## Problem
There are several parts of `compute_ctl` with a very low visibility of
errors:
1. DB migrations that run async in the background after compute start.
2. Requests made to control plane (currently only `GetSpec`).
3. Requests made to the remote extensions server.
## Summary of changes
Add new counters to quickly evaluate the amount of errors among the
fleet.
Part of neondatabase/cloud#17590
add owned_by_superuser field to filter out system extensions.
While on it, also correct related code:
- fix the metric setting: use set() instead of inc() in a loop.
inc() is not idempotent and can lead to incorrect results
if the function called multiple times. Currently it is only called at
compute start, but this will change soon.
- fix the return type of the installed_extensions endpoint
to match the metric. Currently it is only used in the test.
## Problem
It was not always possible to judge what exactly some `cloud_admin`
connections were doing because we didn't consistently set
`application_name` everywhere.
## Summary of changes
Unify the way we connect to Postgres:
1. Switch to building configs everywhere
2. Always set `application_name` and make naming consistent
Follow-up for #9919
Part of neondatabase/cloud#20948
## Problem
We used `set_path()` to replace the database name in the connection
string. It automatically does url-safe encoding if the path is not
already encoded, but it does it as per the URL standard, which assumes
that tabs can be safely removed from the path without changing the
meaning of the URL. See, e.g.,
https://url.spec.whatwg.org/#concept-basic-url-parser. It also breaks
for DBs with properly %-encoded names, like with `%20`, as they are kept
intact, but actually should be escaped.
Yet, this is not true for Postgres, where it's completely valid to have
trailing tabs in the database name.
I think this is the PR that caused this regression
https://github.com/neondatabase/neon/pull/9717, as it switched from
`postgres::config::Config` back to `set_path()`.
This was fixed a while ago already [1], btw, I just haven't added a test
to catch this regression back then :(
## Summary of changes
This commit changes the code back to use
`postgres/tokio_postgres::Config` everywhere.
While on it, also do some changes around, as I had to touch this code:
1. Bump some logging from `debug` to `info` in the spec apply path. We
do not use `debug` in prod, and it was tricky to understand what was
going on with this bug in prod.
2. Refactor configuration concurrency calculation code so it was
reusable. Yet, still keep `1` in the case of reconfiguration. The
database can be actively used at this moment, so we cannot guarantee
that there will be enough spare connection slots, and the underlying
code won't handle connection errors properly.
3. Simplify the installed extensions code. It was spawning a blocking
task inside async function, which doesn't make much sense. Instead, just
have a main sync function and call it with `spawn_blocking` in the API
code -- the only place we need it to be async.
4. Add regression python test to cover this and related problems in the
future. Also, add more extensive testing of schema dump and DBs and
roles listing API.
[1]:
4d1e48f3b9
[2]:
https://www.postgresql.org/message-id/flat/20151023003445.931.91267%40wrigleys.postgresql.orgResolvesneondatabase/cloud#20869
to keep it consistent with existing compute metrics.
flux-fleet change is not needed, because it doesn't have any filter by
metric name for compute metrics.
and add /metrics endpoint to compute_ctl to expose such metrics
metric format example for extension pg_rag
with versions 1.2.3 and 1.4.2
installed in 3 and 1 databases respectively:
neon_extensions_installed{extension="pg_rag", version="1.2.3"} = 3
neon_extensions_installed{extension="pg_rag", version="1.4.2"} = 1
------
infra part: https://github.com/neondatabase/flux-fleet/pull/251
---------
Co-authored-by: Tristan Partin <tristan@neon.tech>
Simple PR to log installed_extensions statistics.
in the following format:
```
2024-10-17T13:53:02.860595Z INFO [NEON_EXT_STAT] {"extensions":[{"extname":"plpgsql","versions":["1.0"],"n_databases":2},{"extname":"neon","versions":["1.5"],"n_databases":1}]}
```
```
warning: first doc comment paragraph is too long
--> compute_tools/src/installed_extensions.rs:35:1
|
35 | / /// Connect to every database (see list_dbs above) and get the list of installed extensions.
36 | | /// Same extension can be installed in multiple databases with different versions,
37 | | /// we only keep the highest and lowest version across all databases.
| |_
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph
= note: `#[warn(clippy::too_long_first_doc_paragraph)]` on by default
help: add an empty line
|
35 ~ /// Connect to every database (see list_dbs above) and get the list of installed extensions.
36 + ///
|
```
Add /installed_extensions endpoint to collect
statistics about extension usage.
It returns a list of installed extensions in the format:
```json
{
"extensions": [
{
"extname": "extension_name",
"versions": ["1.0", "1.1"],
"n_databases": 5,
}
]
}
```
---------
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
