tcp_*

tcp_*

The tcp_* tables store statistical metrics about TCP communications for a Greenplum Database instance.

Note: Deprecated. The tcp_* tables are deprecated and will be removed in a future release.

There are three system tables, all having the same columns:

  • tcp_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data.
  • tcp_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for TCP statistical data that has been cleared from tcp_now but has not yet been committed to tcp__history. It typically only contains a few minutes worth of data.
  • tcp_history is a regular table that stores historical TCP statistical data. 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.
  • tcp_history is a regular table that stores historical TCP statistical data. 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(0) with no time zone Time this record was created.
hostname varchar(64) The hostname associated with this measurement.
segments_received bigint Number of TCP segments received.
segments_sent bigint Number of TCP segments sent.
segments_retransmitted bigint Number of TCP segments retransmitted.
bad_segments_received int Number of bad TCP segments received.
active_connections int Number of active TCP connections.
passive_connections int Number of passive TCP connections.
failed_connection_attempts int Number of failed TCP connection attempts.
connections_established int Number of TCP connections established.
connection_resets_received int Number of TCP connection resets received.
connection_resets_sent int Number of TCP connection resets sent.