Single Cache

Single Cache displays present detailed cache performance metrics for a single cache. Use the Single Cache displays to perform cache utilization analysis. The data in these displays can be sorted and viewed by service or cache.

Single Cache Summary

Use Single Cache - Summary display to do low level cache utilization analysis. Check the metrics for Size, Evictions and Misses to determine whether more capacity is needed. Cache Summary provides summary information about an individual cache.

Cluster	Select a cluster to display.
Service	Select a service to display.
Cache	Select a cache. Click the Detail button to get information specific to the selected cache.
Front	Select for front tier, deselect for back tier.
Type	The type identifier string from the ServiceMBean (ReplicatedCache, DistributedCache, etc.).
Client Nodes	The number of cluster nodes that do not have storage enabled.
Storage Nodes	Select to display storage node data in the trend graphs of this display.
Type	The type of cache.
Storage Nodes	The number of storage nodes in the cache.
Status	The high availability status of the service: ENDANGERED: There is potential data loss in the cluster if a node goes offline. NODE-SAFE: There is no risk of data loss in the cluster if a node goes offline (or is taken offline using kill-9). The data is replicated across multiple nodes and remains available in the cluster. MACHINE-SAFE: There is no risk of data loss in the cluster if a machine goes offline (or is taken offline using kill-9). The data is replicated across multiple machines and remains available in the cluster. RACK-SAFE: There is no risk of data loss in the cluster if a rack goes offline (or is taken offline using kill-9). The data is replicated across multiple racks and remains available in the cluster. SITE-SAFE: There is no risk of data loss in the cluster if a site goes offline (or is taken offline using kill-9). The data is replicated across multiple sites and remains available in the cluster.
Size	Units indicates memory usage for the back tier and number of objects for the front tier. Objects The number of objects in the selected cache. The value is the total across all storage nodes. Avg Size The average size of objects in the selected cache (in bytes if it is the back tier). Units The memory usage if back tier, or number of objects if front tier. The value is the total across all storage nodes. High Units Maximum memory, or number of objects allowed before Coherence starts to evict objects from the selected cache. The value is the total across all storage nodes. Low Units The level of memory, or number of objects to which Coherence will reduce the cache during the eviction process. The value is the total across all storage nodes.
Persistence	Type The persistence type for the cache. Possible values include: NONE, READ-ONLY, WRITE-THROUGH, and WRITE-BEHIND. Failures The number of write (cache store) failures, including load, store and erase operations. NOTE: This value is -1 if the persistence type is NONE. Wr Queue The size of the queue, in kilobytes, that holds data scheduled to be written to the cache store. Writes The number of objects (cache entries) written to the cache store.
Activity	Current: Use the Use Rates checkbox to toggle between two value types: Activity - Current (Rate) and Activity - Current (Delta) (as labeled in the display upon selection).When the Use Rates (checkbox) is NOT selected the Delta values are shown in the Activity - Current (Delta) fields and trend graphs. Delta is the difference in the value since the last sample. When the Use Rates (checkbox) is selected the Rate values are shown in the Activity - Current (Rate) fields and trend graphs. Rate is the value per second. The Rate value is useful when the sampling time period is unknown, has changed, or has a long duration specified. For a given rate, the Rate value does not vary if the sample period changes (whereas the Delta value does vary). The Rate value enables you to directly compare rates on systems with different sample periods. Cumulative: The total since the service was started for the selected cache, or since statistics were reset. Gets The number of requests for data from this cache. Hits The number of successful gets. Misses The number of failed gets. Puts The number of data stores into this cache. Evictions The number of objects removed to make room for other objects.
Use Rates	Select Use Rates to show the Rate values in the Activity - Current (Rate) fields and trend graphs. Rate is the value per second. The Rate value is useful when the sampling time period is unknown, has changed, or has a long duration specified. For a given rate, the Rate value does not vary if the sample period changes (whereas the Delta value does vary). The Rate value enables you to directly compare rates on systems with different sample periods. Deselect Use Rates to show the Delta values in the Activity - Current (Delta) fields and trend graphs. Delta is the difference in the value since the last sample.
Log Scale	Enable to use a logarithmic scale for the Y axis. Use Log Scale to see usage correlations for data with a wide range of values. For example, if a minority of your data is on a scale of tens, and a majority of your data is on a scale of thousands, the minority of your data is typically not visible in non-log scale graphs. Log Scale makes data on both scales visible by applying logarithmic values rather than actual values to the data.
Base at Zero	Use zero for the Y axis minimum for all graphs.
Time Range	Select a time range from the drop down menu varying from 2 Minutes to Last 7 Days, or display All Data. To specify a time range, click Calendar . By default, the time range end point is the current time. To change the time range end point, click Calendar and select a date and time from the calendar or enter the date and time in the text field using the following format: MMM dd, YYYY HH:MM. For example, Aug 21, 2011 12:24 PM. Use the navigation arrows to move forward or backward one time period. NOTE: The time period is determined by your selection from the Time Range drop-down menu. Click Restore to Now to reset the time range end point to the current time.
Trend Graphs	Use the Use Rates checkbox to toggle between two value types: Activity - Current (Rate) and Activity - Current (Delta) (as labeled in the display upon selection). Objects The number of objects in the selected cache. The value is the total across all storage nodes. TotalGets Total requests for data from this cache. CacheMisses Total number of failed gets. TotalPuts Total data stores into this cache. EvictionCounts Number of objects removed from the cache to make room for other objects.

