Summary:
To clean the working directory after this diff you should execute:
```
rm src/database/counters_rpc_messages.capnp
rm src/database/counters_rpc_messages.hpp
rm src/database/serialization.capnp
rm src/database/serialization.hpp
```
Reviewers: teon.banek, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1636
Summary:
This diff splits single node and distributed storage from each other.
Currently all of the storage code is copied into two directories (one single
node, one distributed). The logic used in the storage implementation isn't
touched, it will be refactored in following diffs.
To clean the working directory after this diff you should execute:
```
rm database/state_delta.capnp
rm database/state_delta.hpp
rm storage/concurrent_id_mapper_rpc_messages.capnp
rm storage/concurrent_id_mapper_rpc_messages.hpp
```
Reviewers: teon.banek, buda, msantl
Reviewed By: teon.banek, msantl
Subscribers: teon.banek, pullbot
Differential Revision: https://phabricator.memgraph.io/D1625
Summary:
This should allow us to more easily decouple the code which should be
open sourced. Unfortunately, the downside of this approach is that we
cannot rely on virtual calls to dispatch the serialization to correct
type. Another downside is that members need to be publicly accessible
for serialization.
Reviewers: mtomic, msantl
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1596
Summary:
This diff changes the RPC layer to directly return `TResponse` to the user when
issuing a `Call<...>` RPC call. The call throws an exception on failure
(instead of the previous return `nullopt`).
All servers (network, RPC and distributed) are set to have explicit `Shutdown`
methods so that a controlled shutdown can always be performed. The object
destructors now have `CHECK`s to enforce that the `AwaitShutdown` methods were
called.
The distributed memgraph is changed that none of the binaries (master/workers)
crash when there is a communication failure. Instead, the whole cluster starts
a graceful shutdown when a persistent communication error is detected.
Transient errors are allowed during execution. The transaction that errored out
will be aborted on the whole cluster. The cluster state is managed using a new
Heartbeat RPC call.
Reviewers: buda, teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1604
Summary:
Previous version of code was wrong in some cases. Example:
There's an edge e = (a)->(b). Node (a) belongs to worker 1, node (b) belongs to worker 0. Therefore, edge e belongs to worker 1.
When edge e was serialized on worker 0, address of node b was local and it would be globalized, but the worker id of edge (e) would be used, which is wrong.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1599
Summary:
In a bunch of places `TypedValue` was used where `PropertyValue` should be. A lot of times it was only because `TypedValue` serialization code could be reused for `PropertyValue`, only without providing callbacks for `VERTEX`, `EDGE` and `PATH`. So first I wrote separate serialization code for `PropertyValue` and put it into storage folder. Then I fixed all the places where `TypedValue` was incorrectly used instead of `PropertyValue`. I also disabled implicit `TypedValue` to `PropertyValue` conversion in hopes of preventing misuse in the future.
After that, I wrote code for `VertexAccessor` and `EdgeAccessor` serialization and put it into `storage` folder because it was almost duplicated in distributed BFS and pull produce RPC messages. On the sender side, some subset of records (old or new or both) is serialized, and on the reciever side, records are deserialized and immediately put into transaction cache.
Then I rewrote the `TypedValue` serialization functions (`SaveCapnpTypedValue` and `LoadCapnpTypedValue`) to not take callbacks for `VERTEX`, `EDGE` and `PATH`, but use accessor serialization functions instead. That means that any code that wants to use `TypedValue` serialization must hold a reference to `GraphDbAccessor` and `DataManager`, so that should make clients reconsider if they really want to use `TypedValue` instead of `PropertyValue`.
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1598
Summary:
Since RecordAccessor is often instantiated and copied, using a
factory-like function to allocate concrete types on the heap would be
too costly. The approach in this diff uses a Strategy pattern (see
"Design Patterns" by Gamma et al.), where the Strategy interface is
given as RecordAccessor::Impl. Concrete implementations are then created
for each GraphDb. This allows us to instantiate the concrete
RecordAccessors::Impl *once* and *share* it among all RecordAccessors.
Reviewers: msantl, vkasljevic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1510
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:
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:
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:
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:
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:
- 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: Do it so properties-on-disk can be implemented.
Reviewers: buda, dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1343
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: This is correct, and uses less memory.
Reviewers: teon.banek, buda, mislav.bradac
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1304
Summary:
Also removed some convenience code that became obsolete.
No logic changes.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1303
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:
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
