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 gpperfmon 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.
ColumnTypeDescription
ctimetimestampTime this row was created.
hostnamevarchar(64)Segment or master hostname associated with these system metrics.
mem_totalbigintTotal system memory in Bytes for this host.
mem_usedbigintUsed system memory in Bytes for this host.
mem_actual_usedbigintUsed actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
mem_actual_freebigintFree actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
swap_totalbigintTotal swap space in Bytes for this host.
swap_usedbigintUsed swap space in Bytes for this host.
swap_page_inbigintNumber of swap pages in.
swap_page_outbigintNumber of swap pages out.
cpu_userfloatCPU usage by the Greenplum system user.
cpu_sysfloatCPU usage for this host.
cpu_idlefloatIdle CPU capacity at metric collection time.
load0floatCPU load average for the prior one-minute period.
load1floatCPU load average for the prior five-minute period.
load2floatCPU load average for the prior fifteen-minute period.
quantumintInterval between metric collection for this metric entry.
disk_ro_ratebigintDisk read operations per second.
disk_wo_ratebigintDisk write operations per second.
disk_rb_ratebigintBytes per second for disk read operations.
disk_wb_ratebigintBytes per second for disk write operations.
net_rp_ratebigintPackets per second on the system network for read operations.
net_wp_ratebigintPackets per second on the system network for write operations.
net_rb_ratebigintBytes per second on the system network for read operations.
net_wb_ratebigintBytes per second on the system network for write operations.

Parent topic: The gpperfmon Database