The long description of the `citus.distributed_deadlock_detection_factor`
setting was incorrectly stating that 1000 would disable it. Instead -1
is the value that disables distributed deadlock detection.
DESCRIPTION: Use faster custom copy logic for non-blocking shard moves
Non-blocking shard moves consist of two main phases:
1. Initial data copy
2. Catchup phase
This changes the first of these phases significantly. Previously we used the
copy logic provided by postgres subscriptions. This meant we didn't have
to implement it ourselves, but it came with the downside of little control.
When implementing shard splits we needed more control to even make it
work, so we implemented our own logic for copying data between nodes.
This PR starts using that logic for non-blocking shard moves. Doing so
has four main advantages:
1. It uses COPY in binary format when possible, which is cheaper to encode
and decode. Furthermore it very often results in less data that needs to
be sent over the network.
2. It allows us to create the primary key (or other replica identity) after doing
the initial data copy. This should give some speed up over the total run,
because creating an index is bulk is much faster than incrementally building it.
3. It doesn't require a replication slot per parallel copy. Increasing the maximum
number of replication slots uses resources in postgres, even if they are not used.
So reducing the number of replication slots that shard moves need is nice.
4. Logical replication table_sync workers are slow to start up, so if lots of shards
need to be copied that can make it quite slow. This can happen easily when
combining Postgres partitioning with Citus.
We used to only check whether the PID is valid
or not. However, Postgres does not necessarily
set the PID of the backend to 0 when it exists.
Instead, we need to be able to check it from procArray.
IsBackendPid() is what pg_stat_activity also relies
on for a similar purpose.
use RecurseObjectDependencies api to find if an object is citus depended
make vanilla tests runnable to see if citus_depended function is working correctly
Similar to #5897, one more step for running Citus with PG 15.
This PR at least make Citus run with PG 15. I have not tried running the tests with PG 15.
Shmem changes are based on 4f2400cb3f
Compile breaks are mostly due to #6008
This PR makes all of the features open source that were previously only
available in Citus Enterprise.
Features that this adds:
1. Non blocking shard moves/shard rebalancer
(`citus.logical_replication_timeout`)
2. Propagation of CREATE/DROP/ALTER ROLE statements
3. Propagation of GRANT statements
4. Propagation of CLUSTER statements
5. Propagation of ALTER DATABASE ... OWNER TO ...
6. Optimization for COPY when loading JSON to avoid double parsing of
the JSON object (`citus.skip_jsonb_validation_in_copy`)
7. Support for row level security
8. Support for `pg_dist_authinfo`, which allows storing different
authentication options for different users, e.g. you can store
passwords or certificates here.
9. Support for `pg_dist_poolinfo`, which allows using connection poolers
in between coordinator and workers
10. Tracking distributed query execution times using
citus_stat_statements (`citus.stat_statements_max`,
`citus.stat_statements_purge_interval`,
`citus.stat_statements_track`). This is disabled by default.
11. Blocking tenant_isolation
12. Support for `sslkey` and `sslcert` in `citus.node_conninfo`
* Bug fix for bug #5876. Memset MetadataCacheSystem every time there is an abort
* Created an ObjectAccessHook that saves the transactionlevel of when citus was created and will clear metadatacache if that transaction level is rolled back. Added additional tests to make sure metadatacache is cleared
Columnar: support relation options with ALTER TABLE.
Use ALTER TABLE ... SET/RESET to specify relation options rather than
alter_columnar_table_set() and alter_columnar_table_reset().
Not only is this more ergonomic, but it also allows better integration
because it can be treated like DDL on a regular table. For instance,
citus can use its own ProcessUtility_hook to distribute the new
settings to the shards.
DESCRIPTION: Columnar: support relation options with ALTER TABLE.
* Separate build of citus.so and citus_columnar.so.
Because columnar code is statically-linked to both modules, it doesn't
make sense to load them both at once.
A subsequent commit will make the modules entirely separate and allow
loading them both simultaneously.
Author: Yanwen Jin
* Separate citus and citus_columnar modules.
Now the modules are independent. Columnar can be loaded by itself, or
along with citus.
Co-authored-by: Jeff Davis <jefdavi@microsoft.com>
1) Remove useless columns
2) Show backends that are blocked on a DDL even before
gpid is assigned
3) One minor bugfix, where we clear distributedCommandOriginator
properly.
