Advanced JVM args42. Por ejemplo, a partir de una JVM como la siguiente arrancará con 256 mb de memoria, y permitirá que el proceso use hasta 2048MB de memoria: java -Xmx2048m -Xms256m. -Xmx specifies the precise upper limit for the heap. Note: Never try to give Minecraft more Ram than you have!The 3/8 advice is good for a wide range of applications. See Using -X command-line options for more information about the <size> parameter. Xmn. For example, if you set -Xms128M and -Xmx256M and you start monitoring your application with VisualVM , you'll see something like this:Sorted by: 51. I have a . -Xms specificates how much memory Java will initially allocate for heap space, and -Xmx will. Error: Could not create the Java Virtual Machine. Specifying. My statement regarding the use of -Xmn and -Xms came from my own experience with the arguments. This increases the size of the permagen space. 第二个线程在Heap不足时,遍历Heap,将Young 区升级为Older区. Use this syntax to specify the amount of memory the JVM should use: -Xms is that starting/minimum value. If you want to increase the memory for the program you run from Eclipse, you should define -Xmx in the "Run->Run configurations. l2jfree. 内存标志也. 3（必做）画一张图，展示 Xmx、Xms、Xmn、Meta、DirectMemory、Xss 这些内存参数的关系。 4（选做）检查一下自己维护的业务系统的 JVM 参数配置，用 jstat 和 jstack、jmap 查看一下详情，并且自己独立分析一下大概情况，思考有没有不合理的地方，如何改进。Changes to default Java Maximum Heap Size for Java 8. Viewed 535 times. In your . The -Xmx option can be used with all OpenJ9 GC policies. For example, when starting the Minecraft server on our. Adjust xmx and xms accordingly for your RAM and leave some room for the operating system -- don't allocate 100% of the RAM to your Minecraft. Make plenty of memory available to the young generation. But don't set it too high. g. The -Xmx flag set the max heap size to a fixed size. วิธีการ เพิ่ม RAM ให้เกม Minecraft. How you tune your JVM affects the performance of WebLogic Server and your applications. -Xmx. Even if you've allocated a maximum 4. However, the -Xms option can be used with all GC policies except for the metronome GC policy because the heap is always fully expanded. -XX:MaxPermSize=size Sets the maximum permanent generation space size. For example, to set the maximum heap size to 2GB, set both Xms and Xmx to 2g: -Xms2g -Xmx2g. Best values for min-max RAM, Xms & Xmx arguments Edit: Solved, just set them both to the same value! So when running my server (which has 8GB or RAM) I set. It can take a while and the application is frozen. . JVM调优总结 -Xms -Xmx -Xmn -Xss. チューニングに関連していると思われるフラグのみ抽出. -XX:PermSize. -Xms should be approximately half of the -Xmx setting. -XX:MetaspaceSize specifies the standard value for full GCs that originate in the Metaspace area. Note that this doesn't necessarily cause all of that. , -XX:MaxRAMFraction, -XX:MaxRAMPercentage, -Xmx), always make sure you allocate at least 25% more memory to your container (i. See Using -X command-line options for more information about the <size> parameter. When using the balanced GC policy, specifying -Xmn/-Xmns/-Xmnx may affect balanced GC's ability to satisfy -Xgc:targetPausetimeSo a common solution to it Now in order to change/increase the JVM heap size is made possible by using command-line options. ZGC supports heap sizes from 8MB to 16TB. This could be the cause of your performance issues. For server deployments, -Xms and -Xmx are often set to the same value. Minecraftをプレイしていて、PCのスペックの割に動作が重い、MODを入れた後の設定がよくわからい、バージョンの切り替え方がわからない等で困ったことはありませんか？. 0_25, Oracle Corporation Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle CorporationDefault values for JDK 1. gif: Bye guys!The subreddit for all things related to Modded Minecraft for Minecraft Java Edition --- This subreddit was originally created for discussion around the FTB launcher and its modpacks but has since grown to encompass all aspects of modding the Java edition of Minecraft. 4 to 1. defaultAction openFile --launcher. Step-2. g. The following sections discuss JVM tuning options for. 最大堆大小. Hot Network QuestionsThe flags are proven to be a major improvement. Note: The -Xmo option is not supported by the balanced garbage collection policy. But you also need to take into consideration all the other processes running on the machine and their RAM usage. See Default settings for the OpenJ9 VM for more about default values. java -Xmx4g -Xms4g. 