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new fdab85e Add memory-leak example for JFR diagnostics
fdab85e is described below
commit fdab85e46caa7e89a045726f8517930aea936468
Author: Claus Ibsen <[email protected]>
AuthorDate: Thu Jul 2 09:02:45 2026 +0200
Add memory-leak example for JFR diagnostics
Bundled example that simulates a memory leak (growing HashMap cache
and ArrayList buffers) for testing the JFR Old Object Sample tool.
Co-Authored-By: Claude <[email protected]>
Signed-off-by: Claus Ibsen <[email protected]>
---
camel-jbang-example-catalog.json | 19 +++++++++++++++++++
memory-leak/README.md | 24 ++++++++++++++++++++++++
memory-leak/memory-leak.java | 40 ++++++++++++++++++++++++++++++++++++++++
memory-leak/metadata.json | 12 ++++++++++++
4 files changed, 95 insertions(+)
diff --git a/camel-jbang-example-catalog.json b/camel-jbang-example-catalog.json
index 33129c7..8ac7469 100644
--- a/camel-jbang-example-catalog.json
+++ b/camel-jbang-example-catalog.json
@@ -269,6 +269,25 @@
"keycloak"
]
},
+ {
+ "name": "memory-leak",
+ "title": "Memory Leak",
+ "description": "Simulates a memory leak for testing JFR Old Object
Sample diagnostics",
+ "level": "beginner",
+ "tags": [
+ "observability",
+ "jfr",
+ "diagnostics",
+ "tui"
+ ],
+ "bundled": true,
+ "requiresDocker": false,
+ "hasCitrusTests": false,
+ "files": [
+ "README.md",
+ "memory-leak.java"
+ ]
+ },
{
"name": "message-size",
"title": "Message Size",
diff --git a/memory-leak/README.md b/memory-leak/README.md
new file mode 100644
index 0000000..1391a2d
--- /dev/null
+++ b/memory-leak/README.md
@@ -0,0 +1,24 @@
+## Memory Leak
+
+This example simulates a memory leak for testing the JFR Old Object Sample
diagnostic tool.
+
+It runs three routes:
+- **cache-leak** — adds a 64 KB entry to a HashMap every 200ms (never evicts)
+- **buffer-leak** — appends a 32 KB byte array to a List every 300ms (never
shrinks)
+- **healthy** — a normal route with no leak, for comparison
+
+### How to run
+
+ camel run memory-leak.java
+
+### Diagnose with TUI
+
+ camel tui
+
+Navigate to the **JFR Old Objects** tab and press **R** to start a dual
recording.
+After both runs complete, the comparison table will flag `byte[]` and
`HashMap$Node`
+as `growing` with high growth ratios, confirming the leak.
+
+### Diagnose with CLI
+
+ camel cmd jfr-old-objects
diff --git a/memory-leak/memory-leak.java b/memory-leak/memory-leak.java
new file mode 100644
index 0000000..9e8b890
--- /dev/null
+++ b/memory-leak/memory-leak.java
@@ -0,0 +1,40 @@
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.camel.builder.RouteBuilder;
+
+public class memory_leak extends RouteBuilder {
+
+ // these collections grow forever — simulating a memory leak
+ private final Map<String, byte[]> cache = new HashMap<>();
+ private final List<byte[]> buffers = new ArrayList<>();
+
+ @Override
+ public void configure() {
+ // leak 1: growing cache — adds a 64 KB entry every 200ms, never evicts
+ from("timer:cache-leak?period=200")
+ .process(e -> {
+ String key = "entry-" + cache.size();
+ cache.put(key, new byte[65536]);
+ e.getMessage().setBody("Cache size: " + cache.size()
+ + " (~" + (cache.size() * 64) + " KB)");
+ })
+ .to("log:cache-leak?level=INFO");
+
+ // leak 2: growing buffer list — adds a 32 KB buffer every 300ms
+ from("timer:buffer-leak?period=300")
+ .process(e -> {
+ buffers.add(new byte[32768]);
+ e.getMessage().setBody("Buffers: " + buffers.size()
+ + " (~" + (buffers.size() * 32) + " KB)");
+ })
+ .to("log:buffer-leak?level=INFO");
+
+ // normal route for comparison — no leak
+ from("timer:healthy?period=5000")
+ .setBody(constant("I am healthy"))
+ .to("log:healthy?level=INFO");
+ }
+}
diff --git a/memory-leak/metadata.json b/memory-leak/metadata.json
new file mode 100644
index 0000000..f44f241
--- /dev/null
+++ b/memory-leak/metadata.json
@@ -0,0 +1,12 @@
+{
+ "title": "Memory Leak",
+ "description": "Simulates a memory leak for testing JFR Old Object Sample
diagnostics",
+ "tags": [
+ "observability",
+ "jfr",
+ "diagnostics",
+ "tui"
+ ],
+ "bundled": true,
+ "level": "beginner"
+}
