCache videoSettingCache(ApplicationSettingsCacheProperties cacheProperties) {
             return new SettingsCache(
-                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getRefreshPeriod()
-            );
+                    cacheProperties.getTtlSeconds(), cacheProperties.getCacheSize(), cacheProperties.getJitter());
         }
     }
 
@@ -339,7 +336,6 @@ private static class ApplicationSettingsCacheProperties {
         @NotNull
         @Min(1)
         private Integer cacheSize;
-        @Min(0)
-        private int refreshPeriod;
+        private int jitter;
     }
 }
diff --git a/...activity/infrastructure/creator/privacy/uscustomlogic/USCustomLogicModuleCreatorTest.java b/...activity/infrastructure/creator/privacy/uscustomlogic/USCustomLogicModuleCreatorTest.java
@@ -64,8 +64,7 @@ public void setUp() {
                 .willReturn(new USNationalGppReader(null));
         given(jsonLogic.parse(any())).willReturn(JsonLogicBoolean.TRUE);
 
-        target = new USCustomLogicModuleCreator(
-                gppReaderFactory, jsonLogic, null, null, 0, metrics);
+        target = new USCustomLogicModuleCreator(gppReaderFactory, jsonLogic, null, null, 0, metrics);
     }
 
     @Test