我正在ubuntu 16.04上安装confluent-4.1.1。为了启动zookeeper服务器，我运行了 ./bin/zookeeper-server-start ./etc/kafka/zookeeper.properties.txt 通过遵循本教程从confluent的根目录。
出现的错误是-

log4j:ERROR Could not read configuration file from URL [file:./bin/../config/log4j.properties].
java.io.FileNotFoundException: ./bin/../config/log4j.properties (No such file or directory)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:146)
    at java.io.FileInputStream.<init>(FileInputStream.java:101)
    at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
    at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
    at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:557)
    at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
    at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
    at org.slf4j.impl.Log4jLoggerFactory.<init>(Log4jLoggerFactory.java:66)
    at org.slf4j.impl.StaticLoggerBinder.<init>(StaticLoggerBinder.java:72)
    at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:45)
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
    at org.apache.zookeeper.server.quorum.QuorumPeerMain.<clinit>(QuorumPeerMain.java:64)
log4j:ERROR Ignoring configuration file [file:./bin/../config/log4j.properties].
log4j:WARN No appenders could be found for logger (org.apache.zookeeper.server.quorum.QuorumPeerConfig).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

我是Kafka的新人，我不知道这意味着什么。如有任何帮助，我们将不胜感激。