socket_stats_*

The socket_stats_* tables store statistical metrics about socket usage for a Greenplum Database instance. There are three system tables, all having the same columns:

These tables are in place for future use and are not currently populated.

  • socket_stats_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data.
  • socket_stats_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for socket statistical metrics that has been cleared from socket_stats_now but has not yet been committed to socket_stats_history. It typically only contains a few minutes worth of data.
  • socket_stats_history is a regular table that stores historical socket statistical 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
total_sockets_used int Total sockets used in the system.
tcp_sockets_inuse int Number of TCP sockets in use.
tcp_sockets_orphan int Number of TCP sockets orphaned.
tcp_sockets_timewait int Number of TCP sockets in Time-Wait.
tcp_sockets_alloc int Number of TCP sockets allocated.
tcp_sockets_memusage_inbytes int Amount of memory consumed by TCP sockets.
udp_sockets_inuse int Number of UDP sockets in use.
udp_sockets_memusage_inbytes int Amount of memory consumed by UDP sockets.
raw_sockets_inuse int Number of RAW sockets in use.
frag_sockets_inuse int Number of FRAG sockets in use.
frag_sockets_memusage_inbytes int Amount of memory consumed by FRAG sockets.