This command will be used to send a signal to either a single task within an
allocation, or all of the tasks if <task-name> is omitted. If the sent signal
terminates the allocation, it will be treated as if the allocation has crashed,
rather than as if it was operator-terminated.
Signal validation is currently handled by the driver itself and nomad
does not attempt to restrict or validate them.
Noticed that `detected drivers` log line was misleading - when a driver
doesn't fingerprint before timeout, their health status is empty string
`""` which we would mark as detected.
Now, we log all drivers along with their state to ease driver
fingerprint debugging.
I noticed that `watchNodeUpdates()` almost immediately after
`registerAndHeartbeat()` calls `retryRegisterNode()`, well after 5
seconds.
This call is unnecessary and made debugging a bit harder. So here, we
ensure that we only re-register node for new node events, not for
initial registration.
Here we retain 0.8.7 behavior of waiting for driver fingerprints before
registering a node, with some timeout. This is needed for system jobs,
as system job scheduling for node occur at node registration, and the
race might mean that a system job may not get placed on the node because
of missing drivers.
The timeout isn't strictly necessary, but raising it to 1 minute as it's
closer to indefinitely blocked than 1 second. We need to keep the value
high enough to capture as much drivers/devices, but low enough that
doesn't risk blocking too long due to misbehaving plugin.
Fixes https://github.com/hashicorp/nomad/issues/5579
Currently, when logmon fails to reattach, we will retry reattachment to
the same pid until the task restart specification is exhausted.
Because we cannot clear hook state during error conditions, it is not
possible for us to signal to a future restart that it _shouldn't_
attempt to reattach to the plugin.
Here we revert to explicitly detecting reattachment seperately from a
launch of a new logmon, so we can recover from scenarios where a logmon
plugin has failed.
This is a net improvement over the current hard failure situation, as it
means in the most common case (the pid has gone away), we can recover.
Other reattachment failure modes where the plugin may still be running
could potentially cause a duplicate process, or a subsequent failure to launch
a new plugin.
If there was a duplicate process, it could potentially cause duplicate
logging. This is better than a production workload outage.
If there was a subsequent failure to launch a new plugin, it would fail
in the same (retry until restarts are exhausted) as the current failure
mode.
Renewal time was being calculated as 10s+Intn(lease-10s), so the renewal
time could be very rapid or within 1s of the deadline: [10s, lease)
This commit fixes the renewal time by calculating it as:
(lease/2) +/- 10s
For a lease of 60s this means the renewal will occur in [20s, 40s).
Revert "fingerprint Constraints and Affinities have Equals, as set"
This reverts commit 596f16fb5f1a4a6766a57b3311af806d22382609.
Revert "client tests assert the independent handling of interface and speed"
This reverts commit 7857ac5993a578474d0570819f99b7b6e027de40.
Revert "structs missed applying a style change from the review"
This reverts commit 658916e3274efa438beadc2535f47109d0c2f0f2.
Revert "client, structs comments"
This reverts commit be2838d6baa9d382a5013fa80ea016856f28ade2.
Revert "client fingerprint updateNetworks preserves the network configuration"
This reverts commit fc309cb430e62d8e66267a724f006ae9abe1c63c.
Revert "client_test cleanup comments from review"
This reverts commit bc0bf4efb9114e699bc662f50c8f12319b6b3445.
Revert "client Networks Equals is set equality"
This reverts commit f8d432345b54b1953a4a4c719b9269f845e3e573.
Revert "struct cleanup indentation in RequestedDevice Equals"
This reverts commit f4746411cab328215def6508955b160a53452da3.
Revert "struct Equals checks for identity before value checking"
This reverts commit 0767a4665ed30ab8d9586a59a74db75d51fd9226.
Revert "fix client-test, avoid hardwired platform dependecy on lo0"
This reverts commit e89dbb2ab182b6368507dbcd33c3342223eb0ae7.
