Teradata Machine Learning Engine Connector Properties

Teradata® Vantage User Guide

prodname
Teradata Vantage
vrm_release
1.0
category
User Guide
featnum
B700-4002-098K

In Teradata Vantage, the Teradata® QueryGrid™ fabric is configured for internal communication. Two Teradata QueryGrid links are created to facilitate communication between Teradata SQL Engine and Teradata Machine Learning Engine.

QueryGrid™ Manager shows the properties that you can configure. Teradata Vantage requires that some property defaults cannot be changed.

The ML Engine connector properties are:

Name Default Description Connector Type Change Default
Server Configured specifically to your environment Hostname of ML Engine server. Target No
Port 30002 Port number of ML Engine server. Target No
Authentication Mechanism Trusted Authentication mechanism used to log on to ML Engine. Target No
Realm None Realm name for Kerberos. Target No
Servicename None Service name for Kerberos. Target No
Database Name beehive Database name for ML Engine. Target No
Schema Name none Default schema name. Target Yes
Link Buffer Count 4 Maximum number of write buffers available on a single channel at one time. Initiator, Target Yes
Link Buffer Size 1048576 Maximum size of the write buffers to allocate for row handling and message exchange. Initiator Yes
Link Heartbeat Interval 60000 Maximum interval in milliseconds for heartbeat signal on channel between connector and fabric instance, used for health check status. This interval must be greater than Link Handshake Timeout. Initiator, Target Yes
Link Handshake Timeout 30000 Handshake timeout in milliseconds for link channel setup. Initiator, Target Yes
Read Timeout 30000 Number of milliseconds to wait to read between data packets when importing data messages. Initiator, Target Yes
Write Timeout 30000 Number of milliseconds to wait to write between data packets when exporting data messages. Initiator, Target Yes
Response Timeout 1800000 Number of milliseconds to wait for final data exec response when all data has been transferred. Initiator, Target Yes
Enable Logging WARN Logging level for connector or link properties. Applies to both initiating and target connector; however, if their levels are different, level for initiating connector takes precedence. Initiator, Target Yes
Default String Size 32000 VARCHAR truncation size (size at which data imported from, or exported to, string columns is truncated). Value represents maximum number of Unicode characters to import. Initiator, Target Yes
Transformformatting FALSE Whether to transform array columns to Teradata string format. If FALSE, array columns are returned in JSON format, except those specified in RETURN clause to be returned in Teradata string format. Initiator, Target Yes
User Name beehive Value to use when initiator does not support mechanism to provide user credentials. Value is also used for connectivity diagnostic checks. Target No
Password   Password for User Name. Target Yes
Enable Clob Support TRUE Enables support of CLOB datatype. Initiator, Target Yes
Enable Blob Support FALSE Enables support of BLOB datatype. Initiator, Target No
Large Clob Handling ERROR Action to take if CLOB larger than 10485760 is exported to ML Engine: ERROR causes exception to be raised; TRUNCATE causes data to be truncated to 10485760.

To change this behavior in SQL Engine session, include statement such as:

set foreign server attr = 'servername=coprocessor;largeClobHandling=TRUNCATE;' for session volatile;

Initiator, Target Yes
Large Blob Handling ERROR Action to take if BLOB larger than 10485760 is exported to ML Engine: ERROR causes exception to be raised; TRUNCATE causes data to be truncated to 10485760.

To change this behavior in SQL Engine session, include statement such as:

set foreign server attr = 'servername=coprocessor;largeBlobHandling=TRUNCATE;' for session volatile;

  Yes
In-Memory Tables TRUE Whether to use in-memory tables for data exported to Teradata SQL Engine for input to functions. Target Yes
Connection Max Idle Time 1800 seconds Maximum idle time for connection cache object, after which it is closed and evicted from the cache. It should be used if there are multiple concurrent users/queries running on the system that might lead to starvation of connection objects. Target Yes
Connection Pool Size 100 Maximum number of connection objects that can be stored in the connection pool. When trying to acquire a new connection, the connector checks for entry to be made available in the connection pool or else it fails after 5 minutes. There is one connection pool per connector config, including the username. This can be used to throttle the number of connections that can be established by concurrent queries for one user. Target Yes
Connection Evict Frequency 1 minute Frequency of eviction checks. It checks, closes, and removes the connection object from the pool if the idle time (current time - last time of use) of connection object is greater than connectionMaxIdleTime/sessionConnectionMaxIdleTime. It can be reduced if there are multiple concurrent users running queries and due to high demand, the connections should be freed up more frequently for new users to pick up. Target Yes