The fix seems to be related to the pointer comparison and swapping we
did around killing a non-leader. I actually can't quite explain it, but
when comparing against Consul's version of this test I noticed they used
the slice index to track the killed server instead of pointer swapping.
As soon as I switched to slice index tracking I could no longer
reproduce the failure.
In addition:
- Tested membership counts on all servers instead of just 1 for added
correctness.
- Stopped testing raft v1 because it is unsupported.
Add a new hostname string parameter to the network block which
allows operators to specify the hostname of the network namespace.
Changing this causes a destructive update to the allocation and it
is omitted if empty from API responses. This parameter also supports
interpolation.
In order to have a hostname passed as a configuration param when
creating an allocation network, the CreateNetwork func of the
DriverNetworkManager interface needs to be updated. In order to
minimize the disruption of future changes, rather than add another
string func arg, the function now accepts a request struct along with
the allocID param. The struct has the hostname as a field.
The in-tree implementations of DriverNetworkManager.CreateNetwork
have been modified to account for the function signature change.
In updating for the change, the enhancement of adding hostnames to
network namespaces has also been added to the Docker driver, whilst
the default Linux manager does not current implement it.
This fixes a bug in the event stream API where it currently interprets
namespace=* as an actual namespace, not a wildcard. When Nomad parses
incoming requests, it sets namespace to default if not specified, which
means the request namespace will never be an empty string, which is what
the event subscription was checking for. This changes the conditional
logic to check for a wildcard namespace instead of an empty one.
It also updates some event tests to include the default namespace in the
subscription to match current behavior.
Fixes#10903
Attempt to deflake the test by avoiding shutting down the leaders, as leadership
recovery takes more time, and consequently longer to process raft configuration
changes and potentially failing the test.
When a node becomes ready, create an eval for all system jobs across
namespaces.
The previous code uses `job.ID` to deduplicate evals, but that ignores
the job namespace. Thus if there are multiple jobs in different
namespaces sharing the same ID/Name, only one will be considered for
running in the new node. Thus, Nomad may skip running some system jobs
in that node.
Fix a bug where system jobs may fail to be placed on a node that
initially was not eligible for system job placement.
This changes causes the reschedule to re-evaluate the node if any
attribute used in feasibility checks changes.
Fixes https://github.com/hashicorp/nomad/issues/8448
In a multi-task-group job, treat 0 canary groups as auto-promote.
This change fixes an edge case where Nomad requires a manual promotion,
if the job had any group with canary=0 and rest of groups having
auto_promote set.
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
This PR implements a new "System Batch" scheduler type. Jobs can
make use of this new scheduler by setting their type to 'sysbatch'.
Like the name implies, sysbatch can be thought of as a hybrid between
system and batch jobs - it is for running short lived jobs intended to
run on every compatible node in the cluster.
As with batch jobs, sysbatch jobs can also be periodic and/or parameterized
dispatch jobs. A sysbatch job is considered complete when it has been run
on all compatible nodes until reaching a terminal state (success or failed
on retries).
Feasibility and preemption are governed the same as with system jobs. In
this PR, the update stanza is not yet supported. The update stanza is sill
limited in functionality for the underlying system scheduler, and is
not useful yet for sysbatch jobs. Further work in #4740 will improve
support for the update stanza and deployments.
Closes#2527
Fix a panic in handling one-time auth tokens, used to support `nomad ui
--authenticate`.
If the nomad leader is a 1.1.x with some servers running as 1.0.x, the
pre-1.1.0 servers risk crashing and the cluster may lose quorum. That
can happen when `nomad authenticate -ui` command is issued, or when the
leader scans for expired tokens every 10 minutes.
Fixed#10943 .
Basically the same as #10896 but with the Affinity struct.
Since we use reflect.DeepEquals for job comparison, there is
risk of false positives for changes due to a job struct with
memoized vs non-memoized strings.
Closes#10897
This PR causes Nomad to no longer memoize the String value of
a Constraint. The private memoized variable may or may not be
initialized at any given time, which means a reflect.DeepEqual
comparison between two jobs (e.g. during Plan) may return incorrect
results.