Size Trends

Size Trends provides a method of viewing the degree to which available cache size has been consumed. Under normal operations the cache will evict and reload objects into the cache. This will be displayed as a significant drop in the Units Used trend. However, if these drops are too frequent the application might not be performing optimally. Adding capacity and examining or modifying application usage patterns might be required. The data displayed here is a sum of all storage nodes in the cache filtered by the selected service and cache.

Try changing the High Units setting in the Cache Administration page to something like 100,000 and then see the effect on these trend charts.

Activity Trends

Activity Trends provides a set of trend graphs that show the magnitude of the cache usage and the effectiveness of the implementation. If the overall effectiveness is not as desired, increasing capacity, preloading the cache and increasing the eviction time may result in improvements in cache hits. The data displayed here is a sum of all storage nodes in the cache filtered by the selected service and cache.

Cluster	Select a cluster to display.
Service	Select a service to display.
Cache	Select a cache. Click the Detail button to get information specific to the selected cache.
Front	Select for front tier, deselect for back tier.
Log Scale	Enable to use a logarithmic scale for the Y axis. Use Log Scale to see usage correlations for data with a wide range of values. For example, if a minority of your data is on a scale of tens, and a majority of your data is on a scale of thousands, the minority of your data is typically not visible in non-log scale graphs. Log Scale makes data on both scales visible by applying logarithmic values rather than actual values to the data.
Base at Zero	Use zero for the Y axis minimum for all graphs.
Time Range	Select a time range from the drop down menu varying from 2 Minutes to Last 7 Days, or display All Data. To specify a time range, click Calendar . By default, the time range end point is the current time. To change the time range end point, click Calendar and select a date and time from the calendar or enter the date and time in the text field using the following format: MMM dd, YYYY HH:MM. For example, Aug 21, 2011 12:24 PM. Use the navigation arrows to move forward or backward one time period. NOTE: The time period is determined by your selection from the Time Range drop-down menu. Click Restore to Now to reset the time range end point to the current time.
Activity Metrics for Selected Cache	Hits The number of successful gets from this cache. Total Gets Requests for data from this cache. Cache Misses The number of failed gets by this cache. Total Puts The number of data stores into this cache. Evictions The number of objects removed from the cache to make room for other objects. Write Queue The size of the queue, in kilobytes, that holds data scheduled to be written to the cache store.

Cache Detail Tables

This display presents detailed information about the contribution that each storage node makes to the cache. Select a node in the Statistics By Node for Selected Cache table to drill down to the Node Summary display for that node. The data displayed here is broken down for each storage nodes in the cache filtered by the selected service and cache.

Cluster	Select a cluster to display.
Summary	Toggle between this display and Single Cache - Summary display.
Service	Select a service to display.
Cache	Select a cache. Click the Detail button to get information specific to the selected cache.
Front	Select for front tier, deselect for back tier.
Totals for Selected Cache	Objects Number of objects in this cache. Units Total number of units (typically bytes) in this cache. LowUnits Low limit for cache evictions. HighUnits Highest number of units before evictions occur. Hits Total number of successful gets. Misses Total number of failed gets. Gets Total requests for data from this cache. Puts Total data stores into this cache.
Average for Selected Cache	Objects Number of objects in this cache. AvgSize Average size of objects in this cache. Units Average number of units (typically bytes) in this cache. LowUnits Low limit for cache evictions. HighUnits Highest number of units before evictions occur. Hits Average number of successful gets. Misses Average number of failed gets. Gets Average requests for data from this cache. Puts Average data stores into this cache.
Statistics By Node for Selected Cache	The columns in this table, with the exception of Location, come from Cache and Node MBeans. Location is a unique identifier for each node and defined as: member_name.machine.rack.site. For details about attributes of these MBeans go to: http://download.oracle.com/otn_hosted_doc/coherence/350/com/tangosol/net/management/Registry.html.

