We thought we provided support for this in
b8c493f2c4
However the use of parameters in SQL is not supported in Citus. Since
generic plan queries use parameters, we can't support for now.
Relevant PG16 commit https://github.com/postgres/postgres/commit/3c05284Fixes#7813 with proper error message
DESCRIPTION: Fixes a crash that happens because of unsafe catalog access
when re-assigning the global pid after application_name changes.
When application_name changes, we don't actually need to
try re-assigning the global pid for external client backends because
application_name doesn't affect the global pid for such backends. Plus,
trying to re-assign the global pid for external client backends would
unnecessarily cause performing a catalog access when the cached local
node id is invalidated. However, accessing to the catalog tables is
dangerous in certain situations like when we're not in a transaction
block. And for the other types of backends, i.e., the Citus internal
backends, we need to re-assign the global pid when the application_name
changes because for such backends we simply extract the global pid
inherited from the originating backend from the application_name -that's
specified by originating backend when openning that connection- and this
doesn't require catalog access.
In function MasterAggregateMutator(), when the original Node is a Var node use makeVar() instead
of copyObject() when constructing the Var node for the target list of the combine query.
The varnullingrels field of the original Var node is ignored because it is not relevant for the
combine query; copying this cause the problem in issue 7705, where a coordinator query had
a Var with a reference to a non-existent join relation.
Very small PR, no changes to behaviour. Just a typo fix :-)
Under
`src/backend/distributed/sql/udfs/citus_finalize_upgrade_to_citus11/`
the sql has a typo "runnnig", which will be displayed to the user if the
`citus_check_cluster_node_health()` fails when calling
`citus_finish_citus_upgrade();`
Co-authored-by: eaydingol <60466783+eaydingol@users.noreply.github.com>
When multiple sessions concurrently attempt to add the same coordinator
node using `citus_set_coordinator_host`, there is a potential race
condition. Both sessions may pass the initial metadata check
(`isCoordinatorInMetadata`), but only one will succeed in adding the
node. The other session will fail with an assertion error
(`Assert(!nodeAlreadyExists)`), causing the server to crash. Even though
the `AddNodeMetadata` function takes an exclusive lock, it appears that
the lock is not preventing the race condition before the initial
metadata check.
- **Issue**: The current logic allows concurrent sessions to pass the
check for existing coordinators, leading to an attempt to insert
duplicate nodes, which triggers the assertion failure.
- **Impact**: This race condition leads to crashes during operations
that involve concurrent coordinator additions, as seen in
https://github.com/citusdata/citus/issues/7646.
**Test Plan:**
- Isolation Test Limitation: An isolation test was added to simulate
concurrent additions of the same coordinator node, but due to the
behavior of PostgreSQL locking mechanisms, the test does not trigger the
edge case. The lock applied within the function serializes the
operations, preventing the race condition from occurring in the
isolation test environment.
While the edge case is difficult to reproduce in an isolation test, the
fix addresses the core issue by ensuring concurrency control through
proper locking.
- Existing Tests: All existing tests related to node metadata and
coordinator management have been run to ensure that no regressions were
introduced.
**After the Fix:**
- Concurrent attempts to add the same coordinator node will be
serialized. One session will succeed in adding the node, while the
others will skip the operation without crashing the server.
Co-authored-by: Mehmet YILMAZ <mehmet.yilmaz@microsoft.com>
DESCRIPTION: Add a check to see if the given limit is null.
Fixes a bug by checking if the limit given in the query is null when the
actual limit is computed with respect to the given offset.
Prior to this change, null is interpreted as 0 during the limit
calculation when both limit and offset are given.
Fixes#7663
The sections about the rebalancer algorithm and the backround tasks were
empty.
---------
Co-authored-by: Marco Slot <marco.slot@gmail.com>
Co-authored-by: Steven Sheehy <17552371+steven-sheehy@users.noreply.github.com>
Related to issue #7619, #7620
Merge command fails when source query is single sharded and source and
target are co-located and insert is not using distribution key of
source.
Example
```
CREATE TABLE source (id integer);
CREATE TABLE target (id integer );
-- let's distribute both table on id field
SELECT create_distributed_table('source', 'id');
SELECT create_distributed_table('target', 'id');
MERGE INTO target t
USING ( SELECT 1 AS somekey
FROM source
WHERE source.id = 1) s
ON t.id = s.somekey
WHEN NOT MATCHED
THEN INSERT (id)
VALUES (s.somekey)
ERROR: MERGE INSERT must use the source table distribution column value
HINT: MERGE INSERT must use the source table distribution column value
```
Author's Opinion: If join is not between source and target distributed
column, we should not force user to use source distributed column while
inserting value of target distributed column.
Fix: If user is not using distributed key of source for insertion let's
not push down query to workers and don't force user to use source
distributed column if it is not part of join.
