This adds test coverage for 'compute_ctl', as it is now used by all
the python tests.
There are a few differences in how 'compute_ctl' is called in the
tests, compared to the real web console:
- In the tests, the postgresql.conf file is included as one large
string in the spec file, and it is written out as it is to the data
directory. I added a new field for that to the spec file. The real
web console, however, sets all the necessary settings in the
'settings' field, and 'compute_ctl' creates the postgresql.conf from
those settings.
- In the tests, the information needed to connect to the storage, i.e.
tenant_id, timeline_id, connection strings to pageserver and
safekeepers, are now passed as new fields in the spec file. The real
web console includes them as the GUCs in the 'settings' field. (Both
of these are different from what the test control plane used to do:
It used to write the GUCs directly in the postgresql.conf file). The
plan is to change the control plane to use the new method, and
remove the old method, but for now, support both.
Some tests that were sensitive to the amount of WAL generated needed
small changes, to accommodate that compute_ctl runs the background
health monitor which makes a few small updates. Also some tests shut
down the pageserver, and now that the background health check can run
some queries while the pageserver is down, that can produce a few
extra errors in the logs, which needed to be allowlisted.
Other changes:
- remove obsolete comments about PostgresNode;
- create standby.signal file for Static compute node;
- log output of `compute_ctl` and `postgres` is merged into
`endpoints/compute.log`.
---------
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
If compute_ctl is launched without a spec file, it fetches it from the
control plane with an HTTP request. We cannot get the startup tracing
context from the compute spec in that case, because we don't have it
available on start. We could still read the tracing context from the
compute spec after we have fetched it, but that would leave the fetch
itself out of the context. Pass the tracing context in environment
variables instead.
Our scale-to-zero logic was optimized for short auto-suspend intervals,
e.g. minutes or hours. In this case, if compute was restarted by k8s due
to some reason (OOM, k8s node went down, pod relocation, etc.),
`last_active` got bumped, we start counting auto-suspend timeout again.
It's not a big deal, i.e. we suspend completely idle compute not after 5
minutes, but after 10 minutes or so.
Yet, some clients may want days or even weeks. And chance that compute
could be restarted during this interval is pretty high, but in this case
we could be not able to suspend some computes for weeks.
After this commit, we won't initialize `last_active` on start, so
`/status` could return an unset attribute. This means that there was no
user activity since start. Control-plane should deal with it by taking
`max()` out of all available activity timestamps: `started_at`,
`last_active`, etc.
compute_ctl part of neondatabase/cloud#4853
Do several attempts to get spec from the control-plane and retry network
errors and all reasonable HTTP response codes. Do not hang waiting for
spec without confirmation from the control-plane that compute is known
and is in the `Empty` state.
Adjust the way we track `total_startup_ms` metric, it should be
calculated since the moment we received spec, not from the moment
`compute_ctl` started. Also introduce a new `wait_for_spec_ms` metric
to track the time spent sleeping and waiting for spec to be delivered
from control-plane.
Part of neondatabase/cloud#3533
With this commit one can request compute reconfiguration
from the running `compute_ctl` with compute in `Running` state
by sending a new spec:
```shell
curl -d "{\"spec\": $(cat ./compute-spec-new.json)}" http://localhost:3080/configure
```
Internally, we start a separate configurator thread that is waiting on
`Condvar` for `ConfigurationPending` compute state in a loop. Then it does
reconfiguration, sets compute back to `Running` state and notifies other
waiters.
It will need some follow-ups, e.g. for retry logic for control-plane
requests, but should be useful for testing in the current state. This
shouldn't affect any existing environment, since computes are configured
in a different way there.
Resolvesneondatabase/cloud#4433
Sometimes, it contained real values, sometimes just defaults if the
spec was not received yet. Make the state more clear by making it an
Option instead.
One consequence is that if some of the required settings like
neon.tenant_id are missing from the spec file sent to the /configure
endpoint, it is spotted earlier and you get an immediate HTTP error
response. Not that it matters very much, but it's nicer nevertheless.
This is in preparation of using compute_ctl to launch postgres nodes
in the neon_local control plane. And seems like a good idea to
separate the public interfaces anyway.
One non-mechanical change here is that the 'metrics' field is moved
under the Mutex, instead of using atomics. We were not using atomics
for performance but for convenience here, and it seems more clear to
not use atomics in the model for the HTTP response type.
