Posts Categorized: hadoop

Datanode denied communication with namenode

hadoop

In a Cloudera cluster we had a few nodes reporting the following error message in the logs under hadoop-cmf-hdfs-DATANODE-whatever.com.log.out The error included: Datanode denied communication with namenode because the host is not in the include-list: : DatanodeRegistration One solution could be to ‘Refresh Node List’ as shown in the screenshot below. Find it by clicking… Read more »

Browsing Hadoop HDFS on the Command Line

big data, hadoop

Using the Hadoop command we can send fairly regular filesystem commands to navigate HDFS. On Cloudera I am sending commands to port 8020 of the active name node. If you don’t have the hadoop command available on your system you need to download hadoop, extract it and add the bin directory to your path. For… Read more »

Cloudera Hue User Password Reset

hadoop

I needed to access the Hue file browser service  and for my version of cloudera this was: cd /opt/cloudera/parcels/CDH-5.7.6-1.cdh5.7.6.p0.6/lib/hue Run the createuser command: ./build/env/bin/hue createsuperuser Username (leave blank to use ‘joebloggs’): Email address: joebloggs@whatever.tld Password: Password (again): Superuser created successfully.