Service time histogram buckets, Io size histogram buckets, The statpd table – HP 3PAR System Reporter Software User Manual

Page 210

Advertising
background image

Table 79 Common Performance Metrics for a Sample Row

SQL Expression

Metric

CASE WHEN d_now > 0 THEN d_rcount * 1000000.0/d_now ELSE 0 END

Read IOPs/s

CASE WHEN d_now > 0 THEN d_wcount * 1000000.0/d_now ELSE 0 END

Write IOPs/s

CASE WHEN d_now > 0 THEN (d_rcount + d_wcount) * 1000000.0/d_now

ELSE 0 END

Total IOPs/s

CASE WHEN d_now > 0 THEN d_rbytes * 1000.0/d_now ELSE 0 END

Read KBytes/sec

CASE WHEN d_now > 0 THEN d_wbytes * 1000.0/d_now ELSE 0 END

Write KBytes/sec

CASE WHEN d_now > 0 THEN (d_rbytes + d_wbytes)* 1000.0/d_now ELSE

0 END

Total KBytes/sec

CASE WHEN d_rcount > 0 THEN d_rticks / (d_rcount * 1000.0) ELSE 0

END

Read service time
(millisec)

CASE WHEN d_wcount > 0 THEN d_wticks / (d_wcount * 1000.0) ELSE 0

END

Write service time
(millisec)

CASE WHEN (d_rcount + d_wcount) > 0 THEN (d_rticks + d_wticks) /

((d_rcount + d_wcount) * 1000.0) ELSE 0 END

Total service time
(millisec)

CASE WHEN d_rcount > 0 THEN d_rbytes / (d_rcount * 1000.0) ELSE 0

END

Read IO Size (KBytes)

CASE WHEN d_wcount > 0 THEN d_wbytes / (d_wcount * 1000.0) ELSE 0

END

Write IO Size (KBytes)

CASE WHEN (d_rcount + d_wcount) > 0 THEN (d_rbytes + d_wbytes) /

((d_rcount + d_wcount) * 1000.0) ELSE 0 END

Total IO Size (KBytes)

CASE WHEN qlen > 0 THEN qlen ELSE 0 END

Queue length

The check for qlen > 0 is because qlen < 0 indicates that qlen is invalid for that sample.

AVG(CASE WHEN ((d_now > 0) AND (d_busy < busy)) THEN (d_busy *

100.0/d_now) ELSE 0 END)

Busy%

Service Time Histogram Buckets

The service time range corresponding to each of the rhist and whist buckets depends on the version
of the HP 3PAR OS (os_rev column in the system table, see

“The system Table” (page 195)

). For

os_rev prior to 2.2.2, the nth bucket (rhistn and whistn) correspond to service times from the
previous bucket to (2n*4.096/mhz) millisec where mhz is the mhz column in the system_3 table
(see

“The system Table” (page 195)

). This means that service time histograms from systems with

different CPU frequencies could not be correctly aggregated. Beginning with the 2.2.2 release,
the buckets were made independent of the CPU frequency, and the nth bucket (rhistn and whistn)
corresponds to service times from the previous bucket to (2n-7) millisec.

IO Size Histogram Buckets

There are 16 IO Size buckets correspond IO sizes 512 bytes to 16 MiBytes. The nth bucket holds
the count for IO Sizes from the previous bucket’s max size to 512 * 2n bytes.

The statpd Table

The statpd_<res>_4 table holds physical disk (PD) performance data samples.

210

Database Schema

Advertising