* [Columnar] Build columnar.so and let citus depends on it
Co-authored-by: Yanwen Jin <yanwjin@microsoft.com>
Co-authored-by: Ying Xu <32597660+yxu2162@users.noreply.github.com>
Co-authored-by: jeff-davis <Jeffrey.Davis@microsoft.com>
DESCRIPTION: Add GUC to control ddl creation behaviour in transactions
Historically we would _not_ propagate objects when we are in a transaction block. Creation of distributed tables would not always work in sequential mode, hence objects created in the same transaction as distributing a table that would use the just created object wouldn't work. The benefit was that the user could still benefit from parallelism.
Now that the creation of distributed tables is supported in sequential mode it would make sense for users to force transactional consistency of ddl commands for distributed tables. A transaction could switch more aggressively to sequential mode when creating new objects in a transaction.
We don't change the default behaviour just yet.
Also, many objects would not even propagate their creation when the transaction was already set to sequential, leaving the probability of a self deadlock. The new policy checks solve this discrepancy between objects as well.
The low-level StoreAllActiveTransactions() function filters out
backends that exited.
Before this commit, if you run a pgbench, after that you'd still
see the backends show up:
```SQL
select count(*) from get_global_active_transactions();
┌───────┐
│ count │
├───────┤
│ 538 │
└───────┘
```
After this patch, only active backends show-up:
```SQL
select count(*) from get_global_active_transactions();
┌───────┐
│ count │
├───────┤
│ 72 │
└───────┘
```
With https://github.com/citusdata/citus/pull/5657, Citus uses
a fixed application_name while connecting to remote nodes
for internal purposes.
It means that we cannot allow users to override it via
citus.node_conninfo.
Removed dependency for EnsureTableOwner. Also removed pg_fini() and columnar_tableam_finish() Still need to remove CheckCitusVersion dependency to make Columnar_tableam.h dependency free from Citus.
Replaces citus.enable_object_propagation with citus.enable_metadata_sync
Also, within Citus 11 release cycle, we added citus.enable_metadata_sync_by_default,
that is also replaced with citus.enable_metadata_sync.
In essence, when citus.enable_metadata_sync is set to true, all the objects
and the metadata is send to the remote node.
We strongly advice that the users never changes the value of
this GUC.
multi_log_hook() hook is called by EmitErrorReport() when emitting the
ereport either to frontend or to the server logs. And some callers of
EmitErrorReport() (e.g.: errfinish()) seems to assume that string fields
of given ErrorData object needs to be freed. For this reason, we copy the
message into heap here.
I don't think we have faced with such a problem before but it seems worth
fixing as it is theoretically possible due to the reasoning above.
Simply applies
```SQL
SELECT textlike(command, citus.grep_remote_commands)
```
And, if returns true, the command is logged. Else, the log is ignored.
When citus.grep_remote_commands is empty string, all commands are
logged.
- [x] Add some more regression test coverage
- [x] Make sure returning works fine in case of
local execution + remote execution
(task->partiallyLocalOrRemote works as expected, already added tests)
- [x] Implement locking properly (and add isolation tests)
- [x] We do #shardcount round-trips on `SerializeNonCommutativeWrites`.
We made it a single round-trip.
- [x] Acquire locks for subselects on the workers & add isolation tests
- [x] Add a GUC to prevent modification from the workers, hence increase the
coordinator-only throughput
- The performance slightly drops (~%15), unless
`citus.allow_modifications_from_workers_to_replicated_tables`
is set to false
Clang 13 complains about a suspicious string concatenation. It thinks we
might have missed a comma. This adds parentheses to make it clear that
concatenation is indeed what we meant.
In the past, we allowed users to manually switch to 1PC
(e.g., one phase commit). However, with this commit, we
don't. All multi-shard modifications are done via 2PC.
With Citus 9.0, we introduced `citus.single_shard_commit_protocol` which
defaults to 2PC.
With this commit, we prevent any user to set it to 1PC and drop support
for `citus.single_shard_commit_protocol`.
Although this might add some overhead for users, it is already the default
behaviour (so less likely) and marking placements as INVALID is much
worse.
Jelte Fennema
Teja Mupparti
Sameer Awasekar
aykut-bozkurt
Onder Kalaci
Ahmet Gedemenli
Ying Xu
Marco Slot
jeff-davis
gledis69
jeff-davis
ywj
Nils Dijk
Halil Ozan Akgul
Onur Tirtir
Önder Kalacı
Philip Dubé