If operation with WC are _fast enough_ (e.g. `Init` failed and `Close` is
called immediately) there is a race and a deadlock that do not allow finish
(and start, in fact) an initialization routine because of taken `modeMtx`
and also do not allow finish `Close` call because of awaiting initialization
finish. So do stop initialization _before_ any mutex is taken.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
Do not use WC's internals in the initialization routines without mode
protection. WC should be able to change its mode even if the initialization
is not finished yet.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
In case we have many small objects in the write-cache, `indices` should
not be reused between iterations.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
LRU `Peek`/`Contains` take LRU mutex _inside_ of a `View` transaction.
`View` transaction itself takes `mmapLock` [1], which is lifted after tx
finishes (in `tx.Commit()` -> `tx.close()` -> `tx.db.removeTx`)
When we evict items from LRU cache mutex order is different:
first we take LRU mutex and then execute `Batch` which _does_ take
`mmapLock` in case we need to remap. Thus the deadlock.
[1] 8f4a7e1f92/db.go (L708)
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
It was needed before we started to flush during transition to
`degraded` mode. Now it is confusing.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
All logic errors are wrapped in `logicerr.Logical` type and do not
affect shard error counter.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
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>
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>
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>
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>
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>
