Remove italics, correct CamelCase typos in titles
This commit is contained in:
+14
-15
@@ -7,20 +7,20 @@ title: Daemon Sets
|
||||
* TOC
|
||||
{:toc}
|
||||
|
||||
## What is a Daemon Set?
|
||||
## What is a DaemonSet?
|
||||
|
||||
A _Daemon Set_ ensures that all (or some) nodes run a copy of a pod. As nodes are added to the
|
||||
A _DaemonSet_ ensures that all (or some) nodes run a copy of a pod. As nodes are added to the
|
||||
cluster, pods are added to them. As nodes are removed from the cluster, those pods are garbage
|
||||
collected. Deleting a Daemon Set will clean up the pods it created.
|
||||
collected. Deleting a DaemonSet will clean up the pods it created.
|
||||
|
||||
Some typical uses of a Daemon Set are:
|
||||
Some typical uses of a DaemonSet are:
|
||||
|
||||
- running a cluster storage daemon, such as `glusterd`, `ceph`, on each node.
|
||||
- running a logs collection daemon on every node, such as `fluentd` or `logstash`.
|
||||
- running a node monitoring daemon on every node, such as [Prometheus Node Exporter](
|
||||
https://github.com/prometheus/node_exporter), `collectd`, New Relic agent, or Ganglia `gmond`.
|
||||
|
||||
In a simple case, one Daemon Set, covering all nodes, would be used for each type of daemon.
|
||||
In a simple case, one DaemonSet, covering all nodes, would be used for each type of daemon.
|
||||
A more complex setup might use multiple DaemonSets would be used for a single type of daemon,
|
||||
but with different flags and/or different memory and cpu requests for different hardware types.
|
||||
|
||||
@@ -74,7 +74,7 @@ a node for testing.
|
||||
|
||||
If you specify a `.spec.template.spec.nodeSelector`, then the DaemonSet controller will
|
||||
create pods on nodes which match that [node
|
||||
selector](/docs/user-guide/node-selection/).
|
||||
selector](/docs/user-guide/node-selection/).
|
||||
If you specify a `scheduler.alpha.kubernetes.io/affinity` annotation in `.spec.template.metadata.annotations`,
|
||||
then DaemonSet controller will create pods on nodes which match that [node affinity](../../user-guide/node-selection/#alpha-feature-in-kubernetes-v12-node-affinity).
|
||||
|
||||
@@ -88,18 +88,17 @@ created by the Daemon controller have the machine already selected (`.spec.nodeN
|
||||
when the pod is created, so it is ignored by the scheduler). Therefore:
|
||||
|
||||
- the [`unschedulable`](/docs/admin/node/#manual-node-administration) field of a node is not respected
|
||||
by the daemon set controller.
|
||||
- daemon set controller can make pods even when the scheduler has not been started, which can help cluster
|
||||
by the DaemonSet controller.
|
||||
- DaemonSet controller can make pods even when the scheduler has not been started, which can help cluster
|
||||
bootstrap.
|
||||
|
||||
## Communicating with DaemonSet Pods
|
||||
|
||||
Some possible patterns for communicating with pods in a DaemonSet are:
|
||||
|
||||
- **Push**: Pods in the Daemon Set are configured to send updates to another service, such
|
||||
- **Push**: Pods in the DaemonSet are configured to send updates to another service, such
|
||||
as a stats database. They do not have clients.
|
||||
- **NodeIP and Known Port**: Pods in the Daemon Set use a `hostPort`, so that the pods are reachable
|
||||
via the node IPs. Clients knows the list of nodes ips somehow, and know the port by convention.
|
||||
- **NodeIP and Known Port**: Pods in the DaemonSet use a `hostPort`, so that the pods are reachable via the node IPs. Clients know the list of nodes ips somehow, and know the port by convention.
|
||||
- **DNS**: Create a [headless service](/docs/user-guide/services/#headless-services) with the same pod selector,
|
||||
and then discover DaemonSets using the `endpoints` resource or retrieve multiple A records from
|
||||
DNS.
|
||||
@@ -126,7 +125,7 @@ You cannot update a DaemonSet.
|
||||
|
||||
Support for updating DaemonSets and controlled updating of nodes is planned.
|
||||
|
||||
## Alternatives to Daemon Set
|
||||
## Alternatives to DaemonSet
|
||||
|
||||
### Init Scripts
|
||||
|
||||
@@ -145,9 +144,9 @@ running such processes via a DaemonSet:
|
||||
### Bare Pods
|
||||
|
||||
It is possible to create pods directly which specify a particular node to run on. However,
|
||||
a Daemon Set replaces pods that are deleted or terminated for any reason, such as in the case of
|
||||
a DaemonSet replaces pods that are deleted or terminated for any reason, such as in the case of
|
||||
node failure or disruptive node maintenance, such as a kernel upgrade. For this reason, you should
|
||||
use a Daemon Set rather than creating individual pods.
|
||||
use a DaemonSet rather than creating individual pods.
|
||||
|
||||
### Static Pods
|
||||
|
||||
@@ -159,7 +158,7 @@ in cluster bootstrapping cases. Also, static pods may be deprecated in the futu
|
||||
|
||||
### Replication Controller
|
||||
|
||||
Daemon Set are similar to [Replication Controllers](/docs/user-guide/replication-controller) in that
|
||||
DaemonSet are similar to [Replication Controllers](/docs/user-guide/replication-controller) in that
|
||||
they both create pods, and those pods have processes which are not expected to terminate (e.g. web servers,
|
||||
storage servers).
|
||||
|
||||
|
||||
@@ -9,7 +9,7 @@ assignees:
|
||||
|
||||
This document describes how sysctls are used within a Kubernetes cluster.
|
||||
|
||||
## What is a _Sysctl_?
|
||||
## What is a Sysctl?
|
||||
|
||||
In Linux, the sysctl interface allows an administrator to modify kernel
|
||||
parameters at runtime. Parameters are available via the `/proc/sys/` virtual
|
||||
|
||||
Reference in New Issue
Block a user