Hi everyone,   I’m encountering a critical issue with HBase 2.x: the RegionServer fails to connect to the Master, throwing a “GSS initiate failed” error.   Environment: Master node: host117 RegionServer node: host121 Kerberos security is enabled   To troubleshoot this, I’ve performed the following checks and fixes—all verified as successful (:white_heavy_check_mark: ):   Time Synchronization Clock skew across cluster nodes is only 8 seconds, well within Kerberos tolerance (typically ≤ 5 minutes). Hostname Resolution Added explicit entries in /etc/hosts for both host117 and host121 to ensure bidirectional hostname resolution, eliminating potential Kerberos failures due to DNS issues. Network Connectivity Confirmed TCP connectivity to the Master’s RPC port using telnet host117 16000. Kerberos Client Configuration (/etc/krb5.conf) Verified KDC is reachable and TGS requests succeed. Confirmed support for AES256 and AES128 encryption types, matching HBase requirements. JAAS Configuration Fix Added the Server login module in the JAAS config file. Ensured critical parameters are correctly set: useKeyTab=true, valid keyTab path, and accurate principal. Explicitly set useTicketCache=false to prevent ticket cache interference with keytab-based authentication. HBase Security Settings (hbase-site.xml) Confirmed hbase.security.authentication=kerberos. Validated correct configuration of hbase.master.kerberos.principal and hbase.regionserver.kerberos.principal. Kerberos Ticket Acquisition & Validation Successfully obtained tickets using kinit -kt <keytab> <principal>. Verified ticket validity, service principal, and encryption type via klist. Ticket Cache Cleanup Ran kdestroy to clear any stale tickets that might cause conflicts.   Despite all the above checks passing, the issue persists. Has anyone else encountered a similar “GSS initiate failed” error? Any suggestions on what I might have missed or additional debugging steps would be greatly appreciated!   ... View more