The system is waiting for a log switch because the log being switched into has not been archived yet.
The rest of the information in this section is only valid for this metric when it appears in either the Enterprise Manager Grid Control or the Enterprise Manager Database Control (if applicable).
The following table shows how often the metric's value is collected and compared against the default thresholds. The 'Consecutive Number of Occurrences Preceding Notification' column indicates the consecutive number of times the comparison against thresholds should hold TRUE before an alert is generated.
|
Target Version |
Evaluation and Collection Frequency |
Upload Frequency |
Operator |
Default Warning Threshold |
Default Critical Threshold |
Consecutive Number of Occurrences Preceding Notification |
Alert Text |
|
pre-10g |
Every Minute |
After Every Sample |
> |
1 |
5 |
3 |
%value%%% of service time is spent waiting on the 'log file switch (archiving needed)' event. |
(DeltaLogFileSwitchArchTime/DeltaServiceTime)*100 where:
DeltaLogFileSwitchArchTime: difference of 'sum of time waited for sessions of foreground processes on the 'log file switch (archiving needed)' event' between sample end and start
DeltaServiceTime: difference of 'sum of time waited for sessions of foreground processes on events not in IdleEvents + sum of 'CPU used when call started' for sessions of foreground processes' between sample end and start
See Idle Events
Check the alert file to make sure that archiving has not stopped due to a failed archive write. To speed up archiving consider adding more archive processes or putting the archive files on striped disks.
If the archiver is slow, then it might be prudent to prevent I/O contention between the archiver process and LGWR by ensuring that archiver reads and LGWR writes are separated. This is achieved by placing logs on alternating drives.
Related Topics
About Alerts
About the Metric Detail Page
Editing Thresholds
Understanding Line Charts
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