etcd leader nodes switch frequently

[im-jinxinwang]

Bug report criteria

• [X] This bug report is not security related, security issues should be disclosed privately via security@etcd.io.
• [ ] This is not a support request, support requests should be raised in the etcd discussion forums.
• [X] You have read the etcd bug reporting guidelines.
• [X] Existing open issues along with etcd frequently asked questions have been checked and this is not a duplicate.

What happened?

leader nodes switch frequently， error logs: "ignored out-of-date read index response; local node read indexes queueing up and waiting to be in sync with leader"

What did you expect to happen?

I don't think the problem of frequent master node switching for etcd should occur

How can we reproduce it (as minimally and precisely as possible)?

I can't provide an environment to reproduce this issue, but I can provide log information on three points etcd-4(1).log etcd-5(1).log etcd-6(1).log

Anything else we need to know?

metrics information： etcd-metrics(1).txt

fio command test drive. fsync/fdatasync/sync_file_range in 99.00th=[ 1586]

Etcd version (please run commands below)

```console $ etcd --version etcd Version: 3.5.4 $ etcdctl version # paste output here ```

Etcd configuration (command line flags or environment variables)

# paste your configuration here

Etcd debug information (please run commands below, feel free to obfuscate the IP address or FQDN in the output)

```console $ etcdctl member list -w table # paste output here $ etcdctl --endpoints= endpoint status -w table # paste output here ```

Relevant log output

No response

[jmhbnz]

Hey @WVenus - Can you please confirm what backing storage your etcd instance is using? Also if possible do you have a graph for the etcd_disk_wal_fsync_duration_seconds_bucket metric over time?

[im-jinxinwang]

@jmhbnz Now using SSD as etcd storage. No metric over time, is the current point in time OK? Because the monitoring is not yet connected.

[stale[bot]]

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