After https://github.com/nspcc-dev/neofs-contract/issues/154 alphabet
nodes should call `Register` method for approval of the notary
notifications spawned by `AddPeer` method.
Call `register` method for peer approval in Netmap processor.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Notary event name equals to the name of the method which throws the
event.
Define name const of notary subnet creation.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Use persistent flags on parent command in order to inherit flags in
sub-commands. Turn on notary mode of morph client in `subnet` command of
admin utility for notary environments.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make `Client.EnableNotarySupport` method to call `NNSContractAddress`
for proxy contract if it is not specified in corresponding option.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Add `subnet` command which contains all subnet-related commands. Add
sub-commands:
* `create` for creation;
* `remove` for removal;
* `get` for reading;
* `admin` for admin management;
* `client` for client management.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Define notification events, implement parsers. Add morph client of
Subnet contract. Listen, verify and approve events in Inner Ring app.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Continues replication executed in separate pool of goroutines,
so there is no need in worker to handle replication tasks
asynchronously.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Upgrade NeoFS API Go library to version with status returns. Make all API
clients to pull out and return errors from failed statuses. Make signature
service to respond with status if client version supports it.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
ListWithCursor allows listing physically stored objects
from metabase with small chunks. Cursor tracks last
processed object, therefore new chunks are returned
on each request.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Add hash of the TX that generated notification
to neofsid event structures. Adapt all
neofsid wrapper calls to new structures.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add hash of the TX that generated notification
to neofs/netmap event structures. Adapt all
neofs/netmap wrapper calls to new structures.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add optional parameters to the client call
signature. Group parameters of a client call
into struct to improve future codebase
support.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add optional parameters to the client call
signature. Group parameters of a client call
into struct to improve future codebase
support.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Parsers should have original notification
structure to be able to construct internal
event structure that contains necessary
for unique nonce calculation information.
So notification parsers take raw notification
structure instead of slice of stack items.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Make `BlockExecution` / `ResumeExecution` to not release per-shard worker
pools. Make `StorageEngine.Close` to block these methods and any
data-related operations. It is still releases the pools.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Use `sync.Once` to prevent locks of stopping GC. It will also allow to
safely call `Shard.Close` multiple times.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Add `MAINTENANCE` value to `NetmapStatus` enum in Control API. The status is
going to be used to toggle maintenance mode of the storage node.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to disable execution of local data operation on storage
engine in runtime. If storage engine ops are blocked, node will act like
always but all local object operations will be denied.
Implement `BlockExecution` / `ResumeExecution` methods on `StorageEngine`
which blocks / resumes the execution of data ops. Wait for the completion of
all operations executed at the time of the call. Return error passed to
`BlockExecution` from all data-related methods until `ResumeExecution` call.
Make `Close` to block operations as well.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation IR handler of `AddPeer` notification didn't send
registration to contract if existing peer changed has changed its
information. as a consequence, the network map members could not update the
information without going into offline.
Change `processAddPeer` handler to check if
* candidate in the network map is a brand new
* or information about the network map member was changed
and call `AddPeer` method if so.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
All objects in NeoFS must have owner ID. In previous implementation Object
Delete service handler set owner ID from request session token. If removal
was executed w/o a session, object with tombstone was prepared incorrectly.
In order to fix this node should set its own ID and become an owner of the
tombstone object.
Extend `NetworkInfo` interface required by Object.Delete handler with
`LocalNodeID` method which returns `owner.ID` of the local node. Implement
the method on `networkState` component of storage node application which is
updated on each node state change in NeoFS network map. Set owner returned
by `LocalNodeID` call as tombstone object's owner in Delete handler.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation node returns "access denied" on Object.Put with
object with unset owner. Although object owner must be set, its absence
should not be considered as access error. The same applies to sender key.
Check owner ID and public key emptiness only if sticky bit is set.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Also, add ErrNNSRecordNotFound error that
indicates that required hash is not presented
in `NNS` contract.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
The client needs of the Object service are limited and change not often.
Interface changes of the client library should not affect the operation of
various service packages, if they do not change their requirements for
the provided functionality. To localize the use of the base client and
facilitate further support, an auxiliary package is implemented that will
only be used by the Object service.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Timer is not suitable for notary deposits because it can never fire
in case of desynchronization or external epoch changes. Notary deposits
must be handled on new epoch event.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
a1696a8 introduced some logic which in some situations prevented big objects
to be persisted in FSTree. In this commit a refactoring is done with the
goal of simplifying the code and also checking #866 issue.
1. Split a monstrous function into multiple simple ones: memory objects
can only be small and for writing through the cache we can do a dispatch
in `Put` itself.
2. Determine objects to be put in database before the actual update
as setting up a transaction has non-zero overhead.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
The client needs of the IR application are very limited and rarely change.
Interface changes of the client library should not affect the operation of
various application packages, if they do not change their requirements for
the provided functionality. To localize the use of the base client and
facilitate further support, an auxiliary package is implemented that will
only be used by the IR application.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is no point to pass key storage in parameters because
it can be defined on the service level of application.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
`CommonPrm` structure has private key for remote operations.
It obtained in the beginning of request processing. However,
not every operation triggers remote calls. Therefore, key
might not be used. It is important to avoid early key fetching
because `TokenStore` now returns error if session token does not
exist. This is valid case when container nodes receive request with
session token (for ACL pass) and they should process request locally.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
This is invalid operation for storage nodes that receive part of split
object. While object is signed by session token, the message itself
should be signed by the node key.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Container listing should not ignore tombstone and
storage group objects which are not stored in
primary buckets.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Do not set `till` as some constant:
use maximum of two values instead:
1. currentDepositTill;
2. currentHeight+epochDuration+constant.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Some of the pools are initialized during config initialization,
so it isn't possible currently to release them in one place.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Add name and zone arguments to `Put` method of wrapper over the Container
contract client. Pass result of `container.GetNativeNameWithZone` function
to the method in `Put` helper function. Due to this, the storage node will
call the method depending on the presence of the container name in the
attributes.
Make IR to listen `putNamed` notification event. The event is processed like
`put` event, but with sanity check of the container attributes.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Add `PutArgs.SetNativeNameWithZone` method which sets native name and zone
for container. Call `putNamed` method of Container contract if name is set,
otherwise call `put` method.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `ParsePutNamedNotary` function which parses `PutNamed` structure
from `event.NotaryEvent`. Share common code with `ParsePutNotary` function.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Define `PutNamed` structure of notary notification from `putNamed` method of
Container contract. Embed `Put` type in order to inherit methods and
parsing of common parts with `put` method.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `StringFromOpcode` function that tries to retrieve `string` to
`Op`. Add a comment about neo-go source code that is used for implementation
of converters.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`WSClient` of Neo Go v0.97.3 sets value of notification with
`NotificationEventID` to `subscriptions.NotificationEvent` type which wraps
previously used `state.NotificationEvent`.
Change type cast and pull `state.NotificationEvent` structure from new type.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make the implementation of network info source (Netmap V2 service
dependency) to read MillisecondsPerBlock sidechain parameter and NeoFS
network parameters depending on the client version.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `Client.ListConfig` method which calls `listConfig` method of
Netmap contract. Implement `Wrapper.IterateConfigParameters` method which
uses previous one. Implement `wrapper.WriteConfig` helper function which
allows to interpret parameters by names.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
IR tries to keep 1:3 proportion of GAS and
notary balances respectively. If that proportion
has been messed(means that notary balance is
lower than required) it sends half of its
GAS balance to the notary service.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
After storage engine started to limit number of PUT operations there is no
need to limited worker pool in Object Put service.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make `StorageEngine` to use non-blocking worker pools with the same
(configurable) size for PUT operation. This allows you to switch to using
more free shards when overloading others, thereby more evenly distributing
the write load.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Convert minutes of received coordinates
to decimal parts of degree, and do not
use decimal part of float as storage for
minutes: "5915N 01806E" is
59.25N 18.10E, not 59°15'N 18°06'E.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Session token can be present in both object header and
request meta header. They are the same during initial object
placement.
At the object replication, storage node puts object without
any session tokens attached to the request. If container's eACL
denies object.Put for USER role (use bearer to upload), then
replication might fail on objects with session tokens of the
signed by container owner. It is incorrect, so use session
token directly from request meta header.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
We should be able to read whatever we have written earlier.
Compression setting applies only to the new objects.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Do not log in options constructors. Also failure to
initialize compression module (possibly due to invalid options) is
certainly an error deserving proper treatment.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
There is a need to list addresses of the small objects stored in WriteCache
database.
Implement `IterateDB` function which accepts BoltDB instance and iterate
over all saved objects and passes their addresses to the hander.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to open Blobovnicza instances in read-only mode in some
cases.
Add `ReadOnly` option. Do not create dir path in RO. Open underlying BoltDB
instance with ReadOnly flag. Document thal all writing operations should not
be called in ro (otherwise BoltDB txs fail).
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`Blobovnicza` can be initialized with any number of range buckets, and
reconstructed with different size limit. In previous implementation
`Iterate` could miss some stored objects if we construct `Blobovnicza` with
smaller number of ranges.
Make `Iterate` to traverse all buckets regardless of current instance
bounds.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation `Blobovnicza.Iterate` op decoded object data only
and passed it to the handler. There is a need to iterate over all addresses
of the stored objects.
Add `DecodeAddresses` and `WithoutData` methods of `IteratePrm` type. Add
`Address` method to `IterationElement` type. Make `Iterate` to decode object
addresses if `DecodeAddress` was called and not read the data if
`WithoutData` was called. Implement `IterateAddresses` helper function to
simplify the code.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to check if public key in the RPC response matches the
public key of the related storage node declared in network map.
Define `ErrWrongPublicKey` error. Implement RPC response handler's
constructor `AssertKeyResponseCallback` which checks public key. Construct
handler and pass it to client's option `WithResponseInfoHandler`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to process announced public keys of storage nodes for
intra-container communication.
Implement `PublicKey` / `SetPublicKey` methods of `client.NodeInfo` type.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to have the ability to expand the data needed for client
construction.
Replace `network.AddressGroup` parameter of client cache interfaces with
`client.NodeInfo`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
After recent changes morph client wrappers provide contract address getter.
It can be used to compose notification parsers and handlers.
Use `ContractAddress` method in constructors of notification parsers and
handlers. Remove no longer used script hash parameters of event processors.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to inherit some methods of `StaticClient` type. In order to
not inherit all method via type embedding we can group sub-set of methods
and inherit it.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Accept notification endpoints as string slice from config. Work with the
first successfully initialized WSClient.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation Object PUT used single pool of workers for local
and remote ops, but these ops are heterogeneous.
Use remote/local pool for remote/local operations in PUT service. At first
the pools are configured with the same size.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation `distributedTarget` didn't check if next node is
local. This check was performed by the handlers (target initializer and
relay func).
Make `distributedTarget` to calculate node's locality. Pass locality flag to
the handlers.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Each object from graveyard has tombstone or GC mark. If object has
tombstone, metabase should return `ErrAlreadyRemoved` on object requests.
This is the case when user clearly removed the object from container. GC
marks are used for physical removal which can appear even if object is still
presented in container (Control service, Policer job, etc.). In this case
metabase should return 404 error on object requests.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`List` method of `Shard` must return only physically stored objects.
Use `AddPhyFilter` to select only phy objects.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Forwarding mechanism resends original request. During split object chain traversal,
storage node performs multiple `object.Head` requests on each child. If request
forwarding happens, then `object.Head` returns object ID of the original request.
This produces infinite assembly loop.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Set `Curve` field in `ecdsa.PublicKey` instance from `keys.PublicKey` one in
`checkKeyOwnership` method of container processor.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Tombstone and "alive" objects can be both stored in BlobStor. They can
appear during iterating in different order. Metabase returns
`ErrAlreadyRemoved` error if object is inhumed.
Ignore `object.ErrAlreadyRemoved` errors of `metabase.Put`in Shard's
`refillMetabase` operation.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to refill Metabase data with the objects from BlobStor.
Implement `refillMetabase` method which iterates over all objects from
BlobStor and saves them in Metabase.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to be able to process all objects saved in `BlobStor`.
Implement `BlobStor.Iterate` method which iterates over all objects.
Implement `IterateBinaryObjects` and `IterateObjects` helper functions to
simplify the code.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to be able to process all stored objects saved in
`Blobovnicza`.
Implement `Blobovnicza.Iterate` method which iterates over all objects.
Implement `IterateObjects` helper function to simplify the code.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In the previous implementation of the metabase, there was no possibility of
reinitializing the metabase: clearing information about existing objects and
bringing it back to its initial state. This operation can be useful in
cases when the stored metadata about objects has lost (or possibly lost)
relevance, and you need to generate data from scratch. Also at the
initialization stage, static resources of the base were not created -
container-independent buckets.
Make `Metabase.Init` method to allocate graveyard, container-size and
to-move-it buckets in underlying BoltDB instance. Implement `Metabase.Reset`
method: it works like `Init` but clean up all static buckets and removes
other ones. Due to the logical similarity, the methods share a single piece
of code.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to limit disk space used by write-cache. It is almost
impossible to calculate the value exactly. It is proposed to estimate the
size of the cache by the number of objects stored in it.
Track amounts of objects saved in DB and FSTree separately. To do this,
`ObjectCounters` interface is defined. It is generalized to a store of
numbers that can be made persistent (new option `WithObjectCounters`). By
default DB number is calculated as key number in default bucket, and FS
number is set same to DB since it is currently hard to read the actual value
from `FSTree` instance. Each PUT/DELETE operation to DB or FS
increases/decreases corresponding counter. Before each PUT op an overflow
check is performed with the following formula for evaluating the occupied
space: `NumDB * MaxDBSize + NumFS * MaxFSSize`. If next PUT can cause
write-cache overflow, object is written to the main storage.
By default maximum write-cache size is set to 1GB.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to keep track of each local storage change. Log messages are
the most convenient way to do it.
Implement function which writes log message about the completed writing
operation in storage engine.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Do not pass high level `PACK` opcode to
notary parsers. Add opcode amount check.
Delete `PACK` cases in notary parsers.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Make `errIncompletePut` to be a structure which wraps single client error.
Wrap error of the last client into `errIncompletePut` during placement
execution.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation Object service's handler returned const error in
case of failure (full or partial) of PUT operation. This did not even allow
us to roughly guess what the reason is. Not as a complete solution, but to
alleviate some cases where all nodes in a container return the same error,
it is suggested to return the error of the last server that responded.
Return latest server error from placement loop of `iteratePlacement` method
of `distributedTarget` type.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation sticky bit could disrupt access of container
nodes to replication. According to NeoFS specification sticky bit should not
affect the requests sent by nodes from SYSTEM group.
Add role check to `stickyBitCheck`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Remote RPC node might be in the transition state and produce
events from the past. We should avoid listening such nodes.
To do that subscriber component can await minimal height of
remote node. If minimal height is not reached, then throw
error.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Implement `NotaryContractProcessor` by IR
container processor. Add support for notary
`put` container operation. Do not parse `put`
non-notary notifications in notary enabled
environment.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add `NotarySignAndInvokeTX` method to morph
client. This function allows invoking notary
request with passed main TX(not creating a
new one). It signs passed main TX with
client's key.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add `NotaryInvokeNotAlpha` to low-level
client. It creates and sends notary request
that must be signed by Alphabet nodes, but
does not sign it by current node's private
key.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add preparator for notary requests. Is parses
raw notary requests, checks if it should be
handled by Alphabet node. If handling is required,
returns `NotaryEvent` that contains information
about contract scripthash, method name and
arguments of the call.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Prepare all listening structures for notary events:
rename(add prefix/suffix 'notification') all
notification specific handlers/parsers.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
`fallbackTime` is delta b/w `ValidUntilBlock` of
the main transaction and block when `fallback`
transaction is sent.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
In recent changes, the locality criterion for a node has been changed to
compare public keys.
Remove no longer used `IsLocalAddress` function and `LocalAddressSource`
interface.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Some software components regulate the way of working with placement arrays
when a local node enters it. In the previous implementation, the locality
criterion was the correspondence between the announced network address
(group) and the address with which the node was configured. However, by
design, network addresses are not unique identifiers of storage nodes in the
system.
Change comparisons by network addresses to comparisons by keys in all
packages with the logic described above. Implement `netmap.AnnouncedKeys`
interface on `cfg` type in the storage node application.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Announced keys of storage nodes are required for many application components
to function.
Define a unified interface for the utility for working with public keys of
nodes. Add a method to check if the key has been advertised by the local
node in the application context.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to process public keys of the placement result.
Implement `Node.PublicKey` method which returns storage node's key announced
in netmap.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In previous implementation `placement.Traverser.Next` method returned slice
of `network.AddressGroup` elements. There is a need to process keys of
storage nodes besides network addresses for intra-container communication.
Wrap `network.AddressGroup` in a new type `placement.Node` that summarizes
the storage node information required for communication. Return slice of
`Node` instances from `Traverser.Next` method. Fix compilation breaks in
dependent packages.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
IDs come from NeoFS contract in big endian, but it is customary to write in
the node logs in little endian.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Shard should try to read object headers from write-cache if it is enabled.
Extend `writecache.Cache` interface with `Head` method. Call the method in
`Shard.Head` if `Shard.hasWriteCache` returns true.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Write cache should be able to execute HEAD operations according to spec.
Add simple implementation of `Head` method through the `Get` one. Leave
notes for future optimization.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Caching is performed inside `GetNativeContractHash` method of neo-go client,
so the additional cache level is redundant.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is no need to continue iterating over Neo RPC endpoints in case of
some address-independent error (e.g. NeoFS logic error).
Unwrap and immediately return `neofsError` errors from loop in
`iterateClients`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `error` interface on new `neofsError` type which is a wrapper over
NeoFS-specific error. Wrap all `Client` errors except neo-go client API ones
into `neofsError`. Wrapped errors are going to be used for multi-endpoint
loop control.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Since morph `Client` works in multi-client mode, there is an error case when
we can not get network magic when all endpoints are unavailable.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>