[PATCH] dracut-module-setup.sh: ensure cluster info is ready before query

[Pingfan Liu]

There is a race issue between "pcs" and "kdumpctl restart"

-1. set up cluster

-2. Then here comes the command _immediately_ in kdumpctl

But due to some pcs internal mechanism, "pcs cluster cib" can not
fetch the updated info in time.

Fix these issue by forcing the upgrade of cib.

Signed-off-by: Pingfan Liu 
---
 dracut-module-setup.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 7a2c7b4..5f91c89 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -712,6 +712,7 @@ is_localhost() {
 get_pcs_fence_kdump_nodes() {
     local nodes

+    pcs cluster sync && pcs cluster cib-upgrade
     # get cluster nodes from cluster cib, get interface and ip address
     nodelist=`pcs cluster cib | xmllint --xpath "/cib/status/node_state/@uname" -`

[piliu]

Sorry, it seems I miss some description here. Add them.

On 03/24/2020 11:02 AM, Pingfan Liu wrote:
> There is a race issue between "pcs" and "kdumpctl restart"
>
> -1. set up cluster

# pcs cluster setup --start mycluster node1 node2
# pcs stonith create kdump fence_kdump pcmk_reboot_action="off"
# pcs stonith level add 1 node1 kdump
# pcs stonith level add 1 node2 kdump
> -2. Then here comes the command _immediately_ in kdumpctl

# pcs cluster cib
> But due to some pcs internal mechanism, "pcs cluster cib" can not
> fetch the updated info in time.
>
> Fix these issue by forcing the upgrade of cib.
> Signed-off-by: Pingfan Liu
>
> dracut-module-setup.sh | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
> index 7a2c7b4..5f91c89 100755
> --- a/dracut-module-setup.sh
> +++ b/dracut-module-setup.sh
> @@ -712,6 +712,7 @@ is_localhost() {
>  get_pcs_fence_kdump_nodes() {
>      local nodes
> pcs cluster sync && pcs cluster cib-upgrade
> # get cluster nodes from cluster cib, get interface and ip address
> nodelist=`pcs cluster cib | xmllint --xpath "/cib/status/node_state/@uname" -`

[Kairui Song]

On Tue, Mar 24, 2020 at 4:48 PM piliu  wrote:
> Sorry, it seems I miss some description here. Add them.
>
> On 03/24/2020 11:02 AM, Pingfan Liu wrote:
> > There is a race issue between "pcs" and "kdumpctl restart"
> >
> > -1. set up cluster
>
> # pcs cluster setup --start mycluster node1 node2
> # pcs stonith create kdump fence_kdump pcmk_reboot_action="off"
> # pcs stonith level add 1 node1 kdump
> # pcs stonith level add 1 node2 kdump
> > -2. Then here comes the command _immediately_ in kdumpctl
>
> # pcs cluster cib
> > But due to some pcs internal mechanism, "pcs cluster cib" can not
> > fetch the updated info in time.
> >
> > Fix these issue by forcing the upgrade of cib.
> > Signed-off-by: Pingfan Liu
> >
> > dracut-module-setup.sh | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
> > index 7a2c7b4..5f91c89 100755
> > --- a/dracut-module-setup.sh
> > +++ b/dracut-module-setup.sh
> > @@ -712,6 +712,7 @@ is_localhost() {
> >  get_pcs_fence_kdump_nodes() {
> >      local nodes
> > pcs cluster sync && pcs cluster cib-upgrade

Hi Pingfan, can you add more words about what these two command "pcs
cluster sync" "pcs cluster cib-upgrade" will actually do here? Will
them have any side effect?
> >  # get cluster nodes from cluster cib, get interface and ip address
> >  nodelist=`pcs cluster cib | xmllint --xpath "/cib/status/node_state/@uname" -`

--
Best Regards,
Kairui Song

[piliu]