Revert "refactor error in client fingerprint to include the offending data"
This reverts commit a7fed726c6e0264d42a58410d840adde780a30f5.
Revert "add client updateNodeResources to merge but preserve manual config"
This reverts commit 84bd433c7e1d030193e054ec23474380ff3b9032.
Revert "refactor struts.RequestedDevice to have its own Equals"
This reverts commit 689782524090e51183474516715aa2f34908b8e6.
Revert "refactor structs.Resource.Networks to have its own Equals"
This reverts commit 49e2e6c77bb3eaa4577772b36c62205061c92fa1.
Revert "refactor structs.Resource.Devices to have its own Equals"
This reverts commit 4ede9226bb971ae42cc203560ed0029897aec2c9.
Revert "add COMPAT(0.10): Remove in 0.10 notes to impl for structs.Resources"
This reverts commit 49fbaace5298d5ccf031eb7ebec93906e1d468b5.
Revert "add structs.Resources Equals"
This reverts commit 8528a2a2a6450e4462a1d02741571b5efcb45f0b.
Revert "test that fingerprint resources are updated, net not clobbered"
This reverts commit 8ee02ddd23bafc87b9fce52b60c6026335bb722d.
This adds a `nomad alloc restart` command and api that allows a job operator
with the alloc-lifecycle acl to perform an in-place restart of a Nomad
allocation, or a given subtask.
Remove runLaunched tracking as Run is *always* called for killable
TaskRunners. TaskRunners which fail before Run can be called (during
NewTaskRunner or Restore) are not killable as they're never added to the
client's alloc map.
This PR switches to using plain fifo files instead of golang structs
managed by containerd/fifo library.
The library main benefit is management of opening fifo files. In Linux,
a reader `open()` request would block until a writer opens the file (and
vice-versa). The library uses goroutines so that it's the first IO
operation that blocks.
This benefit isn't really useful for us: Given that logmon simply
streams output in a separate process, blocking of opening or first read
is effectively the same.
The library additionally makes further complications for managing state
and tracking read/write permission that seems overhead for our use,
compared to using a file directly.
Looking here, I made the following incidental changes:
* document that we do handle if fifo files are already created, as we
rely on that behavior for logmon restarts
* use type system to lock read vs write: currently, fifo library returns
`io.ReadWriteCloser` even if fifo is opened for writing only!
I chose to make them more of integration tests since there's a lot more
plumbing involved. The internal implementation details of how we craft
task envs can now change and these tests will still properly assert the
task runtime environment is setup properly.
Noticed that the protobuf files are out of sync with ones generated by 1.2.0 protoc go plugin.
The cause for these files seem to be related to release processes, e.g. [0.9.0-beta1 preperation](ecec3d38de (diff-da4da188ee496377d456025c2eab4e87)), and [0.9.0-beta3 preperation](b849d84f2f).
This restores the changes to that of the pinned protoc version and fails build if protobuf files are out of sync. Sample failing Travis job is that of the first commit change: https://travis-ci.org/hashicorp/nomad/jobs/506285085
Some of the context uses in TR hooks are useless (Killed during Stop
never seems meaningful).
None of the hooks are interruptable for graceful shutdown which is
unfortunate and probably needs fixing.
Builds upon earlier commit that cleans up restored handles of terminal
allocs by also emitting terminated events and calling exited hooks when
appropriate.
The test is sadly quite complicated and peeks into things (logmon's
reattach config) AR doesn't normally have access to.
However, I couldn't find another way of asserting logmon got cleaned up
without resorting to smaller unit tests. Smaller unit tests risk
re-implementing dependencies in an unrealistic way, so I opted for an
ugly integration test.
This commit is a significant change. TR.Run is now always executed, even
for terminal allocations. This was changed to allow TR.Run to cleanup
(run stop hooks) if a handle was recovered.
This is intended to handle the case of Nomad receiving a
DesiredStatus=Stop allocation update, persisting it, but crashing before
stopping AR/TR.
