Fixes a deadlock in leadership handling if leadership flapped.
Raft propagates leadership transition to Nomad through a NotifyCh channel.
Raft blocks when writing to this channel, so channel must be buffered or
aggressively consumed[1]. Otherwise, Raft blocks indefinitely in `raft.runLeader`
until the channel is consumed[1] and does not move on to executing follower
related logic (in `raft.runFollower`).
While Raft `runLeader` defer function blocks, raft cannot process any other
raft operations. For example, `run{Leader|Follower}` methods consume
`raft.applyCh`, and while runLeader defer is blocked, all raft log applications
or config lookup will block indefinitely.
Sadly, `leaderLoop` and `establishLeader` makes few Raft calls!
`establishLeader` attempts to auto-create autopilot/scheduler config [3]; and
`leaderLoop` attempts to check raft configuration [4]. All of these calls occur
without a timeout.
Thus, if leadership flapped quickly while `leaderLoop/establishLeadership` is
invoked and hit any of these Raft calls, Raft handler _deadlock_ forever.
Depending on how many times it flapped and where exactly we get stuck, I suspect
it's possible to get in the following case:
* Agent metrics/stats http and RPC calls hang as they check raft.Configurations
* raft.State remains in Leader state, and server attempts to handle RPC calls
(e.g. node/alloc updates) and these hang as well
As we create goroutines per RPC call, the number of goroutines grow over time
and may trigger a out of memory errors in addition to missed updates.
[1] d90d6d6bda/config.go (L190-L193)
[2] d90d6d6bda/raft.go (L425-L436)
[3] 2a89e47746/nomad/leader.go (L198-L202)
[4] 2a89e47746/nomad/leader.go (L877)
Passes in agent enable_debug config to nomad server and client configs.
This allows for rpc endpoints to have more granular control if they
should be enabled or not in combination with ACLs.
enable debug on client test
This commit ensures that Alloc.AllocatedResources is properly populated
when read from persistence stores (namely Raft and client state store).
The alloc struct may have been written previously by an arbitrary old
version that may only populate Alloc.TaskResources.
When parsing a config file which had the consul.timeout param set,
Nomad was reporting an error causing startup to fail. This seems
to be caused by the HCL decoder interpreting the timeout type as
an int rather than a string. This is caused by the struct
TimeoutHCL param having a hcl key of timeout alongside a Timeout
struct param of type time.Duration (int). Ensuring the decoder
ignores the Timeout struct param ensure the decoder runs
correctly.
copy struct values
ensure groupserviceHook implements RunnerPreKillhook
run deregister first
test that shutdown times are delayed
move magic number into variable
Avoid logging in the `watch` function as much as possible, since
it is not waited on during a server shutdown. When the logger
logs after a test passes, it may or may not cause the testing
framework to panic.
More info in:
https://github.com/golang/go/issues/29388#issuecomment-453648436
Fixes#6853
Canonicalize jobs first before adding any sidecars. This fixes a bug
where sidecar tasks were added without interpolated names and broke
validation. Sidecar tasks must be canonicalized independently.
Also adds a group network to the mock connect job because it wasn't a
valid connect job before!
It has been decided we're going to live in a many core world.
Let's take advantage of that and parallelize these state store
tests which all run in memory and are largely CPU bound.
An unscientific benchmark demonstrating the improvement:
[mp state (master)] $ go test
PASS
ok github.com/hashicorp/nomad/nomad/state 5.162s
[mp state (f-parallelize-state-store-tests)] $ go test
PASS
ok github.com/hashicorp/nomad/nomad/state 1.527s
Copy the updated version of freeport (sdk/freeport), and tweak it for use
in Nomad tests. This means staying below port 10000 to avoid conflicts with
the lib/freeport that is still transitively used by the old version of
consul that we vendor. Also provide implementations to find ephemeral ports
of macOS and Windows environments.
Ports acquired through freeport are supposed to be returned to freeport,
which this change now also introduces. Many tests are modified to include
calls to a cleanup function for Server objects.
This should help quite a bit with some flakey tests, but not all of them.
Our port problems will not go away completely until we upgrade our vendor
version of consul. With Go modules, we'll probably do a 'replace' to swap
out other copies of freeport with the one now in 'nomad/helper/freeport'.
If ACL Request is unauthenticated, we should honor the anonymous token.
This PR makes few changes:
* `GetPolicy` endpoints may return policy if anonymous policy allows it,
or return permission denied otherwise.
* `ListPolicies` returns an empty policy list, or one with anonymous
policy if one exists.
Without this PR, the we return an incomprehensible error.
Before:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
acl token lookup failed: index error: UUID must be 36 characters
$ curl http://localhost:4646/v1/acl/policies; echo
acl token lookup failed: index error: UUID must be 36 characters
```
After:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
Permission denied
$ curl http://localhost:4646/v1/acl/policies; echo
[]
```
