New clusters are created with a lower coefficient. Users with existing clusters or users who prefer a different token coefficient may want to change the token coefficient. Hence, add a note how to change the token coefficient to the admin guide.
Signed-off-by: Friedrich Weber <[email protected]> --- Notes: - should this already include more details (in which cases changing the coefficient may be necessary?) in this first version? - currently, changing the token_coefficient in /etc/pve/corosync.conf without a corosync restart updates token and consensus timeouts, but knet_ping_timeout and knet_ping_interval are not updated, this is the reason why the patch suggests a corosync restart. I filed a bug for this [1] and there is a promising pull request [2] that appears to fix the issue. So the question is whether we want to backport [2] (when it's merged), and if yes, whether we want to remove the restart suggestion from the docs. [1] https://github.com/corosync/corosync/issues/813 [2] https://github.com/corosync/corosync/pull/814 pvecm.adoc | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/pvecm.adoc b/pvecm.adoc index 0ed1bd2..9513a6c 100644 --- a/pvecm.adoc +++ b/pvecm.adoc @@ -1371,6 +1371,23 @@ systemctl restart corosync On errors, check the troubleshooting section below. +Changing the token cofficient +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The token coefficient can be configured in the `totem` section in +`/etc/pve/corosync.conf`. corosync uses the token coefficient to calculate +several timeouts in relation to the cluster size.footnote:[ +`token_coefficient` in the corosync manual page +https://manpages.debian.org/stable/corosync/corosync.conf.5.en.html#token_coefficient] + +If the token coefficient is not explicitly set, it defaults to 650 milliseconds. +New clusters are created with a lower token coefficient of 125ms that is +explicitly set in `/etc/pve/corosync.conf`. + +You can change the token coefficient of an existing cluster by +xref:pvecm_edit_corosync_conf[editing corosync.conf]. For the change to fully +take effect, you need to restart corosync on all nodes. + Troubleshooting ~~~~~~~~~~~~~~~ -- 2.47.3
