Spark Cluster Mode - Too many open files
When running complex Spark Jobs in Cluster mode (Yarn-Client or Yarn-Cluster) mode, it is quite possible the default ulimit (number of open files) of 1024 is not sufficient and hence gets error "Too many open files". One way to address this is issue is by increasing the ulimit size. Steps (as root user): 1) vim /etc/sysctl.conf, append the file with: fs.file-max = 65536 2) vim /etc/security/limits.conf, append the file with: * soft nproc 65535 * hard nproc 65535 * soft nofile 65535 * hard nofile 65535 3) ulimit -n 65535