## Problem
If a user provides a wrong database name in the connection string, it
should be logged as a user error, not postgres error.
I found 4 different places where we log such errors:
1. `proxy/src/stream.rs:193`, e.g.:
```
{"timestamp":"2025-07-15T11:33:35.660026Z","level":"INFO","message":"forwarding error to user","fields":{"kind":"postgres","msg":"database \"[redacted]\" does not exist"},"spans":{"connect_request#9":{"protocol":"tcp","session_id":"ce1f2c90-dfb5-44f7-b9e9-8b8535e8b9b8","conn_info":"[redacted]","ep":"[redacted]","role":"[redacted]"}},"thread_id":22,"task_id":"370407867","target":"proxy::stream","src":"proxy/src/stream.rs:193","extract":{"ep":"[redacted]","session_id":"ce1f2c90-dfb5-44f7-b9e9-8b8535e8b9b8"}}
```
2. `proxy/src/pglb/mod.rs:137`, e.g.:
```
{"timestamp":"2025-07-15T11:37:44.340497Z","level":"WARN","message":"per-client task finished with an error: Couldn't connect to compute node: db error: FATAL: database \"[redacted]\" does not exist","spans":{"connect_request#8":{"protocol":"tcp","session_id":"763baaac-d039-4f4d-9446-c149e32660eb","conn_info":"[redacted]","ep":"[redacted]","role":"[redacted]"}},"thread_id":14,"task_id":"866658139","target":"proxy::pglb","src":"proxy/src/pglb/mod.rs:137","extract":{"ep":"[redacted]","session_id":"763baaac-d039-4f4d-9446-c149e32660eb"}}
```
3. `proxy/src/serverless/mod.rs:451`, e.g. (note that the error is
repeated 4 times — retries?):
```
{"timestamp":"2025-07-15T11:37:54.515891Z","level":"WARN","message":"error in websocket connection: Couldn't connect to compute node: db error: FATAL: database \"[redacted]\" does not exist: Couldn't connect to compute node: db error: FATAL: database \"[redacted]\" does not exist: db error: FATAL: database \"[redacted]\" does not exist: FATAL: database \"[redacted]\" does not exist","spans":{"http_conn#8":{"conn_id":"ec7780db-a145-4f0e-90df-0ba35f41b828"},"connect_request#9":{"protocol":"ws","session_id":"1eaaeeec-b671-4153-b1f4-247839e4b1c7","conn_info":"[redacted]","ep":"[redacted]","role":"[redacted]"}},"thread_id":10,"task_id":"366331699","target":"proxy::serverless","src":"proxy/src/serverless/mod.rs:451","extract":{"conn_id":"ec7780db-a145-4f0e-90df-0ba35f41b828","ep":"[redacted]","session_id":"1eaaeeec-b671-4153-b1f4-247839e4b1c7"}}
```
4. `proxy/src/serverless/sql_over_http.rs:219`, e.g.
```
{"timestamp":"2025-07-15T10:32:34.866603Z","level":"INFO","message":"forwarding error to user","fields":{"kind":"postgres","error":"could not connect to postgres in compute","msg":"database \"[redacted]\" does not exist"},"spans":{"http_conn#19":{"conn_id":"7da08203-5dab-45e8-809f-503c9019ec6b"},"connect_request#5":{"protocol":"http","session_id":"68387f1c-cbc8-45b3-a7db-8bb1c55ca809","conn_info":"[redacted]","ep":"[redacted]","role":"[redacted]"}},"thread_id":17,"task_id":"16432250","target":"proxy::serverless::sql_over_http","src":"proxy/src/serverless/sql_over_http.rs:219","extract":{"conn_id":"7da08203-5dab-45e8-809f-503c9019ec6b","ep":"[redacted]","session_id":"68387f1c-cbc8-45b3-a7db-8bb1c55ca809"}}
```
This PR directly addresses 1 and 4. I _think_ it _should_ also help with
2 and 3, although in those places we don't seem to log `kind`, so I'm
not quite sure. I'm also confused why in 3 the error is repeated
multiple times.
## Summary of changes
Resolves https://github.com/neondatabase/neon/issues/9440
The `std::mem::offset_of` macro was introduced in Rust 1.77.0.
In the passing, mark the function as `const`, as suggested in the
comment. Not sure which compiler version that requires, but it works
with what have currently.
- Remove some unused code
- Use `is_multiple_of()` instead of '%'
- Collapse consecuative "if let" statements
- Elided lifetime fixes
It is enough just to review the code of your team
## Problem
For certificate auth, we need to configure pg_hba and pg_ident for it to
work.
HCC needs to mount this config map to all pg compute pod.
## Summary of changes
Create `databricks_pg_hba` and `databricks_pg_ident` to configure where
the files are located on the pod. These configs are pass down to
`compute_ctl`. Compute_ctl uses these config to update `pg_hba.conf` and
`pg_ident.conf` file.
We append `include_if_exists {databricks_pg_hba}` to `pg_hba.conf` and
similarly to `pg_ident.conf`. So that it will refer to databricks config
file without much change to existing pg default config file.
---------
Co-authored-by: Jarupat Jisarojito <jarupat.jisarojito@databricks.com>
Co-authored-by: William Huang <william.huang@databricks.com>
Co-authored-by: HaoyuHuang <haoyu.huang.68@gmail.com>
## Problem
Monitoring dashboards show aggregates of all proxy instances, including
terminating ones. This can skew the results or make graphs less
readable. Also, alerts must be tuned to ignore certain signals from
terminating proxies.
## Summary of changes
Add a `service_info` metric currently with one label, `state`, showing
if an instance is in state `init`, `running`, or `terminating`. The
metric can be joined with other metrics to filter the presented time
series.
## Problem
Copy certificate and key from secret mount directory to `pgdata`
directory where `postgres` is the owner and we can set the key
permission to 0600.
## Summary of changes
- Added new pgparam `pg_compute_tls_settings` to specify where k8s
secret for certificate and key are mounted.
- Added a new field to `ComputeSpec` called `databricks_settings`. This
is a struct that will be used to store any other settings that needs to
be propagate to Compute but should not be persisted to `ComputeSpec` in
the database.
- Then when the compute container start up, as part of `prepare_pgdata`
function, it will copied `server.key` and `server.crt` from k8s mounted
directory to `pgdata` directory.
## How is this tested?
Add unit tests.
Manual test via KIND
Co-authored-by: Jarupat Jisarojito <jarupat.jisarojito@databricks.com>
Follow up to #12701, which introduced a new regression. When profiling
locally I noticed that writes have the tendency to always reallocate. On
investigation I found that even if the `Connection`'s write buffer is
empty, if it still shares the same data pointer as the `Client`'s write
buffer then the client cannot reclaim it.
The best way I found to fix this is to just drop the `Connection`'s
write buffer each time we fully flush it.
Additionally, I remembered that `BytesMut` has an `unsplit` method which
is allows even better sharing over the previous optimisation I had when
'encoding'.
## Problem
While configuring or reconfiguring PG due to PageServer movements, it's
possible PG may get stuck if PageServer is moved around after fetching
the spec from StorageController.
## Summary of changes
To fix this issue, this PR introduces two changes:
1. Fail the PG query directly if the query cannot request configuration
for certain number of times.
2. Introduce a new state `RefreshConfiguration` in compute tools to
differentiate it from `RefreshConfigurationPending`. If compute tool is
already in `RefreshConfiguration` state, then it will not accept new
request configuration requests.
## How is this tested?
Chaos testing.
Co-authored-by: Chen Luo <chen.luo@databricks.com>
## Problem
We have been dealing with a number of issues with the SC compute
notification mechanism. Various race conditions exist in the
PG/HCC/cplane/PS distributed system, and relying on the SC to send
notifications to the compute node to notify it of PS changes is not
robust. We decided to pursue a more robust option where the compute node
itself discovers whether it may be pointing to the incorrect PSs and
proactively reconfigure itself if issues are suspected.
## Summary of changes
To support this self-healing reconfiguration mechanism several pieces
are needed. This PR adds a mechanism to `compute_ctl` called "refresh
configuration", where the compute node reaches out to the control plane
to pull a new config and reconfigure PG using the new config, instead of
listening for a notification message containing a config to arrive from
the control plane. Main changes to compute_ctl:
1. The `compute_ctl` state machine now has a new State,
`RefreshConfigurationPending`. The compute node may enter this state
upon receiving a signal that it may be using the incorrect page servers.
