Don't download ext_index.json from s3, but instead receive it as a part of spec from control plane.
This eliminates s3 access for most compute starts,
and also allows us to update extensions spec on the fly
Add infrastructure to dynamically load postgres extensions and shared libraries from remote extension storage.
Before postgres start downloads list of available remote extensions and libraries, and also downloads 'shared_preload_libraries'. After postgres is running, 'compute_ctl' listens for HTTP requests to load files.
Postgres has new GUC 'extension_server_port' to specify port on which 'compute_ctl' listens for requests.
When PostgreSQL requests a file, 'compute_ctl' downloads it.
See more details about feature design and remote extension storage layout in docs/rfcs/024-extension-loading.md
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Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Co-authored-by: Alek Westover <alek.westover@gmail.com>
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`.
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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.
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.
