This PR makes the connections to other nodes for
`mark_object_distributed` use the same user as
`execute_command_on_remote_nodes_as_user` so they'll use the same
connection.
ExecuteTaskListIntoTupleDestWithParam and ExecuteTaskListIntoTupleDest
are nearly the same. I parameterized and a made a reusable structure
here
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Remove a few small memory leaks
In #7440 one instance of a strdup was removed. But there were a few
more. This removes the ones that are left over, or adds a comment why
strdup is on purpose.
This change refactors the code by using generate_qualified_relation_name
from id instead of using a sequence of functions to generate the
relation name.
Fixes#6602
DESCRIPTION: Adds comment on database and role propagation.
Example commands are as below
comment on database <db_name> is '<comment_text>'
comment on database <db_name> is NULL
comment on role <role_name> is '<comment_text>'
comment on role <role_name> is NULL
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Running a query from a Citus non-main database that inserts to
pg_dist_object requires a new connection to the main database itself.
This PR adds that connection to the main database.
---------
Co-authored-by: Jelte Fennema-Nio <github-tech@jeltef.nl>
When there are multiple localhost entries in /etc/hosts like following
/etc/hosts:
```
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
127.0.0.1 localhost
```
multi_cluster_management check will failed:
```
@@ -857,20 +857,21 @@
ERROR: group 14 already has a primary node
-- check that you can add secondaries and unavailable nodes to a group
SELECT groupid AS worker_2_group FROM pg_dist_node WHERE nodeport = :worker_2_port \gset
SELECT 1 FROM master_add_node('localhost', 9998, groupid => :worker_1_group, noderole => 'secondary');
?column?
----------
1
(1 row)
SELECT 1 FROM master_add_node('localhost', 9997, groupid => :worker_1_group, noderole => 'unavailable');
+WARNING: could not establish connection after 5000 ms
?column?
----------
1
(1 row)
```
This actually isn't just a problem in test environments, but could occur
as well during actual usage when a hostname in pg_dist_node
resolves to multiple IPs and one of those IPs is unreachable.
Postgres will then automatically continue with the next IP, but
Citus should listen for events on the new socket. Not on the
old one.
Co-authored-by: chuhx43211 <chuhx43211@hundsun.com>
LoadShardList is called twice, which is not neccessary, and there is no
need to sort the shard placement list since we only want to know the list
length.
DESCRIPTION: Adds support for issuing `CREATE`/`DROP` DATABASE commands
from worker nodes
With this commit, we allow issuing CREATE / DROP DATABASE commands from
worker nodes too.
As in #7278, this is not allowed when the coordinator is not added to
metadata because we don't ever sync metadata changes to coordinator
when adding coordinator to the metadata via
`SELECT citus_set_coordinator_host('<hostname>')`, or equivalently, via
`SELECT citus_add_node(<coordinator_node_name>, <coordinator_node_port>, 0)`.
We serialize database management commands by acquiring a Citus specific
advisory lock on the first primary worker node if there are any workers in the
cluster. As opposed to what we've done in https://github.com/citusdata/citus/pull/7278
for role management commands, we try to avoid from running into distributed deadlocks
as much as possible. This is because, while distributed deadlocks that can happen around
role management commands can be detected by Citus, this is not the case for database
management commands because most of them cannot be run inside in a transaction block.
In that case, Citus cannot even detect the distributed deadlock because the command is not
part of a distributed transaction at all, then the command execution might not return the
control back to the user for an indefinite amount of time.
This fixes#7230.
First of all, using HeapTupleHeaderGetDatumLength(heapTuple) is
definetly wrong, it gives a number that's 4 times less than the correct
tuple size (heapTuple.t_len). See
https://github.com/postgres/postgres/blob/REL_16_0/src/include/access/htup_details.h#L455-L456https://github.com/postgres/postgres/blob/REL_16_0/src/include/varatt.h#L279https://github.com/postgres/postgres/blob/REL_16_0/src/include/varatt.h#L225-L226
When I fixed it, the limit_intermediate_size test failed, so I tried to
understand what's going on there. In original commit fd546cf these
queries were supposed to fail. Then in b3af63c three of the queries that
were supposed to fail suddenly worked and tests were changed to pass
without understanding why the output had changed or how to keep test
testing what it had to test. Even comments saying that these queries
should fail were left untouched. Commit message gives no clue about why
exactly test has changed:
> It seems that when we use adaptive executor instead of task tracker,
we
> exceed the intermediate result size less in the test. Therefore
updated
> the tests accordingly.