想定しているJavaのバージョンは11です. WARNING The JVM has a lot of optimization and intelligence when it comes to allocating memory, dividing eden space and older generations etc, so don't do things like making -Xms equal to -Xmx or -XX:PermSize equal to -XX:MaxPermSize as it will remove some of the optimizations the JVM can apply to its allocation strategies and therefor. 0 (Squeeze) Minimal (64Bit) with a ligwebserver with php/mySQL alongside the actual Minecraft server. Run your server and WOOT! It's fixed :smile. 3. La configuración de -Xms no es necesaria ya que el tamaño del montón es estático. Known Issue for Linux Users此值可以设置与-Xmx相同，以避免每次垃圾回收完成后JVM重新分配内存。-Xmn2g ：设置年轻代大小为2G。 整个JVM内存大小=年轻代大小 + 年老代大小 + 持久代大小 。持久代一般固定大小为64m，所以增大年轻代后，将会减小年老代大小。12. 如果程序运行需要占用更多的内存，超出了这个设置值. Computercraft is a community-dead mod. Use -Xss to set the Java thread stack size. 1. When using the balanced GC policy, specifying -Xmn / -Xmns / -Xmnx may affect balanced GC's ability to satisfy -Xgc:targetPausetime. However, the -Xms option can be used with all GC policies except for the metronome GC policy because the heap is always fully expanded. 5 条答案. Xmnx . b. So for a 1G machine maximum heap size is 256MB 2. Format for specifying xms: java -xms {Numerical Size} {Unit. 0 (Squeeze) Minimal (64Bit) with a ligwebserver with php/mySQL alongside the actual Minecraft server. Xmx and Xmn should NOT BE THE SAME. it all depends on the RAM size, you can extend it max upto RAM size. 5 Answers. Realistic Torches - Causes torches to burn out after a configurable amount of time. With these parameters, if the percent of free space in a generation falls below 40%, the generation will be expanded to maintain 40%. The options you're looking for are -Xmx and -Xms (this is "initial" heap size, so probably what you're looking for. Also Java configuration options (command line parameters) can be. Java堆大小设置，Xms 和 Xmx设置为老年代存活对象的3-4倍，即FullGC之后的老年代内存占用的3-4倍 永久代 PermSize和MaxPermSize(元空间)设置为老年代存活对象的1. Really, the rest of the arguments are used to further control what the JVM is doing when doing something with a server, but for a. -Xms<size>. Briefly, -Xmn decides the size of the young space in a JVM. I tried Xmx as 3GB (3272 MB) and after that not allowed to define . Launch your Minecraft launcher with the SpecialK launcher, and the launcher will then "inject" SpecialK into Minecraft. El primero se utiliza para configurar el área de la pila, y la segunda se usa para configurar el área no pile. answered Aug 25, 2015 at 13:36. The resulting output is in bytes. -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC . If your application exceeds the maximum memory (allocated using the Xmx) and the garbage collector cannot free up memory, the JVM will crash with. Then click on Advanced system settings. And they just work fine. If -Xms is set to a low RAM allocation, It will start up with that much RAM, no matter the maximum set by -Xmx. There's a "Game Specific" section in the column on the left side of the settings page. Xms 是指设定程序启动时占用内存大小。. This would allow the game to use up to 4 gigs of ram and start with 1 gig of ram when your launch minecraft. Initial heap size is 1/64th of the computer’s physical memory or reasonable minimum based on platform (whichever is larger) by default. -Xmn 堆内新生代的大小。. The policy uses a global GC cycle of concurrent mark-sweep operations, optionally followed by operations. 第一个线程负责回收Heap的Young区. -Xmx is the max value of your Java heap size. 一般来讲，大点，程序会启动的快一点，但是也可能会导致机器暂时间变慢。. Correct: java -Xmx1024m -jar JavaApplication. The -Xmx option and -Xms option in combination are used to limit the Java heap size. XMX และ Xms Minecraft คืออะไร?. Virtual space for a 64 bit CPU is huge. Second point is that -Xms controls the committed memory in the virtual space. com Best values for min-max RAM, Xms & Xmx arguments Edit: Solved, just set them both to the same value! So when running my server (which has 8GB or RAM) I set my Xms to 2G (minimum RAM) and Xmx to 6GB (maximum RAM). 