* agent: add option to discard health output
In high volatile environments consul will have checks with "noisy"
output which changes every time even though the status does not change.
Since the output is stored in the raft log every health check update
unblocks a blocking call on health checks since the raft index has
changed even though the status of the health checks may not have changed
at all. By discarding the output of the health checks the users can
choose a different tradeoff. Less visibility on why a check failed in
exchange for a reduced change rate on the raft log.
* agent: discard output also when adding a check
* agent: add test for discard check output
* agent: update docs
* go vet
* Adds discard_check_output to reloadable config table.
* Updates the change log.
* Fixes agent error handling when check definition is invalid. Distinguishes between empty checks vs invalid checks
* Made CheckTypes return Checks from service definition struct rather than a new copy, and other changes from code review. This also errors when json payload contains empty structs
* Simplify and improve validate method, and make sure that CheckTypes always returns a new copy of validated check definitions
* Tweaks some small style things and error messages.
* Updates the change log.
* doc: document discrepancy between id and CheckID
* doc: document enable_tag_override change
* config: add TranslateKeys helper
TranslateKeys makes it easier to map between different representations
of internal structures. It allows to recursively map alias keys to
canonical keys in structured maps.
* config: use TranslateKeys for config file
This also adds support for 'enabletagoverride' and removes
the need for a separate CheckID alias field.
* config: remove dead code
* agent: use TranslateKeys for FixupCheckType
* agent: translate enable_tag_override during service registration
* doc: add '.hcl' as valid extension
* config: map ScriptArgs to args
* config: add comment for TranslateKeys
* Adds client-side retry for no leader errors.
This paves over the case where the client was connected to the leader
when it loses leadership.
* Adds a configurable server RPC drain time and a fail-fast path for RPCs.
When a server leaves it gets removed from the Raft configuration, so it will
never know who the new leader server ends up being. Without this we'd be
doomed to wait out the RPC hold timeout and then fail. This makes things fail
a little quicker while a sever is draining, and since we added a client retry
AND since the server doing this has already shut down and left the Serf LAN,
clients should retry against some other server.
* Makes the RPC hold timeout configurable.
* Reorders struct members.
* Sets the RPC hold timeout default for test servers.
* Bumps the leave drain time up to 5 seconds.
* Robustifies retries with a simpler client-side RPC hold.
* Reverts untended delete.
* Fixes handling of stop channel and failed barrier attempts.
There were two issues here. First, we needed to not exit when there
was a timeout trying to write the barrier, because Raft might not
step down, so we'd be left as the leader but having run all the step
down actions.
Second, we didn't close over the stopCh correctly, so it was possible
to nil that out and have the leaderLoop never exit. We close over it
properly AND sequence the nil-ing of it AFTER the leaderLoop exits for
good measure, so the code is more robust.
Fixes#3545
* Cleans up based on code review feedback.
* Tweaks comments.
* Renames variables and removes comments.
This patch backports a fix which will show the correct usage screen for
command line flags.
This is considered a temporary fix until the code has been refactored.
Newer versions of the cli library require that the flag set is populated
when Help() is called or that it is populated within Help() itself.
Fixes#3536
Frank Schroeder