Storage Manager Detail

This display presents detailed information about the Storage Manager. The data displayed here is queried from the Coherence StorageManagerMBean, filtered by the selected service and cache. Click on a row in the table to open the Storage IndexInfo View window.

Cluster	Select a cluster to display.
Service	Select a service to display.
Cache	Select a cache. Click the Detail button to get information specific to the selected cache.
Storage Manager Data	Location A unique identifier for each node. It is defined as member_name.machine.rack.site. EventsDispatched The total number of events dispatched by the Storage Manager since the last time the statistics were reset. EvictionCount The number of evictions from the backing map managed by this Storage Manager caused by entries expiry or insert operations that would make the underlying backing map to reach its configured size limit. InsertCount The number of inserts into the backing map managed by this Storage Manager. In addition to standard inserts caused by put and invoke operations or synthetic inserts caused by get operations with read-through backing map topology, this counter is incremented when distribution transfers move resources `into` the underlying backing map and is decremented when distribution transfers move data `out`. ListenerFilterCount The number of filter-based listeners currently registered with the Storage Manager. ListenerKeyCount The number of key-based listeners currently registered with the Storage Manager. ListenerRegistrations The total number of listener registration requests processed by the Storage Manager since the last time the statistics were reset. LocksGranted The number of locks currently granted for the portion of the partitioned cache managed by the Storage Manager. LocksPending The number of pending lock requests for the portion of the partitioned cache managed by the Storage Manager. RemoveCount The number of removes from the backing map managed by this Storage Manager caused by operations such as clear, remove or invoke.

Storage IndexInfo View

Click on a row in the Storage Manager Data table to open the Storage IndexInfo View window.

Node/Group Distribution

This display presents the distribution of cache activity across all storage nodes in the cluster. The buttons on the left may be used to select the metric by which all six bar charts are to be sorted. Note that the Gets, Hits, Misses, and Puts are shown in the same color as on the other Cache Analysis displays. The data displayed here is broken down for each storage nodes in the cache filtered by the selected service and cache.

Front/Back Analysis

Cluster	Select a cluster to display.
Service	Select a service to display.
Cache	Select a cache. Click the Detail button to get information specific to the selected cache.
FRONT/BACK	Units: Front Number of objects. The value is the total across all storage nodes for the given tier. Back Memory usage. The value is the total across all storage nodes for the given tier. Cache Size: Total number of objects in the cache for the given tier (Front or Back). NOTE: Same value as Units for Front tier. High Units: Front Number of objects allowed before Coherence starts to evict objects from the selected cache. The value is the total across all storage nodes for the given tier. Back Maximum memory allowed before Coherence starts to evict objects from the selected cache. The value is the total across all storage nodes for the given tier. Low Units: Front Number of objects to which Coherence will reduce the cache during the eviction process. The value is the total across all storage nodes for the given tier. Back The level of memory to which Coherence will reduce the cache during the eviction process. The value is the total across all storage nodes for the given tier.
Cache Hits	Number of successful gets
Cache Misses	Number of failed gets
Total Puts	Data stores into this cache
Service	CPU usage (%) for the node.
Network	Front Sent Packet Failure Rate (%) for the node. Back Received Packet Failure Rate (%) for the node.
Misses	Number of failed gets.
Hits	Number of successful gets.
Total Gets	Total requests for data from this cache.
Total Puts	Total data stores into this cache.

Service	The name of the service.
Cache	The name of the cache.
Location Manager Data	The location of the node associated with the cache. Location is a unique identifier for each node and defined as: member_name.machine.rack.site.
(Index Table)	Each row in the table represents a unique index, where: Extractor = the index name. Ordered = true/false to indicate whether or not the data is sorted (false means the data is not sorted). Size = the number of entries in that cache whose value matches that extractor.