Commit graph

129 commits

Author SHA1 Message Date
Evgenii Stratonikov
8b3b16fe62 [#1825] writecache: Flush cache when moving to the DEGRADED mode
Degraded mode allows us to operate without an SSD,
thus writecache should be unavailable in this mode.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-10-04 12:13:09 +03:00
Evgenii Stratonikov
0a411908ee [#1806] writecache: Allow to ignore read errors during flush
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-28 09:28:01 +03:00
Evgenii Stratonikov
0b4c867ef1 [#1806] writecache: Allow to start flush manually
Allow user to initiate flushing objects from a writecache.
We need this in 2 cases:
1. During writecache storage schema update, it should be flushed with
   the old version of node and started clean with a new one.
2. During SSD replacement, to avoid data loss.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-28 09:28:01 +03:00
Evgenii Stratonikov
55148404ee [#1806] writecache: Use interfaces for blobstor and metabase
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-28 09:28:01 +03:00
Evgenii Stratonikov
e6cf0b3d42 [#1745] writecache: Set flush parameters based on max size
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
c04126f35e [#1745] writecache: Remove IsErrNotFound
We specify the error in the doc-comment, and it is the same for all our
components.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
9e41e85295 [#1745] writecache: Actualize docs
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
e9c6ee2623 [#1745] writecache: Rename constants for default values
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
177e8e01b1 [#1745] neofs-node: Remove memcache_capacity from the configuration
It is unused since ddaed283e9 .

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
bda084f331 [#1745] writecache: Simplify object counters
Remove unused option and additional pointers to db/fstree.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
20abdaeed4 [#1745] writecache: Set flush mark only on success
Set flush mark in the inside the flush worker because writing to the blobstor
can fail. Because each evicted object must be deleted, it is reasonable
to do this in the evict callback.

The evict callback is protected by LRU mutex and thus potentially interferes
with `Get` and `Iterate` methods. This problem will be addressed in the
future.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-09-02 11:59:53 +03:00
Evgenii Stratonikov
b8b9d25f9d [#1686] local_object_storage: Add generic tests
Use them for writecache as a simple example.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-08-30 10:02:43 +03:00
Pavel Karpy
30341f2192 [#1687] *: Perform go fmt using go v1.19
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-08-22 18:59:57 +03:00
Evgenii Stratonikov
26b4a258e0 [#1523] neofs-node: Refactor configuration
1. Move compression parameters to the `shard` section.
2. Allow to use multiple sub-storage components in the blobstor.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
266458fe5c [#1523] blobstor: Unify fstree and blobovnicza interfaces
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
5aa3defc67 [#1523] writecache: Remove cloneBytes
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
ddaed283e9 [#1523] writecache: Simplify logic
1. Remove in-memory cache. It doesn't persist objects and if we want
   more speed, `NoSync` option can be used for the bolt DB.
2. Put to the metabase in a synchronous fashion. This considerably
   simplifies overall logic and plays nicely with the metabase bolt DB
   batch settings.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
4176b2a1bc [#1523] local_object_storage: Unify parameters for the Iterate operation
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
73f8bb3e5f [#1523] shard: Store generic storage ID in metabase
Allow to extend blobstor with more storage sub-systems. Currently
objects stored in the FSTree have empty byte slice descriptor and object
from blobovnicza tree have the same id as earlier. Each such change in
the identifier formation should be accompanied with metabase version
increase.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
9eb018672c [#1523] blobstor: Unify parameters for Put operation
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
ca15083a50 [#1523] local_object_storage: Unify parameters for the Exists operation
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
d9a2f280c9 [#1523] local_object_storage: Unify parameters for the Get operation
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-08-22 13:14:19 +03:00
Evgenii Stratonikov
4e361e2ab4 [#1647] writecache: Open DB in sync mode
Close #1647.

