citus

Author	SHA1	Message	Date
Onder Kalaci	5b48de7430	Improve deadlock detection for MX We added a new field to the transaction id that is set to true only for the transactions initialized on the coordinator. This is only useful for MX in order to distinguish the transaction that started the distributed transaction on the coordinator where we could have the same transactions' worker queries on the same node.	2017-08-12 13:28:37 +03:00
Marco Slot	601b17d544	Use distributed transaction number in 2PC identifiers	2017-07-21 17:36:33 +02:00
Marco Slot	18a6e478af	Fix typo in GetCurrentDistributedTransctionId	2017-07-21 17:36:33 +02:00
Onder Kalaci	3369f3486f	Introduce distributed transaction ids 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.	2017-07-18 15:01:42 +03:00