kolla-ansible/releasenotes/notes/fix-TCP-connections-refusing-to-die-after-VIP-switch-5f9e811783c36041.yaml
Michal Arbet 09d0409ed4 Allow user to set sysctl_net_ipv4_tcp_retries2
This patch is adding configuration option to
manipulate with kernel option sysctl_net_ipv4_tcp_retries2.

More informations about kernel option in [1][2]
and RedHat suggestion [3] to set for DBs and HA.

[1]: https://pracucci.com/linux-tcp-rto-min-max-and-tcp-retries2.html
[2]: https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/
[3]: https://access.redhat.com/solutions/726753

Closes-Bug: #1917068
Change-Id: Ia0decbbfa4e33b1889b635f8bb1c9094567a2ce6
2021-06-23 10:34:12 +00:00

14 lines
631 B
YAML

---
features:
- |
Added a new haproxy configuration variable,
``haproxy_host_ipv4_tcp_retries2``,
which allows users to modify this kernel option.
This option sets maximum number of times a TCP packet is retransmitted
in established state before giving up. The default kernel value is 15,
which corresponds to a duration of approximately between 13 to 30
minutes, depending on the retransmission timeout. This variable can be used
to mitigate an issue with stuck connections in case of VIP failover,
see `bug 1917068 <https://bugs.launchpad.net/kolla-ansible/+bug/1917068>`__
for details.