Alexey Kukushkin created IGNITE-16137:
-----------------------------------------
Summary: ContainsKey operation fetches entry value into heap
Key: IGNITE-16137
URL: https://issues.apache.org/jira/browse/IGNITE-16137
Project: Ignite
Issue Type: Improvement
Components: cache
Affects Versions: 2.11
Reporter: Alexey Kukushkin
[See similar problem for the remove()
operation|https://issues.apache.org/jira/browse/IGNITE-15959]
{{IgniteCache#containsKey(key)}} operation fetches full entry into heap memory.
This is inefficient when working with large objects: our application running
with limited heap memory fails with {{java.lang.OutOfMemoryError: Java heap
space}} when trying to check if a key exists.
It seems wrong that Ignite needs to fetch the full entry on heap to check if
the key exists. Please enhance Ignite to not be doing that or explain why
Ignite must do that.
h2. Reproducer
h3. Steps
Create a Gradle project with the below class and run it as
{{./gradlew test --tests apache.ignite.issues.ContainsOperationHeapUsage}}
{{build.gradle}}
{code:groovy}
test {
minHeapSize = "512m"
maxHeapSize = "512m"
}
{code}
{{ContainsOperationHeapUsage.java}}
{code:java}
public class ContainsOperationHeapUsage {
/** Run with -Xmx512m -Xms512m */
@Test
public void containsOperationFetchesValueOnHeap() {
var igniteCfg = new IgniteConfiguration()
.setDiscoverySpi(
new TcpDiscoverySpi()
.setIpFinder(new
TcpDiscoveryVmIpFinder().setAddresses(Collections.singleton("127.0.0.1:47500")))
)
.setCacheConfiguration(new CacheConfiguration<>("blobs"));
try (var ignite = Ignition.start(igniteCfg)) {
Cache<Integer, byte[]> cache = ignite.cache("blobs");
// Put a BLOB having size of 35% of free memory to the cache
Runtime.getRuntime().gc();
var freeMemory = Runtime.getRuntime().freeMemory();
var blobSize = (int)(freeMemory * 0.35);
putBlob(cache, blobSize);
// Use 70% of the free heap
Runtime.getRuntime().gc();
var unused = new byte[2 * blobSize];
// Check if the blob exists in the cache.
// This throws "OutOfMemoryError: Java heap space" since Ignite
retrieves full entry to the heap.
// Why does Ignite retrieve entry value to check if the key exists?
cache.containsKey(1);
}
}
private static void putBlob(Cache<Integer, byte[]> cache, int blobSize) {
var blob = new byte[blobSize];
cache.put(1, blob);
}
}
{code}
h3. Expected
The test passes
h3. Actual
The {{cache.containsKey}} operatoin fails with:
{noformat}
java.lang.OutOfMemoryError: Java heap space
at
org.apache.ignite.internal.processors.cache.IncompleteCacheObject.<init>(IncompleteCacheObject.java:44)
at
org.apache.ignite.internal.processors.cache.binary.CacheObjectBinaryProcessorImpl.toCacheObject(CacheObjectBinaryProcessorImpl.java:1385)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.readIncompleteValue(CacheDataRowAdapter.java:680)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.readFragment(CacheDataRowAdapter.java:500)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.readIncomplete(CacheDataRowAdapter.java:411)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.doInitFromLink(CacheDataRowAdapter.java:316)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.initFromLink(CacheDataRowAdapter.java:165)
at
org.apache.ignite.internal.processors.cache.persistence.CacheDataRowAdapter.initFromLink(CacheDataRowAdapter.java:136)
at
org.apache.ignite.internal.processors.cache.tree.DataRow.<init>(DataRow.java:55)
at
org.apache.ignite.internal.processors.cache.tree.CacheDataRowStore.dataRow(CacheDataRowStore.java:129)
at
org.apache.ignite.internal.processors.cache.tree.CacheDataTree.getRow(CacheDataTree.java:422)
at
org.apache.ignite.internal.processors.cache.tree.CacheDataTree.getRow(CacheDataTree.java:63)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree$GetOne.found(BPlusTree.java:3156)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree$Search.run0(BPlusTree.java:317)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree$GetPageHandler.run(BPlusTree.java:5921)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree$Search.run(BPlusTree.java:290)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree$GetPageHandler.run(BPlusTree.java:5907)
at
org.apache.ignite.internal.processors.cache.persistence.tree.util.PageHandler.readPage(PageHandler.java:174)
at
org.apache.ignite.internal.processors.cache.persistence.DataStructure.read(DataStructure.java:397)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree.read(BPlusTree.java:6108)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree.findDown(BPlusTree.java:1446)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree.doFind(BPlusTree.java:1413)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree.findOne(BPlusTree.java:1379)
at
org.apache.ignite.internal.processors.cache.persistence.tree.BPlusTree.findOne(BPlusTree.java:1364)
at
org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManagerImpl$CacheDataStoreImpl.find(IgniteCacheOffheapManagerImpl.java:2815)
at
org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManagerImpl.read(IgniteCacheOffheapManagerImpl.java:633)
at
org.apache.ignite.internal.processors.cache.distributed.dht.GridPartitionedSingleGetFuture.localGet(GridPartitionedSingleGetFuture.java:483)
at
org.apache.ignite.internal.processors.cache.distributed.dht.GridPartitionedSingleGetFuture.tryLocalGet(GridPartitionedSingleGetFuture.java:445)
at
org.apache.ignite.internal.processors.cache.distributed.dht.GridPartitionedSingleGetFuture.mapKeyToNode(GridPartitionedSingleGetFuture.java:409)
at
org.apache.ignite.internal.processors.cache.distributed.dht.GridPartitionedSingleGetFuture.map(GridPartitionedSingleGetFuture.java:284)
at
org.apache.ignite.internal.processors.cache.distributed.dht.GridPartitionedSingleGetFuture.init(GridPartitionedSingleGetFuture.java:248)
at
org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.getAsync0(GridDhtAtomicCache.java:1456)
{noformat}
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