On 04/02/2020 12:13 AM, Kairui Song wrote:
> On Tue, Mar 24, 2020 at 4:48 PM piliu  wrote:
> > Sorry, it seems I miss some description here. Add them.
> >
> > On 03/24/2020 11:02 AM, Pingfan Liu wrote:
> > > There is a race issue between "pcs" and "kdumpctl restart"
> > >
> > > -1. set up cluster
> >
> > # pcs cluster setup --start mycluster node1 node2
> > # pcs stonith create kdump fence_kdump pcmk_reboot_action="off"
> > # pcs stonith level add 1 node1 kdump
> > # pcs stonith level add 1 node2 kdump
> > > -2. Then here comes the command _immediately_ in kdumpctl
> >
> > # pcs cluster cib
> > > But due to some pcs internal mechanism, "pcs cluster cib" can not
> > > fetch the updated info in time.
> > >
> > > Fix these issue by forcing the upgrade of cib.
> > > Signed-off-by: Pingfan Liu
> > >
> > > dracut-module-setup.sh | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
> > > index 7a2c7b4..5f91c89 100755
> > > --- a/dracut-module-setup.sh
> > > +++ b/dracut-module-setup.sh
> > > @@ -712,6 +712,7 @@ is_localhost() {
> > >  get_pcs_fence_kdump_nodes() {
> > >      local nodes
> > > pcs cluster sync && pcs cluster cib-upgrade
>
> Hi Pingfan, can you add more words about what these two command "pcs
> cluster sync" "pcs cluster cib-upgrade" will actually do here? Will
> them have any side effect?

Sync: corosync configuration to all nodes found from current
corosync.conf file
And cib-upgrade: Upgrade the CIB to conform to the latest version of the
document schema

So in the following command, "pcs cluster cib" can get the latest info.

These two commands has no side effect other than taking some time, maybe
a several seconds.

Thanks,
Pingfan
> > >  # get cluster nodes from cluster cib, get interface and ip address
> > >  nodelist=`pcs cluster cib | xmllint --xpath "/cib/status/node_state/@uname" -`
>
> --
> Best Regards,
> Kairui Song
> _______________________________________________
> kexec mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
> Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
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[Kairui Song]

On Thu, Apr 2, 2020 at 9:26 AM piliu  wrote:
> On 04/02/2020 12:13 AM, Kairui Song wrote:
> > On Tue, Mar 24, 2020 at 4:48 PM piliu  wrote:
> > > Sorry, it seems I miss some description here. Add them.
> > >
> > > On 03/24/2020 11:02 AM, Pingfan Liu wrote:
> > > > There is a race issue between "pcs" and "kdumpctl restart"
> > > >
> > > > -1. set up cluster
> > >
> > > # pcs cluster setup --start mycluster node1 node2
> > > # pcs stonith create kdump fence_kdump pcmk_reboot_action="off"
> > > # pcs stonith level add 1 node1 kdump
> > > # pcs stonith level add 1 node2 kdump
> > > > -2. Then here comes the command _immediately_ in kdumpctl
> > >
> > > # pcs cluster cib
> > > > But due to some pcs internal mechanism, "pcs cluster cib" can not
> > > > fetch the updated info in time.
> > > >
> > > > Fix these issue by forcing the upgrade of cib.
> > > > Signed-off-by: Pingfan Liu
> > > >
> > > > dracut-module-setup.sh | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
> > > > index 7a2c7b4..5f91c89 100755
> > > > --- a/dracut-module-setup.sh
> > > > +++ b/dracut-module-setup.sh
> > > > @@ -712,6 +712,7 @@ is_localhost() {
> > > >  get_pcs_fence_kdump_nodes() {
> > > >      local nodes
> > > > pcs cluster sync && pcs cluster cib-upgrade
> >
> > Hi Pingfan, can you add more words about what these two command "pcs
> > cluster sync" "pcs cluster cib-upgrade" will actually do here? Will
> > them have any side effect?
>
> Sync: corosync configuration to all nodes found from current
> corosync.conf file
> And cib-upgrade: Upgrade the CIB to conform to the latest version of the
> document schema
>
> So in the following command, "pcs cluster cib" can get the latest info.
>
> These two commands has no side effect other than taking some time, maybe
> a several seconds.
>
> Thanks,
> Pingfan
> > > >  # get cluster nodes from cluster cib, get interface and ip address
> > > >  nodelist=`pcs cluster cib | xmllint --xpath "/cib/status/node_state/@uname" -`
> >
> > --
> > Best Regards,
> > Kairui Song
> > _______________________________________________
> > kexec mailing list -- [e-mail]
> > To unsubscribe send an email to [e-mail]
> > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
> > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
> > List Archives: https://lists.fedoraproject.org/archives/list/[e-mail]

Thanks, this patch looks good to me.