7、-Xloggc:filename：与上面几个配合使用，把相关日志信息记录到文件以便分析。. -Xms Sets the minimum heap size. It's failed to run . " 3. Live & ExclusiveMore than a PlaylistA-List Artists & Hosts. 0. 5. Say you have configured -Xmx value to be 2GB, then configure container’s memory size at least to be. Non-standard options :Options that begin with -X are non-standard (not. Então dei uma pesquisada e estou compartilhando oque eu aprendi. -Xmn Memory used by the garbage collector for destroyed variables so having it high means big collections of garbage, having it low. The -Xms has a lot to do with frame performance. Xmn sets the size of the new (nursery) heap. I want to set up a minecraft vanilla server, I have done this for modded multiple times and I have had this problem multiple times aswell. e. 2. edit @Aikar "-Xms matching -Xmx"-Xms is allocated at startup and it will grow up to -Xmx, setting ms == mx effectively turns off this behavior. The default value is 25% of -Xmx and when -Xmx is set to -Xms the nursery will never grow. If the scavenger is enabled, -Xms >= -Xmn + -Xmo. -Xms<var> -Xmx<var> -Xmn<var>. As such, these numbers being the same is not necessary and sometimes not a good idea. However, the virtual machine is then unable to compensate if you make a poor choice. -Xms and -Xmx simply specifies the range in which the JVM can operate and resize the heap. 2-1. That's what you need to change. JAR that apparently uses up too much memory, and throws an exception "Java heap space" (or something similar). Briefly, -Xmn decides the size of the young space in a JVM. The Java heap (the “heap”) is the part of. 4. What to set depend on your application and your hardware. Step-3at net. main(SourceFile:124)-- System Details --Details: Minecraft Version: 1. RAM allocation and Garbage Collection (GC) Your startup Xms and Xmx flags should always have the same value. but the in-game debug screen shows the memory usage of client. The line below shows 3 JVM arguments. STEP 6: Under JVM Arguments, you’ll see a script on the bar. -Xms 堆内存的最小大小，默认为物理内存的1/64. 在Windows、Linux中查看Xmx和Xms默认值的大小. 3. The flag Xmx specifies the maximum memory allocation pool for a Java Virtual Machine (JVM), while Xms specifies the initial memory allocation pool. What are your memory settings in MineOS? Just curious what your Java xms and xmx settings are in the WebGUI for MineOS? Should they be the same number? My heap was at 116% last night with settings for both at 1024 so I bumped both up to 2056 (after everyone was done for the night) lol. Format: -Xms<size> [g|G|m|M|k|K] -Xmx This option sets the maximum Java heap size. Solution: Given the volume of orders, especially during sale events, it was evident that the application needed more memory. 5、常见配置汇总. You can use g if you want to allocate memory in Gigabytes. See Using -X command-line options for more information about the <size> parameter. . In other words, we allow. If -Xmx is set, MaxRAM is never used. The default is calculated from NewRatio and the -Xmx setting. There’s also Xms, though. It is recommended to reduce your Xmx/Xms by about 1000-1500M to avoid running out of memory or “OOMKiller” hitting your server. Quote. Thanks! leaving only 1GB for server will probably not be enough, just for the comparison, my server with 6GB allocated in really use around 7. #5 Expo, Apr 24, 2014. e. The next time you start Minecraft it will use the settings specified in the . -Xms 堆内存的初始大小，默认为物理内存的1/64 -Xmx 堆内存的最大大小，默认为物理内存的1/4 -Xmn 堆内新生代的大小。. Modified 4 years ago. -Xms 堆内存的最小大小，默认为物理内存的1/64. 最开始只有 -Xms 的参数，表示 `初始` memory size (m表示memory，s表示size)；. Must be a boolean (either true or false). There are a lot of complicated arguments listed in there but the two to adjust are -Xmx{nn} and -Xms{nn} (-Xmn on Mac's). Also value of these option can be printed by following command: java -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version 2>&1. Auto Refresh - Automatically refreshes your. New Objects are created in this heap. アプリケーションがうまく動作するために必要なヒープ領域がわかっている場合は、-Xmsと-Xmxを同じ値に設定できます。 