Summary:
This change improves detection of errorneous situations when starting a
distributed cluster on a single machine. It asserts that the user hasn't
started more memgraph nodes on the same machine with the same durability
directory. Also, this diff improves worker registration. Now workers don't have
to have explicitly set IP addresses. The master will deduce them from the
connecting IP when the worker registers.
Reviewers: teon.banek, buda, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1582
Summary: Recovery file is version inconsistent iff it starts with a correct magic number, has at least one integer written after that and that integer differs from kVersion.
Reviewers: mferencevic, ipaljak, vkasljevic, buda
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1565
Summary:
This diff introduces a new flags
* `--synchronous-commit`
The `--synchronous-commit` tells the WAL when should the deltas be flushed to
the disk drive. By default this is off and the WAL flushes deltas every `N`
milliseconds. If it's turned on, on every transaction end, commit or abort, the
WAL will first flush the deltas and only after that will return from ending a
transaction.
Reviewers: buda, vkasljevic, mferencevic, teon.banek, ipaljak
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1542
Summary: A quick clean-up of user visible error messages. Tried to make them gramatically correct by capitalizing the first word in the sentence and putting a dot at the end.
Reviewers: teon.banek, buda, ipaljak
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1571
Summary:
Changed GRANT ROLE to SET ROLE. Now it is `SET ROLE FOR user TO ROLE` instead of `GRANT ROLE role TO user`. It makes more sense because our users can only have 1 role.
Changed REVOKE ROLE to CLEAR ROLE. Now it is `CLEAR ROLE FOR user` instead of `REVOKE ROLE role FOR user`. REVOKE ROLE would throw exception if user was not a member of role. CLEAR ROLE clears the role whatever it is. I find that the latter makes more sense combined with SET ROLE.
Changed `SHOW ROLE FOR USER user` to `SHOW ROLE FOR user`.
Changed `SHOW USERS FOR ROLE role` to `SHOW USERS FOR role`.
Reviewers: mferencevic, teon.banek, buda
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1572
Summary:
Visitor pattern's main issue is cyclical dependency between classes that
are visited and the visitor instance itself. We need to decouple this
dependency if we want to open source part of the code, namely
non-distributed part. This decoupling is achieved through the use of
`dynamic_cast` in distributed operators. Hopefully the solution is good
enough and doesn't cause performance issues. An alternative solution is
to build our own custom double dispatch solution, but that will
basically boil down to our implementation of runtime type information
and casts.
Note, this only decouples the distributed operators. If and when we
decide that other operators shouldn't be open sourced, the same
`dynamic_cast` pattern should be applied in them also.
Depends on D1563
Reviewers: mtomic, msantl, buda
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1566
Summary:
This is the first step in separating the implementation of distributed
features in operators. Following steps are:
* decoupling distributed visitors
* injecting distributed details in operator state
* minor cleanup or anything else that was overlooked
Reviewers: mtomic, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1563
Summary:
We want to make sure that index doesn't miss any results.
This test inserts vertices in the db and checks that the number of inserted
vertices is the same as the number of results from a scan all and a scan all by
label property.
https://app.asana.com/0/478665099752750/762723827276182/f
Reviewers: ipaljak, vkasljevic, teon.banek
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1558
Summary:
Since we switched to Cap'n Proto serialization there's no need for
keeping boost around anymore.
Reviewers: mtomic, mferencevic, buda
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1515
Summary:
The raft implementation has been stale for a while now. It doesn't
compile, nor uses Cap'n Proto for serialization. In the future we would
probably rewrite it, so it doesn't need to be part of the repo at this
moment.
Reviewers: mferencevic, mtomic, buda
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1513
Summary: first step for a cleaner query front end that might be easier to open source
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1511
Summary:
GraphDbAccessor is now constructed only through GraphDb. This allows the
concrete GraphDb to instantiate a concrete GraphDbAccessor. This allows
us to use virtual calls, so that the implementation may be kept
separate. The major downside of doing things this way is heap allocation
of GraphDbAccessor. In case it turns out to be a real performance
issues, another solution with pointer to static implementation may be
used.
InsertVertexIntoRemote is now a non-member function, which reduces
coupling. It made no sense for it to be member function because it used
only the public parts of GraphDbAccessor.
Reviewers: msantl, mtomic, mferencevic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1504
Summary:
This change, hopefully, simplifies the implementation of different kinds
of GraphDb. The pimpl idiom is now simplified by removing all of the
crazy inheritance. Implementations classes are just plain data stores,
without any methods. The interface classes now have a more flat
hierarchy:
```
GraphDb (pure interface)
|
+----+---------- DistributedGraphDb (pure interface)
| |
Single Node +-----+------+
| |
Master Worker
```
DistributedGraphDb is used as an intermediate interface for all the
things that should work only in distributed. Therefore, virtual calls
for distributed stuff have been removed from GraphDb. Some are exposed
via DistributedGraphDb, other's are only in concrete Master and Worker
classes. The code which relied on those virtual calls has been
refactored to either use DistributedGraphDb, take a pointer to what is
actually needed or use dynamic_cast. Obviously, dynamic_cast is a
temporary solution and should be replaced with another mechanism (e.g.
virtual call, or some other function pointer style).
The cost of the above change is some code duplication in constructors
and destructors of classes. This duplication has a lot of little tweaks
that make it hard to generalize, not to mention that virtual calls do
not work in constructor and destructor. If we really care about
generalizing this, we should think about abandoning RAII in favor of
constructor + Init method.
The next steps for splitting the dependencies that seem logical are:
1) Split GraphDbAccessor implementation, either via inheritance or
passing in an implementation pointer. GraphDbAccessor should then
only be created by a virtual call on GraphDb.
2) Split Interpreter implementation. Besides allowing single node
interpreter to exist without depending on distributed, this will
enable the planner and operators to be correctly separated.
Reviewers: msantl, mferencevic, ipaljak
Reviewed By: msantl
Subscribers: dgleich, pullbot
Differential Revision: https://phabricator.memgraph.io/D1493
Summary: This is a simple thing that enables us to use keywords as symbolic names. A bad thing is that planning will be done for queries which differ only in keyword case (e.g. "MATCH (x) RETURN x" and "match (x) return x"), but that should not be a significant performance impact as queries are done programmaticaly when high throughput is expected and we don't expect letter case change in that case.
Reviewers: buda, mferencevic, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1496
Summary:
Previously, our implementation of the Bolt protocol buffered all results in
memory before sending them out to the client. This implementation immediately
streams the results to the client to avoid any memory allocations. Also, this
implementation splits the interpretation and pulling logic into two.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1495
Summary:
This change should completely support planning Optional for distributed
execution. Cartesian matching is handled, as well as dependencies
between optional branch and the main input branch.
Unit tests are expanded to cover the planning algorithm.
Reviewers: msantl, mtomic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1480
Summary:
During the creation of indexes there could be a case in which a vertex contains a label/property but is not a part of index after
index building completes.
This happens if vertices are being inserted while the index is being built.
Reviewers: buda, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1484
Summary:
Session specifics have been move out of the Bolt `executing` state, and
are accessed via pure virtual Session type. Our server is templated on
the session and we are setting the concrete type, so there should be no
virtual call overhead. Abstract Session is used to indicate the
interface, this could have also been templated, but the explicit
interface definition makes it clearer.
Specific session implementation for running Memgraph is now implemented
in memgraph_bolt, which instantiates the concrete session type. This may
not be 100% appropriate place, but Memgraph specific session isn't
needed anywhere else.
Bolt/communication tests now use a dummy session and depend only on
communication, which significantly improves test run times.
All these changes make the communication a library which doesn't depend
on storage nor the database. Only shared connection points, which aren't
part of the base communication library are:
* glue/conversion -- which converts between storage and bolt types, and
* communication/result_stream_faker -- templated, but used in tests and query/repl
Depends on D1453
Reviewers: mferencevic, buda, mtomic, msantl
Reviewed By: mferencevic, mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1456
Summary:
This is the first step in cutting the crazy dependencies of
communication module to the whole database. Includes have been
reorganized and conversion between DecodedValue and other Memgraph types
(TypedValue and PropertyValue) has been extracted to a higher level
component called `communication/conversion`. Encoder, like Decoder, now
relies only on DecodedValue. Hopefully the conversion operations will
not significantly slow down streaming Bolt data.
Additionally, Bolt ID is now wrapped in a class. Our storage model uses
*unsigned* int64, while Bolt expects *signed* int64. The implicit
conversions may lead to encode/decode errors, so the wrapper should
enforce some type safety to prevent such errors.
Reviewers: mferencevic, buda, msantl, mtomic
Reviewed By: mferencevic, mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1453
Summary:
Added test stream functionality. When a stream is configured, it will try to
consume messages from a kafka topic and return them back to the user.
For now, the messages aren't transformed, so it just returns the payload string.
Depends on D1466
Next steps are persisting stream metadata and transforming messages in order to
store them in the graph.
Reviewers: teon.banek, mtomic
Reviewed By: teon.banek
Subscribers: pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D1474
Summary:
Integrated kafka library into memgraph. This version supports all opencypher
features and will only output messages consumed from kafka.
Depends on D1434
Next steps are persisting stream metadata and transforming messages in order to
store them in the graph.
Reviewers: teon.banek, mtomic, mferencevic, buda
Reviewed By: teon.banek
Subscribers: mferencevic, pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D1466
Summary:
Added basic functionality for kafka streams. The `CREATE STREAM` clause is a
simplified version from the one mentioned in D1415 so we can start testing
end-to-end sooner.
This diff also includes a bug fix in `lcp.list ` for operators that have no
members.
Reviewers: teon.banek, mtomic, buda
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1434
Summary:
Wal on workers didn't contain committed transactions ids, this is needed for
distributed recovery so that the master may decide which transactions are
present on all the workers.
Reviewers: buda, msantl
Reviewed By: buda
Subscribers: pullbot, msantl, buda
Differential Revision: https://phabricator.memgraph.io/D1440
