Foglight for Sybase 5.7.5.40 - User and Reference Guide

Buffer Pools Dashboard

Buffer Pools Dashboard

The Buffer Pools dashboard provides performance details for cache operations. This dashboard contains the following:

•	Data Cache Activity Tab

•	Buffer Pools Activity Tab

•	Procedure Cache Activity Tab

•	Data Caches Spinlocks Tab

Data Cache Activity Tab

Data Cache Activity Tab

Data Cache can be divided to Buffer Pools with different I/O sizes.

The cache objects shown in this table are determined by the values set for the following Sybase_MDA agent properties:

•	Cached Objects - Max Rows Returned

•	Cached Objects - Minimum Threshold Value

•	Cached Objects - Sort Criteria

For more information, see Setting Data Retrieval Properties.

Data cache information is provided in a table and charts:

•	Data Cache Activity Table

This table includes two Data Cache Activity Buttons, which provide a simple way to find peaks times.

•	Data Cache Activity Charts

Figure 27. Data Cache Activity Charts

Data Cache Activity Buttons

 

Table 40. Data Cache Activity Buttons Description

Name	Description
Cache Hit Rate Periods	A popup table lists: • Start Time • End Time • Data Cache Summary dcache_hit_rate (%): minimum, average, and maximum. The minimum value is plotted in the Data Cache Activity Charts, Data Cache Hit Rate chart.
Cache Hits - Misses	A popup table lists: • Start Time • End Time • Data Cache Summary Cache Hits/s (c/s): minimum, average, and maximum. • Data Cache Summary Cache Misses/s (c/s): minimum, average, and maximum.

Data Cache Activity Table

You can drill down by clicking any table field. A popup appears providing further drill downs to:

•	Cache Detail Graph— Sybase Data Each Detail Graph popup appears showing Hit Rate Average (in percent) and Hit Rate Minimum (in percent) plotted over time.

•	Cached Objects Table—a Data Cache Objects Table Popup appears.

 

Table 41. Data Cache Activity Table Description

Name	Description
Cache Name	The name of the cache.
Last Sample
Hit Rate %	The percentage of times a requested procedure was found and therefore not read into the named cache.
Cache Hits (buffers) per sec	The number of times per second a requested page was found and therefore not read into the named cache.
Cache Hits (buffers) count	The number of buffers retrieved (that is, the number of Logical Reads) from the cache.
Cache Misses (buffers) per sec	The number of times per second a requested page had to be read into the named cache because it was not found.
Cache Misses (buffers) count	The number of buffers read (that is, the number of Physical Reads) into the cache from disk.
“Dirty” Buffer Retrievals	The number of dirty buffer retrievals.
Time Range Period:
Hit Rate	The number of times per second a requested page was found and therefore not read into the named cache for the selected time range. You can drill down by clicking on any field in this column. A popup appears showing the following three values, plotted over time: • Reads for this device. • APFs (Asynchronous Prefetch Activity) reads for this device. • Writes for this device.
Avg. Hit Rate %	The average percentage of times a requested page was found and therefore not read into the named cache for the selected time range.
Avg. Cache Hits (buffers) per sec	The average number of cache hits per second for the selected time range.
Avg. Cache Hits (buffers) count	The average number of cache hits for the selected time range.
Avg. Cache Misses (buffers) per sec	The average number of cache misses per second for the selected time range.
Avg. Cache Misses (buffers) count	The average number of cache misses for the selected time range.

Data Cache Objects Table Popup

 

Table 42. Data Cache Objects Table Popup Description

Name	Description
Cache Name	The name of the cache.
Name	The name of the data cache object.
Index ID	The identifier of the index. If this value is: • zero, then the table is cached • greater than zero, then the index is cached.
DB Name	The database name.
Cached (MB)	The amount of cached memory in megabytes.
Total Size (MB)	The total size of the cached object in the database in megabytes. NOTE: This field only shows data for Sybase version 15 and later.
Percent Cached	The percentage of the total object's size that is cached memory. NOTE: This field only shows data for Sybase version 15 and later.
Process Accessing	The number of processes currently accessing the object. NOTE: This field only shows data for Sybase version 15 and later.

