From 167746be6ff3e777bc1c48bded45939e7e6ca77c Mon Sep 17 00:00:00 2001 From: jay vyas Date: Sun, 12 Jul 2020 08:20:25 -0400 Subject: [PATCH] Update content/en/docs/concepts/workloads/controllers/statefulset.md Co-authored-by: Tim Bannister --- .../workloads/controllers/statefulset.md | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/content/en/docs/concepts/workloads/controllers/statefulset.md b/content/en/docs/concepts/workloads/controllers/statefulset.md index 0611f6a9a4..0938bd73e6 100644 --- a/content/en/docs/concepts/workloads/controllers/statefulset.md +++ b/content/en/docs/concepts/workloads/controllers/statefulset.md @@ -141,11 +141,16 @@ As each Pod is created, it gets a matching DNS subdomain, taking the form: `$(podname).$(governing service domain)`, where the governing service is defined by the `serviceName` field on the StatefulSet. -Note initial availability of stable DNS name's responsiveness: The initial reachability of a Pod via its DNS -depends on the settings of your DNS provider. It may be 30 seconds before the DNS name for your Pod -is reachable from another Pod in your cluster. For StatefulSets which need to come online via a quorum -in a very short (< 30s) time period, consider tuning your DNS settings -or another mechanism (such as querying the Kubernetes endpoints directly for IP addresses). +{{< note >}} +Depending on how DNS is configured in your cluster, you may not be able to look up the DNS +name for a newly-run Pod immediately. This behavior can occur when other clients in the +cluster have already sent queries for the hostname of the Pod before it was created. +Negative caching (normal in DNS) means that the results of previous failed lookups are +remembered and reused, even after the Pod is running, for at least a few seconds. + +If you need to discover Pods promptly after they are created, consider querying the +Kubernetes API directly (for example, using a watch) rather than relying on DNS lookups. +{{< /note >}} As mentioned in the [limitations](#limitations) section, you are responsible for creating the [Headless Service](/docs/concepts/services-networking/service/#headless-services) @@ -285,4 +290,3 @@ StatefulSet will then begin to recreate the Pods using the reverted template. * Follow an example of [running a replicated stateful application](/docs/tasks/run-application/run-replicated-stateful-application/). -