Logstash optimization

When running on a dedicated server for logstash can we improve the logstash performance by increasing the nice value to 0 in the /etc/init.d/logstash startup script. Is there any os optimization possible to speed up logstash when loading large volume of data with the input-jdbc plugin assuming the database is not the bottleneck.

When running on a dedicated server for logstash can we improve the logstash performance by increasing the nice value to 0 in the /etc/init.d/logstash startup script.

That will only improve performance if you have other processes on the machine that currently are stealing CPU time from Logstash. If the machine is idle except for Logstash it won't make a difference.

Is there any os optimization possible to speed up logstash when loading large volume of data with the input-jdbc plugin assuming the database is not the bottleneck.

Increasing the number of filter/pipeline workers could improve throughput, depending on what your current bottleneck is. See the -w command line flag. Are you maxing out the CPUs? If you're shipping data off to Elasticsearch, perhaps that's your bottleneck?