SysAdmin

Configure AES-NI accelerated encryption in transit for HDFS by setting the cipher suite and key length in hdfs-site.xml on both the NameNode/DataNode and client sides.

Java reads its Kerberos configuration from a fixed set of paths before falling back to the system default. Setting KRB5_CONFIG lets you point a Java application at a custom krb5.conf without touching the OS-level file.

Hadoop requires OS-level user accounts on every cluster node regardless of security configuration. This post explains why, covering both secure and simple mode, and addresses whether the requirement can be removed.

Learn how to check and interpret the kernel entropy pool on Linux, why low entropy can slow down SSL handshakes and SSH sessions, and what to do when the pool runs dry.

Inconsistent forward and reverse DNS lookups can cause a cascade of cluster and security issues. This guide walks through quick Python and Java one-liners to verify that your hostname, IP, and reverse record all line up.

A quick reference for verifying AES-NI hardware acceleration across Java, OpenSSL, and the CPU itself. Includes benchmark commands to confirm the instruction set is actually being used.