Expert Oracle Exadata - Parent Directory

CHAPTER 9 RECOVERING EXADATAThe default retention for metric detail is 7 days, after which it will be summarized by min, max, andaverage (at which time the detail records will be purged). The DESCRIBE METRICHISTORY command showsthe structure of the metrichistory object.CellCLI> describe metrichistorynamealertStatecollectionTimemetricObjectNamemetricTypemetricValuemetricValueAvgmetricValueMaxmetricValueMinobjectTypeThe LIST METRICHISTORY command provides a summarized report of the full history of cell metricsstored in the ADR. Usually you will want to apply filters to specify a date range and possibly a metric typefor this report. To do this, provide a WHERE clause with the metric name and a date filter, as in thisexample:CellCLI> list metrichistory -where name like 'CL_.*' -and collectiontime > '2011-01-01T08:00:00-08:00'Cell AlertsIn addition to tracking metrics for storage cell components, Exadata also evaluates these metrics andapplies thresholds to verify that the components are running within normal parameters. When a metriccrosses one of these operational thresholds, an alert is generated. Some of the alerts generated byExadata include cell temperature, cell disk read/write errors, and software failures. Exadata tracks over70 alert types in the storage cell. Additional alerts may be defined using Grid Control’s monitoring andalerting features. Alert severities fall into four categories: Information, Warning, Critical, and Clear.These are used to manage alert notifications. For example, you may choose to get an email alertnotification for critical alerts only. The Clear severity is used to notify you when a component hasreturned to Normal status. The LIST METRICHISTORY DETAIL command can be used to generate a detailedreport of the alerts generated by the system. The following listing is an example of an alert generated bythe storage cell:name: 209_1alertMessage:"All Logical drives are in WriteThrough caching mode.Either battery is in a learn cycle or it needs to bereplaced. Please contact Oracle Support"alertSequenceID: 209alertShortName: HardwarealertType:StatefulbeginTime:2011-01-17T04:42:10-06:00endTime:2011-01-17T05:50:29-06:00examinedBy:metricObjectName: LUN_CACHE_WT_ALLnotificationState: 1sequenceBeginTime: 2011-01-17T04:42:10-06:00282