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
Summary:
For reasons unknown to man, antlr didn't want to parse calls
to functions whose name is a single hex letter properly. Now it should work.
Reviewers: teon.banek, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1464
Summary:
Added missing string functions.
I also cleaned up error messages a bit in effort to make them uniform.
Reviewers: teon.banek, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1458
Summary:
This diff implements OpenSSL support in the network stack.
Currently SSL support is only enabled for Bolt connections,
support for RPC connections will be added in another diff.
Reviewers: buda, teon.banek
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1328
Summary:
Hopefully, the mechanism of generating Cartesian is general enough, so
this simple change should work correctly in all cases.
Planner tests have been modified to use a FakeDbAccessor in order to
speed them up and potentially allow extracting planning into a library.
Reviewers: msantl, mtomic, buda
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1431
Summary:
This change should correctly plan Cartesian which have dependent Filter
or Expand operators. Tests have been added for those cases. Other cases
are not yet supported and should throw an exception.
Reviewers: msantl, mtomic, buda
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1426
Summary:
Converts the RPC stack to use Cap'n Proto for serialization instead of
boost. There are still some traces of boost in other places in the code,
but most of it is removed. A future diff should cleanup boost for good.
The RPC API is now changed to be more flexible with regards to how
serialize data. This makes the simplest cases a bit more verbose, but
allows complex serialization code to be correctly written instead of
relying on hacks. (For reference, look for the old serialization of
`PullRpc` which had a nasty pointer hacks to inject accessors in
`TypedValue`.)
Since RPC messages were uselessly modeled via inheritance of Message
base class, that class is now removed. Furthermore, that approach
doesn't really work with Cap'n Proto. Instead, each message type is
required to have some type information. This can be automated, so
`define-rpc` has been added to LCP, which hopefully simplifies defining
new RPC request and response messages.
Specify Cap'n Proto schema ID in cmake
This preserves Cap'n Proto generated typeIds across multiple generations
of capnp schemas through LCP. It is imperative that typeId stays the
same to ensure that different compilations of Memgraph may communicate
via RPC in a distributed cluster.
Use CLOS for meta information on C++ types in LCP
Since some structure slots and functions have started to repeat
themselves, it makes sense to model C++ meta information via Common Lisp
Object System.
Depends on D1391
Reviewers: buda, dgleich, mferencevic, mtomic, mculinovic, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1407
Summary:
Add additional structs and functions for handling C++ meta information.
Add capnp-file and capnp-id arguments to lcp:process-file.
Generate cpp along with hpp and capnp in lcp.
Wrap LogicalOperator base class in lcp:define-class.
Modify logical operators for capnp serialization.
Add query/common.capnp.
Reviewers: mculinovic, buda, mtomic, msantl, ipaljak, dgleich, mferencevic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1391
Summary:
Utils source files are now moved to a standalone mg-utils library.
Unit and manual tests are no longer collected using glob recursion in
cmake, but are explicitly listed. This allows us to set only required
dependencies of those tests.
Both of these changes should improve compilation and link times, as well
as lower the disk usage.
Additional improvement would be to cleanup utils header files to be
split in .hpp and .cpp as well as merging threading into utils. Other
potential library extractions that shouldn't be difficult are:
* data_structures
* io/network
* communication
Reviewers: buda, mferencevic, dgleich, ipaljak, mculinovic, mtomic, msantl
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1408
Summary:
Command id is necessary in remote produce to identify an ongoing pull
because a transaction can have multiple commands that all belong under
the same plan and tx id.
Reviewers: teon.banek, mtomic, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1386
Summary:
Removing `AS_IS` from GraphView because it doesn't seem like it is necessary for query execution and it also has weird semantics (you might get a mix of old and new records). `Unwind`, `OrderBy` and `PullRemoteOrderBy` now use `OLD` graph view.
Remove AS_IS from GraphView
Fix query_cost_estimator tests
Fix query_expression_evaluator tests
Fix query_plan_match_filter_return tests
Fix query_plan_create_set_remove_delete tests
Fix query_plan_accumulate_aggregate tests
Reviewers: teon.banek, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1390
Summary:
A simplified end-to-end implementation
POD interface set-up, still have bugs with HDDkeys
Version bug fix and first iterator implementation
Fixed out-of-scope reference in PVS iterator
Added PVS unit tests
Reviewers: buda, mferencevic, dgleich, teon.banek
Reviewed By: buda, dgleich
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D1369
Summary: Global address of `from` was stored in Edge record when created via CreateEdge RPC.
