system_*

system_*

The system_* tables store system utilization metrics. There are three system tables, all having the same columns:

  • system_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. Current system utilization data is stored in system_now during the period between data collection from the Command Center agents and automatic commitment to the system_history table.
  • system_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for system utilization data that has been cleared from system_now but has not yet been committed to system_history. It typically only contains a few minutes worth of data.
  • system_history is a regular table that stores historical system utilization metrics. It is pre-partitioned into monthly partitions. Partitions are automatically added in two month increments as needed. Administrators must drop old partitions for the months that are no longer needed.
Column Type Description
ctime timestamp Time this row was created.
hostname varchar(64) Segment or master hostname associated with these system metrics.
mem_total bigint Total system memory in Bytes for this host.
mem_used bigint Used system memory in Bytes for this host.
mem_actual_used bigint Used actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
mem_actual_free bigint Free actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
swap_total bigint Total swap space in Bytes for this host.
swap_used bigint Used swap space in Bytes for this host.
swap_page_in bigint Number of swap pages in.
swap_page_out bigint Number of swap pages out.
cpu_user float CPU usage by the Greenplum system user.
cpu_sys float CPU usage for this host.
cpu_idle float Idle CPU capacity at metric collection time.
load0 float CPU load average for the prior one-minute period.
load1 float CPU load average for the prior five-minute period.
load2 float CPU load average for the prior fifteen-minute period.
quantum int Interval between metric collection for this metric entry.
disk_ro_rate bigint Disk read operations per second.
disk_wo_rate bigint Disk write operations per second.
disk_rb_rate bigint Bytes per second for disk write operations.
net_rp_rate bigint Packets per second on the system network for read operations.
net_wp_rate bigint Packets per second on the system network for write operations.
net_rb_rate bigint Bytes per second on the system network for read operations.
net_wb_rate bigint Bytes per second on the system network for write operations.