Summary:
Blocking transaction has the ability to stop the transaction engine from
starting new transactions (regular or blocking) and to wait all other active
transactions to finish (to become non active, committed or aborted). One thing
that blocking transactions support is defining the parent transaction which
does not need to end in order for the blocking one to start. This is because of
a use case where we start nested transactions.
One could thing we should build indexes inside those blocking transactions. This
is true and I wanted to implement this, but this would require some digging in
the interpreter which I didn't want to do in this change.
Reviewers: mferencevic, vkasljevic, teon.banek
Reviewed By: mferencevic, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1695
Summary:
This change introduces a pure virtual initial implementation of the transaction
engine which is then implemented in two versions: single node and distributed.
The interface classes now have the following hierarchy:
```
Engine (pure interface)
|
+----+---------- EngineDistributed (common logic)
| |
EngineSingleNode +-------+--------+
| |
EngineMaster EngineWorker
```
In addition to this layout the `EngineMaster` uses `EngineSingleNode` as its
underlying storage engine and only changes the necessary functions to make
them work with the `EngineWorker`.
After this change I recommend that you delete the following leftover files:
```
rm src/distributed/transactional_cache_cleaner_rpc_messages.*
rm src/transactions/common.*
rm src/transactions/engine_rpc_messages.*
```
Reviewers: teon.banek, msantl, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1589
Summary:
- Removed a lot of stuff that was incorrect and/or unnecessary
- Fixed const-correctness in the skiplist family
Reviewers: dgleich, teon.banek, buda
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1351
Summary:
When performing recovery, ensure that the transaction ID in engine is
bumped to one after the max tx id seen in recovery.
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1312
Summary:
Release of per-transaction data in distributed Memgraph refactored. The
master node no longer releases each time a transaction is done, thus
offloading some work from the engine.
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1235
Summary:
On the master cleanups are hooked directly into the transaction engine.
This is beneficial because the master might have bigger caches and we
want to clear them as soon as possible.
On the workers there is a periodic RPC call to the master about living
transactions, which takes care of releasing local caches. This is
suboptimal because long transactions will prevent cache GC (like with
data GC). It is however fairly simple.
Note that all cleanup is not done automatically and `RemotePull` has
been reduced accordingly. @msantl, please verify correctness and
consider if the code can be additionally simplified.
Reviewers: teon.banek, msantl
Reviewed By: msantl
Subscribers: pullbot, msantl
Differential Revision: https://phabricator.memgraph.io/D1202
Summary:
No logic changes, just split `tx::MasterEngine` into
`tx::SingleNodeEngine` and `tx::MasterEngine`. This gives better
responsibility separation and is more appropriate now there is no
Start/Shutdown.
Reviewers: dgleich, teon.banek, buda
Reviewed By: dgleich, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1099