The commit also renames task runner hook data as it was very easy to
accidently set state on Requests instead of Responses using the old
field names.
Port some integration tests of driver fingerprinting.
Some tests (e.g. `TestFingerprintManager_Run_DriversInBlacklist`) have
been subsituted by more isolated tests in
`client/pluginmanager/drivermanager/manager_test.go`
This code chooses to be conservative as opposed to optimal: when failing
to reattach to logmon simply return a recoverable error instead of
immediately trying to restart logmon.
The recoverable error will cause the task's restart policy to be
applied and a new logmon will be launched upon restart.
Trying to do the optimal approach of simply starting a new logmon
requires error string comparison and should be tested against a task
actively logging to assert the behavior (are writes blocked? dropped?).
There were multiple bugs here:
1. Reattach unmarshalling always returned an error because you can't
unmarshal into a nil pointer.
2. The hook data wasn't being saved because it was put on the request
struct, not the response struct.
3. The plugin configuration should only have reattach *or* a command
set. Not both.
4. Setting Done=true meant the hook was never re-run on agent restart so
reattaching was never attempted.
Track the download status of each artifact independently so that if only
one of many artifacts fails to download, completed artifacts aren't
downloaded again.
0.9.0beta2 contains a regression where artifact download errors would
not cause a task restart and instead immediately fail the task.
This restores the pre-0.9 behavior of retrying all artifact errors and
adds missing tests.
Fixes an issue where if a task was restarted after restating the client,
the task dir environment variables would not be populated. This PR fixes
this for both upgrades from 0.8.X and for normal 0.9 restarts.
* master: (23 commits)
tests: avoid assertion in goroutine
spell check
ci: run checkscripts
tests: deflake TestRktDriver_StartWaitRecoverWaitStop
drivers/rkt: Remove unused github.com/rkt/rkt
drivers/rkt: allow development on non-linux
cli: Hide `nomad docker_logger` from help output
api: test api and structs are in sync
goimports until make check is happy
nil check node resources to prevent panic
tr: use context in as select statement
move pluginutils -> helper/pluginutils
vet
goimports
gofmt
Split hclspec
move hclutils
Driver tests do not use hcl2/hcl, hclspec, or hclutils
move reattach config
loader and singleton
...
Added ability to adjust the number of events the TaskRunner keeps as
there's no way to observe all events otherwise.
Task events differ slightly from 0.8 because 0.9 emits Terminated every
time a task exits instead of only when it exits on its own (not due to
restart or kill).
0.9 does not emit Killing/Killed for restarts like 0.8 which seems fine
as `Restart Signaled/Terminated/Restarting` is more descriptive.
Original v0.8 events emitted:
```
expected := []string{
"Received",
"Task Setup",
"Started",
"Restart Signaled",
"Killing",
"Killed",
"Restarting",
"Started",
"Restart Signaled",
"Killing",
"Killed",
"Restarting",
"Started",
"Restart Signaled",
"Killing",
"Killed",
"Not Restarting",
}
```
v0.9.0-dev started emitting a Terminated event every time a task process
exited. While this wasn't true in previous versions, it's a useful task
event because it's the only place for job operators to view the task's
exit code.
This behavior is asserted in the e2e/taskevents tests.
Track current memory usage, `memory.usage_in_bytes`, in addition to
`memory.max_memory_usage_in_bytes` and friends. This number is closer
what Docker reports.
Related to https://github.com/hashicorp/nomad/issues/5165 .
plugins/driver: update driver interface to support streaming stats
client/tr: use streaming stats api
TODO:
* how to handle errors and closed channel during stats streaming
* prevent tight loop if Stats(ctx) returns an error
drivers: update drivers TaskStats RPC to handle streaming results
executor: better error handling in stats rpc
docker: better control and error handling of stats rpc
driver: allow stats to return a recoverable error
This PR fixes various instances of plugins being launched without using
the parent loggers. This meant that logs would not all go to the same
output, break formatting etc.
