- Never release locks
- AddNodeMetadata takes ShareRowExclusiveLock so it'll conflict with the
trigger which prevents multiple primary nodes.
- ActivateNode and SetNodeState used to take AccessShareLock, but they
modify the table so they should take RowExclusiveLock.
- DeleteNodeRow and InsertNodeRow used to take AccessExclusiveLock but
only need RowExclusiveLock.
- master_add_node enforces that there is only one primary per group
- there's also a trigger on pg_dist_node to prevent multiple primaries
per group
- functions in metadata cache only return primary nodes
- Rename ActiveWorkerNodeList -> ActivePrimaryNodeList
- Rename WorkerGetLive{Node->Group}Count()
- Refactor WorkerGetRandomCandidateNode
- master_remove_node only complains about active shard placements if the
node being removed is a primary.
- master_remove_node only deletes all reference table placements in the
group if the node being removed is the primary.
- Rename {Node->NodeGroup}HasShardPlacements, this reflects the behavior it
already had.
- Rename DeleteAllReferenceTablePlacementsFrom{Node->NodeGroup}. This also
reflects the behavior it already had, but the new signature forces the
caller to pass in a groupId
- Rename {WorkerGetLiveGroup->ActivePrimaryNode}Count
GCC 7 added `-Wimplicit-fallthrough` to warn for not explicitly specified switch/case fall-throughs.
According to https://gcc.gnu.org/gcc-7/changes.html, to suppress that warning we could either use `__attribute__(fallthrough)`, which didn't seem to work for earlier GCC versions, or a `/* fallthrough */` comment just before the following `case`.
Previously Citus code had the fall-through comments inside the brackets, which didn't seem to suppress the warning. Putting a `/* fallthrough */` comment outside the brackets and right before the `case` fixes the problem.
This commit adds distributed transaction id infrastructure in
the scope of distributed deadlock detection.
In general, the distributed transaction id consists of a tuple
in the form of: `(databaseId, initiatorNodeIdentifier, transactionId,
timestamp)`.
Briefly, we add a shared memory block on each node, which holds some
information per backend (i.e., an array `BackendData backends[MaxBackends]`).
Later, on each coordinated transaction, Citus sends
`SELECT assign_distributed_transaction_id()` right after `BEGIN`.
For that backend on the worker, the distributed transaction id is set to
the values assigned via the function call.
The aim of the above is to correlate the transactions on the coordinator
to the transactions on the worker nodes.
Comes with a few changes:
- Change the signature of some functions to accept groupid
- InsertShardPlacementRow
- DeleteShardPlacementRow
- UpdateShardPlacementState
- NodeHasActiveShardPlacements returns true if the group the node is a
part of has any active shard placements
- TupleToShardPlacement now returns ShardPlacements which have NULL
nodeName and nodePort.
- Populate (nodeName, nodePort) when creating ShardPlacements
- Disallow removing a node if it contains any shard placements
- DeleteAllReferenceTablePlacementsFromNode matches based on group. This
doesn't change behavior for now (while there is only one node per
group), but means in the future callers should be careful about
calling it on a secondary node, it'll delete placements on the primary.
- Create concept of a GroupShardPlacement, which represents an actual
tuple in pg_dist_placement and is distinct from a ShardPlacement,
which has been resolved to a specific node. In the future
ShardPlacement should be renamed to NodeShardPlacement.
- Create some triggers which allow existing code to continue to insert
into and update pg_dist_shard_placement as if it still existed.
These functions are holdovers from pg_shard and were created for unit
testing c-level functions (like InsertShardPlacementRow) which our
regression tests already test quite effectively. Removing because it
makes refactoring the signatures of those c-level functions
unnecessarily difficult.
- create_healthy_local_shard_placement_row
- update_shard_placement_row_state
- delete_shard_placement_row
Uncrustify 0.65 appears to have changed some defaults, resulting in
breakages for those of us who have already upgraded; Travis still uses
Uncrustify 0.64, but these changes work with both versions (assuming
appropriately updated config), so this should permit use of either
version for the time being.
Before this change, we used ShareLock to acquire lock on distributed tables while
running VACUUM. This makes VACUUM and INSERT block each other. With this change we
changed lock mode from ShareLock to ShareUpdateExclusiveLock, which does not conflict
with the locks INSERT acquire.
MasterIrreducibleExpressionWalker has a copied code from
function check_functions_in_node() which was available with
PG 9.6+. Now PG 9.5 support is dropped we can remove
duplicate code and directly call check_functions_in_node().
Önder Kalacı
Marco Slot
Brian Cloutier
Marco Slot
Brian Cloutier
Hadi Moshayedi
Burak Velioglu
velioglu
Burak Yucesoy
Jason Petersen
Murat Tuncer