This reverts commit fa4fc0b372.
Co-authored-by: paragjain <paragjain@microsoft.com>
Because we want to track PR numbers and to make backporting easy we
(pretty much always) use squash-merges when merging to master. We
accidentally used a rebase merge for PR #7620. This reverts those
changes so we can redo the merge using squash merge.
This reverts all commits from eedb607c to 9e71750fc.
DESCRIPTION: Fix performance issue when using "\d tablename" on a server
with many tables
We introduce a filter to every query on pg_class to automatically remove
shards. This is useful to make sure \d and PgAdmin are not cluttered
with shards. However, the way we were introducing this filter was using
`securityQuals` which can have negative impact on query performance.
On clusters with 100k+ tables this could cause a simple "\d tablename"
command to take multiple seconds, because a skipped optimization by
Postgres causes a full table scan. This changes the code to introduce
this filter in the regular `quals` list instead of in `securityQuals`.
Which causes Postgres to use the intended optimization again.
For reference, this was initially reported as a Postgres issue by me:
https://www.postgresql.org/message-id/flat/4189982.1712785863%40sss.pgh.pa.us#b87421293b362d581ea8677e3bfea920
Variables being modified in the PG_TRY block and read in the PG_CATCH
block should be qualified with volatile.
The variable waitEventSet is modified in the PG_TRY block (line 1085)
and read in the PG_CATCH block (line 1095).
The variable relation is modified in the PG_TRY block (line 500) and
read in the PG_CATCH block (line 515).
Besides, the variable objectAddress doesn't need the volatile qualifier.
Ref: C99 7.13.2.1[^1],
> All accessible objects have values, and all other components of the
abstract machine have state, as of the time the longjmp function was
called, except that the values of objects of automatic storage duration
that are local to the function containing the invocation of the
corresponding setjmp macro that do not have volatile-qualified type and
have been changed between the setjmp invocation and longjmp call are
indeterminate.
[^1]: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf
DESCRIPTION: Correctly mark some variables as volatile
---------
Co-authored-by: Hong Yi <zouzou0208@gmail.com>
DESCRIPTION: Fix performance issue in GetForeignKeyOids on systems with
many constraints
GetForeignKeyOids was showing up in CPU profiles when distributing
schemas on systems with 100k+ constraints. The reason was that this
function was doing a sequence scan of pg_constraint to get the foreign
keys that referenced the requested table.
This fixes that by finding the constraints referencing the table through
pg_depend instead of pg_constraint. We're doing this indirection,
because pg_constraint doesn't have an index that we can use, but
pg_depend does.
DESCRIPTION: Fix PG upgrades when invalid rebalance strategies exist
Without this change an upgrade of a cluster with an invalid rebalance
strategy would fail with an error like this:
```
cache lookup failed for shard_cost_function with oid 6077337
CONTEXT: SQL statement "SELECT citus_validate_rebalance_strategy_functions(
NEW.shard_cost_function,
NEW.node_capacity_function,
NEW.shard_allowed_on_node_function)"
PL/pgSQL function citus_internal.pg_dist_rebalance_strategy_trigger_func() line 5 at PERFORM
SQL statement "INSERT INTO pg_catalog.pg_dist_rebalance_strategy SELECT
name,
default_strategy,
shard_cost_function::regprocedure::regproc,
node_capacity_function::regprocedure::regproc,
shard_allowed_on_node_function::regprocedure::regproc,
default_threshold,
minimum_threshold,
improvement_threshold
FROM public.pg_dist_rebalance_strategy"
PL/pgSQL function citus_finish_pg_upgrade() line 115 at SQL statement
```
This fixes that by disabling the trigger and simply re-inserting the
invalid rebalance strategy without checking. We could also silently
remove it, but this seems nicer.
DESCRIPTION: Fix performance issue when distributing a table that
depends on an extension
When the database contains many objects this function would show up in
profiles because it was doing a sequence scan on pg_depend. And with
many objects pg_depend can get very large.
This starts using an index scan to only look for rows containing FDWs,
of which there are expected to be very few (often even zero).
DESCRIPTION: Fix performance issue when creating distributed tables if
many already exist
This builds on the work to speed up EnsureSequenceTypeSupported, and now
does something similar for SequenceUsedInDistributedTable.
SequenceUsedInDistributedTable had a similar O(number of citus tables)
operation. This fixes that and speeds up creation of distributed tables
significantly when many distributed tables already exist.
Fixes#7022
DESCRIPTION: Fix performance issue when creating distributed tables and many already exist
EnsureSequenceTypeSupported was doing an O(number of distributed tables)
operation. This can become very slow with lots of Citus tables, which
now happens much more frequently in practice due to schema based sharding.
