本文介绍flume后台启动方式，运行日志查看
处理的问题
flume 普通方式启动会有自己自动停掉的问题，这可能是linux的进程机制把他停掉的原因。
普通运行方式：
./flume-ng agent -c ../conf -f ../conf/g01-taildir-avro-sink.conf -n agent1 -Dflume.root.logger=INFO,consoleflume后台运行
nohup加在原命令头，&加在原命令尾部
nohup ./flume-ng agent -c ../conf -f ../conf/g01-taildir-avro-sink.conf -n agent1 -Dflume.root.logger=INFO,console &有人说直接加 & 就可以了，对，但是再加上nohup可以把原本在console输出的运行日志输出在nohup.out中
flume运行日志查看
这里介绍两种方式
nohup后台启动查看控制台日志
以nohup 和 & 组合的运行方式，会将原本在console的输出定向到flume的bin目录下的nohup.out文件中。
大多flume博文都有介绍flume的启动命令，但是命令都是将运行日志打印在控制台，这是入门级的demo运行方式，实际上flume原本就配置了运行日志输出位置，如下小节说明
flume运行日志根据log4j.properties配置输出
在flume的配置文件目录及 conf 目录中有log4j.properties配置文件，其实就已经配置了flume启动日志输出位置。
【log4j.prpoerties】
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
#
# Define some default values that can be overridden by system properties.
#
# For testing, it may also be convenient to specify
# -Dflume.root.logger=DEBUG,console when launching flume.
#flume.root.logger=DEBUG,console
flume.root.logger=INFO,LOGFILE
flume.log.dir=./logs
flume.log.file=flume.log
log4j.logger.org.apache.flume.lifecycle = INFO
log4j.logger.org.jboss = WARN
log4j.logger.org.mortbay = INFO
log4j.logger.org.apache.avro.ipc.NettyTransceiver = WARN
log4j.logger.org.apache.hadoop = INFO
log4j.logger.org.apache.hadoop.hive = ERROR
# Define the root logger to the system property "flume.root.logger".
log4j.rootLogger=${flume.root.logger}
# Stock log4j rolling file appender
# Default log rotation configuration
log4j.appender.LOGFILE=org.apache.log4j.RollingFileAppender
log4j.appender.LOGFILE.MaxFileSize=100MB
log4j.appender.LOGFILE.MaxBackupIndex=10
log4j.appender.LOGFILE.File=${flume.log.dir}/${flume.log.file}
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%d{dd MMM yyyy HH:mm:ss,SSS} %-5p [%t] (%C.%M:%L) %x - %m%n
# Warning: If you enable the following appender it will fill up your disk if you don't have a cleanup job!
# This uses the updated rolling file appender from log4j-extras that supports a reliable time-based rolling policy.
# See http://logging.apache.org/log4j/companions/extras/apidocs/org/apache/log4j/rolling/TimeBasedRollingPolicy.html
# Add "DAILY" to flume.root.logger above if you want to use this
log4j.appender.DAILY=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.DAILY.rollingPolicy=org.apache.log4j.rolling.TimeBasedRollingPolicy
log4j.appender.DAILY.rollingPolicy.ActiveFileName=${flume.log.dir}/${flume.log.file}
log4j.appender.DAILY.rollingPolicy.FileNamePattern=${flume.log.dir}/${flume.log.file}.%d{yyyy-MM-dd}
log4j.appender.DAILY.layout=org.apache.log4j.PatternLayout
log4j.appender.DAILY.layout.ConversionPattern=%d{dd MMM yyyy HH:mm:ss,SSS} %-5p [%t] (%C.%M:%L) %x - %m%n
# console
# Add "console" to flume.root.logger above if you want to use this
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.target=System.err
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d (%t) [%p - %l] %m%n
然而大多博文的命令都是如此：……. -Dflume.root.logger=INFO,console
./flume-ng agent -c ../conf -f ../conf/g01-taildir-avro-sink.conf -n agent1 -Dflume.root.logger=INFO,console其中
-Dflume.root.logger=INFO,console 就表示将运行日志输出到控制台。
那么把该条删除就可以按照log4j的配置输出到对应日志文件中
注意，如果没有输出到对应日志文件，那么看下flume的lib包中是否含有log4j的依赖jar包
log4j-1.2.16.jar
slf4j-api-1.6.4.jar
slf4j-log4j12-1.6.1.jar