Configuring the Krypton service
Krypton is an engine for raw, transcribed recognition and large vocabulary continuous recognition.
Management Station displays commonly-used properties on the Settings tab, and the following tables shows some of these properties. (Management Station does not display less-common parameters, but you can add them to the display at any time. For a complete list, see Speech product parameters.)
Note: Krypton is packaged with a self-signed certificate and pre-configured to enable secure connections using TLS/SSL. You can use the self-signed certificates for testing and development, but for a secure production environment you need to acquire a certificate signed by a Certificate Authority (CA), and a PEM-formatted private key. Then configure the properties described below under HTTPS settings and These HTTP client settings also affect HTTPS communication paths. (The httpClient properties control how the service behaves when acting as a client. ).
HTTPS settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Port where the Krypton listens for HTTPS requests. |
INT |
8600 |
|
https : host |
The host where the Krypton HTTPS listener port (https : port) is defined. |
STRING | |
Path and filename of a private key. |
STRING | ./keys/server.key | |
Path and filename of the signed certificate file for Krypton. |
STRING | ./keys/server.crt | |
The encrypted passphrase for the service's private keyfile. |
STRING | ||
Requests and verifies a certificate from clients that try to connect to via HTTPS. |
BOOLEAN | false | |
When the service acts as a client, this property requires servers to be authorized by valid certificates. |
BOOLEAN | true | |
Certificate authority (CA) files to use when authenticating certificates. |
STRING |
Trust setting
Service property |
Description |
Data type |
Default |
---|---|---|---|
Specifies the drift tolerance (in seconds) between client and server hosts for security verification purposes. Based on difference in UUID timestamps, with a valid range of 1-120 seconds and default value of 15 seconds. | INT | 15 |
Licensing setting
Service property |
Description |
Data type |
Default |
---|---|---|---|
Port and IP address of the Nuance License Manager, using the format: port@ip_address |
STRING | 27000@localhost |
Logging settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Logging level for the Krypton session, one of fatal, error, warn, status, info, debug, or trace. In Management Station, logging levels set on the General tab take precedence over those set via the service Settings tab. |
STRING | info (The Management Station default logging level is STATUS, and it overrides this default value.) | |
Maximum log file size in bytes. |
INT | 5242880 | |
Maximum number of log files. |
INT | 5 |
Data pack settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Optional. One or more data pack names. Use a comma-separated list to specify two or more data packs. For example: [ndp-eng-USA-GEN-3.7.0,ndp-cmn-CHN-GEN-3.7.0] |
STRING | ||
Name of a configuration package that applies to all data packs. The package name is its directory name under NDP_HOME. For example: ndp-s3config-3.7.0 |
STRING |
HTTP client settings (also affects HTTPS)
These HTTP client settings also affect HTTPS communication paths. (The httpClient properties control how the service behaves when acting as a client. )
Service property |
Description |
Data type |
Default |
---|---|---|---|
Maximum time, in milliseconds, to wait for a response. Default is 10000 (10 seconds). |
INT | 10000 | |
Specifies whether to enable HTTP 3xx responses as redirects. When disabled, 3xx responses are treated as errors. |
BOOLEAN | true | |
Maximum number of redirects to follow. |
INT | 10 | |
When the service acts as a client, this property requires servers to be authorized by valid certificates. |
BOOLEAN | false | |
Server's private key PEM filename. The filepath is relative to $KR_DATA_DIR/config. You cannot specify an absolute path. |
STRING | ||
Server's X.509 certificate PEM filename. The filepath is relative to $KR_DATA_DIR/config. You cannot specify an absolute path. |
STRING | ||
Private keyfile encrypted passphrase. |
STRING | ||
Certificate authority (CA) files to use when authenticating certificates. When httpClient : rejectUnauthorized (above) is true, list of certificates to use to validate the certificates of an HTTPS resource. Comma-separated list of certification authority's (CA) X.509 certificate files in PEM format (one file per CA). The filepath is relative to $KR_DATA_DIR/config. You cannot specify an absolute path. |