Then 3fda2c3 also blindly raised the limit for one of the queries to
keep it working:
3fda2c3254 (diff-a9b7b617f9dfd345318cb8987d5897143ca1b723c87b81049bbadd94dcc86570R19)
When in fe3caf3 that HeapTupleHeaderGetDatumLength(heapTuple) call was
finally added, one of those test queries became failing again.
The other two of them now also failing after the fix. I don't understand
how exactly the calculation of "intermediate result size" that is
limited by citus.max_intermediate_result_size had changed through
b3af63c and fe3caf3, but these numbers are now closer to what
they originally were when this limitation was added in
fd546cf. So these queries should fail, like in the original
version of the limit_intermediate_size test.
Co-authored-by: Karina Litskevich <litskevichkarina@gmail.com>
DESCRIPTION: Adds REASSIGN OWNED BY propagation
This pull request introduces the propagation of the "Reassign owned by"
statement. It accommodates both local and distributed roles for both the
old and new assignments. However, when the old role is a local role, it
undergoes filtering and is not propagated. On the other hand, if the new
role is a local role, the process involves first creating the role on
worker nodes before propagating the "Reassign owned" statement.
DESCRIPTION: Adds database connection limit, rename and set tablespace
propagation
In this PR, below statement propagations are added
alter database <database_name> with allow_connections = <boolean_value>;
alter database <database_name> rename to <database_name2>;
alter database <database_name> set TABLESPACE <table_space_name>
---------
Co-authored-by: Jelte Fennema-Nio <github-tech@jeltef.nl>
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Adds support for 2PC from non-Citus main databases
This PR only adds support for `CREATE USER` queries, other queries need
to be added. But it should be simple because this PR creates the
underlying structure.
Citus main database is the database where the Citus extension is
created. A non-main database is all the other databases that are in the
same node with a Citus main database.
When a `CREATE USER` query is run on a non-main database we:
1. Run `start_management_transaction` on the main database. This
function saves the outer transaction's xid (the non-main database
query's transaction id) and marks the current query as main db command.
2. Run `execute_command_on_remote_nodes_as_user("CREATE USER
<username>", <username to run the command>)` on the main database. This
function creates the users in the rest of the cluster by running the
query on the other nodes. The user on the current node is created by the
query on the outer, non-main db, query to make sure consequent commands
in the same transaction can see this user.
3. Run `mark_object_distributed` on the main database. This function
adds the user to `pg_dist_object` in all of the nodes, including the
current one.
This PR also implements transaction recovery for the queries from
non-main databases.
Allowing GRANT ADMIN to now also be INHERIT or SET in support of psql16
GRANT role_name [, ...] TO role_specification [, ...] [ WITH { ADMIN |
INHERIT | SET } { OPTION | TRUE | FALSE } ] [ GRANTED BY
role_specification ]
Fixes: #7148
Related: #7138
See review changes from https://github.com/citusdata/citus/pull/7164
This change adds a script to programatically group all includes in a
specific order. The script was used as a one time invocation to group
and sort all includes throught our formatted code. The grouping is as
follows:
- System includes (eg. `#include<...>`)
- Postgres.h (eg. `#include "postgres.h"`)
- Toplevel imports from postgres, not contained in a directory (eg.
`#include "miscadmin.h"`)
- General postgres includes (eg . `#include "nodes/..."`)
- Toplevel citus includes, not contained in a directory (eg. `#include
"citus_verion.h"`)
- Columnar includes (eg. `#include "columnar/..."`)
- Distributed includes (eg. `#include "distributed/..."`)
Because it is quite hard to understand the difference between toplevel
citus includes and toplevel postgres includes it hardcodes the list of
toplevel citus includes. In the same manner it assumes anything not
prefixed with `columnar/` or `distributed/` as a postgres include.
The sorting/grouping is enforced by CI. Since we do so with our own
script there are not changes required in our uncrustify configuration.
DESCRIPTION: Adds support for propagating `CREATE`/`DROP` database
In this PR, create and drop database support is added.
For CREATE DATABASE:
* "oid" option is not supported
* specifying "strategy" to be different than "wal_log" is not supported
* specifying "template" to be different than "template1" is not
supported
The last two are because those are not saved in `pg_database` and when
activating a node, we cannot assume what parameters were provided when
creating the database.
And "oid" is not supported because whether user specified an arbitrary
oid when creating the database is not saved in pg_database and we want
to avoid from oid collisions that might arise from attempting to use an
auto-assigned oid on workers.
Finally, in case of node activation, GRANTs for the database are also
propagated.
---------
Co-authored-by: Jelte Fennema-Nio <github-tech@jeltef.nl>
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
We propagate `SECURITY LABEL [for provider] ON ROLE rolename IS
labelname` to the worker nodes.
