Documentation: add FAQs on membership operation #7028
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| @@ -62,6 +62,22 @@ With longer latencies, the default etcd configuration may cause frequent electio | |||
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| etcdctl provides a `snapshot` command to create backups. See [backup][backup] for more details. | |||
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| #### Always remove first when replacing member? | |||
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How to replace an etcd member?
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Also i wonder if it is a good idea to link related issue with the question in faq. in that way, it gives reader a context. what do you think?
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why would this need context? it should be self-contained...
| @@ -62,6 +62,22 @@ With longer latencies, the default etcd configuration may cause frequent electio | |||
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| etcdctl provides a `snapshot` command to create backups. See [backup][backup] for more details. | |||
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| #### Always remove first when replacing member? | |||
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#### Should I add a member before removing an unhealthy member?
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| #### Why so strict about membership change? | ||
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| etcd sets `strict-reconfig-check` in order to reject reconfiguration requests that would cause quorum loss. Abandoning quorum is really risky (especially when the cluster is already in a bad way). We're aware that losing quorum is painful, but disabling quorum on membership could lead to full fledged cluster inconsistency and that would be even worse in many applications ("disk geometry corruption" being a candidate for most terrifying). |
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s/ in a bad way/unhealthy
s/We're aware.../Although it may be tempting to disable quorum checking if there's quorum loss to add a new member, this could lead to full fledged cluster inconsistency. For many applications, this will make the problem even worse ("disk geometry corruption" being a candidate for most terrifying).
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| On the other hand, if the downed member is removed from cluster membership first, the number of members becomes 2 and the quorum remains at 2. Following that removal by adding a new member will also keep the quorum steady at 2. So, even if the new node can't be brought up, it's still possible to remove the new member through quorum on the remaining live members. | ||
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| #### Why so strict about membership change? |
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Why won't etcd accept my membership changes?
| @@ -62,6 +62,22 @@ With longer latencies, the default etcd configuration may cause frequent electio | |||
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| etcdctl provides a `snapshot` command to create backups. See [backup][backup] for more details. | |||
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| #### Always remove first when replacing member? | |||
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| When replacing an etcd node, we recommend to remove the member first and then add its replacement. | |||
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s/we recommend/it's important
Copy Anthony's answer from: etcd-io#6103 etcd-io#6114
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All fixed. PTAL. Thanks! |
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lgtm |
Copying @heyitsanthony's answers from: