我正在尝试让 JBoss WildFly 15.0.1 Final 在一个相当小的 ubuntu 14.04 vServer 上启动。服务器只有2 GB的 RAM。
我多次尝试启动 WildFly，但均未成功。JVM 似乎需要比我预想的更多的 RAM。
这是控制台输出：
root@t2g55:~# service wildfly start
* Starting WildFly Application Server wildfly
* WildFly Application Server failed to start within the timeout allowed.
root@t2g55:~# cat /var/log/wildfly/console.log
=========================================================================
JBoss Bootstrap Environment
JBOSS_HOME: /opt/wildfly
JAVA: /usr/bin/java
JAVA_OPTS: -server -Xms768m -Xmx1536m -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=256m -Djava.net.preferIPv4Stack=true -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true
=========================================================================
OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000a0000000, 536870912, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 536870912 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /opt/wildfly-15.0.1.Final/hs_err_pid1379.log
1379
root@t2g55:~# free
total used free shared buffers cached
Mem: 2097152 258748 1838404 64 0 38644
-/+ buffers/cache: 220104 1877048
Swap: 2097152 0 2097152
root@t2g55:~# java -version
openjdk version "1.8.0_222"
OpenJDK Runtime Environment (build 1.8.0_222-8u222-b10-1~14.04-b10)
OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)
root@t2g55:~#
如您所见，我指定JAVA_OPTS: -server -Xms768m -Xmx1536m ...了 ，我认为这足以启动 WildFly 服务器。请不要，它standalone.xml有一个定义为 MySQL 数据库的数据源。
这是转储 .log 的开始：
root@t2g55:~# cat /opt/wildfly-15.0.1.Final/hs_err_pid1379.log
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 536870912 bytes for committing reserved memory.
# Possible reasons:
# The system is out of physical RAM or swap space
# The process is running with CompressedOops enabled, and the Java Heap may be blocking the growth of the native heap
# Possible solutions:
# Reduce memory load on the system
# Increase physical memory or swap space
# Check if swap backing store is full
# Decrease Java heap size (-Xmx/-Xms)
# Decrease number of Java threads
# Decrease Java thread stack sizes (-Xss)
# Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
# Out of Memory Error (os_linux.cpp:2757), pid=1379, tid=0x00007f62486c6700
#
# JRE version: (8.0_222-b10) (build )
# Java VM: OpenJDK 64-Bit Server VM (25.222-b10 mixed mode linux-amd64 compressed oops)
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
--------------- T H R E A D ---------------
.
.
.
问题：
可以用这么多的内存来解决这个问题，还是我的内存太少了？我还能尝试什么？
我真的不希望我的提供者连续使用内存，只是发现 Java、JVM 或任何其他问题...
谢谢
编辑1：
vServer 提供程序使用 OpenVZ 进行虚拟化。
信息：他们只是把我推到4GB，然后有一次，我让 JBoss 启动并运行。重新启动后，WildFly 再次拒绝启动：同样的事情，内存不足（即使我在 Java 8 和 Java 11 运行时之间切换）。
CMD 启动 JBoss WildFly: sh /opt/wildfly/bin/standalone.sh &，standalone.xml 似乎没问题。我删除了 ExampleDS，评论了三个条目。