In order to get better visibility into the backend database tests using
the standard Go tooling, this changeset ports the backend tests away
from `Check`, and into subtests & `testify` for assertions.
This change means that individual sub-tests
1. can be more easily identified in the json test logs, and
2. can be more easily run individually from the command line
During this port I also discovered that some tests are using the fake
clocks incorrectly, which may be a cause of some of our flaky etcd
tests.
* Evaluate watcher events to decide whether keep-alives are effective
instead of relying on arbitrary TTLs (implemented as absolute time which
adds to trouble).
Fixes https://github.com/gravitational/teleport/issues/5346.
* Replace the approximate expire timestamps comparisons with the ordering tests
* Address review comments. Move ordered keep-alive tests back to backend/test/suite
* Use an alternative implementation of FakeClock.Advance for etcd to use real time.Sleep as etcd server cannot use fakeclock
* Address review comments
* Use fake clock in firestore tests
* Add missing import
Co-authored-by: Andrew Lytvynov <andrew@goteleport.com>
Update mirror mode (for both the memory and SQLite backends) to no
longer emit events when an element expires. This allows caches to handle
update/delete logic themselves.
This fixes an issue where services.ProxyWatcher was not getting updates
to the list of proxies.
This commit expands the usage of the caching layer
for auth server API:
* Introduces in-memory cache that is used to serve all
Auth server API requests. This is done to achieve scalability
on 10K+ node clusters, where each node fetches certificate authorities,
roles, users and join tokens. It is not possible to scale
DynamoDB backend or other backends on 10K reads per seconds
on a single shard or partition. The solution is to introduce
an in-memory cache of the backend state that is always used
for reads.
* In-memory cache has been expanded to support all resources
required by the auth server.
* Experimental `tctl top` command has been introduced to display
common single node metrics.
Replace SQLite Memory Backend with BTree
SQLite in memory backend was suffering from
high tail latencies under load (up to 8 seconds
in 99.9%-ile on load configurations).
This commit replaces the SQLite memory caching
backend with in-memory BTree backend that
brought down tail latencies to 2 seconds (99.9%-ile)
and brought overall performance improvement.
Jakub Nyckowski