I Installed ELK (Elasticsearch, Logstash and Kibana) with YUM onto our centos based system and set them as start at boot time. Then When I tried command systemctl list-unit-files, the output only contains Kibana and Elasticsearch without Logstash at all. But Logstash is indeed listed in command chkconfig --list
According to my understanding, it means that Logstash is a SysV service, whereas Kibana and Elasticsearch are systemd services. Is it so? If so why is Logstash different from Elasticsearch and Kibana as a SysV service other than systemd service?
