Daemon applications are commonly used in operating systems and programming languages as long-running applications or threads that run as background processes. The names of the daemon applications are httpd, sshd, and containerd; the trailing letter indicates that the services are daemons. Within the microservice architecture, some services should run and scale without any relation to consumer usage. These applications should run on every node in the cluster to ensure the daemon application's requirements, such as:

• Cluster storage daemons: glusterd, ceph.
• Log collection daemons: fluentd, logstash.
• Node monitoring daemons: collectd, Datadog agent, New Relic agent.

In Kubernetes, DaemonSets are designed for deploying ongoing background tasks that need to run on all or certain nodes. Without any further management considerations, Kubernetes handles running these daemon pods on the newly joined nodes in the cluster.