The Logs page presents log information for Hadoop services, filtered by service, role, host, or search phrase as well log level (severity).
To configure logs, see Configuring Log Events.
- Select on the top navigation bar.
- Click Search.
The logs for all roles display. If any of the hosts cannot be searched, an error message notifies you of the error and the host(s) on which it occurred.
Log results are displayed in a list with the following columns:
- Host - The host where this log entry appeared. Clicking this link will take you to the Host Status page (see Host Details).
- Log Level - The log level (severity) associated with this log entry.
- Time - The date and time this log entry was created.
- Source - The class that generated the message.
- Message - The message portion of the log entry. Clicking View Log File displays the Log Details page, which presents a display of the full log, showing the selected message (highlighted) and the 100 messages before and after it in the log.
If there are more results than can be shown on one page (per the Results per Page setting you selected), Next and Prev buttons let you view additional results.
You filter logs by selecting a time range and specifying filter parameters.
You can use the Time Range Selector or a duration link ( ) to set the time range. (See Time Line for details). However, logs are, by definition, historical, and are meaningful only in that context. So the Time Marker, used to pinpoint status at a specific point in time, is not available on this page. The Now button () is available.
- Specify any of the log filter parameters:
- Search Phrase - A string to match against the log message content. The search is case-insensitive, and the string can be a regular expression, such that wildcards and other regular expression primitives are supported.
- Select Sources - A list of all the service instances and roles currently instantiated in your cluster. By default, all services and roles are selected to be included in your log search; the All Sources checkbox lets you select or deselect all services and roles in one operation. You can expand each service and limit the search to specific roles by selecting or deselecting individual roles.
- Hosts - The hosts to be included in the search. As soon as you start typing a hostname, Cloudera Manager provides a list of hosts that match the partial name. You can add multiple names, separated by commas. The default is to search all hosts.
- Minimum Log Level - The minimum severity level for messages to be included in the search results. Results include all log entries at the selected level or higher. This defaults to WARN (that is, a search will return log entries with severity of WARN, ERROR, or FATAL only.
- Additional Settings
- Search Timeout - A time (in seconds) after which the search will time out. The default is 20 seconds.
- Results per Page - The number of results (log entries) to be displayed per page.
- Click Search. The Logs list displays the log entries that match the specified filter.
The Log Details page presents a portion of the full log, showing the selected message (highlighted), and messages before and after it in the log. The page shows you:
- The host
- The role
- The full path and name of the log file you are viewing.
- Messages before and after the one you selected.
The log displays the following information for each message:
- Time - the time the entry was logged
- Log Level - the severity of the entry
- Source - the source class that logged the entry
- Log Message
You can switch to display only messages or all columns using the buttons.
In addition, from the Log Details page you can:
- View the log entries in either expanded or contracted form using the buttons to the left of the date range at the top of the log.
- Download the full log using the Download Full Log button at the top right of the page.
- View log details for a different host or for a different role on the current host, by clicking the Change... link next to the host or role at the top of the page. In either case this shows a pop-up where you can select the role or host you want to see.