The maintenance system implements a high availability (HA) feature
designed to detect the simultaneous heartbeat failure of a group
of hosts and avoid failing all those hosts until heartbeat resumes
or after a set period of time.
This feature is called Multi-Node Failure Avoidance, aka MNFA, and
currently has the hosts threshold set to 3 and timeout set to 100 secs.
This update implements enhancements to that existing feature by
making the 'number-of-hosts threshold' and 'timeout period'
customer configurable service parameters.
The new service parameters are listed under platform:maintenance which
display with the following command
> system service-parameter-list
mnfa_threshold: This new label and value is added to the puppet
managed /etc/mtc.ini and represents the number of hosts that are
required to fail heartbeat as a group; within the heartbeat
failure window (heartbeat_failure_threshold) after which maintenance
activates MNFA Mode.
This update changes the default number of failing hosts from
3 to 2 while allowing a configurable range from 2 to 100.
mnfa_timeout: This new label and value is added to the puppet
managed /etc/mtc.ini. While MNFA mode is active, it will remain active
until the number of failing hosts drop below the mnfa_threshold or this
timer expires. The MNFA mode deactivates on the first occurance of
either case. Upon deactivation the remaining failed hosts are no
longer treated as a failure group but instead are all Gracefully
Recovered individually. A value of zero imposes no timeout making the
deactivation criteria solely host based.
This update changes the default 100 second timer to 0; no-timeout
while permitting valid a times range from 100 to 86400 secs or 1 day.
Test Plan:
PASS - Verify duplex and 4 compute DOR
PASS - Verify default MNFA - 1 inactive controller and 4 computes
PASS - Verify default MNFA - 4 computes
PASS - Verify default MNFA - 1 active controller and 3 computes and failed host
PASS - Verify Single host heartbeat failure handling - fail host
PASS - Verify Multi Node failure below mnfa_threshold - fail hosts
PASS - Verify MNFA handling with timeout of zero and threshold of 3
PASS - Verify MNFA timeout handling with timeout set at 100 sec
PASS - Verify MNFA service parameter lising, default value and mtc.ini
PASS - Verify MNFA service parameter change and inservice apply
PASS - Verify MNFA timeout service parameter change from value to 0
PASS - Verify MNFA timeout service parameter change from to inrange value
PASS - Verify MNFA service parametrer out of range change handling
PASS - Verify MNFA timeout change from No-Timeout to 100 sec (while active)
DocImpact
Story: 2003576
Task: 24903
Change-Id: Ib56dd79b38c3726e042cf34aae361f229c89940b
Signed-off-by: Eric MacDonald <eric.macdonald@windriver.com>
82e851d651