This PR improves how killing a task is handled. Before the kill function
directly orchestrated the killing and was only valid while the task was
running. The new behavior is to mark the desired state and wait for the
task runner to converge to that state.
We were just emitting Killed/Terminated events before. In v0.8 we
emitted Killing/Killed, but lacked Terminated when explicitly stopping
a task. This change makes it so Terminated is always included, whether
explicitly stopping a task or it exiting on its own.
New output:
2019-01-04T14:58:51-08:00 Killed Task successfully killed
2019-01-04T14:58:51-08:00 Terminated Exit Code: 130, Signal: 2
2019-01-04T14:58:51-08:00 Killing Sent interrupt
2019-01-04T14:58:51-08:00 Leader Task Dead Leader Task in Group dead
2019-01-04T14:58:49-08:00 Started Task started by client
2019-01-04T14:58:49-08:00 Task Setup Building Task Directory
2019-01-04T14:58:49-08:00 Received Task received by client
Old (v0.8.6) output:
2019-01-04T22:14:54Z Killed Task successfully killed
2019-01-04T22:14:54Z Killing Sent interrupt. Waiting 5s before force killing
2019-01-04T22:14:54Z Leader Task Dead Leader Task in Group dead
2019-01-04T22:14:53Z Started Task started by client
2019-01-04T22:14:53Z Task Setup Building Task Directory
2019-01-04T22:14:53Z Received Task received by client
Simplify allocDir.Build() function to avoid depending on client/structs,
and remove a parameter that's always set to `false`.
The motivation here is to avoid a dependency cycle between
drivers/cstructs and alloc_dir.
**The Bug:**
You may have seen log lines like this when running 0.9.0-dev:
```
... client.alloc_runner.task_runner: some environment variables not available for rendering: ... keys="attr.driver.docker.volumes.enabled, attr.driver.docker.version, attr.driver.docker.bridge_ip, attr.driver.qemu.version"
```
Not only should we not be erroring on builtin driver attributes, but the
results were nondeterministic due to map iteration order!
The root cause is that we have an old root attribute for all drivers
like:
```
attr.driver.docker = "1"
```
When attributes were opaque variable names it was fine to also have
"nested" attributes like:
```
attr.driver.docker.version = "1.2.3"
```
However in the HCLv2 world the variable names are no longer opaque: they
form an object tree. The `docker` object can no longer both hold a value
(`"1"`) *and* nested attributes (`version = "1.2.3"`).
**The Fix:**
Since the old `attr.driver.<name> = "1"` attribues are useless for task
config interpolation, create a new precedence rule for creating the task
config evaluation context:
*Maps take precedence over primitives.*
This means `attr.driver.docker.version` will always take precedence over
`attr.driver.docker`. The results are determinstic and give users access
to the more useful metadata.
I made this a general precedence rule instead of special-casing driver
attrs because it seemed like better default behavior than spamming
WARNings to logs that were likely unactionable by users.
Unfortunately I don't know how to test these errors. As far as I can
tell they should only happen if there was a programming error in the
upgrade code or the underlying boltdb was corrupted somehow.
* Prefix task bucket with task- to prevent name conflicts
* Shorten device manager bucket name
* Remove commented out outdated var
* Update layout comment
The driver manager is modeled after the device manager and is started by the client.
It's responsible for handling driver lifecycle and reattachment state, as well as
processing the incomming fingerprint and task events from each driver. The mananger
exposes a method for registering event handlers for task events that is used by the
task runner to update the server when a task has been updated with an event.
Since driver fingerprinting has been implemented by the driver manager, it is no
longer needed in the fingerprint mananger and has been removed.
The RestartCount is not really suitable for use as a source of
uniqueness within task invocations as it is not monotonic, and interacts
with the restart stanza in a users config, so conflates restarts due to
task failures, with restarts due to enviromental changes, such as consul
template or vault secrets changing.
Here we instead use a substring from a uuid, which is more random than
we strictly need, but is nicer than rolling our own random string
generator here.
