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Using the kodbc driver

This section describes how to use the sample c program 'csvupload' to send the data from the sample.csv file to the sdk_sample_assembly inside kdb Insights Enterprise, which can be downloaded using the instructions here.

Downloading

The kodbc driver samples-${VERSION}.zip file, downloaded from the kdb Insights Nexus registry, contains the following files:

  • csvupload.c - csv upload source code.
  • CMakeLists.txt - cmake file.
  • sample.csv - sample data based on the sdk_sample_assembly which can be downloaded using the instructions here.

Note

Before using the sample program you need to download and install the kodbc driver as described here.

The source code can be taken and edited for use inside your applications.

Prerequisites

Before building the sample program the following pre-requisites are required:

  • kodbc driver
  • unixodbc package
  • unixodbc-dev package
  • cmake package
  • libcsv-dev package
  • libcsv package

Building

Once these are installed:

  • Extract the files from the zip file
  • Move to the extracted folder

  • Build the application:

    cmake --clean-first --build . && make

Application parameters

  • -c str, ODBC connection string
  • -t str, Table name
  • -s str, Schema (e.g., field1:datatype,field2:datatype)

Note

The schema must match that defined in the pipeline assembly. For the SDK, described here, the schema definition is as follows: sensorID:int,captureTS:ts,readTS:ts,valFloat:float,qual:int,alarm:int

ODBC connection string parameters

The following list includes the recognized ODBC connection string parameters that can be included in the -c parameter:

parameter default description
DRIVER none Path to the driver file.
URL none URL of the configuration file. In the form: 'https://{INSIGHTS_HOSTNAME}/informationservice/details/{KC_CLIENT_ID}'.
RTDIR /tmp/rt Path to the RT log directory.
CONF_SLEEP 5000 Time in ms to sleep between fetches of the configuration details from the Information Service.
CONF_MAX_AGE 300000 Maximum age of configuration details in ms. After this amount of time, if still unable to fetch a new configuration, the connection is considered to be broken and any subsequent attempts to send data to kdb Insights Enterprise will fail with Not connected error.
LOCAL_PERSIST_PERIOD 600000 Local persistence period (in milliseconds)
TIMEOUT 2000 Connection timeout in ms.
LOG info Log level (example: "info", "err", "warn")

The URL is mandatory, as well as one of the following: DRIVER or DSN.

Supported data types

The following data types are supported by the sample application:

type schema notation example
string string name
symbol symbol LLOY
int int 1
byte byte 0
long long 200000
float float 1.2345
timestamp ts 2000.01.01D00:00:00.000000000

Publishing data using csvupload

In the example below the environment variables INSIGHTS_HOSTNAME and INSIGHTS_CLIENT_URL have been initialized.

DSN="DRIVER=/usr/local/lib/kodbc/libkodbc.so;URL=https://{INSIGHTS_HOSTNAME}/informationservice/details/{KC_CLIENT_ID}"
Schema="sensorID:int,captureTS:ts,readTS:ts,valFloat:float,qual:byte,alarm:byte"
    Table="trace"
./csvupload -c "$DSN" -t "$Table" -s "$Schema" < sample.csv

Note

The path to the DRIVER may be different in your environment.