Initially, `Sync: false` was provided because we can already lose
objects cached in memory. However, future changes in writecache will
remove inmemory cache and speed up it via other means.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
2022-08-16 15:27:18 +04:00
Pavel Karpy
da2975a2f9 [#1664] write-cache: Fix panic on Delete operation
If an object is found in the Write-cache and is placed at the end of
the in-memory cache, the memory counter update operation tries to
dereference the index that is out of the sliced array. Moreover, even if
panic does not appear, the counter is updated with the wrong value.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-08-09 20:18:26 +03:00
Pavel Karpy
156ba85326 [#1634] node: Do not return expired objects
If an object has not been marked for removal by the GC in the current epoch
yet but has already expired, respond with `ErrObjectNotFound` api status.
Also, optimize shard iteration: a node must stop any iteration if the object
 is found but gonna be removed soon.
All the checks are performed by the Metabase.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-08-04 16:31:49 +03:00
Evgenii Stratonikov
1691364653 [#1559] local_object_storage: Fix tests and some data races
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
3df62769c0 [#1559] local_object_storage: Allow to set mode for all components
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
1e786233bf [#1559] local_object_storage: Provide readOnly flag to Open
We should be able to reopen storage in readonly in runtime.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
339864b720 [#1559] local_object_storage: Move shard.Mode to a separate package
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
34d319fed2 [#1559] metabase: Use Set prefix for parameter setting
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
f58234aa2f [#1559] metabase: Remove public functions
Reduce public interface of this package. Later each result will contain
an additional status, so it makes more sense to use the same functions
and result processing everywhere.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-21 17:56:06 +03:00
Evgenii Stratonikov
11c9df6f00 [#1611] shard: Print shard ID in component logs
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-19 15:57:53 +03:00
Evgenii Stratonikov
972ca83e23 [#1524] writecache: Add some bolt parameters to the configuration
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-20 17:04:35 +03:00
Evgenii Stratonikov
38772e1a2e writecache: provide timeout to bbolt.Open
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-09 14:19:47 +03:00
Evgenii Stratonikov
feef9a98f7 [#1462] writecache: remove useless logs
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Evgenii Stratonikov
43e776dfb1 [#1462] writecache: Persist objects in batches
`Update` becomes a botleneck under a heavy load.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Evgenii Stratonikov
6ad87e7959 [#1462] writecache: Fill flush marks during startup
Some of the objects are already flushed, don't do it twice.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Evgenii Stratonikov
f2a7503964 [#1462] fstree: Allow to fetch file content lazily
If we should process address based on some condition, there is no need
to read file content in memory.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Evgenii Stratonikov
54d4503701 [#1462] writecache: Rename flushWorkersCount
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Evgenii Stratonikov
0148209168 [#1462] writecache: Use Timer instead of Ticker in flush
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-06-03 14:30:00 +03:00
Pavel Karpy
281befec67 [#1418] blobstor: Do not use pointers as parameters
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-06-03 07:35:17 +03:00
Pavel Karpy
1c100fb4b0 [#1418] writecache: Do not use pointers as parameters
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-06-03 07:35:17 +03:00
Leonard Lyubich
1c30414a6c [#1454] Upgrade NeoFS SDK Go module with new IDs
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>
2022-06-01 17:41:45 +03:00
Elizaveta Chichindaeva
cc7a723d77 [#1320] English Check
Signed-off-by: Elizaveta Chichindaeva <elizaveta@nspcc.ru>
2022-05-11 10:40:02 +03:00
Evgenii Stratonikov
48eb87d32c [#1149] writecache: Prevent corruption in Head
Also, remove optimization comments:
1. Having to maintain an execute the same logic for headers as for
   objects is quite inefficient, as it increases memory footprint.
2. Unmarshaling object is a cheap operation if data slice is in memory.
3. For unmarshaling header-only, I think we need SDK support.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-03-31 15:40:25 +03:00
Evgenii Stratonikov
6472a170eb [#1143] shard: Introduce explicit Degraded mode
`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>
2022-03-31 15:33:22 +03:00
Leonard Lyubich
318639e5bf [#1247] *: Clarify docs about returned errors from apistatus package
`apistatus` package provides types which implement build-in `error`
interface. Add `error of type` pattern when documenting these errors in
order to clarify how these errors should be handled (e.g. `errors.Is` is
not good).

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2022-03-17 16:34:00 +03:00
Leonard Lyubich
70ffdf3478 [#1247] object: Return NOT_FOUND and ALREADY_REMOVED statuses
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>
2022-03-17 16:34:00 +03:00
Leonard Lyubich
7ccd1625af [#1214] *: Use single Object type in whole project
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>
2022-03-04 17:45:00 +03:00
Evgenii Stratonikov
050a4bb2b0 [#1115] *: link TODOs to corresponding issues
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-02-11 12:58:59 +03:00
Pavel Karpy
1667ec9e6d [#1131] *: Adopt SDK changes
`object.Address` has been moved to `object/address`
`object.ID` has been moved to `object/id`

