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https://issues.apache.org/jira/browse/JENA-2354?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17762164#comment-17762164
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Andy Seaborne commented on JENA-2354:
-------------------------------------
Yes - they are the parameters.
{noformat}
nodeToIdCacheSize (default: 200000)
idToNodeCacheSize (default: 1000000)
missCacheSize (default: 1000){noformat}
{quote}How was the initial capacity set before the switch to Caffeine?
{quote}
Google Guava cache default setting. i.e. Jena didn't set anything itself.
{quote}However, I'm a bit hesitant as reducing the maximum cache size might
have an impact on performance depending on the size of the dataset.
. . .
potentially lead to a performance degradation for bigger datasets.
{quote}
{{StoreParams}} is per dataset.
{quote}we currently keep all databases permanently.
{quote}
Then initial size can't be replied on. You'll have to assume caches will grow
until they reach stability - either everything is cached or it reaches the
iniital size, below the LRU limit and grows.
What initial cache size does do is limit the cache resources when the whole
data gets cached and that hasn't reached the point the cache has to grow. If
the app is using the dataset, then if initial cache size isn't big enough, the
cache will grow at some point (or the app isn't touching all the data).
> OOM / increased memory consumption with TDB 4.9.0
> -------------------------------------------------
>
> Key: JENA-2354
> URL: https://issues.apache.org/jira/browse/JENA-2354
> Project: Apache Jena
> Issue Type: Bug
> Components: TDB2
> Affects Versions: Jena 4.9.0
> Reporter: Damien Obrist
> Assignee: Andy Seaborne
> Priority: Major
> Fix For: Jena 4.10.0
>
> Attachments: tdb-4.8.0-run-2-memory.png, tdb-4.9.0-run-6-memory.png,
> tdb-4.9.0-run-7-memory.png, tdb-490-memory-increase-4.8.0-memory.png,
> tdb-490-memory-increase-4.9.0-exception.png,
> tdb-490-memory-increase-4.9.0-memory.png, tdb-490-memory-increase.zip
>
>
> I have observed that after upgrading from TDB 4.8.0 to 4.9.0, memory
> consumption seems to have increased substantially.
> Our application creates many TDB datasets, which are queried and updated
> concurrently. To profile the memory increase, I have implemented a small
> script, which creates up to 50 of our application-level objects, one after
> another. Each of these objects is backed by a TDB dataset under the hood,
> which gets created from scratch and filled with data (around 30k triples,
> 200MB folder size).
> The following shows the memory profiles when running the script against our
> application for both TDB 4.8.0 / 4.9.0 and using 1G of heap space.
> h3. TDB 4.8.0
> Memory increases only slightly and the script completes the creation of all
> 50 objects / TDB datasets:
> !tdb-4.8.0-run-2-memory.png|width=800,height=207!
> h3. TDB 4.9.0
> Memory increases fast and the application crashes with an OOM after having
> created 8 objects / TDB datasets, during the creation of the 9th:
> !tdb-4.9.0-run-6-memory.png|width=800,height=207!
> Stack trace:
> {code:java}
> java.lang.OutOfMemoryError: Java heap space
> at
> com.github.benmanes.caffeine.cache.FrequencySketch.ensureCapacity(FrequencySketch.java:92)
> at com.github.benmanes.caffeine.cache.SSMS.<init>(Unknown Source)
> at
> java.base/java.lang.invoke.LambdaForm$DMH/0x00000008028f7c40.newInvokeSpecial(LambdaForm$DMH)
> at
> java.base/java.lang.invoke.DelegatingMethodHandle$Holder.reinvoke_L(DelegatingMethodHandle$Holder)
> at
> java.base/java.lang.invoke.LambdaForm$MH/0x00000008028f7040.invoke_MT(LambdaForm$MH)
> at
> com.github.benmanes.caffeine.cache.LocalCacheFactory.loadFactory(LocalCacheFactory.java:86)
> at
> com.github.benmanes.caffeine.cache.LocalCacheFactory.newBoundedLocalCache(LocalCacheFactory.java:40)
> at
> com.github.benmanes.caffeine.cache.BoundedLocalCache$BoundedLocalManualCache.<init>(BoundedLocalCache.java:3947)
> at
> com.github.benmanes.caffeine.cache.BoundedLocalCache$BoundedLocalManualCache.<init>(BoundedLocalCache.java:3943)
> at com.github.benmanes.caffeine.cache.Caffeine.build(Caffeine.java:1051)
> at
> org.apache.jena.atlas.lib.cache.CacheCaffeine.<init>(CacheCaffeine.java:62)
> at
> org.apache.jena.atlas.lib.CacheFactory.createCache(CacheFactory.java:45)
> at
> org.apache.jena.atlas.lib.CacheFactory.createCache(CacheFactory.java:33)
> at
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.createCache(NodeTableCache.java:101)
> at
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.<init>(NodeTableCache.java:95)
> at
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.create(NodeTableCache.java:87)
> at
> org.apache.jena.tdb2.store.TDB2StorageBuilder.addNodeTableCache(TDB2StorageBuilder.java:302)
> at
> org.apache.jena.tdb2.store.TDB2StorageBuilder.buildNodeTable(TDB2StorageBuilder.java:287)
> at
> org.apache.jena.tdb2.store.TDB2StorageBuilder.buildStorage(TDB2StorageBuilder.java:189)
> at
> org.apache.jena.tdb2.store.TDB2StorageBuilder.build(TDB2StorageBuilder.java:97)
> at org.apache.jena.tdb2.sys.StoreConnection.make(StoreConnection.java:95)
> at
> org.apache.jena.tdb2.sys.StoreConnection.connectCreate(StoreConnection.java:63)
> at
> org.apache.jena.tdb2.sys.DatabaseOps.createSwitchable(DatabaseOps.java:139)
> at org.apache.jena.tdb2.sys.DatabaseOps.create(DatabaseOps.java:86)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection.build(DatabaseConnection.java:112)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection.lambda$make$0(DatabaseConnection.java:74)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection$$Lambda$8502/0x00000008028e3c40.apply(Unknown
> Source)
> at
> java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1705)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection.make(DatabaseConnection.java:74)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection.connectCreate(DatabaseConnection.java:63)
> at
> org.apache.jena.tdb2.sys.DatabaseConnection.connectCreate(DatabaseConnection.java:54)
> at org.apache.jena.tdb2.DatabaseMgr.DB_ConnectCreate(DatabaseMgr.java:41)
> {code}
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