2. Upon entering the `RefreshConfigurationPending` state, the background
configurator thread in `compute_ctl` wakes up, pulls a new config from
the control plane, and reconfigures PG (with `pg_ctl reload`) according
to the new config.
3. The compute node may enter the new `RefreshConfigurationPending`
state from `Running` or `Failed` states. If the configurator managed to
configure the compute node successfully, it will enter the `Running`
state, otherwise, it stays in `RefreshConfigurationPending` and the
configurator thread will wait for the next notification if an incorrect
config is still suspected.
4. Added various plumbing in `compute_ctl` data structures to allow the
configurator thread to perform the config fetch.
The "incorrect config suspected" notification is delivered using a HTTP
endpoint, `/refresh_configuration`, on `compute_ctl`. This endpoint is
currently not called by anyone other than the tests. In a follow up PR I
will set up some code in the PG extension/libpagestore to call this HTTP
endpoint whenever PG suspects that it is pointing to the wrong page
servers.
## How is this tested?
Modified `test_runner/regress/test_change_pageserver.py` to add a
scenario where we use the new `/refresh_configuration` mechanism instead
of the existing `/configure` mechanism (which requires us sending a full
config to compute_ctl) to have the compute node reload and reconfigure
its pageservers.
I took one shortcut to reduce the scope of this change when it comes to
testing: the compute node uses a local config file instead of pulling a
config over the network from the HCC. This simplifies the test setup in
the following ways:
* The existing test framework is set up to use local config files for
compute nodes only, so it's convenient if I just stick with it.
* The HCC today generates a compute config with production settings
(e.g., assuming 4 CPUs, 16GB RAM, with local file caches), which is
probably not suitable in tests. We may need to add another test-only
endpoint config to the control plane to make this work.
The config-fetch part of the code is relatively straightforward (and
well-covered in both production and the KIND test) so it is probably
fine to replace it with loading from the local config file for these
integration tests.
In addition to making sure that the tests pass, I also manually
inspected the logs to make sure that the compute node is indeed
reloading the config using the new mechanism instead of going down the
old `/configure` path (it turns out the test has bugs which causes
compute `/configure` messages to be sent despite the test intending to
disable/blackhole them).
```test
2024-09-24T18:53:29.573650Z INFO http request{otel.name=/refresh_configuration http.method=POST}: serving /refresh_configuration POST request
2024-09-24T18:53:29.573689Z INFO configurator_main_loop: compute node suspects its configuration is out of date, now refreshing configuration
2024-09-24T18:53:29.573706Z INFO configurator_main_loop: reloading config.json from path: /workspaces/hadron/test_output/test_change_pageserver_using_refresh[release-pg16]/repo/endpoints/ep-1/spec.json
PG:2024-09-24 18:53:29.574 GMT [52799] LOG: received SIGHUP, reloading configuration files
PG:2024-09-24 18:53:29.575 GMT [52799] LOG: parameter "neon.extension_server_port" cannot be changed without restarting the server
PG:2024-09-24 18:53:29.575 GMT [52799] LOG: parameter "neon.pageserver_connstring" changed to "postgresql://no_user@localhost:15008"
...
```
Co-authored-by: William Huang <william.huang@databricks.com>
Another go at #12341. LKB-2497
We now only need 1 connect mechanism (and 1 more for testing) which
saves us some code and complexity. We should be able to remove the final
connect mechanism when we create a separate worker task for
pglb->compute connections - either via QUIC streams or via in-memory
channels.
This also now ensures that connect_once always returns a ConnectionError
type - something simple enough we can probably define a serialisation
for in pglb.
* I've abstracted connect_to_compute to always use TcpMechanism and the
ProxyConfig.
* I've abstracted connect_to_compute_and_auth to perform authentication,
managing any retries for stale computes
* I had to introduce a separate `managed` function for taking ownership
of the compute connection into the Client/Connection pair
## Problem
A large insert or a large row will cause the codec to allocate a large
buffer. The codec never shrinks the buffer however. LKB-2496
## Summary of changes
1. Introduce a naive GC system for codec buffers
2. Try and reduce copies as much as possible
## Problem
Tenant split test revealed another bug with PG backpressure throttling
that under some cases PS may never report its progress back to SK (e.g.,
observed when aborting tenant shard where the old shard needs to
re-establish SK connection and re-ingest WALs from a much older LSN). In
this case, PG may get stuck forever.
