Discuss writecache scenario with no space in the blobstor #117

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opened 2023-03-08 23:34:45 +00:00 by snegurochka · 1 comment

snegurochka commented

2023-03-08 23:34:45 +00:00

Collaborator

Original issue: https://github.com/nspcc-dev/neofs-node/issues/1754

Currently we put the object in the writecache and fail to flush it to the blobstor.
We could check the amount of free space in advance and fail PUT request irregardless of whether we can put an object in the writecache.
cc @realloc

Original issue: https://github.com/nspcc-dev/neofs-node/issues/1754 Currently we put the object in the writecache and fail to flush it to the blobstor. We could check the amount of free space in advance and fail PUT request irregardless of whether we can put an object in the writecache. cc @realloc

fyrchik commented

2023-03-23 08:39:29 +00:00

Owner

Copy of my comments from the linked issue:

Add atomic total size of all not-yet-flushed object in the writecache.
Maintain cache with X sec TTL of free space in blobstor.
Use (2) and (1) to test if an object has high probability of being flushed.

Scenario: put lots of objects until fail, wait some time, remove SSD, all objects must be available.

Copy of my comments from the linked issue: ``` Add atomic total size of all not-yet-flushed object in the writecache. Maintain cache with X sec TTL of free space in blobstor. Use (2) and (1) to test if an object has high probability of being flushed. ``` ``` Scenario: put lots of objects until fail, wait some time, remove SSD, all objects must be available. ```