Doctor RPC performs complex operations on the storage engine.
Currently only duplicate removal is supported.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
In case of session token (ST) with object IDs search should
return only objects allowed in static session
Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
Initially it was there to check whether an update is being initiated by
a proper node. It is now obsolete for 2 reasons:
1. Background synchronization fetches all operations from a single node.
2. There are a lot more problems with trust in the tree service, it is
only used in controlled environments.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
This reverts commit 2567f8020e. It assumes
that assembling logic could break some failover scenarios if request
forwarding is done. However, it also breaks requesting big objects via a
non-container node with TTL=2. Failover has been rechecked without that
commit and no problems were found. Any (if found) other bugs related to
the forwarding and object assembling must be solved more carefully.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
Allow replication of any (expired too) locked object. Information about
object locking is considered to be presented on the _container nodes_.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
Previously a token could've expired in the middle of an object.PUT
stream, leading to upload being interrupted. This is bad, because user
doesn't always now what is the right values for the session token
lifetime. More than that, setting it to a very high value will
eventually blow up the session token database.
In this commit we read the session token once and reuse it for the whole
stream duration.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Currently, under high load clients are blocked on channel send
and the number of goroutines can increase indefinitely.
In this commit we drop replication messages if send/recv queue is full
and rely on a background synchronization.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Because synchronization _most likely_ will have apply already existing
operations, it is much faster to check their presence in a read
transaction. However, always doing this will degrade the perfomance
for normal `Apply`. And, let's be honest, it is already not good.
Thus we add a separate parameter which specifies whether this logic is
enabled.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
`GETRANGEHASH` request spawns `GETRANGE` requests if an object could not be
found locally. If the original request contains session, it can be static
and, therefore, fetching session key can not be performed successfully.
As the best effort a node could request object's range with its own key.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
We use cache to avoid policing the same object multiple times in a short
time span (< 30 seconds). If we have 200_000 objects in a blobstor, it is a bit useless
-- if it takes 1 second to process an object and we have `replicator.pool_size: 20`
in config, the next iteration will happen in 10_000 second which is much
larger than 30 second. However we still consume a lot of memory, so it
makes sense to use saner default.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Stop child objects collection if the last returned object (the most "left"
object in the collected chain) starts exactly from the `GETRANGE`'s `from`
value.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
That could happen if a node forwards request to a node that closed the
connection during the original object stream.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
```
2022/11/15 08:40:56 worker exits from a panic: runtime error: index out of range [0] with length 0
2022/11/15 08:40:56 worker exits from panic: goroutine 1188 [running]:
github.com/panjf2000/ants/v2.(*goWorker).run.func1.1()
github.com/panjf2000/ants/v2@v2.4.0/worker.go:58 +0x10c
panic({0x1042b60, 0xc0015ae018})
runtime/panic.go:1038 +0x215
github.com/nspcc-dev/neofs-node/pkg/services/policer.(*Policer).shardPolicyWorker.func1()
github.com/nspcc-dev/neofs-node/pkg/services/policer/process.go:65 +0x366
github.com/panjf2000/ants/v2.(*goWorker).run.func1()
github.com/panjf2000/ants/v2@v2.4.0/worker.go:68 +0x97
created by github.com/panjf2000/ants/v2.(*goWorker).run
github.com/panjf2000/ants/v2@v2.4.0/worker.go:48 +0x68
```
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
Includes extending listing methods in the Storage Engine with object types.
It allows tuning replication/policer algorithms: container nodes do
not remove `LOCK` objects as redundant and try to fulfill `LOCK` placement
on the ohter container nodes.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
A container node is expected to have full "get" access to assemble the
object.
A non-container node is expected to forward any request to a container node.
Any token is expected to be issued for an original request sender not for a
node so any new request is invalid by design with that token.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Do not lose meta information of the original requests: cache session and
bearer tokens of the original request b/w a new generated ones. Middle
request wrappers should not contain any meta information, since it is
useless (e.g. ACL service checks only the original tokens).
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
After presenting request statuses on the API level, all the errors are
unwrapped before sending to the caller side. It led to a losing invalid
request's context.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Do not use node's local storage if it is clear that an object will be
removed anyway as a redundant. It requires moving the changing local storage
logic from the validation step to the local target implementation.
It allows performing any relations checks (e.g. object locking) only if a
node is considered as a valid container member and is expected to store
(stored previously) all the helper objects (e.g. `LOCK`, `TOMBSTONE`, etc).
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
In previous implementation turning to maintenance mode using NeoFS CLI
required NeoFS API endpoint. This was not convenient from the user
perspective. It's worth to move networks settings' check to the server
side.
