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. |