[jira] [Resolved] (CAMEL-23870) Add HeapHistogram dev console and TUI panel for class-level memory analysis

["Claus Ibsen (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CAMEL-23870?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Claus Ibsen resolved CAMEL-23870.
---------------------------------
    Resolution: Fixed

> Add HeapHistogram dev console and TUI panel for class-level memory analysis
> ---------------------------------------------------------------------------
>
>                 Key: CAMEL-23870
>                 URL: https://issues.apache.org/jira/browse/CAMEL-23870
>             Project: Camel
>          Issue Type: Improvement
>          Components: camel-core, camel-jbang
>            Reporter: Claus Ibsen
>            Assignee: Claus Ibsen
>            Priority: Major
>              Labels: tui
>             Fix For: 4.22.0
>
>
> Add a new dev console that exposes a JVM class histogram from the running Camel application, and a corresponding TUI panel to visualize it.
> h3. Dev Console: HeapHistogramDevConsole
> A new dev console (e.g. jvm/heap-histogram) that uses DiagnosticCommandMBean to invoke gcClassHistogram inside the running JVM:
> {code:java}
> MBeanServer server = ManagementFactory.getPlatformMBeanServer();
> ObjectName name = new ObjectName("com.sun.management:type=DiagnosticCommand");
> String histogram = (String) server.invoke(name, "gcClassHistogram",
>     new Object[]{null}, new String[]{"[Ljava.lang.String;"});
> {code}
> This returns the same output as {{jcmd <pid> GC.class_histogram}} but runs inside the target JVM through the dev console - no external jcmd access needed. This fits the existing pattern used by MemoryDevConsole and JvmDevConsole.
> The JSON response should include:
> * Array of class entries: class name, instance count, total bytes
> * Top N classes by default (e.g. top 50) to keep response size manageable
> * Option to trigger a full GC before collecting (live objects only)
> * Summary totals
> h3. TUI Panel
> A new tab (accessible via More menu) showing the class histogram as a sortable table:
> * Columns: class name, instance count, total bytes
> * Sortable by any column (default: bytes descending)
> * Search/filter support
> * Complements the existing Memory tab which shows aggregate heap/GC stats but not what is consuming the heap
> h3. Use Case
> When investigating memory issues in a running Camel integration, users currently see heap totals in the Memory tab but cannot determine *what* is consuming the heap without attaching an external tool like VisualVM or MAT. The class histogram gives immediate visibility into the largest consumers directly from the TUI.
> h3. Reference
> The boot-ui project (https://github.com/jdubois/boot-ui) has a similar Heap Dump panel that captures and analyzes heap dumps showing class histograms (names and sizes only, never object values).



--
This message was sent by Atlassian Jira
(v8.20.10#820010)