Add `force_maintenance` field to `SetNetmapStatusRequest.Body` message
of Control API. Add `force` flag to `neofs-cli control set-status`
command which sets corresponding field in the requests body if status is
`maintenance`. Force flag is ignored for any other status.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Add `SynchronizeAllTrees` method of the Tree service. It allows fetching
tree IDs and sync all of them. Share common logic b/w the new method and
the `SynchronizeTree`.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add the node position in a container and the container size to the CID
descriptor that is passed to the `TreeApply`. Previously, `checkValid` does
not allow any log operarations.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Storage node should not provide NeoFS Object API service when it is
under maintenance.
Declare `Common` service that unifies behavior of all object operations.
The implementation pre-checks if node is under maintenance and returns
`apistatus.NodeUnderMaintenance` if so. Use `Common` service as a first
logical processor in object service pipeline.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
In some scenarios original session can be unrelated to the objects which
are read internally by the node. For example, node requests child
objects when removing the parent one.
Tune internal NeoFS API client used by node's Object API server to
ignore unrelated sessions in `GetObject` / `HeadObject` / `PayloadRange`
ops.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Make it store its internal `zap.Logger`'s level. Also, make all the
components to accept internal `logger.Logger` instead of `zap.Logger`; it
will simplify future refactor.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Current spec allows denying GET_RANGE requests from other storage nodes.
However, GET should always be allowed and it is enough to perform
GET_RANGE locally
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
In previous implementation `ObjectService.Get` RPC handler failed with
`parent address in child object differs` while assembling the "big"
object. This was caused by the child check which required parent
reference to be set in all child objects. The check was impracticable
because not all elements of the split-chain have a link to the parent.
Make `execCtx.isChild` to return `true` if parameterized object has no
parent header in its own header.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Node response with `NODE_UNDER_MAINTENANCE` status signals that the node
was switched to maintenance mode. There is a delay between the actual
switch and the reflection in the network map of up to one epoch. To
speed up the reaction to the maintenance, it is required to recognize
such node responses in the Policer.
Make `Policer.processNodes` to exclude elements with shortage decreasing
on `NODE_UNDER_MAINTENANCE` status response.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Nodes under maintenance SHOULD not respond to object requests. Based on
this, storage node's Policer SHOULD consider such nodes as problem ones.
However, to prevent spam with the new replicas, on the contrary, Policer
should consider them normal.
Make `Policer.processNodes` to exclude elements if `IsMaintenance()`
with shortage decreasing.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Make `replicator.TaskResult` to accept `netmap.NodeInfo` type instead of
uint64 in order to clarify the meaning and prevent passing the random
numbers.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
It doesn't make sense to check object relation in session check of
`ObjectService.Put` RPC which has been spawned by `ObjectService.Delete`
with session. Session issuer can't predict identifier of the tombstone
object to be created.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
In previous implementation of `neofs-node` app object session was not
checked for substitution of the object related to it. Also, for access
checks, the session object was substituted instead of the one from the
request. This, on the one hand, made it possible to inherit the session
from the parent object for authorization for certain actions. On the
other hand, it covered the mentioned object substitution, which is a
critical vulnerability.
Next changes are applied to processing of all Object service requests:
- check if object session relates to the requested object
- use requested object in access checks.
Disclosed problem of object context inheritance will be solved within
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
In previous implementation node blocked any operation of local object
storage in maintenance mode. There is a need to perform some storage
operations like data evacuation or restoration.
Do not call block storage engine in maintenance mode. Make all Object
service operations to return `apistatus.NodeUnderMaintenance` error from
each local op.
Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>
Replace `ProcessCurrentNetMap` method of `NodeState` interface with
`ReadCurrentNetMap` one with two changes:
* Replace network map type from NeoFS SDK package with the
protocol-generated message. This replaces all the business logic to
the application layer.
* Support error return. This allows to cover problem node states.
Return an error from `NodeState.ReadCurrentNetMap` method implemeted
through `atomic.Value` if `Store` method has not been called yet.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Use a simple loop at the callsite. This way we remove as much as we can.
Also, `Delete` metrics is more meaningful now.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
Do not call `CalculateAction` for the eACL checks since it requires object
headers that are meaningless in the tree context.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
1. Do not require a request to be signed by the container owner if a
bearer token is missing
2. Do not check the system role since public requests are not expected to
be signed by IR or a container node (unlike the object requests)
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Previously, the depth was restricted because with BFS the amount of
nodes we have in memory blows up exponentially. With DFS is is linear,
so we can process trees of arbitrary depth.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
Also, try to fetch object header info from the local storage to find as much
object info as possible for the requests which do not assume returning
object header as a response.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
`Degraded` mode can be set by the administrator if needed.
