Configuring the Natural Language Engine service
The Natural Language Engine (NLE) is Nuance's text-to-meaning engine, also called a semantic engine.
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: NLE 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 generate a new keystore and certificate. Then configure the properties described below under SSL settings.
General settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
NLE base installation directory. Default is the value of the NLE_HOME environment variable (see Data pack locations). |
STRING | ||
Base directory for the data files downloaded and/or created by NLE. Note: Nuance recommends that you change the value to a path outside the installation directory so that NLE does not create any files in the installation directory. |
STRING | ${nle.home}/data | |
IP address or hostname of the machine on which the NLE instance is running. This property is used by NLE when providing model URLs to NTpE. The value |
STRING | ||
Port on which NLE listens for incoming requests, either HTTP or WebSocket. |
INT | 9091 | |
usingJava8 |
Indicates Java 8 is installed on the Natural Language Engine service host. Only relevant when using Management Station. Note: If using Management Station and running NLE on a host with Java 17, you must set usingJava8 to false in the Natural Language Engine service properties. |
BOOLEAN | true |
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 |
Resource Manager settings
You must configure NLE to point to the Resource Manager for engine registration purposes.
Service property |
Description |
Data type |
Default |
---|---|---|---|
Allows the Natural Language Engine to register its capabilities with the Resource Manager. When the NTpE property resourceManager : enabled is also enabled, NLE publishes its capabilities to the Resource Manager, and requests from the Resource Manager a suitable NTpE instance when it needs to perform tokenization for a given session. |
BOOLEAN | ||
Hostname (or IP address) and port (usually 9001) to connect to the Nuance Resource Manager listener. |
STRING | ||
rm.retryInterval |
Specifies the time to wait, in milliseconds, before the Natural Language Engine attempts to reconnect to Resource Manager. |
||
The service requests SSL validation with a CA-signed certificate when registering with Nuance Resource Manager servers when using HTTPS. |
BOOLEAN | false |
NTpE settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Hostname (or IP address) and port of the NTpE instance that NLE will use to perform tokenization. The default port is 9092. This value is used when ntpe.resourceManagerEnabled is false. |
STRING | wss://localhost:9092/NTpE | |
When enabled, NLE will locate a suitable NTpE resource via the Nuance Resource Manager, in which case the property above is ignored. |
BOOLEAN | ||
Specifies whether to use a self-signed certificate for SSL validation with NTpE or alternatively, to perform a complete validation with a CA-signed SSL certifcate. |
BOOLEAN | false |
Resource downloading and management settings
Note that the resource.preloadOnStartup[i] is an array of modules to preload, where [i] refers to the array index.
Service property |
Description |
Data type |
Default |
---|---|---|---|
Timeout, in milliseconds, when connecting to the remote server when downloading resources. Default is 10 seconds. |
INT | 10000 | |
Timeout, in milliseconds, when performing a resource download request from the remote server. Default is 10 seconds. |
INT | 10000 | |
Specifies whether the HTTP client cache for resources is used. Note: Do not set this property to false, because it causes the NLE service to fail. |
BOOLEAN | true | |
Maximum number of serialized cache entries that will be stored on disk in the HTTP client cache (by default ${nle.dataHome}/httpModelCache). Note: These caches are small so it is acceptable to have them on disk. |
INT | 1000 | |
resource.download.ssl.certificateVerificationEnabled |
Specifies whether NLE verifies the resource HTTPS server certificate when downloading resources. |
BOOLEAN | false |
Metric to use to measure maximum size of resource files that can be stored in disk cache, either Count or Size. Determines which of the following parameters to apply. | String | Count | |
Maximum number of resource files that can be stored in the disk cache. This parameter is ignored when resource.diskCache.maximumSizeMetric (above) is set to Size, in which case parameter below applies. |
INT | 1000 | |
Maximum size of all resource files stored in the disk cache, in megabytes (MB). This parameter is ignored when resource.diskCache.maximumSizeMetric is set to Count, in which case parameter above applies. |
INT | 100 | |
resource.preloadOnStartup.id | ID of the artifact to preload . | STRING | |
resource.preloadOnStartup.type | Type of artifact to preload. | STRING | application/x-nuance-semantic-model |
resource.preloadOnStartup.uri | URI of the artifact to preload. | STRING |
Model settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Maximum number of semantic models that can be stored in the cache. |
INT | 100 | |
Specifies how long a model is kept in the cache after being accessed. After this interval (expressed in seconds), models are removed the next time the cache is cleaned. Default is 5 days. |
INT | 432000 | |
Delay, in minutes, between cache maintenance operations. This indicates how often the disk cache is cleaned. Default is 1 hour. |
INT | 60 |
Wordset settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Maximum number of wordsets that can be stored in the cache. | INT | 500 | |
Specifies how long a wordset is kept in the cache after being accessed. After this interval (expressed in seconds), wordsets are removed the next time the cache is cleaned. Default: 5 days |
INT | 432000 | |
Delay, in minutes, between cache maintenance operations. This indicates how often the disk cache is cleaned. Default: 1 hour |
INT | 60 |
Watcher settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Specifies whether the watcher service is enabled. Note: Do not change unless instructed by Nuance. |
BOOLEAN | true | |
Specifies whether NLE sends alarms to the watcher service. Note: Do not change unless instructed by Nuance. |
BOOLEAN | true |
Trust setting
Service property |
Description |
Data type |
Default |
---|---|---|---|
Specifies the drift tolerance (in milliseconds) 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 10 seconds. |
INT | 10000 |
SSL settings
Service property |
Description |
Data type |
Default |
---|---|---|---|
Specifies whether SSL (TLS) is enabled. |
BOOLEAN | true | |
Path to the keystore file, which holds a valid SSL certificate. Note: Nuance highly recommends that you generate a new keystore and certificate. |
STRING | ${nle.home}/config/nle_keystore.jks | |
Encrypted keystore password used to protect the keystore file. |
STRING |