log4j log 送到 logstash log4j input

jvm 程式，像是hadoop solr 可以把log 送到ELK 集中控管

ex: 修改hadoop log4j.properties
log4j.appender.server=org.apache.log4j.net.SocketAppender
log4j.appender.server.Port=4560
log4j.appender.server.RemoteHost=172.1.1.1
log4j.appender.server.LocationInfo=true
log4j.appender.server.Application=hadoop

logstash 設定
input {
  log4j {
    host => "172.1.1.1"
    port => 4560
  }
}
filter {
  grok {
    match => { "host" => "%{IPORHOST:host}:%{POSINT}" }  // 修改1.2.3.4:8888 => 1.2.3.4
    overwrite => [ "host" ]
  }
}

output {
  elasticsearch { hosts => ["localhost:9200"] }
}