AIX Performance Metrics

The up.time AIX agent collects the following performance metrics from the systems on which it is installed:

• CPU
• Memory
• Disk
• Network
• Process
• User

The AIX agent uses a number of utilities to gather these metrics including:

• sar: collects information about system activity. This version of sar is bundled with AIX.
• mpstat: collects processor-related metrics.
• ifconfig: configures the parameters for network interfaces.
• ps: reports on the status of processes.

Each set of performance metrics is averaged between the interval at which the up.time monitoring station polls the agent (e.g. every 10 minutes).

Whenever the sar command uses the -f option to specify a file, that file is generated using the sadc 1 1 command. The sadccommand polls the system counters at a one-second interval, and writes the information that it receives to a file. The sar command then reads this file.

CPU

The up.time agent uses the sar -u -f command to collect CPU metrics from an AIX system. The statistics that the agent returns are averaged for all CPUs on the system and the sar command compares the system counters during a one-second interval. If you have multiple CPUs, the CPU statistics output by the agent are an average of all the CPUs on the server.

Memory

The up.time agent uses the vmstat 1 2 command to average statistics for the entire system. The agent also uses the sar utility with the following options to collect memory metrics from an AIX system:

• -b -f (cache metrics)
• -r -f (unused memory pages and disk blocks)
• -q -f (the average queue length while it is occupied, and the percentage of time the queue is occupied)
• -c -f (system calls)

The sar commands compare the system counters over a one-second interval.

Disk

The up.time agent uses the following commands to collect disk statistics:

• df -k to gather file system capacity statistics, for file system.
• sar -d -f to output disk statistics (e.g. %busy, Read/Write/s) per disk, and compare those statisitics between polling intervals.

By default, the disk statistics are generated for all disks (including disks that are not active). This can be changed within the agent by setting the ACTIVEONLY flag in the perfparse.sh file to 0.

Network

The up.time agent uses the netstat command with the following options to collect network metrics from an AIX system:

• netstat -s to combine TCP retransmits for all interfaces
• netstat -I <interface> to average statistics (e.g. kbps, errors and collisions) per interface.

Process and Workload

The up.time agent uses the ps -eo command to collect process metrics from an AIX system. By default, the agent only gathers the top 20 processes and sorts them by the highest CPU usage.

Workload statistics are sorted within up.time's core. However, the core uses the same 20 processes that were gathered from the Process method. The following data are also gathered with the processes: the names of users, groups and processes along with their invividual statistics (e.g. memory and CPU usage). up.time's core will then sort the statistics based on the graph you want to generate (e.g. user, group or process name).

User

The up.time agent uses the following utilities to collect user metrics from an AIX system:

• ps -eo
• last | head 10 (login history for the last 10 users on the system)
• who (lists who is currently logged into the system)