Fixes#10836
When a task group with `service` block(s) is validated, we validate that there
are no duplicates, but this validation doesn't have access to the task environment
because it hasn't been created yet. Services and checks with interpolation can
be flagged incorrectly as conflicting. Name conflicts in services are not
actually an error in Consul and users have reported wanting to use the same
service name for task groups differentiated by tags.
This PR adds validation during job submission that Connect proxy upstreams
within a task group are using different listener addresses. Otherwise, a
duplicate envoy listener will be created and not be able to bind.
Closes#7833
Fix deployment watchers to avoid creating unnecessary deployment watcher goroutines and blocking queries. `deploymentWatcher.getAllocsCh` creates a new goroutine that makes a blocking query to fetch updates of deployment allocs.
## Background
When operators submit a new or updated service job, Nomad create a new deployment by default. The deployment object controls how fast to place the allocations through [`max_parallel`](https://www.nomadproject.io/docs/job-specification/update#max_parallel) and health checks configurations.
The `scheduler` and `deploymentwatcher` package collaborate to achieve deployment logic: The scheduler only places the canaries and `max_parallel` allocations for a new deployment; the `deploymentwatcher` monitors for alloc progress and then enqueues a new evaluation whenever the scheduler should reprocess a job and places the next `max_parallel` round of allocations.
The `deploymentwatcher` package makes blocking queries against the state store, to fetch all deployments and the relevant allocs for each running deployments. If `deploymentwatcher` fails or is hindered from fetching the state, the deployments fail to make progress.
`Deploymentwatcher` logic only runs on the leader.
## Why unnecessary deployment watchers can halt cluster progress
Previously, `getAllocsCh` is called on every for loop iteration in `deploymentWatcher.watch()` function. However, the for-loop may iterate many times before the allocs get updated. In fact, whenever a new deployment is created/updated/deleted, *all* `deploymentWatcher`s get notified through `w.deploymentUpdateCh`. The `getAllocsCh` goroutines and blocking queries spike significantly and grow quadratically with respect to the number of running deployments. The growth leads to two adverse outcomes:
1. it spikes the CPU/Memory usage resulting potentially leading to OOM or very slow processing
2. it activates the [query rate limiter](abaa9c5c5b/nomad/deploymentwatcher/deployment_watcher.go (L896-L898)), so later the watcher fails to get updates and consequently fails to make progress towards placing new allocations for the deployment!
So the cluster fails to catch up and fails to make progress in almost all deployments. The cluster recovers after a leader transition: the deposed leader stops all watchers and free up goroutines and blocking queries; the new leader recreates the watchers without the quadratic growth and remaining under the rate limiter. Well, until a spike of deployments are created triggering the condition again.
### Relevant Code References
Path for deployment monitoring:
* [`Watcher.watchDeployments`](abaa9c5c5b/nomad/deploymentwatcher/deployments_watcher.go (L164-L192)) loops waiting for deployment updates.
* On every deployment update, [`w.getDeploys`](abaa9c5c5b/nomad/deploymentwatcher/deployments_watcher.go (L194-L229)) returns all deployments in the system
* `watchDeployments` calls `w.add(d)` on every active deployment
* which in turns, [updates existing watcher if one is found](abaa9c5c5b/nomad/deploymentwatcher/deployments_watcher.go (L251-L255)).
* The deployment watcher [updates local local deployment field and trigger `deploymentUpdateCh` channel]( abaa9c5c5b/nomad/deploymentwatcher/deployment_watcher.go (L136-L147))
* The [deployment watcher `deploymentUpdateCh` selector is activated](abaa9c5c5b/nomad/deploymentwatcher/deployment_watcher.go (L455-L489)). Most of the time the selector clause is a no-op, because the flow was triggered due to another deployment update
* The `watch` for-loop iterates again and in the previous code we create yet another goroutine and blocking call that risks being rate limited.
Co-authored-by: Tim Gross <tgross@hashicorp.com>
Mahmood Ali