Preemption (#16820)

* zh trans host-aliases.md

* Update host-aliases.md

* zh trans preemption.md

* Update host-aliases.md

content/zh/docs/reference/glossary/host-aliases.md

@@ -0,0 +1,45 @@
+---
+title: HostAliases
+id: HostAliases
+date: 2019-01-31
+full_link: /docs/reference/glossary/host-aliases.md
+
+short_description: >
+
+  HostAliases 是要注入 Pod 的 hosts 文件的 IP 地址和主机名之间的映射。
+
+aka:
+tags:
+- operation
+---
+
+<!--
+---
+title: HostAliases
+id: HostAliases
+date: 2019-01-31
+full_link: /docs/reference/glossary/host-aliases.md
+
+short_description: >
+
+   A HostAliases is a mapping between the IP address and hostname to be injected into a Pod's hosts file.
+
+aka:
+tags:
+- operation
+---
+-->
+
+<!--
+ A HostAliases is a mapping between the IP address and hostname to be injected into a Pod's hosts file.
+-->
+
+HostAliases 是要注入 Pod 的 hosts 文件的 IP 地址和主机名之间的映射。
+
+<!--more-->
+
+<!--
+[HostAliases](/docs/reference/glossary/host-aliases.md) is an optional list of hostnames and IP addresses that will be injected into the Pod's hosts file if specified. This is only valid for non-hostNetwork Pods.
+-->
+
+[HostAliases](/docs/reference/generated/kubernetes-api/v1.13/#hostalias-v1-corev) 是一个可选的主机名和 IP 地址列表，如果指定，它们将被注入 Pod 的 hosts 文件中。 这仅适用于非 hostNetwork 的 Pod。

content/zh/docs/reference/glossary/preemption.md

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+---
+title: Preemption
+id: preemption
+date: 2019-01-31
+full_link: /docs/concepts/configuration/pod-priority-preemption/#preemption
+short_description: >
+  Kubernetes 中的抢占逻辑通过驱逐该节点上存在的低优先级 Pod 来帮助待处理的 Pod 找到合适的节点。
+
+aka:
+tags:
+- operation
+---
+<!--
+ Preemption logic in Kubernetes helps a pending Pod to find a suitable Node by evicting low priority Pods existing on that Node.
+-->
+
+Kubernetes 中的抢占逻辑通过驱逐该节点上存在的低优先级 Pod 来帮助待处理的 Pod 找到合适的节点。
+
+<!--more-->
+
+<!--
+If a Pod cannot be scheduled, the scheduler tries to [preempt](/docs/concepts/configuration/pod-priority-preemption/#preemption) lower priority Pods to make scheduling of the pending Pod possible.
+-->
+
+
+如果无法调度 Pod，则调度程序会尝试[抢占](/docs/concepts/configuration/pod-priority-preemption/#preemption) 优先级较低的 Pod ，以便可以调度待处理的 Pod 。