This creates a new buffered channel and goroutine on the allocrunner for
serializing updates to allocations. This allows us to take updates off
the routine that is used from processing updates from the server,
without having complicated machinery for tracking update lifetimes, or
other external synchronization.
This results in a nice performance improvement and signficantly better
throughput on batch changes such as preempting a large number of jobs
for a larger placement.
This commit reduces the locking required to shutdown or destroy
allocrunners, and allows parallel shutdown and destroy of allocrunners during
shutdown.
The assertion here is causing many spurious failures that aren't
actually relevant to the test itself.
We are tracking the cause for this failure independently, and it would
make more sense to have a dedicated test for clean shutdown.
Currently, there is a race condition between creating a taskrunner, and
updating node attributes via fingerprinting.
This is because the taskenv builder will try to iterate over the
clientconfig.Node.Attributes map, which can be concurrently updated by
the fingerprinting process, thus causing a panic.
This fixes that by providing a copy of the clientconfg to the
allocrunner inside the Read lock during config creation.
The allocLock is used to synchronize access to the alloc runner map, not
to ensure internal consistency of the alloc runners themselves. This
updates the updateAlloc process to avoid hanging on to an exclusive lock
of the map while applying changes to allocrunners themselves, as they
should be internally consistent.
This fixes a bug where any client allocation api will block during the
shutdown or updating of an allocrunner and its child taskrunners.
Fixes a bug where a driver health and attributes are never updated from
their initial status. If a driver started unhealthy, it may never go
into a healthy status.
Noticed few places where tests seem to block indefinitely and panic
after the test run reaches the test package timeout.
I intend to follow up with the proper fix later, but timing out is much
better than indefinitely blocking.
When starting an allocation that is preempting other allocs, we create a
new group allocation watcher, and then wait for the allocations to
terminate in the allocation PreRun hooks.
If there's no preempted allocations, then we simply provide a
NoopAllocWatcher.
The Group Alloc watcher is an implementation of a PrevAllocWatcher that
can wait for multiple previous allocs before terminating.
This is to be used when running an allocation that is preempting upstream
allocations, and thus only supports being ran with a local alloc watcher.
It also currently requires all of its child watchers to correctly handle
context cancellation. Should this be a problem, it should be fairly easy
to implement a replacement using channels rather than a waitgroup.
It obeys the PrevAllocWatcher interface for convenience, but it may be
better to extract Migration capabilities into a seperate interface for
greater clarity.
As of now, FileRotator uses bufio.Write under the hood to write data to
configured output file. Due to the way how bufio handles any occurred io
error - saves it into `err` variable never resetting it automatically -
any operation like `Write`, `Flush` etc will become a no-op, returning the very same,
saved error (eg. Out of disk space) even when the problem is fixed (eg. disk
space is available again).
That automatically means that FileRotator will stop writing any logs,
reporting the same error over and over again, even if it's no longer
valid.
This PR fixes it by resetting the bufio Writer, which resets any errors
and tries to write requested data.
IOPS have been modelled as a resource since Nomad 0.1 but has never
actually been detected and there is no plan in the short term to add
detection. This is because IOPS is a bit simplistic of a unit to define
the performance requirements from the underlying storage system. In its
current state it adds unnecessary confusion and can be removed without
impacting any users. This PR leaves IOPS defined at the jobspec parsing
level and in the api/ resources since these are the two public uses of
the field. These should be considered deprecated and only exist to allow
users to stop using them during the Nomad 0.9.x release. In the future,
there should be no expectation that the field will exist.
The previous integration test was broken during the client refactor, and
it seems to be some sort of race with state updating.
I'm going to try and construct a replacement test as part of work on
performance, but for now, the underlying behaviour is still being
tested.
This removes a cyclical dependency when importing client/structs from
dependencies of the plugin_loader, specifically, drivers. Due to
client/config also depending on the plugin_loader.