## Summary of changes
As a general precaution that PS feedback mechanism may not always be
reliable, this PR uses the previously introduced WAL write rate limit
mechanism to slow down write rates instead of completely pausing it. The
idea is to introduce a new
`databricks_effective_max_wal_bytes_per_second`, which is set to
`databricks_max_wal_mb_per_second` when no PS back pressure and is set
to `10KB` when there is back pressure. This way, PG can still write to
SK, though at a very low speed.
The PR also fixes the problem that the current WAL rate limiting
mechanism is too coarse grained and cannot enforce limits < 1MB. This is
because it always resets the rate limiter after 1 second, even if PG
could have written more data in the past second. The fix is to introduce
a `batch_end_time_us` which records the expected end time of the current
batch. For example, if PG writes 10MB of data in a single batch, and max
WAL write rate is set as `1MB/s`, then `batch_end_time_us` will be set
as 10 seconds later.
## How is this tested?
Tweaked the existing test, and also did manual testing on dev. I set
`max_replication_flush_lag` as 1GB, and loaded 500GB pgbench tables.
It's expected to see PG gets throttled periodically because PS will
accumulate 4GB of data before flushing.
Results:
when PG is throttled:
```
9500000 of 3300000000 tuples (0%) done (elapsed 10.36 s, remaining 3587.62 s)
9600000 of 3300000000 tuples (0%) done (elapsed 124.07 s, remaining 42523.59 s)
9700000 of 3300000000 tuples (0%) done (elapsed 255.79 s, remaining 86763.97 s)
9800000 of 3300000000 tuples (0%) done (elapsed 315.89 s, remaining 106056.52 s)
9900000 of 3300000000 tuples (0%) done (elapsed 412.75 s, remaining 137170.58 s)
```
when PS just flushed:
```
18100000 of 3300000000 tuples (0%) done (elapsed 433.80 s, remaining 78655.96 s)
18200000 of 3300000000 tuples (0%) done (elapsed 433.85 s, remaining 78231.71 s)
18300000 of 3300000000 tuples (0%) done (elapsed 433.90 s, remaining 77810.62 s)
18400000 of 3300000000 tuples (0%) done (elapsed 433.96 s, remaining 77395.86 s)
18500000 of 3300000000 tuples (0%) done (elapsed 434.03 s, remaining 76987.27 s)
18600000 of 3300000000 tuples (0%) done (elapsed 434.08 s, remaining 76579.59 s)
18700000 of 3300000000 tuples (0%) done (elapsed 434.13 s, remaining 76177.12 s)
18800000 of 3300000000 tuples (0%) done (elapsed 434.19 s, remaining 75779.45 s)
18900000 of 3300000000 tuples (0%) done (elapsed 434.84 s, remaining 75489.40 s)
19000000 of 3300000000 tuples (0%) done (elapsed 434.89 s, remaining 75097.90 s)
19100000 of 3300000000 tuples (0%) done (elapsed 434.94 s, remaining 74712.56 s)
19200000 of 3300000000 tuples (0%) done (elapsed 498.93 s, remaining 85254.20 s)
19300000 of 3300000000 tuples (0%) done (elapsed 498.97 s, remaining 84817.95 s)
19400000 of 3300000000 tuples (0%) done (elapsed 623.80 s, remaining 105486.76 s)
19500000 of 3300000000 tuples (0%) done (elapsed 745.86 s, remaining 125476.51 s)
```
Co-authored-by: Chen Luo <chen.luo@databricks.com>
https://github.com/neondatabase/cloud/issues/19011
- Accept `ComputeSpec` in `/promote` instead of just passing safekeepers
and LSN. Update API spec
- Add corner case tests for promotion when promotion or perwarm fails
(using failpoints)
- Print root error for prewarm and promotion in status handlers
## Problem
OTel 0.28+ by default uses blocking operations in a dedicated thread and
doesn't start a tokio runtime. Reqwest as currently configured wants to
spawn tokio tasks.
