Description of the illustration cldbperf002.gif

The screenshot shows the Cluster Cache Coherency page. The introductory text on this page reads "Charts below show time spent by all instances waiting to receive database blocks, global cache transfer rate, and disk & network I/O activity in comparison to logical reads on this cluster database." The page contains the following graphs, from top to bottom: the Global Cache Block Access Latency chart, the Global Cache Block Transfer Rate chart, and the Global Cache Block Transfers and Physical Reads (vs. Logical Reads) chart. Each chart has a title on the top left side of the chart, axis labels, a date at the bottom left side of the chart, and a legend box to the right of the chart. On each chart, the horizontal axis shows the time in five minute increments. Each chart has different lines on it to represent different performance statistics measured.

The Global Cache Block Access Latency chart has the label Milli-seconds for the vertical axis. The legend for this chart lists Average CR Block Receive Time and Average Current Block Access Receive Time.

The Global Cache Block Trasnfer Rate chart has the label Block Per Second for the vertical axis. The legend for this chart lists GC CR Blocks Received and GC Current Blocks Received.

The Global Cache Block Trasnfers and Physical Reads (vs. Logical Reads) chart has the label % for the vertical axis. The legend for this chart lists Global Cache Block Transfers and Physical Reads.

Below the last chart on the page is the following note: "TIP: The latencies for RAC operations should be monitored over time, and significant increases in the values should be investigated. The typical average receive time for a CR block is 5 milliseconds, and the upper bound is 10; the typical average receive time for a current block is 5 milliseconds, and the upper bound is 10."

The text preceding the screenshot explains how to access this page. The text following the screenshot explains how to access the Cluster Cache Coherency Instances page, and explains the purpose of the Cluster Cache Coherency page.

End of description.