Prevent the main keepalive thread from getting stuck due to a subthread
taking an enormous time. If this happens, the rest of the main keepalive
will continue onward, thus ensuring that the main keepalive does not
fail for a significant number of cycles, which would cause a fence.
Make the provisioner a bit more robust. This way, even if a provisioning
step fails, cleanup is still performed this preventing the system from
being left in an undefined state requiring manual correction.
Addresses #91
The previous saving throw limit (3/15s) seems to have been too low. I
was observing bizarre failures where a node would be fenced while it was
still starting up. Some of this may have been related to Zookeeper
connections taking too long, but this was inconsistent.
Increase this to 6 saving throws (30s). This provides significantly more
time for a node to properly check in on startup before another node
fences it. In the real world, 15s vs 30s isn't that big of a downtime
change, but prevents false-positive fences.
Allow the specifying of arbitrary provisioner script install() args on
the provisioner create CLI, either overriding or adding additional
per-VM arguments to those found in the profile. Reference example is
setting a "vm_fqdn" on a per-run basis.
Closes#100
Provides a CLI and API argument to force live migration, which triggers
a new VM state "migrate-live". The node daemon VMInstance during migrate
will read this flag from the state and, if enforced, will not trigger a
shutdown migration.
Closes#95
Instead of using group-based validation, which breaks the help context
for subcommands, use a decorator to validate the cluster status for each
command. The eager help option will then override this decorator for
help commands, while enforcing it for others.
Prevents a rare edge case where a node can end up "migrating" to itself.
Quick hack to fix this, though like most of the VM management should
probably be rethought/rewritten later.
Fixes#92
Joshua Boniface