Bug 259528
| Summary: | [carp] Backup node becomes second active master when master have some negative demotion values | ||||||||
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| Product: | Base System | Reporter: | Marius Halden <marius.halden> | ||||||
| Component: | kern | Assignee: | Kristof Provost <kp> | ||||||
| Status: | Closed FIXED | ||||||||
| Severity: | Affects Only Me | CC: | kp | ||||||
| Priority: | --- | ||||||||
| Version: | CURRENT | ||||||||
| Hardware: | Any | ||||||||
| OS: | Any | ||||||||
| Attachments: |
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Description
Marius Halden
2021-10-29 12:58:37 UTC
Created attachment 229122 [details]
carp-negative-demote.patch
The attached patch solves the issue by not allowing the demoted advskew to be less than zero.
https://reviews.freebsd.org/D32759 and https://reviews.freebsd.org/D32760 Seems reasonable. A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=1019354b54161c140d10a8203ff1e849c09c8010 commit 1019354b54161c140d10a8203ff1e849c09c8010 Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:18:42 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-01 16:08:23 +0000 carp: deal with negative net.inet.carp.demotion Given nodes 1 and 2, where node 1 has an advskew of 0 and node 2 has an advskew of 100, making them master and backup respectively. If net.inet.carp.demotion is set to a negative value on node 1, node 2 might become master while node 1 still retains it master status. Wether or not node 2 becomes master seems to depend on the nodes advskew and what the demotion sysctl was set to on node 1. The reason for node 2 becoming master seems to be that the calculated advskew taking demotion into account is truncated to a single unsigned byte when copied into the carp header for sending, and node 1 stays master since it takes uses the whole non-truncated calculated advskew when deciding wether to stay master. PR: 259528 Reviewed by: donner, glebius MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32759 sys/netinet/ip_carp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=847b0d07c43c1190f0015c4c93a9e8fd953e3ab5 commit 847b0d07c43c1190f0015c4c93a9e8fd953e3ab5 Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:22:10 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-01 16:08:23 +0000 carp tests: negative demotion PR: 259528 Reviewed by: donner MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32760 tests/sys/netinet/carp.sh | 67 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 59 insertions(+), 8 deletions(-) A commit in branch stable/12 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=d42231181626b2fe0f75514c9b5753083cdf362b commit d42231181626b2fe0f75514c9b5753083cdf362b Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:22:10 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-22 01:58:10 +0000 carp tests: negative demotion PR: 259528 Reviewed by: donner MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32760 (cherry picked from commit 847b0d07c43c1190f0015c4c93a9e8fd953e3ab5) tests/sys/netinet/carp.sh | 67 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 59 insertions(+), 8 deletions(-) A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=0909e05779eed325fa0c2d4c1daa6916dbbc83e3 commit 0909e05779eed325fa0c2d4c1daa6916dbbc83e3 Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:18:42 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-22 01:55:02 +0000 carp: deal with negative net.inet.carp.demotion Given nodes 1 and 2, where node 1 has an advskew of 0 and node 2 has an advskew of 100, making them master and backup respectively. If net.inet.carp.demotion is set to a negative value on node 1, node 2 might become master while node 1 still retains it master status. Wether or not node 2 becomes master seems to depend on the nodes advskew and what the demotion sysctl was set to on node 1. The reason for node 2 becoming master seems to be that the calculated advskew taking demotion into account is truncated to a single unsigned byte when copied into the carp header for sending, and node 1 stays master since it takes uses the whole non-truncated calculated advskew when deciding wether to stay master. PR: 259528 Reviewed by: donner, glebius MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32759 (cherry picked from commit 1019354b54161c140d10a8203ff1e849c09c8010) sys/netinet/ip_carp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=b6237b80891f1a6e9808f630a4626eab6ea203bc commit b6237b80891f1a6e9808f630a4626eab6ea203bc Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:22:10 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-22 01:55:07 +0000 carp tests: negative demotion PR: 259528 Reviewed by: donner MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32760 (cherry picked from commit 847b0d07c43c1190f0015c4c93a9e8fd953e3ab5) tests/sys/netinet/carp.sh | 67 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 59 insertions(+), 8 deletions(-) A commit in branch stable/12 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=1c16de99bd7ddddad9d5877ba0f91aa2a2f57eb3 commit 1c16de99bd7ddddad9d5877ba0f91aa2a2f57eb3 Author: Marius Halden <marius.halden@modirum.com> AuthorDate: 2021-10-31 20:18:42 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-11-22 01:55:13 +0000 carp: deal with negative net.inet.carp.demotion Given nodes 1 and 2, where node 1 has an advskew of 0 and node 2 has an advskew of 100, making them master and backup respectively. If net.inet.carp.demotion is set to a negative value on node 1, node 2 might become master while node 1 still retains it master status. Wether or not node 2 becomes master seems to depend on the nodes advskew and what the demotion sysctl was set to on node 1. The reason for node 2 becoming master seems to be that the calculated advskew taking demotion into account is truncated to a single unsigned byte when copied into the carp header for sending, and node 1 stays master since it takes uses the whole non-truncated calculated advskew when deciding wether to stay master. PR: 259528 Reviewed by: donner, glebius MFC after: 3 weeks Sponsored by: Modirum MDPay Differential Revision: https://reviews.freebsd.org/D32759 (cherry picked from commit 1019354b54161c140d10a8203ff1e849c09c8010) sys/netinet/ip_carp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) |
