Re: Ignite server memory spiking up - Ignite 2.16 and Java 17

[Humphrey]

Ignite also doesn’t release the off heap memory it allocated. On 12 Feb 2026, at 12:52, Stephen Darlington <sdarling...@apache.org> wrote:  We should probably improve the documentation around this issue, as it's a common misunderstanding. Simplifying slightly, Ignite has two kinds of memory: on-heap and off-heap. The memory you configured in XML is the off-heap memory. That's where Ignite stores your data. There's also the Java heap, which you can think of as its working set. I don't know the default in your environment. You need to add the types together (and then add a bit) to find Ignite's total memory footprint. See here for how to configure the heap memory: https://ignite.apache.org/docs/ignite2/latest/perf-and-troubleshooting/memory-tuning On Thu, 12 Feb 2026 at 10:27, Charlin S <charli...@hotelhub.com> wrote: Hi All, I've encountered an issue where memory usage is spiking on the Ignite server, and the memory is not being released back to the OS. I am hosting three grids on this server: two use replication cache mode with no expiry policy, and the third uses partition cache mode with an expiry policy. This issue first appeared with Amazon Linux 2023.9.20251027 and `openjdk version "1.8.0_402-402"`. We subsequently upgraded to Java 17, focusing on the primary JVM options designed to encourage the release of unused heap memory to the operating system. We start Ignite using `ignite.sh config/grid1.xml`. Please suggest ways to finetune the configuration for better memory management. The current upgraded version details are: ``` openjdk version "17.0.17" 2025-10-21 LTS OpenJDK Runtime Environment Microsoft-12574440 (build 17.0.17+10-LTS) OpenJDK 64-Bit Server VM Microsoft-12574440 (build 17.0.17+10-LTS, mixed mode, sharing) ``` Observations: * One Ignite grid (partition mode, 2-cluster) uses 19GB of memory, but its data region is only 18GB. * Another grid (replication mode, 2-cluster) uses 21GB of memory, but its data region is only 10GB. bean xml file <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"        xmlns:util="http://www.springframework.org/schema/util"        xsi:schemaLocation="http://www.springframework.org/schema/beans                            http://www.springframework.org/schema/beans/spring-beans.xsd                            http://www.springframework.org/schema/util                            http://www.springframework.org/schema/util/spring-util.xsd">   <bean class="org.apache.ignite.configuration.IgniteConfiguration">     <property name="clientMode" value="false"/>     <property name="clientFailureDetectionTimeout" value="120000"/>     <property name="igniteInstanceName" value="Productiongrid"/>     <property name="longQueryWarningTimeout" value="4000"/>     <property name="failureDetectionTimeout" value="120000"/>     <property name="segmentationPolicy" value="RESTART_JVM"/>     <property name="segmentCheckFrequency" value="20000"/>     <property name="segmentationResolveAttempts" value="10"/>     <property name="discoverySpi">       <bean class="org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi">         <property name="localPort" value="55500"/>         <property name="ipFinder">           <bean class="org.apache.ignite.spi.discovery.tcp.ipfinder.vm.TcpDiscoveryVmIpFinder">             <property name="addresses">               <list>                         <value>IP:55500</value>                         <value>IP:55500</value>               </list>             </property>           </bean>         </property>       </bean>     </property>         <property name="dataStorageConfiguration">             <bean class="org.apache.ignite.configuration.DataStorageConfiguration">                 <property name="defaultDataRegionConfiguration">                     <bean class="org.apache.ignite.configuration.DataRegionConfiguration">                         <property name="name" value="Dynamic_Data_Region"/>                         <property name="initialSize" value="#{1L * 1024 * 1024 * 1024}"/>                         <property name="maxSize" value="#{18L * 1024 * 1024 * 1024}"/>                         <property name="pageEvictionMode" value="RANDOM_2_LRU"/>                         <property name="evictionThreshold" value="0.7"/>                         <property name="emptyPagesPoolSize" value="65536"/>                     </bean>                 </property>             </bean>         </property>         <property name="communicationSpi">         <bean class="org.apache.ignite.spi.communication.tcp.TcpCommunicationSpi">             <property name="sharedMemoryPort" value="-1"/>             <property name="localPort" value="55605"/>         </bean>     </property>   </bean> </beans> Thanks & Regards, Charlin