It was possible to block maintenance daemon by taking an SHARE ROW
EXCLUSIVE lock on pg_dist_placement. Until the lock is released
maintenance daemon would be blocked.
We should not block the maintenance daemon under any case hence now we
try to get the pg_dist_placement lock without waiting, if we cannot get
it then we don't try to drop the old placements.
DESCRIPTION: introduce `citus.local_hostname` GUC for connections to the current node
Citus once in a while needs to connect to itself for some systems operations. This used to be hardcoded to `localhost`. The hardcoded hostname causes some issues, for example in environments where `sslmode=verify-full` is required. It is not always desirable or even feasible to get `localhost` as an alt name on the certificate.
By introducing a GUC to use when connecting to the current instance the user has more control what network path is used and what hostname is required to be present in the server certificate.
Every move in the rebalancer algorithm results in an improvement in the
balance. However, even if the improvement in the balance was very small
the move was still chosen. This is especially problematic if the shard
itself is very big and the move will take a long time.
This changes the rebalancer algorithm to take the relative size of the
balance improvement into account when choosing moves. By default a move
will not be chosen if it improves the balance by less than half of the
size of the shard. An extra argument is added to the rebalancer
functions so that the user can decide to lower the default threshold if
the ignored move is wanted anyway.
* Make VACUUM hint for upgrade scenario actually work
* Suggest using VACUUM if metapage doesn't exist
Plus, suggest upgrading sql version as another option.
* Always force read metapage block
* Fix two typos
* Columnar: introduce columnar storage API.
This new API is responsible for the low-level storage details of
columnar; translating large reads and writes into individual block
reads and writes that respect the page headers and emit WAL. It's also
responsible for the columnar metapage, resource reservations (stripe
IDs, row numbers, and data), and truncation.
This new API is not used yet, but will be used in subsequent
forthcoming commits.
* Columnar: add columnar_storage_info() for debugging purposes.
* Columnar: expose ColumnarMetadataNewStorageId().
* Columnar: always initialize metapage at creation time.
This avoids the complexity of dealing with tables where the metapage
has not yet been initialized.
* Columnar: columnar storage upgrade/downgrade UDFs.
Necessary upgrade/downgrade step so that new code doesn't see an old
metapage.
* Columnar: improve metadata.c comment.
* Columnar: make ColumnarMetapage internal to the storage API.
Callers should not have or need direct access to the metapage.
* Columnar: perform resource reservation using storage API.
* Columnar: implement truncate using storage API.
* Columnar: implement read/write paths with storage API.
* Columnar: add storage tests.
* Revert "Columnar: don't include stripe reservation locks in lock graph."
This reverts commit c3dcd6b9f8.
No longer needed because the columnar storage API takes care of
concurrency for resource reservation.
* Columnar: remove unnecessary lock when reserving.
No longer necessary because the columnar storage API takes care of
concurrent resource reservation.
* Add simple upgrade tests for storage/ branch
* fix multi_extension.out
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
* When moving a shard to a new node ensure there is enough space
* Add WairForMiliseconds time utility
* Add more tests and increase readability
* Remove the retry loop and use a single udf for disk stats
* Address review
* address review
Co-authored-by: Jelte Fennema <github-tech@jeltef.nl>
This allows running the following command to update the expected files
with normalized output files for upgrade tests too:
```bash
cp src/test/regress/{results,expected}/upgrade_rebalance_strategy_before.out
```
The comment of DropMarkedShards described the behaviour that after a
failure we would continue trying to drop other shards. However the code
did not do this and would stop after the first failure. Instead of
simply fixing the comment I fixed the code, because the described
behaviour is more useful. Now a single shard that cannot be removed yet
does not block others from being removed.
We decrease memory usage by:
- Freeing temporary buffers
- Using separate memory context for blocks that uses "small" amount of
memory but can be repeated many times such as loops