Summary:
TransactionReplicator replicates transactions on follower machines in
HA memgraph. Our DB accessor API doesn't provide us with the functionality to
begin transactions with non-increasing ids. This is why the
`TransactionReplicator` uses a internal map that maps tx ids from the leader
node to transactions on the follower node (whose id doesn't have to match the
leaders tx id).
If the leader has the following transaction timeline:
```
L
tx1
|
| tx2
| |
| |
| |
| |
| |
| tx2
|
|
|
|
tx1
```
`tx2` will commit first and will be replicated. When applying `tx2` on follower
nodes, they will start a new transaction with tx id `1`. When `tx1` starts
replicating, followers will start a new transaction with tx id `2`. And this is
wehre `TransactionReplicator` kicks in.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1775
Summary:
Explicitly start and stop raft server.
This way we can be sure that raft won't try to use coordination after it's
shutdown, and we can define the start of th raft protocol easier.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1766
Summary:
This is just the first diff that tries to wire the raft protocol into
memgraph.
In this diff I'm introducing transaction engine reset functionality. I also
introduced `RaftInterface` which should be used wherever someone wants to access
Raft from Memgraph.
For design decisions see the feature spec.
Reviewers: ipaljak, teon.banek
Reviewed By: ipaljak
Subscribers: pullbot, teon.banek
Differential Revision: https://phabricator.memgraph.io/D1758
Summary: This diff contains a rough implementation of the Raft protocol which ends at leader election.
Reviewers: msantl
Reviewed By: msantl
Subscribers: teon.banek, pullbot
Differential Revision: https://phabricator.memgraph.io/D1744
Summary:
Classes marked with `:serialize (:slk)` will now generate SLK
serialization code. This diff also changes how the `:serialize` option
is parsed, so that multiple different serialization backends are
supported.
Reviewers: mtomic, llugovic, mferencevic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1755
Summary: This change undoes the performance impact that was introduced in D1117
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1756
Summary:
This should cover the minimum required feature set for generating the
serialization code for SLK. There are some TODO comments, mostly
concerning quality of life improvements. The documentation on LCP has
been updated.
Additionally, any previous CHECK which would trigger if loading went
wrong is now replaced by raising SlkDecodeException. Other assertions of
code misuse are left as CHECK invocations.
Reviewers: mtomic, llugovic, mferencevic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1754
Summary:
Serialization of std::unique_ptr and std::shared_ptr now requires a
custom callback for handling the concrete element that is pointed to.
We use C++ type trait which checks whether the we are using a
polymorphic type --- class that has at least 1 virtual function. This
obviously doesn't work with pointers to base classes of hierarchies
without virtual member functions. But we don't use that kind of
inheritance, why would we, right? :)
(Luckily the breaking case isn't serialized, and hopefully never will
be. Perhaps we fix such inheritance in the future.)
Reviewers: mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1753
Summary: Starting memgraph with logging verbosity level 12 would crash memgraph, because extended and regular callbacks were not properly differentiated in logging.
Reviewers: mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1747
Summary:
It doesn't make sense to tie skipping a member for serialization to a
particular serialization implementation.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1743
Summary:
With quite frequent changes of serialization backend, it's getting
really painful updating the C++ implementation. This diff defines the
Symbol class via LCP, so that the C++ serialization is generated instead
of written by hand.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1741
Summary:
Instantiation with VertexAccessor was never used, so the template
needlessly complicated the rest of the codebase.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D1736
Summary:
TypeInfo will be needed for upcoming serialization via SLK. This diff
changes the already defined TypeInfo by removing the reliance on
capnp::typeId calls. The struct itself is now in utils.
Hopefully, this shouldn't break our RPC stack due to new ID generation.
Reviewers: mferencevic, mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1735
Summary:
This is the initial work on transferring our serialization code from
Cap'n Proto to SaveLoadKit. The commit contains tests for generated
code, but still requires work on supporting some features. Most notably,
generating and storing type IDs for derived classes so that they can be
loaded from a base pointer. Naturally, loading implementation hasn't
even been started yet.
Reviewers: mtomic, llugovic, mferencevic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1733
Summary:
GraphDb now has GetStorageStat method that returns live view to
object containing vertex_count, edge_count and avg_degree().
Stat is updated on each garbage collection run and represents number of
objects that are visible to any transaction.
Reviewers: teon.banek, msantl, ipaljak
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1731
Summary: SmallVector data structure introduction. This is the first step. In this revision are SmallVector implementation and tests. The second step will be swapping std::vector with SmallVector in the current codebase.
Reviewers: teon.banek, buda, ipaljak, mtomic
Reviewed By: teon.banek, ipaljak
Subscribers: ipaljak, pullbot
Differential Revision: https://phabricator.memgraph.io/D1730
Summary:
Basic RPC messages for Raft protocol. They will most likely be updated as we
move along with the implementation.
Reviewers: msantl, teon.banek, mferencevic
Reviewed By: msantl, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1726
Summary:
Since we need to send `StateDelta`s over the wire in HA, we need to be
able to serialize those bad boys.
This diff hopefully does this the right way.
Reviewers: teon.banek, mferencevic, ipaljak
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1725
Summary:
This change makes HierarchicalTreeVisitor visit only Cypher related AST
nodes. QueryVisitor can be used to differentiate between various query
types we have. The next step is to either rename HierarchicalTreeVisitor
to something like CypherQueryVisitor, or perhaps extract Clause visiting
from it.
Reviewers: mtomic, llugovic
Reviewed By: llugovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1710
Summary:
The single-binary distributed tests didn't wait for the whole cluster to be up
and running before they started running their tests. Now all tests ensure that
all workers are registered to the master and all other workers before starting
any tests.
Reviewers: mculinovic
Reviewed By: mculinovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1724