We also make sure to run the relevant `SecLabelStmt` commands on a
newly added node by looking at roles found in `pg_shseclabel`.
See official docs for explanation on how this command works:
https://www.postgresql.org/docs/current/sql-security-label.html
This command stores the role label in the `pg_shseclabel` catalog table.
This commit also fixes the regex string in
`check_gucs_are_alphabetically_sorted.sh` script such that it escapes
the dot. Previously it was looking for all strings starting with "citus"
instead of "citus." as it should.
To test this feature, I currently make use of a special GUC to control
label provider registration in PG_init when creating the Citus extension.
DESCRIPTION: Adds support from issuing role management commands from worker nodes
It's unlikely to get into a distributed deadlock with role commands, we
don't care much about them at the moment.
There were several attempts to reduce the chances of a deadlock but we
didn't any of them merged into main branch yet, see:
#7325#7016#7009
When executing a prepared CALL, which is not pure SQL but available with
some drivers like npgsql and jpgdbc, Citus entered a code path where a
plan is not defined, while trying to increase its cost. Thus SIG11 when
plan is a NULL pointer.
Fix by only increasing plan cost when plan is not null.
However, it is a bit suspicious to get here with a NULL plan and maybe a
better change will be to not call
ShardPlacementForFunctionColocatedWithDistTable() with a NULL plan at
all (in call.c:134)
bug hit with for example:
```
CallableStatement proc = con.prepareCall("{CALL p(?)}");
proc.registerOutParameter(1, java.sql.Types.BIGINT);
proc.setInt(1, -100);
proc.execute();
```
where `p(bigint)` is a distributed "function" and the param the
distribution key (also in a distributed table), see #7242 for details
Fixes#7242
One of our most flaky and most anoying tests is
multi_cluster_management. It usually fails like this:
```diff
SELECT citus_disable_node('localhost', :worker_2_port);
citus_disable_node
--------------------
(1 row)
SELECT public.wait_until_metadata_sync(60000);
+WARNING: waiting for metadata sync timed out
wait_until_metadata_sync
--------------------------
(1 row)
```
This tries to address that by hardening wait_until_metadata_sync. I
believe the reason for this warning is that there is a race condition in
wait_until_metadata_sync. It's possible for the pre-check to fail, then
have the maintenance daemon send a notification. And only then have the
backend start to listen. I tried to fix it in two ways:
1. First run LISTEN, and only then read do the pre-check.
2. If we time out, check again just to make sure that we did not miss
the notification somehow. And don't show a warning if all metadata is
synced after the timeout.
It's hard to know for sure that this fixes it because the test is not
repeatable and I could not reproduce it locally. Let's just hope for the
best.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
I just enhanced the existing code to check if the relation is an index
belonging to a distributed table.
If so the shardId is appended to relation (index) name and the *_size
function are executed as before.
There is a change in an extern function:
`extern StringInfo GenerateSizeQueryOnMultiplePlacements(...)`
It's possible to create a new function and deprecate this one later if
compatibility is an issue.
Fixes https://github.com/citusdata/citus/issues/6496.
DESCRIPTION: Allows using Citus size functions on distributed tables
indexes.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: This change starts a maintenance deamon at the time of
server start if there is a designated main database.
This is the code flow:
1. User designates a main database:
`ALTER SYSTEM SET citus.main_db = "myadmindb";`
2. When postmaster starts, in _PG_Init, citus calls
`InitializeMaintenanceDaemonForMainDb`
This function registers a background worker to run
`CitusMaintenanceDaemonMain `with `databaseOid = 0 `
3. `CitusMaintenanceDaemonMain ` takes some special actions when
databaseOid is 0:
- Gets the citus.main_db value.
- Connects to the citus.main_db
- Now the `MyDatabaseId `is available, creates a hash entry for it.
- Then follows the same control flow as for a regular db,
HasDistributionKey & HasDistributionKeyCacheEntry returns true when the
corresponding table has a distribution key, the comments state the
opposite,
which should be fixed.
Signed-off-by: Zhao Junwang <zhjwpku@gmail.com>
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Send keepalive messages during the logical replication
phase of large shard splits to avoid timeouts.
During the logical replication part of the shard split process, split
decoder filters out the wal records produced by the initial copy. If the
number of wal records is big, then split decoder ends up processing for
a long time before sending out any wal records through pgoutput. Hence
the wal receiver may time out and restarts repeatedly causing our split
driver code catch up logic to fail.