Partially addresses #7022
And when that is the case, directly use it as "host" parameter for the
connections between nodes and use the "hostname" provided in
pg_dist_node / pg_dist_poolinfo as "hostaddr" to avoid host name lookup.
This is to avoid allowing dns resolution (and / or setting up DNS names
for each host in the cluster). This already works currently when using
IPs in the hostname. The only use of setting host is that you can then
use sslmode=verify-full and it will validate that the hostname matches
the certificate provided by the node you're connecting too.
It would be more flexible to make this a per-node setting, but that
requires SQL changes. And we'd like to backport this change, and
backporting such a sql change would be quite hard while backporting this
change would be very easy. And in many setups, a different hostname for
TLS validation is actually not needed. The reason for that is
query-from-any node: With query-from-any-node all nodes usually have a
certificate that is valid for the same "cluster hostname", either using
a wildcard cert or a Subject Alternative Name (SAN). Because if you load
balance across nodes you don't know which node you're connecting to, but
you still want TLS validation to do it's job. So with this change you
can use this same "cluster hostname" for TLS validation within the
cluster. Obviously this means you don't validate that you're connecting
to a particular node, just that you're connecting to one of the nodes in
the cluster, but that should be fine from a security perspective (in
most cases).
Note to self: This change requires updating
https://docs.citusdata.com/en/latest/develop/api_guc.html#citus-node-conninfo-text.
DESCRIPTION: Allows overwriting host name for all inter-node connections
by supporting "host" parameter in citus.node_conninfo
DESCRIPTION: Fixes a crash caused by some form of ALTER TABLE ADD COLUMN
statements. When adding multiple columns, if one of the ADD COLUMN
statements contains a FOREIGN constraint ommitting the referenced
columns in the statement, a SEGFAULT occurs.
For instance, the following statement results in a crash:
```
ALTER TABLE lt ADD COLUMN new_col1 bool,
ADD COLUMN new_col2 int references rt;
```
Fixes#7520.
Fixes https://github.com/citusdata/citus/issues/7536.
Note to reviewer:
Before this commit, the following results in an assertion failure when
executed locally and this won't be the case anymore:
```console
make -C src/test/regress/ check-citus-upgrade-local citus-old-version=v10.2.0
```
Note that this doesn't happen on CI as we don't enable assertions there.
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
RunPreprocessNonMainDBCommand and RunPostprocessNonMainDBCommand are
the entrypoints for this module. These functions are called from
utility_hook.c to support some of the node-wide object management
commands from non-main databases.
To add support for a new command type, one needs to define a new
NonMainDbDistributeObjectOps object and add it to
GetNonMainDbDistributeObjectOps.
This PR changes the order in which the locks are acquired (for the
target and reference tables), when a modify request is initiated from a
worker node that is not the "FirstWorkerNode".
To prevent concurrent writes, locks are acquired on the first worker
node for the replicated tables. When the update statement originates
from the first worker node, it acquires the lock on the reference
table(s) first, followed by the target table(s). However, if the update
statement is initiated in another worker node, the lock requests are
sent to the first worker in a different order. This PR unifies the
modification order on the first worker node. With the third commit,
independent of the node that received the request, the locks are
acquired for the modified table and then the reference tables on the
first node.
The first commit shows a sample output for the test prior to the fix.
Fixes#7477
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
When using a CASE WHEN expression in the body
of the function that is used in the DO block, a segmentation
fault occured. This fixes that.
Fixes#7381
---------
Co-authored-by: Konstantin Morozov <vzbdryn@yahoo.com>
This fixes#7551 reported by Egor Chindyaskin
Function activate_node_snapshot() is not meant to be called on a cluster
without worker nodes. This commit adds ERROR report for such case to
prevent server crash.
DESCRIPTION: Adds support for distributed `ALTER/DROP ROLE` commands
from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
In preprocess phase, we save the original database name, replace
dbname field of CreatedbStmt with a temporary name (to let Postgres
to create the database with the temporary name locally) and then
we insert a cleanup record for the temporary database name on all
nodes **(\*\*)**.
And in postprocess phase, we first rename the temporary database
back to its original name for local node and then return a list of
distributed DDL jobs i) to create the database with the temporary
name and then ii) to rename it back to its original name on other
nodes. That way, if CREATE DATABASE fails on any of the nodes, the
temporary database will be cleaned up by the cleanup records that
we inserted in preprocess phase and in case of a failure, we won't
leak any databases called as the name that user intended to use for
the database.
Solves the problem documented in
https://github.com/citusdata/citus/issues/7369
for CREATE DATABASE commands.
**(\*\*):** To ensure that we insert cleanup records on all nodes,
with this PR we also start requiring having the coordinator in the
metadata because otherwise we would skip inserting a cleanup record
for the coordinator.