Data Cache Activity Charts

 

Table 43. Data Cache Activity Charts Description

Name	Description
Data Cache Summary	The following three values are the total for all of the monitored caches, plotted over time: • Number of hits per second. • Number of misses per second. • Number of dirty buffer retrievals per second.
Data Cache Hit Rate	The following two values for the monitored caches, plotted over time: • Cache Hit Average. • Cache Hit Minimum.

Buffer Pools Activity Tab

Buffer Pools Activity Tab

Buffer pools information is provided in a table and charts:

•	Buffer Pools Spaces Table

•	Buffer Pools Charts

Figure 28. Buffer Pools Activity Tab

Buffer Pools Spaces Table

 

Table 44. Buffer Pools Spaces Table Description

Name	Description
Cache Name/Pool	The name of the cache being monitored.
Pool Size (MB)	The number of megabytes that have been allocated for the pool.
Last Sample
Physical Reads incl. APF (buffers)	The number of buffers, including APF (Asynchronous Prefetch Activity) that have been read from disk into the pool.
Physical Reads (Pages)	The number of buffer pages that have been read from disk into the pool.
Pages Touched	The number of pages that are currently being used within the pool.
Percent Used (%)	Data space used as a percentage of total data space available.
Buffers Grabbed Dirty	The number of dirty buffer retrievals.
Time Range Period (Average)
Physical Reads incl. APF (buffers)	The number of buffers, including APF (Asynchronous Prefetch Activity) that have been read from disk into the pool for this time period.
Buffers Grabbed Dirty	The number of dirty buffer retrievals for this time period.
Pages to LRU	The number of buffers that were fetched and replaced in the least recently used portion of the pool.
Pages to MRU	The number of buffers that were fetched and replaced in the most recently used portion of the pool.

Buffer Pools Charts

 

Table 45. Buffer Pools Charts Description

Name	Description
Data Cache Summary	The following three values, plotted over time: • Dirty Buffers per second • Hits per second • Miss per second
Data Cache Hit Rate	The Hit Rate Average plotted over time:

Procedure Cache Activity Tab

Procedure Cache Activity Tab

Procedure cache activity information is provided in a table and charts:

•	Procedures Cache Activity Table

•	Procedure Cache Activity Charts

Figure 29. Procedure Cache Activity Tab

Procedures Cache Activity Table

 

Table 46. Procedures Cache Activity Table Description

Name	Description
Cache Size (MB)	The size of the cache in megabytes.
Last Sample
Hit Rate %	The percentage of times a requested page was found and therefore not read into the named cache.
Procedure Requests per sec	The number of procedure requests per second resulting in reads from disk.
Procedure Requests count	The number of procedure requests resulting in reads from disk.
Procedure Loads per sec	The number of procedures per second loaded into cache.
Procedure Loads count	The number of procedures loaded into cache.
Time Range Period:
Hit Rate	The number of times per second a requested page was found and therefore not read into the named cache for the selected time range. You can drill down by clicking on any field in this column. A popup appears showing the following three values, plotted over time: • Reads for this device. • APFs (Asynchronous Prefetch Activity) reads for this device. • Writes for this device.
Avg. Proc. Hit Rate %	The average percentage of procedure requests resulting in reads from disk.
Avg. Proc. Requests per sec	The average number of procedure requests per second resulting in reads from disk.
Avg. Proc. Requests count	The average number of procedure requests resulting in reads from disk.
Avg. Proc. Loads per sec	The average number of procedures per second loaded into cache.
Avg. Proc. Loads count	The average number of procedures loaded into cache.

Procedure Cache Activity Charts

 

Table 47. Procedure Cache Activity Charts Description

Name	Description
Procedure Cache Summary	The following three values are the total for all of the monitored procedure caches, plotted over time: • Loads per second. • Requests per second. • Writes per second.
Procedure Cache Hit Rate	The Hit Rate Average plotted over time.