Using the Host Inspector
You can use the host inspector to gather information about hosts that Cloudera Manager is currently managing. You can review this information to better understand system status and troubleshoot any existing issues. For example, you might use this information to investigate potential DNS misconfiguration.
The inspector runs tests to gather information for functional areas including:
- System time
- User and group configuration
- HDFS settings
- Component versions
Common cases in which this information is useful include:
- Installing components
- Upgrading components
- Adding hosts to a cluster
- Removing hosts from a cluster
Running the Host Inspector
To use the Host Inspector:
- Click the Hosts tab.
- Click Host Inspector. Cloudera Manager begins several tasks to inspect the managed hosts.
- After the inspection completes, click Download Result Data or Show Inspector Results to review the results.
The results of the inspection displays a list of all the validations and their results, and a summary of all the components installed on your managed hosts.
If the validation process finds problems, the Validations section will indicate the problem. In some cases the message may indicate actions you can take to resolve the problem. If an issue exists on multiple hosts, you may be able to view the list of occurrences by clicking a small triangle that appears at the end of the message.
The Version Summary section shows all the components that are available from Cloudera, their versions (if known) and the CDH distribution to which they belong (CDH3 or CDH4). If you are running CDH3, the Version will be listed as "Unavailable". Version identification is not available with CDH3. In a CDH3 cluster, CDH4 components will be listed as "Not installed or path incorrect".
If you are running multiple clusters with both CDH3 and CDH4, the lists will be organized by distribution (CDH3 or CDH4). The hosts running that version are shown at the top of each list.
Viewing Past Host Inspector Results
You can view the results of a past host inspection by looking for the Host Inspector command using the Recent Commands feature.
- Click the Running Commands indicator () just to the left of the Search box at the right hand side of the navigation bar.
- Click the Recent Commands button.
- If the command is too far in the past, you can use the Time Range Selector to move the time range back to cover the time period you want.
- When you find the Host Inspector command, click its name to display its subcommands.
- Click the Show Inspector Results button to view the report.
See Viewing Running and Recent Commands for more information about viewing past command activity.