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2022-02-08 09:45:38 +03:00
Evgenii Stratonikov
674f520da7 [#1132] *: Use path/filepath package when working with files
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-02-03 10:12:07 +03:00
Evgenii Stratonikov
36eebb5932 [#1085] writecache: allow to ignore errors during iteration
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
Evgenii Stratonikov
c954f0e71b [#1085] fstree: allow to ignore errors during iteration
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
Evgenii Stratonikov
0ef3d5ab03 [#1085] writecache: persist in-memory objects before shutdown
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
Evgenii Stratonikov
c0f6c988f0 [#1085] shard: dump data from write-cache
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
Evgenii Stratonikov
ad01aaf8bf [#1085] writecache: add read-only mode
In read-only mode modifying operations are immediately returned with
error and all background operations are suspended.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
Evgenii Stratonikov
9f963e001b [#1085] writecache: set metaOnly flag for receiving from priority channel
This can lead to objects being flushed twice.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00
ZhangTao1596
ac82899e85 [#1088] writecache: Fix small flushed when persist
Signed-off-by: ZhangTao1596 <zhangtao@ngd.neo.org>
2022-01-19 12:55:33 +03:00
Evgenii Stratonikov
486d5c2e86 [#1060] writecache: compress big object if needed
Small objects use `blobstor.Put`, so no changes are required.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-13 14:20:36 +03:00
Evgenii Stratonikov
0d969d7a06 [#1060] blobstor: allow to disable compression based on content-type
For some data compression makes little sense, as it is already compressed.
This commit allows to leave such data unchanged based on `Content-Type`
attribute. Currently exact, prefix and suffix matching are supported.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-13 14:20:36 +03:00
Pavel Karpy
284188f8f9 [#1048] node: Fill shard's info with its components' infos
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-12-28 13:21:44 +03:00
ZhangTao1596
1be0c42726 [#1022] writecache: Fix db counter decrement and flushed big object
Signed-off-by: ZhangTao1596 <zhangtao@ngd.neo.org>
2021-12-15 14:23:49 +03:00
Leonard Lyubich
fc42844fbf [#1028] writecache: Evict flushed big objects
Make `flushBigObjects` routine to call `evictObjects` which was
successfully written to `BlobStor`.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2021-12-14 13:49:47 +03:00
Leonard Lyubich
d246e5193b [#1028] writecache: Mark big objects as flushed after write
Make `flushBigObjects` routine to mark objects which are written to
`BlobStor`. This prevents already flushed objects from being written on
the next iterator tick.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2021-12-14 13:49:47 +03:00
Evgenii Stratonikov
95893927aa *: replace neofs-api-go with neofs-sdk-go
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2021-11-12 17:29:09 +03:00
Evgenii Stratonikov
1462824ab8 [#947] writecache: refactor object persisting
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>
2021-11-01 15:52:56 +03:00
Pavel Karpy
616013cb8a [#933] write-cache: Use real number of objects in counters
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-10-25 18:49:10 +03:00
Evgenii Stratonikov
1a1435be3d [#791] neofs-lens: inspect objects by address
```
> neofs-lens list --path ./blob/blobovnicza/1/1/0
6ay4GfhR9RgN28d5ufg63toPetkYHGcpcW7G3b7QWSek/9ibXu6v4uTwLEcME5vyHev6Zi8LpxqiWTe1dahKpAbb6
H3VBttoLQoknzMDgnVNyLZ8EpkDnQjnaxDr9fnAWeEHA/Hw1titdGh7BrTe2yLotiYbVh9FQaRRNhoNzXTyetpFgt

> neofs-lens inspect --path ./blob/blobovnicza/1/1/0 \
    --address 6ay4GfhR9RgN28d5ufg63toPetkYHGcpcW7G3b7QWSek/9ibXu6v4uTwLEcME5vyHev6Zi8LpxqiWTe1dahKpAbb6 \
    --header --out payload
Version: v2.1
Type: REGULAR
CID: 6ay4GfhR9RgN28d5ufg63toPetkYHGcpcW7G3b7QWSek
ID: 9ibXu6v4uTwLEcME5vyHev6Zi8LpxqiWTe1dahKpAbb6
Owner: 2dokPzmmcLnnR21jQB3qPppTQRgwMNMKEWD
CreatedAt: 0
PayloadSize: 32
Attributes:
  foo: bar

> hexdump -C payload
00000000  ff 6c d4 71 c4 83 f1 5f  b9 0b ad b3 7c 58 21 b6  |.l.q..._....|X!.|
00000010  d9 55 26 a4 1a 95 04 68  0b 4e 7c 8b 76 3a 1b 1d  |.U&....h.N|.v:..|
00000020
```

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2021-10-18 11:55:02 +03:00
Leonard Lyubich
8a1593fdcc [#791] writecache: Export OpenDB function
The function will be useful for the tool which works with write-cache parts.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2021-10-05 10:51:10 +03:00
Leonard Lyubich
ca4c9d4673 [#791] writecache: Implement iterator over small objects
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>
2021-10-05 10:51:10 +03:00
Leonard Lyubich
a1696a81b6 [#776] writecache: Limit size of used disk space
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>
2021-09-15 18:07:36 +03:00
Leonard Lyubich
3258d9c616 [#790] writecache: Log each writing operation
Call `storagelog.Write` in all places after the successful writing op.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2021-09-13 15:02:13 +03:00
Leonard Lyubich
3f293cb55e [#762] storage/shard: Try to read headers from write-cache
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>
2021-09-02 11:33:17 +03:00
Leonard Lyubich
aa2151fbeb [#762] write-cache: Implement Head operation
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>
2021-09-02 11:33:17 +03:00
Pavel Karpy
c54f524df9 [#773] writecache: Delete unused dbSize param
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-08-27 15:05:53 +03:00
Pavel Karpy
7a10d902be [#727] Use util.MkdirAllX instead of os.MkdirAll
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-07-30 16:42:22 +03:00
ZhangTao1596
9b87e6267d [#568] shard/writecache: Maintain memory size and db size
Signed-off-by: ZhangTao1596 <zhangtao@ngd.neo.org>
2021-06-21 14:26:30 +03:00
Evgenii Stratonikov
59de521fd1 [#472] blobstor: implement write-cache
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2021-04-29 17:36:36 +03:00