STRING | ||
Specifies whether to enable disk caching. This optional disk cache holds downloaded recognition objects including wordsets and domain language models. |
BOOLEAN | false | |
Maximum size of the disk cache, in kilobytes. |
INT | 500 | |
After this number of session terminations, the cache purges itself of any expired objects. |
INT | 5 | |
Specifies whether to save the cache status on exit and reload it when the host restarts. |
BOOLEAN | false |
Resource Manager settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Krypton hostname used by Resource Manager. When provided, this value specifies a particular hostname to register with the Resource Manager. When not set, the hostname is determined by defaultNetworkInterface (see below), or defaults to the name of the host where the Krypton instance is running. For hosts with a single assigned hostname no setting is required, but for multi-homed hosts these parameters allow you to specify which of several host addresses to use. The defaultHostName setting takes precedence over defaultNetworkInterface settings. |
STRING | ||
Network interface name and protocol family of the Krypton instance. Where:
When both parameters are set, they provide the default value for defaultHostName above. |
STRING | ||
Hostname or IP address of the Resource Manager host. Setting this parameter enables Resource Manager, allowing Krypton to publish its capabilities to Resource Manager. |
STRING | ||
Time to wait, in milliseconds, before attempting to reconnect to Resource Manager. Default is 5 seconds. |
INT | 5000 | |
rmRegistration : urls |
Connects Krypton to the hostname and port of the Resource Manager listener. |
STRING |
Preloading Krypton Modules
To preload Krypton modules, edit the service’s configuration file and then start the service.
Open the krypton.yaml file manually and specify the DLM in the preload
section of the configuration.
Note: this must be done by editing the configuration file. You can view the preload configuration in Management Station but please do not edit these settings from Management Station because they will not be parsed correctly.
Note: Krypton modules (DLMs) are not cached across application restarts.
The preload
section of the .yaml file uses the following format:
preload: - dataPack: language: topic: objects: - url: weight: type:
These fields are defined as follows:
Service property |
Description |
Data type |
Default |
---|---|---|---|
preload:dataPack | An array of one or more data packs with DLMs to preload into the instance. For multi-language applications, repeat the language, topic, and objects fields. | object | n/a |
preload:dataPack:language | Language and locale identifier in the form xxx-YYY, for example eng-USA. The value is case-sensitive. | string | none |
preload:dataPack:topic | Language model name, for example GEN. The value is case-sensitive. | string | none |
preload:dataPack:objects | One or more DLMs to preload, to be available as static content for all sessions in the instance. The maximum number of loaded DLMs for a single recognition turn is 5. | object | n/a |
preload:dataPack:objects:url | URL of the DLM zip file, either remotely with http[s]:// or locally with file:// | string | none |
preload:dataPack:objects:weight | The weight of the DLM compared to the data pack: lowest, low, medium, high, highest, or an integer 0-1000. Default is 0. This value is optional. | int | 0 |
preload:dataPack:objects:type | A keyword representing the type of object to be preloaded. This value is optional. | string | none |
Here's an example that preloads DLMs for three different domains in two languages, with one object defined for each language. Note that the values do not need to be surrounded by quotes or double-quotes but they are used here for legibility.
preload: - dataPack: language: 'eng-USA' topic: 'GEN' objects: - url: 'http://host/path/finance-dlm.zip' weight: 0 type: application/x-nuance-domainlm - url: 'http://host/path/airline-dlm.zip' weight: 0 type: application/x-nuance-domainlm - url: 'http://host/path/pizza-dlm.zip' weight: 0 type: application/x-nuance-domainlm - dataPack: language: 'cmn-PRC' topic: 'GEN' objects: - url: 'http://host/path/finance-mandarin-dlm.zip' weight: 0 application/x-nuance-domainlm - url: 'http://host/path/airline-mandarin-dlm.zip' weight: 0 type: application/x-nuance-domainlm - url: 'http://host/path/pizza-mandarin-dlm.zip' weight: 0 type: application/x-nuance-domainlm
For details about configuring the Krypton service, see Configuring Krypton.