Reviewers: buda, msantl, dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1387
Summary:
Pointers in AstTreeStorage can point to same nodes. These nodes
should be serialized(saved) only once when serializing Ast tree.
Same goes for deserializing(loading).
When deserializing nodes, one should not use storage Create method,
because it will add node which isn't completely loaded to storage vector.
Therefore, one should use new Deserialize method which doesn't
add node to storage vector. Inserting node into storage vector
is defered until all node data is loaded.
Pass pointer to saved uids set, instead of storage
Delete unused set
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1344
Summary:
Added a new markdown file for concepts and a new test to test the edge
case with upper bound.
Reviewers: teon.banek, mtomic, dgleich, buda, ipaljak
Reviewed By: teon.banek, dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1366
Summary:
Wal retention test was flaky, this kinda fixes it.
It's hard to fix it completely since there are separate threads happening which
are not synchronized, and forcing the synchronization from the outside would
not agree to the specifications i.e. single-threadness of WAL.
Reviewers: buda
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1358
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:
Implemented cluster discovery in distributed memgraph.
When a worker registers, it sends a RPC request to master.
The master assigns that worker an id and sends the information about other
workers (pairs of <worker_id, endpoint>) to the new worker.
Master also sends the information about the new worker to all existing workers
in the process of worker registration.
After the last worker registers, all memgraph instances in the clusters should
know about every other.
Reviewers: mtomic, buda, florijan
Reviewed By: mtomic
Subscribers: teon.banek, dgleich, pullbot
Differential Revision: https://phabricator.memgraph.io/D1339
Summary: Make synchronized snapshot. This invokese the snapshooter on workers on the master snapshot scheduler interval.
Reviewers: msantl, mtomic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1334
Summary: Adds a commit log garbage collector, which clears old transactions from the commit log
Reviewers: florijan
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1310
Summary:
When commiting/aborting a transaction in tx master engine, make a two
phase commit to all workers so they can stop all futures and clear
transactional cache.
Reviewers: dgleich, florijan
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1320
Summary:
The network layer now has a `Session` that handles all things that should be
done before the `Execute` method is called on sessions. Also, all sessions
now communicate using streams instead of holding the input buffer and writing
to the `Socket`. This design will allow implementation of a SSL middleware.
Reviewers: buda, dgleich
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1314
Summary:
Remove "produce_" and "Produce" as prefix from all distributed stuff.
It's not removed in src/query/ stuff (operators).
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1315
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:
Find[Vertex|Edge] -> Find[Vertex|Edge]Optional
Find[Vertex|Edge]Checked -> Find[Vertex|Edge]
In some places change old code that finds-optional and immediately checks
to use the checked functionality.
It seems that in all the src/ stuff optional finds are no loger used,
only in tests, but there they are used extensively so I don't feel those
functions should be removed.
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1309
Summary:
Writers preference is not guaranteed by the standard and as such
there are variations between implementations in different versions
of libphthread.
Reviewers: dgleich
Reviewed By: dgleich
Differential Revision: https://phabricator.memgraph.io/D1305
Summary:
Ensures that query plans are invalidated on the remote only when it's
guaranteed they will never be used on the master. This is done by
invalidating remote caches in the `CachedPlan` destructor.
There are two unplesant side-effects. First, an RPC call is made in an
object destructor. This is somewhat ugly, but not that different then
making an RPC call that must succeed in any other function. Note that
this does NOT slow down any query execution because the relevant
destructor is called by the skiplist garbage collector. The second ugly
side-effect is that in the unit test now we need to sleep to ensure the
skiplist GC destructs a cached plan before checking that it's
invalidated on the remote worker.
We might want to redesign this at some point.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1302
Summary:
- Remove caches on workers as a result of plan expiration or race
during insertion.
- Extract caching functionality into a class.
- Minor refactor of Interpreter::operator()
- New RPC and test for it.
