Estimating Your Performance Database Size
This section provides an overview of estimating your performance database size.
Because performance monitoring can store a significant amount of data in your performance database, you may want to estimate the amount of data to be stored in your performance database so that you have, or are able to provide, the appropriate amount of space.
Performance database sizing estimates are based on the sum of space requirements for events and performance measurement unit (PMU) performance data. Event data resides in the PSPMEVENTHIST table. PMU data resides in the PSPMTRANSHIST and PSPMTRANSCURR tables.
This section presents formulas that you can use to estimate the potential size of your performance database.
These formulas incorporate the following assumptions and considerations:
Performance Monitor is set to Standard agent filter mode.
Estimates do not include space required for Verbose or Debug agent filter mode.
Index overhead is included in the estimate.
Performance history data is purged after a number of days (see parameter D in the following section).
The archive mode of a monitored system is set to Delete Data after N days and the performance data archive program is scheduled to run daily.
The reaper program is scheduled to run at least once a day.
No performance data is stored in the archive tables (PSPMTRANSARCH and PSPMEVENTARCH).
The calculation formulas use only the parameters that are presented in this section to calculate the estimates. In all cases, the numbers are conservative. For example, the exact formula may use (App – 1) but we choose to round up and use App instead.
This section discusses two formulas that are used for estimating event data space requirements (in kilobytes).
Standard formula: Use the standard formula if the application server domain configuration is based on PeopleSoft-delivered small, medium, or large template.
Customized formula: Use the customized formula if the configuration is different from the templates.
This table describes the variables that are used in the formulas.
|
Notation |
Description |
Performance Monitor Default Value |
Navigation |
|---|---|---|---|
|
A |
Performance Monitor agent event sampling rate. |
300 seconds |
|
|
N |
Number of PeopleSoft systems that are monitored by Performance Monitor. This is the number of PeopleSoft databases appearing on the System Definitions search page. |
NA |
|
|
D |
Performance history retention period in days. This is the value that is set for the After N days option. |
NA |
|
|
W |
Number of web server domains for a monitored system. This is the total number of web servers appearing on the System Performance page. |
NA |
|
|
P |
Number of application server domains for a monitored system. This is the total number of application servers appearing on the System Performance page. |
NA |
|
|
App |
Number of server processes running in an application server domain for a monitored system. This is the number of program names appearing on for Server Status. |
Use the following number per domain template that you choose:
|
|
|
S |
Number of monitored PeopleSoft Process Scheduler domains for a monitored system. This is the total number of Process Scheduler domains appearing on the System Performance page. |
NA |
|
|
Prcs |
Number of server processes running in a PeopleSoft Process Scheduler domain for a monitored system. This is the number of program names appearing for Server status. |
8 Increase this number if more than three Application Engine processes are configured. |
|
|
MPrcs |
Number of Master Scheduler for a monitored system. |
1 |
NA |
|
E |
Number of KB per event row in the table. |
Refer to the value in the following table for the target database. |
NA |
The following table helps you to determine the appropriate value for E (Number of KB per event row in the table).
|
Parameter |
ANSI/Unicode |
Oracle |
Microsoft SQL Server |
DB2 UDB |
DB2/390 |
|---|---|---|---|---|---|
|
E |
ANSI |
.4 |
.4 |
.5 |
.6 |
|
E |
Unicode |
.7 |
.7 |
.9 |
1.1 |
Using the Standard Formula
The formula that you use differs depending on the template used in the application server configuration.
|
Field or Control |
Definition |
|---|---|
| Large |
N x D x [8 x W + 180 x P + 16 x S + 1] x 86400 / A x E |
| Medium |
N x D x [8 x W + 120 x P + 16 x S + 1] x 86400 / A x E |
| Small |
N x D x [8 x W + 60 x P + 16 x S + 1] x 86400 / A x E |
Using the Customized Formula
Use this formula if the application server configuration is different from the standard templates.
N x D x [8 x W + 3 x P x App + 2 x S x Prcs + MPrcs] x 86400 / A x E
Note: Eight events are reported per web server domain. Two events are reported per web server (JVM status and network status), one event per web site, and five events per web site for PeopleSoft servlets (psp, psc, cs, *, and Scheduler Transfer).