## Summary of changes
Use blocking reqwest.
This PR just mitigates the current issue.
Session variables can be set during one sql-over-http query and observed
on another when that pooled connection is re-used. To address this we
can use `RESET ALL;` before re-using the connection. LKB-2495
To be on the safe side, we can opt for a full `DISCARD ALL;`, but that
might have performance regressions since it also clears any query plans.
See pgbouncer docs
https://www.pgbouncer.org/config.html#server_reset_query.
`DISCARD ALL` is currently defined as:
```
CLOSE ALL;
SET SESSION AUTHORIZATION DEFAULT;
RESET ALL;
DEALLOCATE ALL;
UNLISTEN *;
SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
```
I've opted to keep everything here except the `DISCARD PLANS`. I've
modified the code so that this query is executed in the background when
a connection is returned to the pool, rather than when taken from the
pool.
This should marginally improve performance for Neon RLS by removing 1
(localhost) round trip. I don't believe that keeping query plans could
be a security concern. It's a potential side channel, but I can't
imagine what you could extract from it.
---
Thanks to
https://github.com/neondatabase/neon/pull/12659#discussion_r2219016205
for probing the idea in my head.
## Problem
LKB-197, #9516
To make sure the migration path is smooth.
The previous plan is to store new relations in new keyspace and old ones
in old keyspace until it gets dropped. This makes the migration path
hard as we can't validate v2 writes and can't rollback. This patch gives
us a more smooth migration path:
- The first time we enable reldirv2 for a tenant, we copy over
everything in the old keyspace to the new one. This might create a short
spike of latency for the create relation operation, but it's oneoff.
- After that, we have identical v1/v2 keyspace and read/write both of
them. We validate reads every time we list the reldirs.
- If we are in `migrating` mode, use v1 as source of truth and log a
warning for failed v2 operations. If we are in `migrated` mode, use v2
as source of truth and error when writes fail.
- One compatibility test uses dataset from the time where we enabled
reldirv2 (of the original rollout plan), which only has relations
written to the v2 keyspace instead of the v1 keyspace. We had to adjust
it accordingly.
- Add `migrated_at` in index_part to indicate the LSN where we did the
initialize.
TODOs:
- Test if relv1 can be read below the migrated_at LSN.
- Move the initialization process to L0 compaction instead of doing it
on the write path.
- Disable relcache in the relv2 test case so that all code path gets
fully tested.
## Summary of changes
- New behavior of reldirv2 migration flags as described above.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Second attempt at #12130, now with a smaller diff.
This allows us to skip allocating for things like parameter status and
notices that we will either just forward untouched, or discard.
LKB-2494
## Problem
With safekeeper migration in mind, we can now pull/exclude the timeline
multiple times within the same safekeeper. To avoid races between out of
order requests, we need to ignore the pull/exclude requests if we have
already seen a higher generation.
- Closes: https://github.com/neondatabase/neon/issues/12186
- Closes: [LKB-949](https://databricks.atlassian.net/browse/LKB-949)
## Summary of changes
- Annotate timeline tombstones in safekeeper with request generation.
- Replace `ignore_tombstone` option with `mconf` in
`PullTimelineRequest`
- Switch membership in `pull_timeline` if the existing/pulled timeline
has an older generation.
- Refuse to switch membership if the timeline is being deleted
(`is_canceled`).
- Refuse to switch membership in compute greeting request if the
safekeeper is not a member of `mconf`.
- Pass `mconf` in `PullTimelineRequest` in safekeeper_service
---------
Co-authored-by: Arpad Müller <arpad-m@users.noreply.github.com>
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>
A replacement for #10254 which allows us to introduce notice messages
for sql-over-http in the future if we want to. This also removes the
`ParameterStatus` and `Notification` handling as there's nothing we
could/should do for those.
## Problem
`ShardStripeSize` will be used in the compute spec and internally in the
communicator. It shouldn't require pulling in all of `pageserver_api`.
## Summary of changes
Move `ShardStripeSize` into `utils::shard`, along with other basic shard
types. Also remove the `Default` implementation, to discourage clients
from falling back to a default (it's generally a footgun).
The type is still re-exported from `pageserver_api::shard`, along with
all the other shard types.
