Previously VMs in stop/shutdown/restart states wouldn't be properly
handled during a node flush. This fixes the bugs and ensures that the
transient VM states (shutdown/restart) are completed before proceeding,
and then avoids setting a stopped/shutdown VM to shutdown/auotstart.
It didn't make any sense to me for mem(prov) to be the default selector,
since this has too many caveats versus mem(free). Switch to using
mem(free) as the default (i.e. "mem") and make memprov the alternative.
This replicates some of the more important functionality of the defunct
pvc-flush.service unit. On presence of a trigger file (i.e.
/etc/pvc/autoready), it will trigger a "node ready" on boot. It does
nothing on shutdown as this must be handled by other mechanisms, though
a similar autoflush could be added as well.
This service caused more headaches than it was worth, so remove it.
The original goal was to cleanly flush nodes on shutdown and unflush
them on startup, but this is tightly controlled by Ansible playbooks at
this point, and this is something best left to the Administrator and
their particular situation anyways.
Adds commands to both replace an OSD disk, and refresh (reimport) an
existing OSD disk on a new node. This handles the cases where an OSD
disk should be replaced (either due to upgrades or failures) or where a
node is rebuilt in-place and an existing OSD must be re-imported to it.
This should avoid the need to do a full remove/add sequence for either
case.
Also cleans up some aspects of OSD removal that are identical between
methods (e.g. using safe-to-destroy and sleeping after stopping) and
fixes a bug if an OSD does not truly exist when the daemon starts up.
With the OSD LVM information stored in Zookeeper, we can use this to
determine the actual block device to zap rather than relying on runtime
determination and guestimation.
Ensures that information like the FSIDs and the OSD LVM volume are
stored in Zookeeper at creation time and updated at daemon start time
(to ensure the data is populated at least once, or if the /dev/sdX
path changes).
This will allow safer operation of OSD removals and the potential
implementation of re-activation after node replacements.
Allows specifying blockdevs in the OSD and OSD-DB addition commands as
detect strings rather than actual block device paths. This provides
greater flexibility for automation with pvcbootstrapd (which originates
the concept of detect strings) and in general usage as well.
Use a power off (and then make the power on a requirement) during a node
fence. Removes some potential ambiguity in the power state, since we
will know for certain if it is off.
Refactors some of the code in VXNetworkInterface to handle MTUs in a
more streamlined fashion. Also fixes a bug whereby bridge client
networks were being explicitly given the cluster dev MTU which might not
be correct. Now adds support for this option explicitly in the configs,
and defaults to 1500 for safety (the standard Ethernet MTU).
Addresses #144
Ensure that all keepalive timeouts are set (prevent the queue.get()
actions from blocking forever) and set the thread timeouts to line up as
well. Everything here is thus limited to keepalive_interval seconds
(default 5s) to keep it uniform.
Remove two superfluous synchronization steps which are not needed here,
since the exclusive lock handles that situation anyways.
Still does not fix the weird flush->unflush lock timeout bug, but is
better worked-around now due to the cancelling of the other wait freeing
this up and continuing.
Make the block on stage C only wait for 900 seconds (15 minutes) to
prevent indefinite blocking.
The issue comes if a VM is being received, and the current unflush is
cancelled for a flush. When this happens, this lock acquisition seems to
block for no obvious reason, and no other changes seem to affect it.
This is certainly some sort of locking bug within Kazoo but I can't
diagnose it as-is. Leave a TODO to look into this again in the future.
Rather than using a cumbersome and overly complex ping-pong of read and
write locks, instead move to a much simpler process using exclusive
locks.
Describing the process in ASCII or narrative is cumbersome, but the
process ping-pongs via a set of exclusive locks and wait timers, so that
the two sides are able to synchronize via blocking the exclusive lock.
The end result is a much more streamlined migration (takes about half
the time all things considered) which should be less error-prone.
1. Output from ipmitool was not being stripped, and stray newlines were
throwing off the comparisons. Fixes this.
2. Several stages were lacking meaningful messages. Adds these in so the
output is more clear about what is going on.
3. Reduce the sleep time after a fence to just 1x the
keepalive_interval, rather than 2x, because this seemed like excessively
long even for slow IPMI interfaces, especially since we're checking the
power state now anyways.
4. Set the node daemon state to an explicit 'fenced' state after a
successful fence to indicate to users that the node was indeed fenced
successfully and not still 'dead'.
The previous implementation did not work with /dev/nvme devices or any
/dev/disk/by-* devices due to some logical failures in the partition
naming scheme, so fix these, and be explicit about what is supported in
the PVC CLI command output.
The 'echo | gdisk' implementation of partition creation also did not
work due to limitations of subprocess.run; instead, use sgdisk which
allows these commands to be written out explicitly and is included in
the same package as gdisk.
The default of 0.05 (5%) is likely ideal in the initial implementation,
but allow this to be set explicitly for maximum flexibility in
space-constrained or performance-critical use-cases.
Adds in three parts:
1. Create an API endpoint to create OSD DB volume groups on a device.
Passed through to the node via the same command pipeline as
creating/removing OSDs, and creates a volume group with a fixed name
(osd-db).
2. Adds API support for specifying whether or not to use this DB volume
group when creating a new OSD via the "ext_db" flag. Naming and sizing
is fixed for simplicity and based on Ceph recommendations (5% of OSD
size). The Zookeeper schema tracks the block device to use during
removal.
