Suppress stats streaming error log messages when task finishes.
Streaming errors are expected when a task finishes and they aren't
actionable to users.
Also, note that the task runner Stats hook retries collecting stats
after a delay. If the connection terminates prematurely, it will be
retried, and closing the stats stream is not very disruptive.
Ideally, executor terminates cleanly when task exits, but that's a more
substantial change that may require changing the executor/drivers interface.
Fixes#10814
Fix a logmon leak causing high goroutine and memory usage when a task
restarts.
Logmon `FileRotator` buffers the task stdout/stderr streams and
periodically flushing them to log files. Logmon creates a new
FileRotator for each stream for each task run. However, the
`flushPeriodically` goroutine is leaked when a task restarts,
holding a reference to a no-longer-needed `FileRotator` instance
along with its 64kb buffer.
The cause is that the code assumed `time.Ticker.Stop()` closes the
ticker channel, thereby terminating the goroutine, but the documentation
says otherwise:
> Stop turns off a ticker. After Stop, no more ticks will be sent. Stop does not close the channel, to prevent a concurrent goroutine reading from the channel from seeing an erroneous "tick".
https://pkg.go.dev/time#Ticker.Stop
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.
* Update filesystem.mdx
Update summary of alloc directory to include information on access differences between task drivers and filesystem isolation modes.
Co-authored-by: Tim Gross <tim@0x74696d.com>
By default we should not expose the NOMAD_LICENSE environment variable
to tasks.
Also refactor where the DefaultEnvDenyList lives so we don't have to
maintain 2 copies of it. Since client/config is the most obvious
location, keep a reference there to its unfortunate home buried deep
in command/agent/host. Since the agent uses this list as well for the
/agent/host endpoint the list must be accessible from both command/agent
and client.
