Instead of exiting and trusting systemd to restart us, instead leverage
the os.execv() call to reload the process in the current PID context.
Also improves the log messages so it's very clear what's going on.
A hot reload isn't possible due to DataWatch and ChildrenWatch
constructs, so we instead need to terminate the daemon to "apply" the
schema update. Thus we use exit code 150 (Application defined in LSB)
and reorder some of the elements of the schema validation to ensure
things happen in the right order.
Add nicer easy-to-find (yay ASCII art) banners for the startup printouts
of both the node and API daemons. Also adds the safe loader to pvcnoded
to prevent hassle messages and a version string in the API daemon file.
Should correct issues on cold start as well as if a VM crashes
uncleanly, which would prevent the VM from starting due to stale RBD
locks.
This implementation has four parts:
1. Update how IP addresses are handled, specifically by replacing all
previous instances of "vni_ipaddr" with "vni_floatingipaddr", and then
adding the "vni_ipaddr" with the real data for this node's IPs. Also
include the storage IPs in this where they weren't before, so each
this_node actually has the local IPs plus floating IPs. This enables
the next two steps.
2. Modify flush_locks to take this_node as an argument, and update the
run_command function to only operate against this node, rather than on
the primary coordinator.
3. Have the flush_locks check each lock against the current node, to
verify that the lock is actually held by the current node. This is the
only way to do this safely. During fencing, we override this by not
passing a this_node which bypasses this check.
4. Have the VM start do the check for VM failure/startup and execute a
flush_locks before actually starting the VM.
Instead of each node uploading its own OSD stats, which would not work
if the PVC daemon wasn't running, instead have the primary upload stats
for all OSDs in the cluster.
Adds a separate field to the node memory, "provisioned", which totals
the amount of memory provisioned to all VMs on the node, regardless of
state, and in contrast to "allocated" which only counts running VMs.
Allows for the detection of potential overprovisioned states when
factoring in non-running VMs.
Includes the supporting code to get this data, since the original
implementation of VM memory selection was dependent on the VM being
running and getting this from libvirt. Now, if the VM is not active, it
gets this from the domain XML instead.
Prevents a bug where the thread can crash due to a change in the
d_domain object while running the for loop. By copying and iterating
over the copy, this becomes safer.
The keepalive was getting stuck gathering memoryStats from the
non-running VM, since it was in a paused state. Avoid this by just
skipping past the rest of the stats gathering if the VM isn't running.
Using simple print statements was annoying (lack of timing info and
formatting), so move to using the debug logger for these instead with a
custom state ('d') with white text to differentiate them. Also indicate
which subthread of the keepalive each task is being executed in for
easier tracing of issues.
Verify our IPMI state on startup, and then warn if fencing will fail.
For now, this is sufficient, but in future (requires refactoring) we
might want to adjust how fencing occurs based on this information.
Using the Ceph library was a disaster here; it had no timeout or way to
force it to continue, so keepalives would become stuck and trigger fence
storms. Go back to the manual osd dump command with a 2s timeout which
is far more reliable and can be adequately terminated if it runs long.
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.
Joshua Boniface