Notes:
1. If the wal_receiver_timeout is set to a very small number e.g. 600ms,
it may time out before receiving the keepalives. My tests show that this
code works best when the` wal_receiver_timeout `is set to 1minute, which
is the default value.
2. Once a logical replication worker time outs, a new one gets launched.
The new logical replication worker sets the pg_stat_subscription columns
to initial values. E.g. the latest_end_lsn is set to 0. Our driver logic
in `WaitForGroupedLogicalRepTargetsToCatchUp` can not handle LSN value
to go back. This is the main reason for it to get stuck in the infinite
loop.
DESCRIPTION: Fix leaking of memory and memory contexts in Foreign
Constraint Graphs
Previously, every time we (re)created the Foreign Constraint
Relationship Graph, we created a new Memory Context while loosing a
reference to the previous context. This old context could still have
left over memory in there causing a memory leak.
With this patch we statically have one memory context that we lazily
initialize the first time we create our foreign constraint relationship
graph. On every subsequent creation, beside destroying our previous
hashmap we also reset our memory context to remove any left over
references.
This commit aims to add a comprehensive guide that covers all essential
aspects of Citus, including planning, execution, locking mechanisms,
shard moves, 2PC, and many other major components of Citus.
Co-authored-by: Marco Slot <marco.slot@gmail.com>
DESCRIPTION: Shard moves/isolate report LSN's in lsn format
While investigating an issue with our catchup mechanism on certain
postgres versions we noticed we print LSN's in the format of the native
long type. This is an uncommon representation for LSN's in postgres
logs.
This patch changes the output of our log message to go from the long
type representation to the native LSN type representation. Making it
easier for postgres users to recognize and compare LSN's with other
related reports.
example of new output:
```
2023-09-25 17:28:47.544 CEST [11345] LOG: The LSN of the target subscriptions on node localhost:9701 have increased from 0/0 to 0/E1ED20F8 at 2023-09-25 17:28:47.544165+02 where the source LSN is 1/415DCAD0
```
When cdc got added the makefiles hardcoded the `.so` extension instead
of using the platform specifc `$(DLSUFFIX)` variable used by `pgxs.mk`.
Also don't remove installed cdc artifacts on `make clean`.
DESCRIPTION: Adds support for ALTER DATABASE <db_name> SET .. statement
propagation
SET statements in Postgres has a common structure which is already being
used in Alter Function
statement.
In this PR, I added a util file; citus_setutils and made it usable for
both for
alter database<db_name>set .. and alter function ... set ... statements.
With this PR, below statements will be propagated
```sql
ALTER DATABASE name SET configuration_parameter { TO | = } { value | DEFAULT }
ALTER DATABASE name SET configuration_parameter FROM CURRENT
ALTER DATABASE name RESET configuration_parameter
ALTER DATABASE name RESET ALL
```
Additionally, there was a bug in processing float values in the common
code block.
I fixed this one as well
Previous
```C
case T_Float:
{
appendStringInfo(buf, " %s", strVal(value));
break;
}
```
Now
```C
case T_Float:
{
appendStringInfo(buf, " %s", nodeToString(value));
break;
}
```
DESCRIPTION: Adds ALTER DATABASE WITH ... and REFRESH COLLATION VERSION
support
This PR adds supports for basic ALTER DATABASE statements propagation
support. Below statements are supported:
ALTER DATABASE <database_name> with IS_TEMPLATE <true/false>;
ALTER DATABASE <database_name> with CONNECTION LIMIT <integer_value>;
ALTER DATABASE <database_name> REFRESH COLLATION VERSION;
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
We currently don't support propagating these options in Citus
Relevant PG commits:
https://github.com/postgres/postgres/commit/e3ce2dehttps://github.com/postgres/postgres/commit/3d14e17
Limitation:
We also need to take care of generated GRANT statements by dependencies
in attempt to distribute something else. Specifically, this part of the
code in `GenerateGrantRoleStmtsOfRole`:
```
grantRoleStmt->admin_opt = membership->admin_option;
```
In PG16, membership also has `inherit_option` and `set_option` which
need to properly be part of the `grantRoleStmt`. We can skip for now
since #7164 will take care of this soon, and also this is not an
expected use-case.
Halil Ozan Akgül
Gürkan İndibay
Teja Mupparti
Jelte Fennema-Nio
Marco Slot
eaydingol
Valery
zhjwpku
LightDB Enterprise Postgres
Onur Tirtir
Karina
Jodi-Ann Francis
Nils Dijk
Naisila Puka
cvbhjkl
Cédric Villemain
Cédric Villemain
Emel Şimşek
Önder Kalacı
aykut-bozkurt