* Use CalculateUniformHashRangeIndex in HashPartitionId
INT32_MIN definition can change among different platforms hence it is
possible to get overflow, we would see crashes because of this in debian
distros. We have already solved a similar problem with introducing
CalculateUniformHashRangeIndex method, hence to solve it we can use the
same method, this also removes some duplication and has a single place
to decide that.
* Use PG_INT32_XX instead of INT32_XX to be safer
(cherry picked from commit ef841115de)
Conflicts:
src/backend/distributed/commands/multi_copy.c
Here are the updated make targets:
- install: install everything except downgrade scripts.
- install-downgrades: build and install only the downgrade migration scripts.
- install-all: install everything along with the downgrade migration scripts.
(cherry picked from commit 315b323d47)
This commit is heavily modified to support an earlier release version.
- Downgrade scripts that are relevant for versions 9.4+ are stripped
- multi_extension tests are copied from master and then stripped
Some GUCs support a list of values which is indicated by GUC_LIST_INPUT flag.
When an ALTER ROLE .. SET statement is executed, the new configuration
default for affected users and databases are stored in the
setconfig(text[]) column in a pg_db_role_setting record.
If a GUC that supports a list of values is used in an ALTER ROLE .. SET
statement, we need to split the text into items delimited by commas.
(cherry picked from commit e534dbae4a)
DESCRIPTION: Force aliases in deparsing for queries with anonymous column references
Fixes: #3985
The root cause has todo with discrepancies in the query tree we create. I think in the future we should spend some time on categorising all changes we made to ruleutils and see if we can change the data structure `query` we pass to the deparser to have an actual valid postgres query for the deparser to render.
For now the fix is to keep track, besides changing the names of the entries in the target list, also if we have a reference to an anonymous columns. If there are anonymous columns we set the `printaliases` flag to true which forces the deparser to add the aliases.
DESCRIPTION: Adds support to partially push down tdigest aggregates
tdigest extensions: https://github.com/tvondra/tdigest
This PR implements the partial pushdown of tdigest calculations when possible. The extension adds a tdigest type which can be combined into the same structure. There are several aggregate functions that can be used to get;
- a quantile
- a list of quantiles
- the quantile of a hypothetical value
- a list of quantiles for a list of hypothetical values
These function can work both on values or tdigest types.
Since we can create tdigest values either by combining them, or based on a group of values we can rewrite the aggregates in such a way that most of the computation gets delegated to the compute on the shards. This both speeds up the percentile calculations because the values don't have to be sorted while at the same time making the transfer size from the shards to the coordinator significantly less.
(cherry picked from commit da8f2b0134)
DESCRIPTION: Ignore pruned target list entries in coordinator plan
The postgres planner has the ability to prune target list entries that are proven not used in the output relation. When this happens at the `CitusCustomScan` boundary we need to _not_ return these pruned columns to not upset the rest of the planner.
By using the target list the planner asks us to return we fix issues that lead to Assertion failures, and potentially could be runtime errors when they hit in a production build.
Fixes#3809
(cherry picked from commit 105de7beb8)
The reason is that PQconnectPoll() may change the underlying
socket. If we don't rebuild the wait event set, the low level
APIs (such as epoll_ctl()) may fail due to invalid sockets.
Instead, rebuilding ensures that we'll use accurate/active sockets.
(cherry picked from commit 77c397e9ae)
* Not append empty task in ExtractLocalAndRemoteTasks
ExtractLocalAndRemoteTasks extracts the local and remote tasks. If we do
not have a local task the localTaskPlacementList will be NIL, in this
case we should not append anything to local tasks. Previously we would
first check if a task contains a single placement or not, now we first
check if there is any local task before doing anything.
* fix copy of node task
Task node has task query, which might contain a list of strings in its
fields. We were using postgres copyObject for these lists. Postgres
assumes that each element of list will be a node type. If it is not a
node type it will error.
As a solution to that, a new macro is introduced to copy a list of
strings.
(cherry picked from commit cbda951395)
The previous default was 5 seconds, and we change it to 30 seconds.
The main motivation for this is that for busy clusters, 5 seconds
can be too aggressive. Especially with connection throttling, the servers
might be kept busy for a really long time, and users may see the
connection errors more frequently.
We've done some sanity checks, for really quick queries (like
`SELECT count(*) from table`), 30 seconds is a decent value even
if users execute 300 distributed queries on the coordinator. We've
verified this on Hyperscale(Citus).
(cherry picked from commit bc54c5125f)
Physical planner doesn't support parameters. If the parameters have already
been resolved when the physical planner handling the queries, mark it.
The reason is that the executor is unaware of this, and sends the parameters
along with the worker queries, which fails for composite types.
