Database Server Resources graphs

The Database Server Resources graphs show statistics for Oracle and SQL Server databases. These graphs require that from Controller, you specify the resources you want to measure, before running the load test scenario.

Oracle graph

The Oracle graph displays a summary of the resource usage on the Oracle Server, which includes information from Oracle V$ tables: Session statistics, V$SESSTAT, system statistics, V$SYSSTAT, and other table counters defined by the user in the custom query.

Note: In order to obtain data for this graph, enable the Oracle online monitor from Controller, select the default measurements you want to display, and then run the scenario. See Oracle performance counters for a description of each available measurement.

Axis Description
X-axis Elapsed time since the start of the run.
Y-axis The resource usage on the Oracle server.

Oracle server monitoring measurements

The following measurements are most commonly used when monitoring the Oracle server (from the V$SYSSTAT table):

Measurement

Description

CPU used by this session

The amount of CPU time (in tens of milliseconds) used by a session between the time a user call started and ended. Some user calls can be completed within 10 milliseconds and, as a result, the start- and end-user call time can be the same. In this case, 0 milliseconds are added to the statistic. A similar problem can exist in the operating system reporting, especially on systems that suffer from many context switches.

Bytes received via SQL*Net from client

The total number of bytes received from the client over Net8.

Logons current

The total number of current logons.

Opens of replaced files

The total number of files that needed to be reopened because they were no longer in the process file cache.

User calls

Oracle allocates resources (Call State Objects) to keep track of relevant user call data structures every time you log in, parse, or execute. When determining activity, the ratio of user calls to RPI calls gives you an indication of how much internal work is generated as a result of the type of requests the user is sending to Oracle.

SQL*Net roundtrips to/from client

The total number of Net8 messages sent to, and received from, the client.

Bytes sent via SQL*Net to client

The total number of bytes sent to the client from the foreground process(es).

Opened cursors current

The total number of current open cursors.

DB block changes

Closely related to consistent changes, this statistic counts the total number of changes that were made to all blocks in the SGA that were part of an update or delete operation. These are changes that generate redo log entries and hence cause permanent changes to the database if the transaction is committed. This statistic is a rough indication of total database work and indicates (possibly on a per-transaction level) the rate at which buffers are being dirtied.

Total file opens

The total number of file opens being performed by the instance. Each process needs a number of files (control file, log file, database file) in order to work against the database.

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SQL Server graph

The SQL Server graph displays a usage summary of standard Windows resources on the SQL Server.

Note: To obtain data for this graph, from Controller and before running the scenario, you need to enable the SQL Server online measurements you want to display. See SQL Server performance counters for a description of each available measurement.

Axis Description
X-axis Elapsed time since the start of the load test scenario run.
Y-axis The resource usage on the SQL Server.

SQL server default counters

Measurement

Description

% Total Processor Time

The average percentage of time that all the processors on the system are busy executing non-idle threads. On a multi-processor system, if all processors are always busy, this is 100%, if all processors are 50% busy this is 50% and if 1/4 of the processors are 100% busy this is 25%. It can be viewed as the fraction of the time spent doing useful work. Each processor is assigned an Idle thread in the Idle process which consumes those unproductive processor cycles not used by any other threads.

Cache Hit Ratio

The percentage of time that a requested data page was found in the data cache (instead of being read from disk).

I/O - Batch Writes/sec

The number of pages written to disk per second, using Batch I/O. The checkpoint thread is the primary user of Batch I/O.

I/O - Lazy Writes/sec

The number of pages flushed to disk per second by the Lazy Writer.

I/O - Outstanding Reads

The number of physical reads pending.

I/O - Outstanding Writes

The number of physical writes pending.

I/O - Page Reads/sec

The number of physical page reads per second.

I/O - Transactions/sec

The number of Transact-SQL command batches executed per second.

User Connections

The number of open user connections.

% Processor Time

The percentage of time that the processor is executing a non-idle thread. This counter was designed as a primary indicator of processor activity. It is calculated by measuring the time that the processor spends executing the thread of the idle process in each sample interval, and subtracting that value from 100%. (Each processor has an idle thread which consumes cycles when no other threads are ready to run). It can be viewed as the percentage of the sample interval spent doing useful work. This counter displays the average percentage of busy time observed during the sample interval. It is calculated by monitoring the time the service was inactive, and then subtracting that value from 100%.

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