Add Liveness, Readiness, and Startup Probes Concepts and supply clean up example
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title: Liveness, Readiness, and Startup Probes
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content_type: concept
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weight: 40
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---
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<!-- overview -->
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Kubernetes has various types of probes:
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- [Liveness probe](#liveness-probe)
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- [Readiness probe](#readiness-probe)
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- [Startup probe](#startup-probe)
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<!-- body -->
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## Liveness probe
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Liveness probes determine when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress.
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If a Pod fails health-checks continuously, the Kubernetes terminates the Pod and starts a new one.
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Liveness probes do not wait for readiness probes to succeed. If you want to wait before executing a liveness probe you should use initialDelaySeconds or a startupProbe.
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## Readiness probe
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Readiness probes determine when a container is ready to start accepting traffic. This is useful when waiting for an application to perform time-consuming initial tasks, such as establishing network connections, loading files, and warming caches.
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If the readiness probe returns a failed state, Kubernetes removes the pod from all matching service endpoints.
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Readiness probes runs on the container during its whole lifecycle.
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## Startup probe
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A startup probe verifies whether the application within a container is started. This can be used to adopt liveness checks on slow starting containers, avoiding them getting killed by the kubelet before they are up and running.
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If such a probe is configured, it disables liveness and readiness checks until it succeeds.
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This type of probe is only executed at startup, unlike readiness probes, which are run periodically.
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* Read more about the [Configure Liveness, Readiness and Startup Probes](/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes).
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This page shows how to configure liveness, readiness and startup probes for containers.
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For more information about probes, see [Liveness, Readiness and Startup Probes](/docs/concepts/configuration/liveness-readiness-startup-probes)
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The [kubelet](/docs/reference/command-line-tools-reference/kubelet/) uses
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liveness probes to know when to restart a container. For example, liveness
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probes could catch a deadlock, where an application is running, but unable to
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