Modifying operations in this mode can lead node into an inconsistent state
because metabase checks such as lock checking are not performed.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Do not check that a node indeed belongs to the container, because the
synchronization will fail in this case anyway.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Do not return backend type from the service for now, because memory
backend is expected to vanish.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
In case node is down or failing for some reason, we can expect `Dial` to
fail. In case we actively try to replicate and `Dial` always takes 2
seconds, replication-related channels quickly become full. That affects
latency of all other write operations.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Before this commit the replication channel was quickly filled under
heavy load. This lead to the continuously increasing latency for all
write operations. Now it looks better.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Also fix a bug with replicator using the multiaddress instead of
<host>:<port> format expected by gRPC library.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Replace `ErrRangeOutOfBounds` error from `pkg/core/object` package with
`ObjectOutOfRange` from `apistatus` package. That error is returned by
storage node's server as NeoFS API statuses.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Do not calculate and do not write homomorphic hash for containers that were
configured to store objects without hash.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Do not use homomorphic hash in storage group for containers that have
`homomorphic_hashing_disabled` set to `true`.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
If the container ID is not nil and not equal to the container ID in the
request, consider bearer token invalid.
See also nspcc-dev/neofs-api#207.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Allocate memory only if a node chosen as the forwarded request receiver
has responded with a successful status.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
After fixing version fields in forwarded requests, a node does not check
statuses since errors are not covered by direct call error checks.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Error checkers now support wrapped errors so there is no need to
explicitly unwrap errors in `Policer`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Forwarded requests contained zero version in their meta header. It did not
allow responding with API statuses (`v0.0` version considered to be older
than `v2.11`) to the forwarding node and, therefore, did not allow analyzing
responses.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
`auditor` does not need to request SG: processor will fetch that info before
audit context initialization.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
That allows using `ClientCache` for storage group searching before task
context is initialized. Also, that makes it more general purpose.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
After recent changes in NeoFS SDK Go library session tokens aren't
embedded into `container.Container` and `eacl.Table` structures.
Group value, session token and signature in a structure for container
and eACL.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Cache object that are being processed. That prevents concurrent
object handling when there is a few number of objects and object handling
takes more time that the policer needs for starting that object handling one
more time.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
If placement contains two vectors with intersecting nodes it was possible to
send the object to the nodes twice.
Also optimizes requests: do not ask about storing the object twice from the
same node.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
The node does not support asynchronous object replication anymore, so it
does not need to have replicator worker, channel and `AddTask` function.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
In case we have lots of objects in a single container,
`GetContainerNodes` invoked indirectly by a policer can be seen in
pprof.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Node shouldn't perform eACL verification during GET/HEAD request
processing until full object header is received. Otherwise, for some
eACL tables request may be falsely rejected.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Scenario:
* HEAD request of some object
* 1st eACL record allows op for objects with specific user attribute
* 2nd eACL record forbids op by object ID
* node doesn't store the requested object locally
With this scenario node shouldn't deny request.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
It is redundant to process object headers in responses w/o object field
since result will be the same.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Request processing should not be interrupted in case of local storage
failure since error case in normal for relay nodes.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
ACL service should not deny request on local storage failure since in
this case relay nodes won't be able to continue the operation.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`log.With` is suitable during initialization, but in other places it induces
some overhead, even when branches with logging are not taken.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Core changes:
* avoid package-colliding variable naming
* avoid using pointers to IDs where unnecessary
* avoid using `idSDK` import alias pattern
* use `EncodeToString` for protocol string calculation and `String` for
printing
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Helper function `client.IsErrObjectNotFound` doesn't support error
unwrapping, so we need to do it on caller side.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`Policer` should pass list of selected candidates into `WithNodes`
method of `replicator.Task`. In previous implementation `processNodes`
method passed an opposite list: failed nodes and/or the local one.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Not all the NeoFS requests must contain OID in their bodies (or must NOT
contain them at all). Do not pass object address in helper functions, pass
CID and OID separately instead.
Also, fixed NPE in the ACL service: updated SDK library brought errors
when working with `Put` and `Search` requests without OID fields.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
In previous implementation `Policer` considered local object copy as
redundant on processing single placement vector.
Make `Policer` to call redundant copy callback after full placement
processing. Also fix 404 error parsing.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Parse all headers beforehand and reject invalid requests.
Another approach would be to remember the error and check
it after `CalculateAction`, which is a bit faster.
The rule of thumb here is "first validate, then use".
