Java interface Query API

KX Nexus

The KX Nexus repository will be sunsetted in the future. Nexus links on this page are provided as a temporary alternative to the KX Downloads Portal for existing users. The KX Downloads Portal is the preferred repository for all use cases and KX Nexus links will be removed once the KX Nexus repository is decommissioned.

The Java interface includes a Query API that allows you to extract data from kdb Insights Enterprise over IPC. You can download it from the KX Downloads Portal or from the KX Nexus repository, until Nexus is removed in the future.

The primary class used for querying data from the kdb Insights Enterprise is the DataAccessClient class.

Below is a description of the methods available in the DataAccessClient class:

Constructors

DataAccessClient()

If you use this constructor, the components are built using data from environment variables that must be supplied to the process that is using the interface.

Sample

import kx.insights.dataaccess.DataAccessClient;
...
DataAccessClient dac = new DataAccessClient();

DataAccessClient(ConfigRequestor configRequestor, String authUrl)

This constructor allows you to override just the ConfigRequestor and the URL that requests are made to for authorization. If no Authorization is needed, just set the authUrl to null. If you need to determine the authorization URL from the information services URL, the DataAccessClient.getAutUrlFromConfigUrl() static method can use used to do this.

import kx.insights.dataaccess.DataAccessClient;
...
FileConfigRequestor fcr = new FileConfigRequestor("/path/to/config.json", new ConfigParser());
DataAccessClient dac = new DataAccessClient(fcr, null);

DataAccessClient(HttpsConfigRequestor configRequestor, SSLContextManager sslManager, QConnectionFactory qConnectionFactory, DataAccessTokenFactory credentialsFactory)

With this constructor you must supply all of the dependencies of the DataAccessClient.

Sample

import kx.insights.dataaccess.DataAccessClient;
import kx.insights.dataaccess.DataAccessTokenFactory;
...
String configUrl = "$KXI_CONFIG_URL";
HttpsConfigRequestor configRequestor = new HttpsConfigRequestor(configUrl);
SSLContextManager sslManager = new SSLContextManager();
QConnectionFactory qConnectionFactory = new QConnectionFactory();
InsightsDataAccessTokenFactory credFactory = new InsightsDataAccessTokenFactory(configUrl);
credFactory.setClientIdAndSecret(clientId, clientSecret);
DataAccessClient dac = new DataAccessClient(configRequestor, sslManager, qConnectionFactory, credFactory);

connect

DataAccessClient.connect()

This is called to establish a connection to the kdb Insights Enterprise.

Note

It must be called before any requests can be called. Calling these methods before calling connect() results in an exception being thrown.

Sample

DataAccessClient dac = new DataAccessClient();
dac.connect();

getMeta

DataAccessClient.getMeta()

This returns the result of the getMeta() call. This is returned as an object, and will need to be parsed by the caller. More information can be found here.

Sample

DataAccessClient dac = new DataAccessClient();
dac.connect();
dac.getMeta();

getData

DataAccessClient.getData(String table, Timestamp startTS, Timestamp endTS)

Returns the result of the getData call on the specified table for the specified time range. More information can be found here.

Sample

DataAccessClient dac = new DataAccessClient();
dac.connect();
Timestamp oneHourAgo = new Timestamp(System.currenttimemillis() - 3600000);
Timestamp now = new Timestamp(System.currenttimemillis());
Object result = dac.getData("trace", oneHourAgo, now);

DataAccessClient.getData(Map argsMap)

Returns the result of the getData call on the specified parameters. More information can be found here.

Sample

DataAccessClient dac = new DataAccessClient();
dac.connect();
HashMap<String, Object> getDataArgs = new HashMap();
getDataArgs.put("startTS", startTime);
getDataArgs.put("endTS", endTime);
getDataArgs.put("table", "trace");
Object result = dac.getData(getDataArgs);

ping

DataAccessClient.ping()

Runs the ping command. More information can be found here.

Sample

DataAccessClient dac = new DataAccessClient();
dac.connect();
boolean pingResult = dac.ping(); //Should always be true

isConnected

DataAccessClient.isConnected()

Returns true if the client is connected. Otherwise returns false.

Sample

DataAccessClient dac = new DataAccessClient();
...
if(!dac.isConnected())
{
 dac.connect();
}

Making queries from within a Kubernetes cluster

If you want to make queries from within a Kubernetes cluster, directly to the Service Gateway without SSL and with authorization disabled, do the following:

Make a custom config.json, The "query" element needs to be a single element array that contains the host name and port of the pod you which to connect to. "useSslQuery" needs to be set to false so that SSL is disabled. The result should look like this.

{"name":"dgm-service","query":[":sg-hostname:5050"],"useSslQuery":false}

Constuct the DataAccessClient in your java code, as follows

FileConfigRequestor fcr = new FileConfigRequestor("/path/to/config.json", new ConfigParser());
DataAccessClient dac = new DataAccessClient(fcr, null);

You can now use the DataAccessClient as before.

ADVANCED: What if I am unable to create a config.json ahead of time, but I can get the hostname I want to connect to at runtime

In this case you will need to create your own implementation of the ConfigRequestor interface, that will generate configs with the hostname of the host you want to query in the "queries" member variable. This will need to be passed into the DataAccessClient instead of the FileConfigRequestor that is passed in the example above.

Environment variables

These are the environment variables that are used by the basic form of the DataAccessClient() constructor.

variable	required	details
`KXI_CONFIG_URL`	Mandatory	Authenticated client URL
`KXI_QUERY_USER`	Conditional	The Keycloak client that is used to generate bearer tokens to log in for query. Must be set if KXI_QUERY_TOKEN is not.
`KXI_QUERY_SECRET`	Conditional	The Keycloak client secret that is used to generate bearer tokens for query. Must be set if KXI_QUERY_TOKEN is not.
`KXI_QUERY_TOKEN`	Conditional	A bearer token used for authentication when making queries. If this is set, then KXI_QUERY_USER and KXI_QUERY_SECRET are ignored.