そうでない場合は、JVMが初期ヒープ・サイズを使用して開始され、ヒープ使用量とパフォーマンスのバランスが取れるまで、Javaヒープが. There is only a need for graphics processing if the machine in question is also running a client (i. -Xms can be added to allocate RAM at the beginning, but is not required. This means that when you start your program the JVM will allocate this amount of memory instantly. If you have historical data about your application server's stable memory-usage point, then set -Xms to be around that value. MaxHeapSize（最大堆大小）就是Xmx的默认值，InitialHeapSize（最小堆大小）时Xms的默认值，默认值和Java的版本有关，像上面的截图Windows中的Xmx默认值是256M，java version "1. The line below shows 3 JVM arguments. If the value of the -Xms parameter is smaller than the value of the -Xmx parameter, than not all of the space that is reserved is immediately committed to the virtual machine. NOT AN OFFICIAL MINECRAFT. 7. 32位系统 下，一般限制在1. 系统的可用物理内存限制. GuestNo8655 • 2 yr. JVM引数の値を変更して、パソコンのメモリを最大限までマイクラに割り当てます。. 如果程序运行需要占用更多的内存，超出了这个设置值，就会抛出OutOfMemory异常。. jar 如果Heap Size设置偏小，除了这些异常信息外，还会发现程序的响应速度变慢了。The -Xmx flag specifies the maximum amount of RAM that the server can use. If the value of the -Xms parameter is smaller than the value of the -Xmx. Oracle recommends that -Xmn and -Xmx be set to the same value. JVM does not allocate all memory that is defined with -Xmx argument. See full list on game-horizon. . The Xmx and Xms options are often confused because they both affect the size of the Java heap. Options. If you have historical data about your application server's stable memory-usage point, then set -Xms to be around that value. e. I'll take the example of Linux's memory allocation terminology here. ) ALL need a bit of memory. WilsonXRS. The -xmx option is used to set the final and maximum heap size in Java. Run: java -X for details. -Xms<size> set initial Java heap size -Xmx<size> set maximum Java heap size <size> can be defined in. Enter -Xmx8G if you want to specify a maximum of 8 GB of RAM to your game. -XX:MaxRAM does not define the heap size directly. -Xmx<size>. QFdongdong 阅读 399 评论 0 赞 0. client. 以 -X 开头的参数是和实现有关的，并不是适用于所有的 VMs，对于 -Xms 和 -Xmx 其含义为：. Minecraft creates a lot of short-lived objects, so it is better to set this to a larger value like 40% of. ZGC supports heap sizes from 8MB to 16TB. Xms と Xmx を同じ値に設定することで、JVMはアプリケーションの開始時に最大ヒープサイズを確保し、そのサイズでヒープを初期化します。 これにより、ヒープサイズの動的な拡大・縮小のオーバーヘッドを回避することができます。 The flag -XX:+UseCGroupMemoryLimitForHeap lets the JVM detect what the max heap size in a container should be. If you monitor your java process with an OS tool like top or. Default xms size is 1/4th of the physical memory size. 这样可以减少堆空间调整的频率，提高程序的执行效率。. Call me a skeptic but you have to REALLY understand the Java platform to start making claims about that subsystem. jar tells the JVM to allocate 512MB for heap space when it launches, and it can grow to 2048MB before stopping. 0_29 on Windows 7/32-bit: -Xmx256m -XX:MaxPermSize=64m. Default values of heap size parameters on 64-bit systems have been scaled up by approximately 30%. Step 2: Click on the Advanced system settings. Community content is available under CC BY-NC-SA unless. is the initial memory allocation pool, does not reflect what is being set. I want 2 gigs of ram. While this is fine for most applications, it can hurt Minecraft (especially modded) by trying to CONSTANTLY achieve minimum memory usage. サーバサイドのオンライン処理や常駐処理向けに書いています。. Try to increase -Xmx value. Related javadoc here. The Z Garbage Collector is enabled with the command-line option -XX:+UseZGC. If you click Edit Profile to the left of the Play button, at the bottom of the Profile Editor is a checkbox "JVM Arguments". If the scavenger is disabled, -Xms >= -Xmo. 10 Operating System: Windows 8. Please help here. This heap is always being replenished with new objects. To configure the heap size, add the Xms and Xmx JVM arguments to a custom JVM options file with the extension . 8*10308. I have 4 Gb Ram on my pc,here the startGameServer. Like Greg says, everything after -vmargs are VM args which are supplied to the JVM when an application starts. 通过. Estes parâmetros são passados em linha de comando. The actual RAM usage will be higher, as java needs some space for itself, for loaded classes, for garbage collection temporary internals, etc. Often for client the default value is 1/4th of your physical memory or 1GB (whichever is smaller). Memory -Xmx and -Xms "should" be the same. 4. For example -Xms could format your hard drive depending on the VM (it would not - but strictly speaking it could. -Xmn is the new space value (which is a different thing, entirely). この範囲は、-XX:MinHeapFreeRatio=minimum パラメータと -XX:MaxHeapFreeRatio=maximum パラメータでパーセント値として設定され、合計サイズは -Xms と -Xmx によって制限されます。 