Commit graph

8 commits

Author SHA1 Message Date
Evgenii Stratonikov
ad01aaf8bf [] 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
ZhangTao1596
ac82899e85 [] 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 [] 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
1462824ab8 [] 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  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
Leonard Lyubich
a1696a81b6 [] 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 [] 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
ZhangTao1596
9b87e6267d [] 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 [] blobstor: implement write-cache
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2021-04-29 17:36:36 +03:00