(See `DissuadePlannerFromUsingPlan()` for the details of paramater resolving)
(cherry picked from commit 0cb7ab2d05)
We currently put the actual error message to the detail part. However,
many drivers don't show detail part.
As connection errors are somehow common, and hard to trace back, can't
we added the detail to the message itself.
In addition to that, we changed "connection error" message, as it
was confusing to the users who think that the error was happening
while connecting to the coordinator. In fact, this error is showing
up when the coordinator fails to connect remote nodes.
* invalidate plan cache in master_update_node
If a plan is cached by postgres but a user uses master_update_node, then
when the plan cache is used for the updated node, they will get the old
nodename/nodepost in the plan. This is because the plan cache doesn't
know about the master_update_node. This could be a problem in prepared
statements or anything that goes into plancache. As a solution the plan
cache is invalidated inside master_update_node.
* add invalidate_inactive_shared_connections test function
We introduce invalidate_inactive_shared_connections udf to be used in
testing. It is possible that a connection count for an inactive node
will be greater than 0 and in that case it will not be removed at the
time of invalidation. However, later we don't have a mechanism to remove
it, which means that it will stay in the hash. For this not to cause a
problem, we use this udf in testing.
* move invalidate_inactive_shared_connections to udfs from test as it will be used in mx
* remove the test udf
* remove the IsInactive check
This copies over fixes from reference counting branch,
all CitusTableCacheEntry data may be freed when a GetCitusTableCacheEntry call occurs for its relationId
This fix is not complete, but reference counting is being deferred until 9.4
CopyShardInterval: remove dest parameter, always return newly allocated object
We initially considered removing entries just before any change to
pg_dist_node. However, that ended-up being very complex and making
MX even more complex.
Instead, we're switching to a simpler solution, where we remove entries
when the counter gets to 0.
With certain workloads, this may have some performance penalty. But, two
notes on that:
- When counter == 0, it implies that the cluster is not busy
- With cached connections, that's not possible
When we call SetTaskQueryString we would set the task type to
TASK_QUERY_TEXT, and some parts of the codebase rely on the fact that if
TASK_QUERY_TEXT is set, the data can be read safely. However if
SetTaskQueryString is called with a NULL taskQueryString this can cause
crashes. In that case taskQueryType will simply be set to
TASK_QUERY_NULL.
DESCRIPTION: Alter role only works for citus managed roles
Alter role was implemented before we implemented good role management that hooks into the object propagation framework. This is a refactor of all alter role commands that have been implemented to
- be on by default
- only work for supported roles
- make the citus extension owner a supported role
Instead of distributing the alter role commands for roles at the beginning of the node activation role it now _only_ executes the alter role commands for all users in all databases and in the current database.
In preparation of full role support small refactors have been done in the deparser.
Earlier tests targeting other roles than the citus extension owner have been either slightly changed or removed to be put back where we have full role support.
Fixes#2549
We had 9+ parameters in some of the functions related to execution.
Execution params is created to simplify this a bit so that we can set
only the fields that we are interested in and it is easier to read.
With this commit, we're introducing a new infrastructure to throttle
connections to the worker nodes. This infrastructure is useful for
multi-shard queries, router queries are have not been affected by this.
The goal is to prevent establishing more than citus.max_shared_pool_size
number of connections per worker node in total, across sessions.
To do that, we've introduced a new connection flag OPTIONAL_CONNECTION.
The idea is that some connections are optional such as the second
(and further connections) for the adaptive executor. A single connection
is enough to finish the distributed execution, the others are useful to
execute the query faster. Thus, they can be consider as optional connections.
When an optional connection is not allowed to the adaptive executor, it
simply skips it and continues the execution with the already established
connections. However, it'll keep retrying to establish optional
connections, in case some slots are open again.
We currently don't use any cursor flags in local execution, but we can
use CURSOR_OPT_PARALLEL_OK flag to potentially benefit from parallelism
when possible.
This PR:
- Declares variables when they are needed.
- Creates DoCopyFromLocalTableIntoShards for better readability.
- Doesn't use a hardcoded value, instead use a variable for better
readability.
We have two variables that are related to local execution status.
TransactionAccessedLocalPlacement and
TransactionConnectedToLocalGroup. Only one of these fields should be
set, however we didn't have any check for this contraint and it was
error prone.
What those two variables are used is that we are trying to understand if
we should use local execution, the current session, or if we should be
using a connection to execute the current query, therefore the tasks. In
the enum, now it is more clear what these variables mean.
Also, now we have a method to change the local execution status. The
method will error if we are trying to transition from a state to a wrong
state. This will help us avoid problems.
Halil Ozan Akgul
SaitTalhaNisanci
Hanefi Onaldi
Marco Slot
Nils Dijk
Hadi Moshayedi
Onder Kalaci
Jelte Fennema
Philip Dubé
Önder Kalacı