- Rename ConsumePlanRes to DispatchPlanRes for consistency, remove
return value as it's always true and never used.
- Interpreter is now constructed with a `GraphDb` reference. At the
moment only for reaching the `distributed::PlanDispatcher`, but in
the future we should probably use that primarily for planning.
I added a function to `PlanConsumer` that is only used for testing.
I prefer not doing this, but I felt this needed testing. I can remove
it now if you like.
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1292
Summary:
Instead of waiting for a fix period for the coordinations to start and
coordinate with the master, wait for each of them individually to report
being done.
Also: rename `WorkerInThread` to `WorkerCoordinationInThread`.
Reviewers: dgleich, teon.banek, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1288
Summary:
This fixes a bug where the planning would raise NotYetImplemented error,
due to preventing plan splitting while the operator is already on
master. For example, `MATCH (a), (b) CREATE (a)-[e:r]->(b) RETURN e`
would split the plan after Cartesian and before Create. Thus, the rest
of the plan would be on master, including the Accumulate before Produce.
We still can (and must) replace Accumulate with Synchronize but this
would fail due to unneeded check.
Reviewers: florijan, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1272
Summary:
I have not thoroughly thought this through, especially the worker
destruction (is it legit to abort all running tx?), but it's tested to
abort during remote pull, what we need.
Also I improved error handling for vertex deletion failure during
remote pull (@dgleich).
Reviewers: teon.banek, msantl, dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1263
Summary:
Instead of passing `coordination`, pass `rpc_worker_clients` that
holds a map of worker_id->clientPool. By having only one instance of
`RpcWorkerClients` that is owned by `GraphDB` and passing it by refference
we'll share the same client pools for rpc clients.
Reviewers: teon.banek, florijan, dgleich, mferencevic
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1261
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:
Remove a method in tx::Engine whose results can be obtained from commit
log info (also guaranteed to be globally correct in distributed).
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1240
Summary:
Difficult to test properly as the problem was an implicit conversion of
`gid::Gid` to `mvcc::VersionList<> *`. The only proper way to defend
against this would be to make `gid::Gid` a type.
The `CHECK` added in this diff does not help, but should be there, so...
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1244
Summary:
During distributed execution, OrderBy is split across workers and the
master gets to merge those results via PullRemoteOrderBy. Since this
operator may be an input to almost any other operator, virtual accessors
to `input` have been added in LogicalOperator.
Depends on D1221
Reviewers: florijan, msantl, buda
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1232
Summary:
Extracted `TypedValueVectorCompare` and `RemotePuller` from operators
so it can be reused.
The new `PullRemoteOrerBy` operator pulls one result from each worker and one
from master, relies on the fact that workers/master returned sorted results,
returns the next one in order, and pulls the source of that result to get the
next one.
Depends on D1215 that (at the moment) is still in review.
Reviewers: florijan, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1221
Summary:
- The expansion vertex gets created on the origin's worker
- The edge automatically gets created wherever necessary
- Vertex creation logic reuse
- End to end test
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1227
Summary:
To see the thread names in htop press <F2> to enter setup and under
'Display options' choose 'Show custom thread names'.
Reviewers: buda, teon.banek, florijan
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1234
Summary:
- Add the said test
- Add `workerid` function
- Add random wait (enabled with flag) to `rpc::Client::Call` for network
latency simulation
Reviewers: buda, mferencevic, teon.banek
Reviewed By: buda, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1222
Summary:
Previously, the RPC stack used the network stack only to receive messages. The
messages were then added to a separate queue that was processed by different
thread pools. This design was inefficient because there was a lock when
inserting and getting messages from the common queue.
This diff removes the need for separate thread pools by utilising the new
network stack design. This is possible because the new network stack allows
full processing of the network request without blocking the whole queue.
Reviewers: buda, florijan, teon.banek, dgleich, mislav.bradac
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1229
Summary:
This may improve the query execution workload, because the Expand will
yield local results while it waits for remote ones. Note that we rely on
the fact that walking the graph produces results without any predetermined
order. Therefore, we can yield paths as we see fit. Enforcing the order
is done through OrderBy operator, and this change shouldn't affect that.
Reviewers: florijan, msantl, buda
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1215
