Merge pull request #84674 from dagiro/ts_hbase7

ts_hbase7

Author: GitHubber17

articles/hdinsight/hbase/TOC.yml

@@ -162,6 +162,8 @@
     items:
     - name: Troubleshoot resources  
       href: ../hdinsight-troubleshoot-guide.md?toc=/azure/hdinsight/hbase/toc.json&bc=/azure/hdinsight/hbase/breadcrumb/toc.json
+    - name: Issues with region servers
+      href: ./hbase-troubleshoot-unassigned-regions.md
     - name: Apache Phoenix connectivity issues
       href: ./hbase-troubleshoot-phoenix-connectivity.md
     - name: Apache HBase REST not responding

articles/hdinsight/hbase/hbase-troubleshoot-unassigned-regions.md

@@ -0,0 +1,85 @@
+---
+title: Issues with region servers in Azure HDInsight
+description: Issues with region servers in Azure HDInsight
+ms.service: hdinsight
+ms.topic: troubleshooting
+author: hrasheed-msft
+ms.author: hrasheed
+ms.date: 08/07/2019
+---
+
+# Issues with region servers in Azure HDInsight
+
+This article describes troubleshooting steps and possible resolutions for issues when interacting with Azure HDInsight clusters.
+
+## Scenario: Unassigned regions
+
+### Issue
+
+When running `hbase hbck` command, you see an error message similar to:
+
+```
+multiple regions being unassigned or holes in the chain of regions
+```
+
+From the Apache HBase Master UI, it can be seen that the count of regions being unbalanced across all the region servers.
+
+### Cause
+
+Holes may be the result of offline regions.
+
+### Resolution
+
+Fix the assignments. Follow the steps below to bring the unassigned regions back to normal state:
+
+1. Sign in to HDInsight HBase cluster using SSH.
+
+1. Run `hbase zkcli` command to connect with zookeeper shell.
+
+1. Run `rmr /hbase/regions-in-transition` or `rmr /hbase-unsecure/regions-in-transition` command.
+
+1. Exit zookeeper shell by using `exit` command.
+
+1. Open Ambari UI and restart Active HBase Master service from Ambari.
+
+1. Run `hbase hbck` command again (without any further options). Check the output and ensure that all regions are being assigned.
+
+---
+
+## Scenario: Dead region servers
+
+### Issue
+
+Region servers fail to start.
+
+### Cause
+
+Multiple splitting WAL directories.
+
+1. Get list of current wals: `hadoop fs -ls -R /hbase/WALs/ > /tmp/wals.out`.
+
+1. Inspect the `wals.out` file. If there are too many splitting directories (starting with *-splitting), the region server is probably failing because of these directories.
+
+### Resolution
+
+1. Stop HBase from Ambari portal.
+
+1. Execute `hadoop fs -ls -R /hbase/WALs/ > /tmp/wals.out` to get fresh list of WALs.
+
+1. Move the *-splitting directories to a temporary folder, `splitWAL`, and delete the *-splitting directories.
+
+1. Execute `hbase zkcli` command to connect with zookeeper shell.
+
+1. Execute `rmr /hbase-unsecure/splitWAL`.
+
+1. Restart HBase service.
+
+## Next steps
+
+If you didn't see your problem or are unable to solve your issue, visit one of the following channels for more support:
+
+* Get answers from Azure experts through [Azure Community Support](https://azure.microsoft.com/support/community/).
+
+* Connect with [@AzureSupport](https://twitter.com/azuresupport) - the official Microsoft Azure account for improving customer experience. Connecting the Azure community to the right resources: answers, support, and experts.
+
+* If you need more help, you can submit a support request from the [Azure portal](https://portal.azure.com/?#blade/Microsoft_Azure_Support/HelpAndSupportBlade/). Select **Support** from the menu bar or open the **Help + support** hub. For more detailed information, review [How to create an Azure support request](https://docs.microsoft.com/azure/azure-supportability/how-to-create-azure-support-request). Access to Subscription Management and billing support is included with your Microsoft Azure subscription, and Technical Support is provided through one of the [Azure Support Plans](https://azure.microsoft.com/support/plans/).