tcp_stats_*
The tcp_stats_*
tables store statistical metrics about TCP communications for a Greenplum Database instance.
These tables are in place for future use and are not currently populated.
There are three system tables, all having the same columns:
-
tcp_stats_now
is an external table whose data files are stored in$MASTER_DATA_DIRECTORY/gpperfmon/data
. -
tcp_stats_tail
is an external table whose data files are stored in$MASTER_DATA_DIRECTORY/gpperfmon/data
. This is a transitional table for TCP statistical data that has been cleared fromtcp_stats_now
but has not yet been committed totcp_stats_history
. It typically only contains a few minutes worth of data. -
tcp_stats_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 |
---|---|---|
segments_received |
bigint | Number of TCP segments received. |
segments_sent |
bigint | Number of TCP segments sent. |
segments_retransmitted |
bigint | Number of TCP segments retransmitted. |
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. |