https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1673562#M43601 <P>I’m trying to better understand how the Java heap behaves in ArcGIS Enterprise. I don’t have any background in Java memory management beyond some recent research, so I’d appreciate clarification to make sure I’m interpreting this correctly.</P><P>From what I’ve gathered, Java in ArcGIS Enterprise is configured to allow the heap to grow up to the configured -Xmx value (typically 80% of available physical memory). However, it appears that once the heap expands, the Garbage Collector does not shrink the heap, even if memory within the heap is freed.</P><P>If this understanding is correct, then:</P><UL><LI>The javaw.exe process may continue to show a large amount of committed memory, even when much of that heap space is no longer actively in use.</LI><LI>As a result, overall memory utilization on the machine can appear high, driven primarily by Java’s committed memory, even though this does not necessarily reflect memory pressure or exhaustion within ArcGIS Server itself.</LI><LI>This makes me question the effectiveness of monitoring physical memory usage alone in ArcGIS Enterprise, as there would be cases where the Java heap is exhausted, causing a component to become unresponsive or crash, while system memory utilization never reaches 100%.</LI></UL><P>I'm considering submitting an ArcGIS Idea to request that ArcGIS Monitor expose Java heap related metrics, but I just wanted to confirm my understanding first. Ideally, I’d prefer not to rely on third-party Java heap monitoring tools, though I’d be interested to hear if others are using any specific tools or approaches.</P> Wed, 17 Dec 2025 12:22:24 GMT TimoT 2025-12-17T12:22:24Z https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1673562#M43601 <P>I’m trying to better understand how the Java heap behaves in ArcGIS Enterprise. I don’t have any background in Java memory management beyond some recent research, so I’d appreciate clarification to make sure I’m interpreting this correctly.</P><P>From what I’ve gathered, Java in ArcGIS Enterprise is configured to allow the heap to grow up to the configured -Xmx value (typically 80% of available physical memory). However, it appears that once the heap expands, the Garbage Collector does not shrink the heap, even if memory within the heap is freed.</P><P>If this understanding is correct, then:</P><UL><LI>The javaw.exe process may continue to show a large amount of committed memory, even when much of that heap space is no longer actively in use.</LI><LI>As a result, overall memory utilization on the machine can appear high, driven primarily by Java’s committed memory, even though this does not necessarily reflect memory pressure or exhaustion within ArcGIS Server itself.</LI><LI>This makes me question the effectiveness of monitoring physical memory usage alone in ArcGIS Enterprise, as there would be cases where the Java heap is exhausted, causing a component to become unresponsive or crash, while system memory utilization never reaches 100%.</LI></UL><P>I'm considering submitting an ArcGIS Idea to request that ArcGIS Monitor expose Java heap related metrics, but I just wanted to confirm my understanding first. Ideally, I’d prefer not to rely on third-party Java heap monitoring tools, though I’d be interested to hear if others are using any specific tools or approaches.</P> Wed, 17 Dec 2025 12:22:24 GMT https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1673562#M43601 TimoT 2025-12-17T12:22:24Z https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1676612#M43661 <P>Submitted an idea in ArcGIS Monitor Ideas -&nbsp;<A href="https://community.esri.com/t5/arcgis-monitor-ideas/include-java-heap-metrics-in-arcgis-monitor/idi-p/1674615" target="_blank" rel="noopener">Include Java heap metrics in ArcGIS Monitor</A></P> Thu, 08 Jan 2026 07:43:50 GMT https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1676612#M43661 TimoT 2026-01-08T07:43:50Z https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1683775#M43789 <P>I don't recall looking at JAva Heap settins before, but I have noticed that a system which seems to not have a lot o ffree memory, a restart may restore some of that 'data space'.</P> Wed, 11 Feb 2026 19:43:50 GMT https://community.esri.com/t5/arcgis-enterprise-questions/understanding-java-heap-behavior/m-p/1683775#M43789 TimWestern 2026-02-11T19:43:50Z