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
It is nice to have different paths for different components and also
check that the information returned is different for different shards.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
The service fetches tombstones from the network via object service, every
request is handled in the following order:
1. checks local LRU cache;
2. checks local storage engine;
3. tries to find object in the placement nodes.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
`Degraded` mode is set automatically after error counter is over the
threshold. `ReadOnly` mode can still be set by an administrator.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Add `WithEncryption` option that passes ECDSA key to the persistent session
storage. It uses 32 bytes from marshalled ECDSA key in ASN.1 DER from in
AES-256 algorithm encryption in Galois/Counter Mode.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Move in-memory session storage to the separate directory of `storage`. It is
done for future support of different kind of session storages.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Return `apistatus.ObjectAccessDenied` error on access violation from ACL
service. Write reason in format of the errors from the previous
implementation. These errors are returned by storage node's server as
NeoFS API statuses.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Replace `core/container.ErrNotFound` error returned by `Source.Get`
interface method with `apistatus.ContainerNotFound` status error. This
error is returned by storage node's server as NeoFS API statuses.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Replace `ErrNotFound`/`ErrAlreadyRemoved` error from
`pkg/core/object` package with `ObjectNotFound`/`ObjectAlreadyRemoved`
one from `apistatus` package. These errors are returned by storage
node's server as NeoFS API statuses.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Return `SessionTokenExpired`/`SessionTokenNotFound` error from
`apistatus` package if private session token is expired/missing. These
errors are returned by storage node's server as NeoFS API statuses.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make all epoch independent in reputation process. Do not reset any timers
related to reputation. Make it possible to finish iteration after the
unexpected `NewEpoch` event.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
In previous implementation `SignService` converted all `error` values to
`INTERNAL` server failure status. That was done for simplification only.
There is a need to transmit status errors as corresponding status
messages.
Make `SignService` to unwrap errors and convert them to status message
during writing to the response. Non-status errors are converted to
`INTERNAL` server failures. Status errors can also be wrapped in the
depths of the executable code, so `SignService` tries to unwrap them.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
After `putsvc.Service` started to support additional container broadcast
of the saved objects there is no more need to perform broadcast of
tombstone object in `deletesvc.Service`.
Make `putsvc.Service` to perform additional broadcast of `TOMBSTONE`
objects. Remove `broadcastTombstone` stage from `deletesvc.execCtx`,
from now it is encapsulated in `saveTombstone` stage. Remove no longer
needed `putsvc.PutInitPrm.WithTraverseOption` method.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There are several cases when we need to spread the object around the
container after its primary placement (e.g. objects of type TOMBSTONE).
It'd be convenient to support this feature in `putsvc.Service`.
Add additional stage of container broadcast after the object is stored.
This stage is carried out no more than once and does not affect the
outcome of the main PUT operation.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make all operations that related to `neofs-api-go` library be placed in `v2`
packages. They parse all v2-versioned structs info `neofs-sdk-go`
abstractions and pass them to the corresponding `acl`/`eacl` packages. `v2`
packages are the only packages that do import `neofs-api-go` library. `eacl`
and `acl` provide public functions that only accepts `sdk` structures.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Remove `Object` and `RawObject` types from `pkg/core/object` package.
Use `Object` type from NeoFS SDK Go library everywhere. Avoid using the
deprecated elements.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
- Update `neofs-sdk-go`:
v0.0.0-20211230072947-1fe37df88f80 => v0.0.0-20220113123743-7f3162110659
- Add client interface that duplicates SDK's client behaviour and new
`MultiAddressClient` interface that has method that iterates over wrapped
clients.
- Also start using simple client mode that does not require parsing statuses
outside the SDK library.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Reverse payload overtake triggers direct payload overtake that
sets status and error. We should not override that.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
It is much more convenient to skip source creation.
Also fix some bugs:
1. `cryptoSource.Int63()` now returns number in [0, 1<<63) as required
by `rand.Source` interface.
2. Replace `cryptoSource.Uint63()` with `cryptoSource.Uint64` to allow
generate uint64 numbers directly (see rand.Source64 docs).
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
In previous implementation `Search` method of transport splitter skipped
responses with empty ID list.
Replace while-loop with do-while one in `TransportSplitter.Search`
method implementation in order to send responses with empty result too.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Without sanity check, container service provides successful response,
even though such request will never be approved by Alphabet nodes.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
When application is being terminated, replicator routine
might be on the object picking phase. Storage is terminated
asynchronously, thus `Select()` may return corresponding
error. If we don't process `context.Done()` in this case,
then application freezes on shutdown.
Signed-off-by: Alex Vanin <alexey@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>
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>
