Archivo mensual: enero 2017

HBase and Zookeeper debugging


I came across some scenarios where an application (i.e. Mapreduce) communicating to HBase through YARN could silently fail with a timeout like the following: 2017-01-30 19:42:03,657 DEBUG [main] org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation: locateRegionInMeta parentTable=hbase:meta, metaLocation=, attempt=9 of 35 failed; retrying after sleep of … Seguir leyendo

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Checking Yarn child execution environment


Never go out without this: $ sudo -u yarn jps 27343 YarnChild 4156 NodeManager 27292 Jps $ sudo strings -f /proc/27343/environ /proc/27343/environ: STDERR_LOGFILE_ENV=/var/log/hadoop-yarn/containers/application_1485807340469_0019/container_1485807340469_0019_01_000003/stderr /proc/27343/environ: SHELL=/bin/bash /proc/27343/environ: TERM=linux /proc/27343/environ: HADOOP_HOME=/usr/lib/hadoop /proc/27343/environ: YARN_PID_DIR=/var/run/hadoop-yarn /proc/27343/environ: NM_HOST=ip-172-31-5-156.us-west-2.compute.internal /proc/27343/environ: HADOOP_PREFIX=/usr/lib/hadoop /proc/27343/environ: YARN_OPTS= -XX:OnOutOfMemoryError=’kill -9 %p’ … Seguir leyendo

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Create multiple files at once with ‘touch’


Sometimes we might need to create thousands or millions of files at once. This command will create the number specified in the range using touch: touch bspl{00001..70000}.c

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