ヒープサイズを固定する場合は、-Xms と -Xmx に同じ値を設定します。To assign more RAM to the default Minecraft launcher, you need to do the following: Open your Minecraft launcher and click on the Installations tab. The -Xms and -Xmx parameters define the minimum and maximum heap sizes, respectively. JVMオプションについてのまとめです。. 堆内存相关配置. 相关操作系统的数据模型 (32-bt还是64-bit)限制;2. Aloque mais memória. Activa la optimización del heap de Java. 3. See Default settings for the OpenJ9 VM for more about default values. Surprisingly yes! This is carried to prevent resizing during startup and enhance the startup time of JVM. For efficient garbage collection, the -Xmn value should be lower than the -Xmx value. Para um correto gerenciamento de memória, o HEAP conta com dois parâmetros: Xms: Total de memória inicial, quanto de memória o HEAP terá após a inicialização da JVM; Xmx: Quantidade máxima de memória que um HEAP pode requerer. -Xmn - new space (this is a more specific tuning parameter) For client-side Minecraft, it generally makes sense to set the Xmx and Xms to the same value (-Xmx2G -Xms2G). You can create a desktop shortcut to your Minecraft launcher through the SpecialK UI for even more convenience. Heap size does not determine the amount of memory your process uses. They are common to all JVM garbage collectors. java -Xmx####M -Xms####M -exe Minecraft_Server . Sort By Name; Sort By Date;La configuración de los parámetros está empaquetada. Since it is a fixed heap so JVM will never grow or shrink the heap, which is what usually happens after each GC cycle if -Xms is not same as -Xmx. Another option is to set -Xms to the memory-usage value observed at the end of InitServlet. 举个例子：机器采用4核8G，然后-Xms和-Xmx设置为3G，给整个堆内存3G内存空间，-Xmn设置为2G，给新生代2G内存空间。 而且假设你的业务量如果更大，你可以考虑不只部署3台机器，可以横向扩展部署5台机器，或者10台机器，这样每台机器处理的请求更少，对JVM的压力. . The -Xms and -Xmx options are used to set the initial and maximum heap sizes, respectively, for the Java Virtual Machine (JVM). /temp/jdk-11. A resize requires to reallocate large amount of memory and move all existing java objects. Xmx 是指设定程序运行期间最大可占用的内存大小。. You want. Java is designed to handle memory automatically, but you shouldn't make it manage more memory than it needs. Pause times are independent of heap size that is being used. One option you could consider is setting the initial heap size (the -Xms part) to 1GB, and setting your maximum heap size (-Xmx) at something around 3. Virtual space for a 64 bit CPU is huge. HoD. -Xms1024m to -Xmx2048m). Solution: Given the volume of orders, especially during sale events, it was evident that the application needed more memory. The Java Heap Size of Java applications can be changed, we use -Xms and -Xmx parameters to control it. Sorted by: 13. Equal -Xms and -Xmx in JVM. The Java/JVM Xms and Xmx settings should both pre-allocate the amount of memory to start along with the maximum defined value to designate to the Java/JVM instance. You can also set the heap size according to your requirement. ) Some products like Ant or Tomcat might come with a batch script that looks for the JAVA_OPTS environment variable. Your -Xms decides the allocated memory your server uses, which will increase automatically when your server needs more ram. -Xms: this option sets the initial and minimum Java heap size. Therefore, the -Xmx flag in Java, changes the maximum heap size for the JVM. The start memory. Each thread in a Java application has its own stack. 1/4th of the physical memory or 1GB. 1. You can increase or change the size of the Java heap space using the -Xms, -Xmx, and -Xmn JVM command line option. Use -XX:MaxRAMPercentage / -XX:InitialRAMPercentage instead. Do not use the absolute minimum memory, that is horrible for performance. 2. cyveris 2 years, 1 month ago. The default value is 25% of -Xms and that is a good value that doesn't need any changing. Committed memory becomes resident in a lazy fashion (resident is actual in RAM, for example). 