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12-16-2024
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@divyank Have you resolved this issue if not the issue you're encountering is common when Kerberos is enabled for HDFS, as it introduces authentication requirements that need to be properly configured. Here’s how to diagnose and resolve the problem: 1. Root Cause Analysis When Kerberos is enabled: Authentication: Every interaction with HDFS now requires a Kerberos ticket. Misconfiguration: The HDFS service or client-side configurations may not be aligned with Kerberos requirements. Keytabs: Missing or improperly configured keytab files for the HDFS service or users accessing the service. Browser Access: The HDFS Web UI may not support unauthenticated access unless explicitly configured. 2. Steps to Resolve Step 1: Verify Kerberos Configuration Check the Kerberos principal and keytab file paths for HDFS in Cloudera Manager: Navigate to HDFS Service > Configuration. Look for settings like: hadoop.security.authentication → Should be set to Kerberos. dfs.namenode.kerberos.principal → Should match the principal defined in the KDC. dfs.namenode.keytab.file → Ensure the file exists on the NameNode and has correct permissions. Step 2: Validate Kerberos Ticket Check if the HDFS service has a valid Kerberos ticket: klist -kte /path/to/hdfs.keytab If missing, reinitialize the ticket: kinit -kt /path/to/hdfs.keytab hdfs/<hostname>@<REALM> Test HDFS access from the command line: hdfs dfs -ls / If you get authentication errors, the Kerberos ticket might be invalid. Step 3: Validate HDFS Web UI Access Post-Kerberos, accessing the HDFS Web UI (e.g., http://namenode-host:50070) often requires authentication. By default: Unauthenticated Access: May be blocked. Browser Integration: Ensure your browser is configured for Kerberos authentication or the UI is set to allow unauthenticated users. Enable unauthenticated access in Cloudera Manager (if needed): Go to HDFS Service > Configuration. Search for hadoop.http.authentication.type and set it to simple. Step 4: Review Logs for Errors Check NameNode logs for Kerberos-related errors: less /var/log/hadoop/hdfs/hadoop-hdfs-namenode.log Look for errors like: "GSSException: No valid credentials provided" "Principal not found in the keytab" Step 5: Synchronize Clocks Kerberos is sensitive to time discrepancies. Ensure all nodes in the cluster have synchronized clocks ntpdate <NTP-server> Step 6: Restart Services Restart the affected HDFS services via Cloudera Manager after making changes: Restart NameNode, DataNode, and HDFS services. Test the status of HDFS hdfs dfsadmin -report 3. Confirm Resolution Verify HDFS functionality: Test browsing HDFS via the CLI: hdfs dfs -ls / Access the Web UI to confirm functionality: http://<namenode-host>:50070 If HDFS is working via CLI but not in the Web UI, revisit the Web UI settings in Cloudera Manager to allow browser access or configure browser Kerberos support. 4. Troubleshooting Tips If the issue persists: Check the Kerberos ticket validity with: klist Use the following commands to troubleshoot connectivity: hdfs dfs -mkdir /test hdfs dfs -put <local-file> /test Let me know how it goes or if further guidance is needed!
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