= 2009-09-07 =

 * Hadoop 測試叢集安裝 Ganglia 環境 - http://hadoop.nchc.org.tw/ganglia
  * 目前 hadoop 叢集有一台似乎常出現 ata 的錯誤
  * [[Image(09-09-07_hadoop.jpg,width=400)]]
 * [wiki:jazz/drbl-ganglia DRBL 與 Ganglia 的整合測試]
  * [狀況] VMWare Host-Only 不支援 Multicast ??
  * [參考] [http://kerneltrap.org/node/16225 Localhost does not Response to Ping to Multicast Address 224.0.0.1]
   * 如果沒辦法 ping 224.0.0.1 的話，代表 Broadcast ICMP 封包被濾掉了，因為預設 Linux kernel 2.6 是 disable 的。解法如下：
{{{
# echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
}}}
  * [參考] [http://yalb.net/?p=137 enabling multicast ping on modern Linux distros]
   * 另一個解法是寫在 /etc/sysctl.conf 並執行 sysctl -p 即可。
{{{
~# echo "net.ipv4.icmp_echo_ignore_broadcasts = 0" >> /etc/sysctl.conf
~# sysctl -p
net.ipv4.ip_forward = 1
net.ipv4.icmp_echo_ignore_broadcasts = 0
}}}

== Ganglia ==

 * [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=239582 ganglia-monitor: Lm-sensors support]
  * 如果要讓 Ganglia 支援其他軟體，可以使用 [http://wiki.apache.org/hadoop/GangliaMetrics gmetric]
  * [http://code.google.com/p/embeddedgmetric/  embeddedgmetric] - a simple interface (c/c++/python/perl/php/java) to inject 'gmetric' data into gmond
 * [http://www.cloudera.com/blog/2009/03/12/hadoop-metrics/ Hadoop Metrics]
  * Cloudera 的文章，說明 Hadoop 可以用 [http://java.sun.com/developer/technicalArticles/J2SE/jconsole.html jconsole], Ganglia, 以及支援 Java Management Extensions (JMX) 的 [http://hyperic.com/ Hyperic] 或 [http://www.nagios.org/ Nagios]，[http://crawler.archive.org/cmdline-jmxclient/downloads.html cmdline-jmxclient], [http://www.jboss.org/community/docs/DOC-12458 Twiddle], [http://www.nagiosexchange.org/cgi-bin/page.cgi?g=Detailed%2F2338.html;d=1 check_jmx]