Currently we don't see from the logs, if shutting down tracing takes
long time or not. We do see that shutting down computes gets delayed for
some reason and hits thhe grace period limit. Moving the shutdown
message to slightly later, when we don't have anything else than just
exit left.
## Issue ticket number and link
## Checklist before requesting a review
- [x] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
We read the pageserver connection string from the spec file, so let's
read the auth token from the same place.
We've been talking about pre-launching compute nodes that are not
associated with any particular tenant at startup, so that the spec
file is delivered to the compute node later. We cannot change the env
variables after the process has been launched.
We still pass the token to 'postgres' binary in the NEON_AUTH_TOKEN
env variable, but compute_ctl is now responsible for setting it.
This allows fine-grained distributed tracing of the 'start_compute'
operation from the cloud console. The startup actions performed by
'compute_ctl' are now performed in a child of the 'start_compute'
context, so you can trace through the whole compute start operation.
This needs a corresponding change in the cloud console to fill in the
'startup_tracing_context' field in the json spec. If it's missing, the
startup operations are simply traced as a separate trace, without
a parent.
This allows tracing the startup actions e.g. with Jaeger
(https://www.jaegertracing.io/). We use the "tracing-opentelemetry"
crate, which turns tracing spans into OpenTelemetry spans, so you can
use the usual "#[instrument]" directives to add tracing.
I put the tracing initialization code to a separate crate,
`tracing-utils`, so that we can reuse it in other programs. We
probably want to set up tracing in the same way in all our programs.
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
Refactors Compute::prepare_and_run. It's split into subroutines
differently, to make it easier to attach tracing spans to the
different stages. The high-level logic for waiting for Postgres to
exit is moved to the caller.
Replace 'env_logger' with 'tracing', and add `#instrument` directives
to different stages fo the startup process. This is a fairly
mechanical change, except for the changes in 'spec.rs'. 'spec.rs'
contained some complicated formatting, where parts of log messages
were printed directly to stdout with `print`s. That was a bit messed
up because the log normally goes to stderr, but those lines were
printed to stdout. In our docker images, stderr and stdout both go to
the same place so you wouldn't notice, but I don't think it was
intentional.
This changes the log format to the default
'tracing_subscriber::format' format. It's different from the Postgres
log format, however, and because both compute_tools and Postgres print
to the same log, it's now a mix of two different formats. I'm not
sure how the Grafana log parsing pipeline can handle that. If it's a
problem, we can build custom formatter to change the compute_tools log
format to be the same as Postgres's, like it was before this commit,
or we can change the Postgres log format to match tracing_formatter's,
or we can start printing compute_tool's log output to a different
destination than Postgres
The general idea is that the VM informant binary is added to the
vm-compute-node images only. `compute_tools` then will run whatever's at
`/bin/vm-informant`, if the path exists.
It failed in staging environment a few times, and all we got in the
logs was:
ERROR could not start the compute node: failed to get basebackup@0/2D6194F8 from pageserver host=zenith-us-stage-ps-2.local port=6400
giving control plane 30s to collect the error before shutdown
That's missing all the detail on *why* it failed.
+ neondatabase/cloud#1103
This adds a couple of control endpoints to simplify compute state
discovery for control-plane. For example, now we may figure out
that Postgres wasn't able to start or basebackup failed within
seconds instead of just blindly polling the compute readiness
for a minute or two.
Also we now expose startup metrics (time of the each step: basebackup,
sync safekeepers, config, total). Console grabs them after each
successful start and report as histogram to prometheus and grafana.
OpenAPI spec is added and up-tp date, but is not currently used in the
console yet.
Currently it's included with minimal changes and lives aside of the main
workspace. Later we may re-use and combine common parts with zenith
control_plane.
This change is mostly needed to unify cloud deployment pipeline:
1.1. build compute-tools image
1.2. build compute-node image based on the freshly built compute-tools
2. build zenith image
So we can roll new compute image and new storage required by it to
operate properly. Also it becomes easier to test console against some
specific version of compute-node/-tools.
