The LSN lease api actually accepts a tenant_shard_id, not a tenant_id.
But we put the Display of the tenant_shard_id into the tenant_id field.
This PR fixes it.
Refs
- fixes https://databricks.atlassian.net/browse/LKB-2930
## Problem
We don't detect if safekeeper migration fails after the the commiting
the membership configuration to the database. As a result, we might
leave stale timelines on excluded safekeepers and do not notify
cplane/safekepeers about new configuration.
- Implements solution proposed in
https://github.com/neondatabase/neon/pull/12432
- Closes: https://github.com/neondatabase/neon/issues/12192
- Closes: [LKB-944](https://databricks.atlassian.net/browse/LKB-944)
## Summary of changes
- Add `sk_set_notified_generation` column to `timelines` database
- Update `*_notified_generation` in database during the finish state.
- Commit reconciliation requests to database atomically with membership
configuration.
- Reload pending ops and retry "finish" step if we detect
`*_notified_generation` mismatch.
- Add failpoints and test that we handle failures well
## Problem
Post LKB-198 rollout. We added a new strategy to generate image layers
at the L0-L1 boundary instead of the latest LSN to ensure too many L0
layers do not trigger image layer creation.
## Summary of changes
We already rolled it out to all users so we can remove the feature flag
now.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Currently, the exporter exposes the same LFC metrics that are exposed by
the "autoscaling" sql_exporter in the docker image. With this, we can
remove the dedicated sql_exporter instance. (Actually doing the removal
is left as a TODO until this is rolled out to production and we have
changed autoscaling-agent to fetch the metrics from this new endpoint.)
The exporter runs as a Postgres background worker process. This is
extracted from the Rust communicator rewrite project, which will use the
same worker process for much more, to handle the communications with the
pageservers. For now, though, it merely handles the metrics requests.
In the future, we will add more metrics, and perhaps even APIs to
control the running Postgres instance.
The exporter listens on a Unix Domain socket within the Postgres data
directory. A Unix Domain socket is a bit unconventional, but it has some
advantages:
- Permissions are taken care of. Only processes that can access the data
directory, and therefore already have full access to the running
Postgres instance, can connect to it.
- No need to allocate and manage a new port number for the listener
It has some downsides too: it's not immediately accessible from the
outside world, and the functions to work with Unix Domain sockets are
more low-level than TCP sockets (see the symlink hack in
`postgres_metrics_client.rs`, for example).
To expose the metrics from the local Unix Domain Socket to the
autoscaling agent, introduce a new '/autoscaling_metrics' endpoint in
the compute_ctl's HTTP server. Currently it merely forwards the request
to the Postgres instance, but we could add rate limiting and access
control there in the future.
---------
Co-authored-by: Conrad Ludgate <conrad@neon.tech>
It's helpful to correlate requests and responses in local investigations
where the issue is reproducible. Hence, log the rel, fork and block of
the get page response.
NB: effectively a no-op in the neon env since the handling is config
gated
in storcon
## Problem
When a pageserver suffers from a local disk/node failure and restarts,
the storage controller will receive a re-attach call and return all the
tenants the pageserver is suppose to attach, but the pageserver will not
act on any tenants that it doesn't know about locally. As a result, the
pageserver will not rehydrate any tenants from remote storage if it
restarted following a local disk loss, while the storage controller
still thinks that the pageserver have all the tenants attached. This
leaves the system in a bad state, and the symptom is that PG's
pageserver connections will fail with "tenant not found" errors.
## Summary of changes
Made a slight change to the storage controller's `re_attach` API:
* The pageserver will set an additional bit `empty_local_disk` in the
reattach request, indicating whether it has started with an empty disk
or does not know about any tenants.
* Upon receiving the reattach request, if this `empty_local_disk` bit is
set, the storage controller will go ahead and clear all observed
locations referencing the pageserver. The reconciler will then discover
the discrepancy between the intended state and observed state of the
tenant and take care of the situation.
To facilitate rollouts this extra behavior in the `re_attach` API is
guarded by the `handle_ps_local_disk_loss` command line flag of the
storage controller.
---------
Co-authored-by: William Huang <william.huang@databricks.com>
## Problem
See https://databricks.slack.com/archives/C092W8NBXC0/p1752924508578339
In case of larger number of databases and large `max_connections` we can
open too many connection for parallel apply config which may cause `Too
many open files` error.
## Summary of changes
Limit maximal number of parallel config apply connections by 100.
---------
Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
## Problem
While running tenant split tests I ran into a situation where PG got
stuck completely. This seems to be a general problem that was not found
in the previous chaos testing fixes.
What happened is that if PG gets throttled by PS, and SC decided to move
some tenant away, then PG reconfiguration could be blocked forever
because it cannot talk to the old PS anymore to refresh the throttling
stats, and reconfiguration cannot proceed because it's being throttled.
Neon has considered the case that configuration could be blocked if the
PG storage is full, but forgot the backpressure case.
## Summary of changes
The PR fixes this problem by simply skipping throttling while PS is
being configured, i.e., `max_cluster_size < 0`. An alternative fix is to
set those throttle knobs to -1 (e.g., max_replication_apply_lag),
however these knobs were labeled with PGC_POSTMASTER so their values
cannot be changed unless we restart PG.
## How is this tested?
Tested manually.
Co-authored-by: Chen Luo <chen.luo@databricks.com>
## Problem
We want to have the data-api served by the proxy directly instead of
relying on a 3rd party to run a deployment for each project/endpoint.
## Summary of changes
With the changes below, the proxy (auth-broker) becomes also a
"rest-broker", that can be thought of as a "Multi-tenant" data-api which
provides an automated REST api for all the databases in the region.
The core of the implementation (that leverages the subzero library) is
in proxy/src/serverless/rest.rs and this is the only place that has "new
logic".
---------
Co-authored-by: Ruslan Talpa <ruslan.talpa@databricks.com>
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Co-authored-by: Conrad Ludgate <conrad@neon.tech>
## Problem
Add a test for max_wal_rate
## Summary of changes
Test max_wal_rate
## How is this tested?
python test
Co-authored-by: Haoyu Huang <haoyu.huang@databricks.com>
Include the ip address (optionally read from an env var) in the
pageserver's registration request.
Note that the ip address is ignored by the storage controller at the
moment, which makes it a no-op
in the neon env.