3. Adds CLI support for the new and modified API endpoints, as well as
displaying the block device and DB block device in the OSD list.
While I debated supporting adding a DB device to an existing OSD, in
practice this ended up being a very complex operation involving stopping
the OSD and setting some options, so this is not supported; this can be
specified during OSD creation only.
Closes#142
Adds a new API endpoint to support hot attach/detach of devices, and the
corresponding client-side logic to use this endpoint when doing VM
network/storage add/remove actions.
The live attach is now the default behaviour for these types of
additions and removals, and can be disabled if needed.
Closes#141
This branch commit refactors the pvcnoded component to better adhere to
good programming practices. The previous Daemon.py was a massive file
which contained almost 2000 lines of direct, root-level code which was
directly imported. Not only was this poor practice, but this resulted
in a nigh-unmaintainable file which was hard even for me to understand.
This refactoring splits a large section of the code from Daemon.py into
separate small modules and functions in the `util/` directory. This will
hopefully make most of the functionality easy to find and modify without
having to dig through a single large file.
Further the existing subcomponents have been moved to the `objects/`
directory which clearly separates them.
Finally, the Daemon.py code has mostly been moved into a function,
`entrypoint()`, which is then called from the `pvcnoded.py` stub.
An additional item is that most format strings have been replaced by
f-strings to make use of the Python 3.6 features in Daemon.py and the
utility files.
We need to do a bit more finagling with the logger on termination to
ensure that all messages are written and the queue drained before
actually terminating.
Adds the ability to send node daemon logs to Zookeeper to facilitate a
command like "pvc node log", similar to "pvc vm log". Each node stores
its logs in a separate tree under "/logs" which can then be combined or
queried. By default, set by config, only 2000 lines are kept.
Previously, if the node failed to restart, it was declared a "bad fence"
and no further action would be taken. However, there are some
situations, for instance critical hardware failures, where intelligent
systems will not attempt (or succeed at) starting up the node in such a
case, which would result in dead, known-offline nodes without recovery.
Tweak this behaviour somewhat. The main path of Reboot -> Check On ->
Success + fence-flush is retained, but some additional side-paths are
now defined:
1. We attempt to power "on" the chassis 1 second after the reboot, just
in case it is off and can be recovered. We then wait another 2 seconds
and check the power status (as we did before).
2. If the reboot succeeded, follow this series of choices:
a. If the chassis is on, the fence succeeded.
b. If the chassis is off, the fence "succeeded" as well.
c. If the chassis is in some other state, the fence failed.
3. If the reboot failed, follow this series of choices:
a. If the chassis is off, the fence itself failed, but we can treat
it as "succeeded"" since the chassis is in a known-offline state.
This is the most likely situation when there is a critical hardware
failure, and the server's IPMI does not allow itself to start back
up again.
b. If the chassis is in any other state ("on" or unknown), the fence
itself failed and we must treat this as a fence failure.
Overall, this should alleviate the aforementioned issue of a critical
failure rendering the node persistently "off" not triggering a
fence-flush and ensure fencing is more robust.
This reverts commit 65d14ccd92.
This was actually a bad idea. For inexplicable reasons, running these
Ceph commands manually (not even via Python, but in a normal shell)
takes 7 * two orders of magnitude longer than running them with the
Rados module, so long in fact that some basic commands like "ceph
health" would sometimes take longer than the 1 second timeout to
complete. The Rados commands would however take about 1ms instead.
Despite the occasional issues when monitors drop out, the Rados module
is clearly far superior to the shell commands for any moderately-loaded
Ceph cluster. We can look into solving timeouts another way (perhaps
with Processes instead of Threads) at a later time.
Rados module "ceph health":
b'{"checks":{},"status":"HEALTH_OK"}'
0.001204 (s)
b'{"checks":{},"status":"HEALTH_OK"}'
0.001258 (s)
Command "ceph health":
joshua@hv1.c.bonilan.net ~ $ time ceph health >/dev/null
real 0m0.772s
user 0m0.707s
sys 0m0.046s
joshua@hv1.c.bonilan.net ~ $ time ceph health >/dev/null
real 0m0.796s
user 0m0.728s
sys 0m0.054s
Using the Rados module was very problematic, specifically because it had
no sensible timeout parameters and thus would hang for many seconds.
This has poor implications since it blocks further keepalives.
Instead, remove the Rados usage entirely and go back completely to using
manual OS commands to gather this information. While this may cause PID
exhaustion more quickly it's worthwhile to avoid failure scenarios when
Ceph stats time out.
Closes#137
Not sure how this didn't cause an issue until now, but the wrong key
path was used and this was getting unexpected data with the newly-added
version string instead of the proper mode string.
When doing a stop_vm or terminate_vm, check again after 0.2 seconds
and try re-terminating if it's still running. Covers cases where a VM
doesn't stop if given the 'stop' state.
Trying to do this on the VMInstance side had problems because we can't
differentiate the 3 types of migration there. So, just update this in
the API side and hope everything goes well.
This introduces an edge bug: if a VM is using a macvtap SR-IOV device,
and then tries to migrate, and the migrate is aborted, the NIC lists
will be inconsistent.
When I revamp the VMInstance in the future, I should be able to correct
this, but for now we'll have to live with that edgecase.
Joshua Boniface