Return 429 response on HTTP max connection limit. Instead of silently closing
the connection, return a `429 Too Many Requests` HTTP response with a helpful
error message to aid debugging when the connection limit is unintentionally
reached.
Set a 10-millisecond write timeout and rate limiter for connection-limit 429
response to prevent writing the HTTP response from consuming too many server
resources.
Add `nomad.agent.http.exceeded metric` counting the number of HTTP connections
exceeding concurrency limit.
This PR creates a top-level 'check' page for job-specification docs.
The content for checks is about half the content of the service page, and
is about to increase in size when we add docs about Nomad service checks.
Seemed like a good idea to just split the checks section out into its own
thing (e.g. check_restart is already a topic).
Doing the move first lets us backport this change without adding Nomad service
check stuff yet.
Mostly just a lift-and-shift but with some tweaked examples to de-emphasize
the use of script checks.
The "Secure Nomad with Access Control" guide provides a tutorial for
bootstrapping Nomad ACLs, writing policies, and creating tokens. Add a reference
guide just for the ACL policy specification.
* docs: tighten up parameterized job metrics docs
* docs: improve alloc status descriptions
Remove `nomad.client.allocations.start` as it doesn't exist.
Related to #13740
- blocked_evals.total_blocked is the number of evals blocked for *any*
reason
- blocked_evals.total_quota_limit is the number of evals blocked by
quota limits, but critically: their resources are *not* counted in the
cpu/memory
Plan rejections occur when the scheduler work and the leader plan
applier disagree on the feasibility of a plan. This may happen for valid
reasons: since Nomad does parallel scheduling, it is expected that
different workers will have a different state when computing placements.
As the final plan reaches the leader plan applier, it may no longer be
valid due to a concurrent scheduling taking up intended resources. In
these situations the plan applier will notify the worker that the plan
was rejected and that they should refresh their state before trying
again.
In some rare and unexpected circumstances it has been observed that
workers will repeatedly submit the same plan, even if they are always
rejected.
While the root cause is still unknown this mitigation has been put in
place. The plan applier will now track the history of plan rejections
per client and include in the plan result a list of node IDs that should
be set as ineligible if the number of rejections in a given time window
crosses a certain threshold. The window size and threshold value can be
adjusted in the server configuration.
To avoid marking several nodes as ineligible at one, the operation is rate
limited to 5 nodes every 30min, with an initial burst of 10 operations.
Fixes#13505
This fixes#13505 by treating reserved_ports like we treat a lot of jobspec settings: merging settings from more global stanzas (client.reserved.reserved_ports) "down" into more specific stanzas (client.host_networks[].reserved_ports).
As discussed in #13505 there are other options, and since it's totally broken right now we have some flexibility:
Treat overlapping reserved_ports on addresses as invalid and refuse to start agents. However, I'm not sure there's a cohesive model we want to publish right now since so much 0.9-0.12 compat code still exists! We would have to explain to folks that if their -network-interface and host_network addresses overlapped, they could only specify reserved_ports in one place or the other?! It gets ugly.
Use the global client.reserved.reserved_ports value as the default and treat host_network[].reserverd_ports as overrides. My first suggestion in the issue, but @groggemans made me realize the addresses on the agent's interface (as configured by -network-interface) may overlap with host_networks, so you'd need to remove the global reserved_ports from addresses shared with a shared network?! This seemed really confusing and subtle for users to me.
So I think "merging down" creates the most expressive yet understandable approach. I've played around with it a bit, and it doesn't seem too surprising. The only frustrating part is how difficult it is to observe the available addresses and ports on a node! However that's a job for another PR.
The sidebar navigation tree for the `operator` sub-sub commands is
getting cluttered and we have a new set of commands coming to support
secure variables keyring as well. Move these all under their own
subtrees.
Use the same output format when listing multiple evals in the `eval
list` command and when `eval status <prefix>` matches more than one
eval.
Include the eval namespace in all output formats and always include the
job ID in `eval status` since, even `node-update` evals are related to a
job.
Add Node ID to the evals table output to help differentiate
`node-update` evals.
Co-authored-by: James Rasell <jrasell@hashicorp.com>
* core: allow pause/un-pause of eval broker on region leader.
* agent: add ability to pause eval broker via scheduler config.
* cli: add operator scheduler commands to interact with config.
* api: add ability to pause eval broker via scheduler config
* e2e: add operator scheduler test for eval broker pause.
* docs: include new opertor scheduler CLI and pause eval API info.
This PR adds the 'choose' query parameter to the '/v1/service/<service>' endpoint.
The value of 'choose' is in the form '<number>|<key>', number is the number
of desired services and key is a value unique but consistent to the requester
(e.g. allocID).
Folks aren't really expected to use this API directly, but rather through consul-template
which will soon be getting a new helper function making use of this query parameter.
Example,
curl 'localhost:4646/v1/service/redis?choose=2|abc123'
Note: consul-templte v0.29.1 includes the necessary nomadServices functionality.
In addition to jobs, there are other objects in Nomad that have a
specific format and can be provided to commands and API endpoints.
This commit creates a new menu section to hold the specification for
volumes and update the command pages to point to the new centralized
definition.
Redirecting the previous entries is not possible with `redirect.js`
because they are done server-side and URL fragments are not accessible
to detect a match. So we provide hidden anchors with a link to the new
page to guide users towards the new documentation.
Co-authored-by: Tim Gross <tgross@hashicorp.com>
