我遵循了官方文档并编写了以下内容：
# Update repository
sudo apt-get update
# Install necessary things. Like SSL support and JDK
sudo apt-get install apt-transport-https default-jdk -y
# Download and install the GPG KEY. Add the repository for elasticsearch version 7. Update and install logstash
wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-7.x.list
sudo apt-get update && sudo apt-get install logstash -y
# configure ES daemon
sudo /bin/systemctl daemon-reload
sudo /bin/systemctl enable logstash.service
sudo systemctl start logstash.service
但出现了以下内容：
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.headius.backport9.modules.Modules to method sun.nio.ch.NativeThread.signal(long)
WARNING: Please consider reporting this to the maintainers of com.headius.backport9.modules.Modules
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/pleaserun-0.0.31/lib/pleaserun/platform/base.rb:112: warning: constant ::Fixnum is deprecated
Successfully created system startup script for Logstash
Created symlink /etc/systemd/system/multi-user.target.wants/logstash.service → /etc/systemd/system/logstash.service.
尽管它是在我运行以下命令手动测试时安装的：
/usr/share/logstash/bin/logstash -e "input { stdin { } } output { stdout {} }"
并且错误重复并且不允许做任何事情。
luis@ubuntu18:~$ /usr/share/logstash/bin/logstash -e "input { stdin { } } output { stdout {} }"
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.headius.backport9.modules.Modules (file:/usr/share/logstash/logstash-core/lib/jars/jruby-complete-9.2.11.1.jar) to method sun.nio.ch.NativeThread.signal(long)
WARNING: Please consider reporting this to the maintainers of com.headius.backport9.modules.Modules
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
WARNING: Could not find logstash.yml which is typically located in $LS_HOME/config or /etc/logstash. You can specify the path using --path.settings. Continuing using the defaults
Could not find log4j2 configuration at path /usr/share/logstash/config/log4j2.properties. Using default config which logs errors to the console
[FATAL] 2020-07-18 21:49:19.544 [main] runner - An unexpected error occurred! {:error=>#<ArgumentError: Path "/usr/share/logstash/data" must be a writable directory. It is not writable.>, :backtrace=>["/usr/share/logstash/logstash-core/lib/logstash/settings.rb:528:in `validate'", "/usr/share/logstash/logstash-core/lib/logstash/settings.rb:288:in `validate_value'", "/usr/share/logstash/logstash-core/lib/logstash/settings.rb:199:in `block in validate_all'", "org/jruby/RubyHash.java:1415:in `each'", "/usr/share/logstash/logstash-core/lib/logstash/settings.rb:198:in `validate_all'", "/usr/share/logstash/logstash-core/lib/logstash/runner.rb:310:in `execute'", "/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/clamp-0.6.5/lib/clamp/command.rb:67:in `run'", "/usr/share/logstash/logstash-core/lib/logstash/runner.rb:268:in `run'", "/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/clamp-0.6.5/lib/clamp/command.rb:132:in `run'", "/usr/share/logstash/lib/bootstrap/environment.rb:88:in `<main>'"]}
[ERROR] 2020-07-18 21:49:19.633 [main] Logstash - java.lang.IllegalStateException: Logstash stopped processing because of an error: (SystemExit) exit
我不知道是因为java版本(openjdk 11.0.7 2020-04-14(还是其他错误。我从来没有使用过java，所以这些错误让我有点困惑。谢谢大家。
查看下面一行特定的错误堆栈跟踪，这意味着/usr/share/logstash/data对于运行logstash进程的用户来说是不可写的
错误=><ArgumentError：路径"/usr/share/logstash/data"；必须写入目录。它不可写>，
这不是java问题，而是权限问题，您需要将写访问权限授予运行此进程的该文件夹上的用户，并且有大量资源可供使用。