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dlmarion pushed a commit to branch 2.1
in repository https://gitbox.apache.org/repos/asf/accumulo.git
The following commit(s) were added to refs/heads/2.1 by this push:
new d6ef7c8400 Attempt at reducing GC memory usage when gathering
candidates (#6449)
d6ef7c8400 is described below
commit d6ef7c8400d9a90d251f7bafe94c4e1ed6c4ddb2
Author: Dave Marion <[email protected]>
AuthorDate: Tue Jun 30 07:23:34 2026 -0400
Attempt at reducing GC memory usage when gathering candidates (#6449)
This change pushes the Value filtering to the server-side
using an iterator instead of using a filter in a Stream, and
sets an initial size on the candidate ArrayList to try and
reduce resize operations.
---
.../server/metadata/GcCandidateFilter.java | 33 ++++++++++++++++++++++
.../accumulo/server/metadata/ServerAmpleImpl.java | 5 ++--
.../main/java/org/apache/accumulo/gc/GCRun.java | 2 +-
3 files changed, 37 insertions(+), 3 deletions(-)
diff --git
a/server/base/src/main/java/org/apache/accumulo/server/metadata/GcCandidateFilter.java
b/server/base/src/main/java/org/apache/accumulo/server/metadata/GcCandidateFilter.java
new file mode 100644
index 0000000000..146734395f
--- /dev/null
+++
b/server/base/src/main/java/org/apache/accumulo/server/metadata/GcCandidateFilter.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.accumulo.server.metadata;
+
+import org.apache.accumulo.core.data.Key;
+import org.apache.accumulo.core.data.Value;
+import org.apache.accumulo.core.iterators.Filter;
+import
org.apache.accumulo.core.metadata.schema.MetadataSchema.DeletesSection.SkewedKeyValue;
+
+public class GcCandidateFilter extends Filter {
+
+ @Override
+ public boolean accept(Key k, Value v) {
+ return v.equals(SkewedKeyValue.NAME);
+ }
+
+}
diff --git
a/server/base/src/main/java/org/apache/accumulo/server/metadata/ServerAmpleImpl.java
b/server/base/src/main/java/org/apache/accumulo/server/metadata/ServerAmpleImpl.java
index 22cb7a941f..b47a410396 100644
---
a/server/base/src/main/java/org/apache/accumulo/server/metadata/ServerAmpleImpl.java
+++
b/server/base/src/main/java/org/apache/accumulo/server/metadata/ServerAmpleImpl.java
@@ -36,6 +36,7 @@ import java.util.stream.StreamSupport;
import org.apache.accumulo.core.client.BatchScanner;
import org.apache.accumulo.core.client.BatchWriter;
import org.apache.accumulo.core.client.IsolatedScanner;
+import org.apache.accumulo.core.client.IteratorSetting;
import org.apache.accumulo.core.client.MutationsRejectedException;
import org.apache.accumulo.core.client.Scanner;
import org.apache.accumulo.core.client.TableNotFoundException;
@@ -60,7 +61,6 @@ import
org.apache.accumulo.core.metadata.schema.ExternalCompactionFinalState;
import org.apache.accumulo.core.metadata.schema.ExternalCompactionId;
import org.apache.accumulo.core.metadata.schema.MetadataSchema.BlipSection;
import org.apache.accumulo.core.metadata.schema.MetadataSchema.DeletesSection;
-import
org.apache.accumulo.core.metadata.schema.MetadataSchema.DeletesSection.SkewedKeyValue;
import
org.apache.accumulo.core.metadata.schema.MetadataSchema.ExternalCompactionSection;
import
org.apache.accumulo.core.metadata.schema.MetadataSchema.ScanServerFileReferenceSection;
import
org.apache.accumulo.core.metadata.schema.MetadataSchema.TabletsSection.BulkFileColumnFamily;
@@ -270,7 +270,8 @@ public class ServerAmpleImpl extends AmpleImpl implements
Ample {
throw new RuntimeException(e);
}
scanner.setRange(range);
- return scanner.stream().filter(entry ->
entry.getValue().equals(SkewedKeyValue.NAME))
+ scanner.addScanIterator(new IteratorSetting(25, "gcCandidate",
GcCandidateFilter.class));
+ return scanner.stream()
.map(
entry -> new
GcCandidate(DeletesSection.decodeRow(entry.getKey().getRow().toString()),
entry.getKey().getTimestamp()))
diff --git a/server/gc/src/main/java/org/apache/accumulo/gc/GCRun.java
b/server/gc/src/main/java/org/apache/accumulo/gc/GCRun.java
index 9c8b1da8b5..2a2261a8dd 100644
--- a/server/gc/src/main/java/org/apache/accumulo/gc/GCRun.java
+++ b/server/gc/src/main/java/org/apache/accumulo/gc/GCRun.java
@@ -150,7 +150,7 @@ public class GCRun implements GarbageCollectionEnvironment {
// Converting the bytes to approximate number of characters for batch size.
long candidateBatchSize = getCandidateBatchSize() / 2;
- List<GcCandidate> candidatesBatch = new ArrayList<>();
+ List<GcCandidate> candidatesBatch = new ArrayList<>(256);
batchCount.incrementAndGet();
while (candidates.hasNext()) {