If multiple systems are monitored and each is configured slightly differently, that is, the numbers of application server processes are different, then use the formula to estimate the requirement for each system separately.
The total space requirements, in kilobytes, for PMU data that is stored in PSPMTRANSHIST and PSPMTRANSCURR tables can be estimated using the following formula:
N x [D + 1] x L x R x M x T
This table describes the variables that are used in this formula.
|
Notation |
Description |
Performance Monitor Value Default |
Navigation |
|---|---|---|---|
|
N |
Number of PeopleSoft systems that are monitored by Performance Monitor. This is the number of PeopleSoft databases appearing on the System Definitions search page. |
NA |
|
|
D |
Performance history retention period in days. This is the value that is set for the After N days option. |
NA |
|
|
L |
Number of user sessions per day for a monitored system. A session means that a user signs on, performs a few transactions, and signs off. |
NA |
NA |
|
R |
Number of user interactions per session. User interactions are anything that triggers a server trip, including clicking a button, clicking TAB, and so on. |
NA |
NA |
|
M |
Number of PMU rows that are captured per user interaction. |
9 |
NA |
|
T |
Number of KB per PMU row in the table. |
Refer to the value in the following table for the target database. |
NA |
The following table helps you to determine the value for T.
|
Parameter |
ANSI/Unicode |
Oracle |
Microsoft SQL Server |
DB2 UDB |
DB2/390 |
|---|---|---|---|---|---|
|
T |
ANSI |
1.3 |
1.4 |
1.8 |
2.1 |
|
T |
Unicode |
2.4 |
2.6 |
3.3 |
3.8 |
This section presents an example of using the formulas to estimate the performance database size for a fictitious organization.
Company ABC uses Performance Monitor to monitor two PeopleSoft Applications, Financials and HCM (N=2). Both applications use DB2 UDB Unicode databases. The company has decided that the performance history data will be kept for a 7-day period (D=7). Each system has two web server domains (W=2), two application server domains (P=2), and two PeopleSoft Process Scheduler domains (S=2). The implementation team decides to use the medium application server configuration for both domains. One Master Scheduler exists for each of the systems (MPrcs=1).
It is estimated, on the average, that 10,000 user sessions (L=10000) will be logged per day in each of the systems. During each session, 50 user interactions (clicking buttons, tab to next field or page, and so on) will occur (R=50).
This is the sample calculation for event data space (using the standard formula for a medium configuration):
N x D x [8 x W + 120 x P + 16 x S + 1] x 86400 / A x E
= 2 x 7 x [8 x 2 + 120 x 2 + 16 x 2 + 1] x 86400 / 300 x E
= 1,165,248 rows x 0.9 KB per row
= 1,024 MB
This is the sample calculation for PMU data space:
N x [D + 1] x L x R x M x T
= 2 x [7 + 1] x 10000 x 50 x 9 x T
= 72,000,000 rows x 3.3 KB per row
= 232,032 MB
This is the formula for space requirement for storing performance data on a DB2 UDB Unicode database:
1,024 MB + 232,032 MB = 233,056 MB
Company ABC decides to add a 1 TB disk.
Business is going well for ABC Company. The demand for the Financial application increased by 50 percent. The IT department decided to add new web server, application server, and PeopleSoft Process Scheduler domains for the Financials application (N=1). According to the system administrator, when the application server domain is booted, a “22 processes started” message appears (App=22), and the PeopleSoft Process Scheduler domain shows a “12 processes started” message (Prcs=12). The IT department needs to estimate whether enough disk space is available to store additional performance data.
Use the customized formula to calculate the space requirement for event data that is generated by the new configuration.
N x D x [8 x W + 3 x P x App + 2 x S x Prcs + MPrcs] x 86400 / A x E
= 1 x 7 x [8 x 1 + 3 x 1 x 22 + 2 x 1 x 12] x 86400 / 300 x E
= 153,216 rows x 3.3 KB per row
= 494 MB
System usage increased by 50 percent for the Financials application, so the total space requirement is:
233,056 MB + 494 MB + [233,032 MB/2 x 50%]
= 291,558 MB
The IT department concludes that enough space is available to store the performance data.