When adding CREATE/DROP DATABASE propagation in #7240, luckily
we've added EnsureSupportedCreateDatabaseCommand() check into
deparser too just to be on the safe side. That way, today CREATE
DATABASE commands from non-main dbs don't silently allow unsupported
options.
I wasn't aware of this when merging #7439 and hence wanted to add
a test so that we don't mistakenly remove that check from deparser
in future.
This fixes#7454: master_disable_node() has only two arguments, but
calls citus_disable_node() that tries to read three arguments
Co-authored-by: Karina Litskevich <litskevichkarina@gmail.com>
DESCRIPTION: Adds support for distributed `CREATE/DROP DATABASE `
commands from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Adds support for distributed `GRANT .. ON DATABASE TO USER`
commands from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
Rename InsertCleanupRecordInCurrentTransaction ->
InsertCleanupOnSuccessRecordInCurrentTransaction and hardcode policy
type as CLEANUP_DEFERRED_ON_SUCCESS.
Rename InsertCleanupRecordInSubtransaction ->
InsertCleanupRecordOutsideTransaction.
DESCRIPTION: Adds support for distributed role-membership management
commands from the databases where Citus is not installed (`GRANT <role>
TO <role>`)
This PR also refactors the code-path that allows executing some of the
node-wide commands so that we use send deparsed query string to other
nodes instead of the `queryString` passed into utility hook.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Fixes incorrect propagating of `GRANTED BY` and
`CASCADE/RESTRICT` clauses for `REVOKE` statements
There are two issues fixed in this PR
1. granted by statement will appear for revoke statements as well
2. revoke/cascade statement will appear after granted by
Since granted by statements does not appear in statements, this bug
hasn't been visible until now. However, after activating the granted by
statement for revoke, order problem arised and this issue was fixed
order problem for cascade/revoke as well
In summary, this PR provides usage of granted by statements properly now
with the correct order of statements.
We can verify the both errors, fixed with just single statement
REVOKE dist_role_3 from non_dist_role_3 granted by test_admin_role
cascade;
DESCRIPTION: Resolves an issue that disrupts distributed GRANT
statements with the grantor option
In this issue 3 issues are being solved:
1.Correcting the erroneous appending of multiple granted by in the
deparser.
2Adding support for grantor (granted by) in grant role propagation.
3. Implementing grantor (granted by) support during the metadata sync
grant role propagation phase.
Limitations: Currently, the grantor must be created prior to the
metadata sync phase. During metadata sync, both the creation of the
grantor and the grants given by that role cannot be performed, as the
grantor role is not detected during the dependency resolution phase.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
Moves the following functions to the Citus internal schema:
citus_internal_local_blocked_processes
citus_internal_global_blocked_processes
citus_internal_mark_node_not_synced
citus_internal_unregister_tenant_schema_globally
citus_internal_update_none_dist_table_metadata
citus_internal_update_placement_metadata
citus_internal_update_relation_colocation
citus_internal_start_replication_origin_tracking
citus_internal_stop_replication_origin_tracking
citus_internal_is_replication_origin_tracking_active
#7405
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
DESCRIPTION: citus_move_shard_placement now fails early when shard
cannot be safely moved
The implementation is quite simplistic -
`citus_move_shard_placement(...)` will fail with an error if there's any
new node in the cluster that doesn't have reference tables yet.
It could have been finer-grained, i.e. erroring only when trying to move
a shard to an unitialized node. Looking at the related functions -
`replicate_reference_tables()` or `citus_rebalance_start()`, I think
it's acceptable behaviour. These other functions also treat "any"
unitialized node as a temporary anomaly.
Fixes#7426
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Since Postgres commit da9b580d files and directories are supposed to
be created with pg_file_create_mode and pg_dir_create_mode permissions
when default permissions are expected.
This fixes a failure of one of the postgres tests:
If we create file add.conf containing
```
shared_preload_libraries='citus'
```
and run postgres tests
```
TEMP_CONFIG=/path/to/add.conf make installcheck -C src/bin/pg_ctl/
```
then 001_start_stop.pl fails with
```
.../data/base/pgsql_job_cache mode must be 0750
```
in the log.
In passing this also stops creating directories that we haven't used
since Citus 7.4
This change explicitely doesn't change permissions of certificates/keys
that we create.
---------
Co-authored-by: Karina Litskevich <litskevichkarina@gmail.com>
Naisila Puka
Teja Mupparti
Onur Tirtir
Pavel Seleznev
Colm McHugh
Erik Karsten
Parag Jain
Mehmet YILMAZ
eaydingol
Jelte Fennema-Nio
paragjain
Gürkan İndibay
Evgeny Nechayev
Xing Guo
Emel Şimşek
Hanefi Onaldi
copetol
Karina
Halil Ozan Akgül
Filip Sedlák