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Title
Cluster IC Latency Alerts from an Oracle instance -
Description
Why does Foglight reporting a high latency?
What Oracle object does Foglight query to run the above test?
How often does this test fire?
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Resolution
If there are very high lost block counts (relative to blocks received) – or if the time associated with lost blocks becomes significant compared to total database time – then the most likely cause is a network hardware issue. This can be as simple as a poorly mounted network card, crimped networking cables or faulty network components.
The SQL query itself it proprietary, but what we do is total various sys.v_$sysstat
The collection is called "Cluster Latency" and it has a default offline frequency of 300ms (no one is in the system), 60 seconds for online (if someone is in Foglight), and 20 seconds realtime (if someone is in the DB agent drilldowns).If you access the Topology, the raw data can be seen here:Configuration | Data | All Data | DBO_Data_Model | Oracle Data Model | clusters| instances| cluster_latency