Configuring channel support for the NLP service on Linux

The NLP service runs under the user nuance and group nuance account. You can set file limits for the nuance user on an NLP service host to accommodate the number of channels in your environment. When starting the NLP service, if the number of channels in your environment exceeds the default limits, the diagnostic logs for the NLP service might contain these errors: “Too many open files.” or “Unable to create new native thread.” Increasing the file limits might resolve these errors.

To set limits for the nuance user on an NLP service host:

1. Log in to the host as root.
2. Edit the file /etc/security/limits.conf.
3. Add the following text to the end of limits.conf:

   nuance     hard     nofile    4096

   nuance     soft     nofile    4096

   nuance     hard     nproc     31205

   nuance     soft     nproc     8192

   The text above sets these hard and soft limits:

   • The max open file limits (nofile) are set to 4096, which supports up to 200 channels. The default hard and soft limits are 2048. If you are using 200 channels or fewer, you only need to set the nofile limits.
   • The max open processes limits (nproc) are set to 31025 and 8192, which supports between 200 and 250 channels. The default soft limit is 4096 and the default hard limit is 31205. If you are using between 200 and 250 channels, you must set both the nofile and nproc limits using the hard and soft values above.

   Note: Nuance tested the values above on a CentOS 7 host with a quad-core CPU and 8GB of RAM. You can increase these limits further depending on the hardware specifications of your host.

4. Save limits.conf.
5. Reboot the NLP service host to apply the new limit values.