14. Instead of 200, it may use 300. JVM tuning is not an exact science and will vary across individual. New and used Minecraft Sets & Toys for sale in Victoria, British Columbia on Facebook Marketplace. I have a Java microserive that is increasing in memory daily in production that I have just inheritted. 4. Also if you are using Java 8, no other additionnal args are necessary other than Xmx and Xms. The Xms was increased to give the application a healthy start, and Xmx was significantly raised to accommodate the volume of data during peak times. Assuming that you've downloaded and installed Tomcat as Windows Service Installer exe file from the Tomcat homepage, then check the Apache feather icon in the systray (or when absent, run Monitor. Since GC occurs when the generations fill up, throughput is inversely proportional to the amount of the memory available. -Xms : To set an initial java heap size -Xmx : To set maximum java heap size -Xss : To set the Java thread stack size -Xmn : For setting the size of young generation, rest of the space goes for old generation. プログラムです。. Setting it to a more appropriate value eliminates the overhead of increasing this part of the heap. -Xmn is used with -Xgcpolicy:gencon, but can NOT be used with -Xmx or -Xms By default, the launcher will start the game with -Xmx 512M -Xms -128M Which is fine for running vanilla Minecraft, but bad for Modded Minecraft. 1) For Solution, enter CR with a Workaround if a direct Solution is not available. They control the amount of memory that is available to a Java application. gc()或Runtime. The Z Garbage Collector is enabled with the command-line option -XX:+UseZGC. -Xmx is the maximum of RAM wich Minecraft can allocate. Porém não era um dos melhores e eu sofri para jogar com mods. The -Xmx option sets the maximum size of the heap. and so on. java version "1. 机器. The Java heap can never grow larger than -Xmx. For example, starting a JVM like below will start it with 256. 如果程序运行需要占用更多的内存，超出了这个设置值，就会抛出OutOfMemory异常。. REM ----- REM Default parameters for a basic server. 18, JRE version 17 is required. alla then ktlv gi ayto m dhmiourgithike to pa. 2 Answers. The maximum theoretical heap limit for the 32-bit JVM is 4G. 标志 Xmx 指定Java虚拟机（JVM）的最大内存分配池，而 Xms 指定初始内存分配池。. The numerical size must be a whole number. The -Xms has a lot to do with frame performance. . 为什么一些程序频繁发生GC?有如下原因: l 程序内调用了System. 1 (x86) version 6. The -Xmx option and -Xms option in combination are used to limit the heap size in Java. The amount allocated for the older generation is the value of -Xmx minus the -Xmn. bat settings. 1) It's necessary to avoid heap resize. ・メタスペースの最大値を512MB確保して、それ以上. Consider when Xms == Xmx, I'd expect the heap usage would never quite meet Xms. Souls - After you die, a hostile Soul that stores your inventory will spawn. By using the -Xmx switch can be used to change the maximum heap size. In layman terms this means that the application can use a maximum of 1024MB of memory. PAUSE . For previous versions or if the IDE crashes, you can change the value of the -Xmx option manually as described in JVM options. Explicit Heap Memory – Xms. And yeah, this is a pretty good ram usage for your server. That's it. 6 GB. Why does setting the -Xmx too high sometimes cause the JVM to fail, even if there's available RAM? 0. 通过这个值也可以得到老生. Size of the. Esto significa que la máquina virtual se pondrá en marcha con la cantidad Xms de memoria y será capaz de utilizar un máximo de Xmx cantidad de memoria. Xmn should be set to half of the value specified by the Xmx parameter. -XX:+CheckEndorsedAndExtDirs. The -Xmx option and -Xms option in combination are used to limit the heap size in Java. edit @Aikar "-Xms matching -Xmx"-Xms is allocated at startup and it will grow up to -Xmx, setting ms == mx effectively turns off this behavior. -Xms 堆内存 的初始大小，默认为物理内存的1/64. Format for specifying xms: java -xms{Numerical Size}{Unit} where Unit is k/K for kilobytes, m/M for megabytes, and g/G for gigabytes. Click on the "Edit Profile" button. . When tuning GC, you need to collect the GC statistics over a longer period of time and then act on that. Second point is that -Xms controls the committed memory in the virtual space. You can replace that flag with either -Xmx4G or -Xmx4096M to raise this limit to 4GB.