It also better reflects the ownership of fingerprint structs, as they
are fairly internal to the fingerprint manager.
The logging package is used by logmon and the legacy mock_driver. Because the
legacy drivers are going away, I'm moving it here to signify its actual
ownership.
As part of deprecating legacy drivers, we're moving the env package to a
new drivers/shared tree, as it is used by the modern docker and rkt
driver packages, and is useful for 3rd party plugins.
Looking at NewTaskRunner I'm unsure whether TaskRunner.TaskResources
(from which req.TaskResources is set) is intended to be nil at times or
if the TODO in NewTaskRunner is intended to ensure it is always non-nil.
The old approach was incomplete. Hook env vars are now:
* persisted and restored between agent restarts
* deterministic (LWW if 2 hooks set the same key)
This PR introduces a device hook that retrieves the device mount
information for an allocation. It also updates the computed node class
computation to take into account devices.
TODO Fix the task runner unit test. The environment variable is being
lost even though it is being properly set in the prestart hook.
The group utility struct does not support asynchronously launched
goroutines (goroutines-inside-of-goroutines), so switch those uses to a
normal go call.
This means watchNodeUpdates and watchNodeEvents may not be shutdown when
Shutdown() exits. During nomad agent shutdown this does not matter.
During tests this means a test may leak those goroutines or be unable to
know when those goroutines have exited.
Since there's no runtime impact and these goroutines do not affect alloc
state syncing it seems ok to risk leaking them.
We were incorrectly returning a 0 duration to the taskrunner when
determining when a task should restart. This would cause tasks to be
restarted immediately, ignoring the restart {} stanza in a users
configuration.
This commit causes us to return the restart duration to the task runner
so it may correctly delay further execution.
This change makes few compromises:
* Looks up the devices associated with tasks at look up time. Given
that `nomad alloc status` is called rarely generally (compared to stats
telemetry and general job reporting), it seems fine. However, the
lookup overhead grows bounded by number of `tasks x total-host-devices`,
which can be significant.
* `client.Client` performs the task devices->statistics lookup. It
passes self to alloc/task runners so they can look up the device statistics
allocated to them.
* Currently alloc/task runners are responsible for constructing the
entire RPC response for stats
* The alternatives for making task runners device statistics aware
don't seem appealing (e.g. having task runners contain reference to hostStats)
* On the alloc aggregation resource usage, I did a naive merging of task device statistics.
* Personally, I question the value of such aggregation, compared to
costs of struct duplication and bloating the response - but opted to be
consistent in the API.
* With naive concatination, device instances from a single device group used by separate tasks in the alloc, would be aggregated in two separate device group statistics.
In state values, we need to be able to distinguish between zero values
(e.g. `false`) and unset values (e.g. `nil`).
We can alternatively use protobuf `oneOf` and nested map to ensure
consistency of fields that are set together, but the golang
representation does not represent that well and introducing a mismatch
between representations. Thus, I opted not to use it.
Tests expect that as soon as eventer shuts down immediately on context
cancellations; but golang does not guarantee priority when multiple
pending channels are ready in a select statement.
The default job here contains some exec task config (for setting
command and args) that aren't used for mock driver. Now, the alloc
runner seems stricter about validating fields and errors on unexpected
fields.
Updating configs in tests so we can have an explicit task config
whenever driver is set explicitly.
Introduce a device manager that manages the lifecycle of device plugins
on the client. It fingerprints, collects stats, and forwards Reserve
requests to the correct plugin. The manager, also handles device plugins
failing and validates their output.
For lifecycle operations such as Restart and Kill, the client should not
expect driver plugins to be well behaved and close their waitCh on
context cancelation. Always wait on the passed in context as well as the
waitCh.
* Migrated all of the old leader task tests and got them passing
* Refactor and consolidate task killing code in AR to always kill leader
tasks first
* Fixed lots of issues with state restoring
* Fixed deadlock in AR.Destroy if AR.Run had never been called
* Added a new in memory statedb for testing
