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https://issues.apache.org/jira/browse/FLINK-28539?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17629684#comment-17629684
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Yanfei Lei edited comment on FLINK-28539 at 11/7/22 8:50 AM:
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Since 1) We can enable CompactionDynamicLevelBytes for SSD by configuring
"RocksDBConfigurableOptions.USE_DYNAMIC_LEVEL_SIZE: true" manually.
2)From [rocksdb
wiki|https://github.com/facebook/rocksdb/wiki/Tuning-RocksDB-on-Spinning-Disks]
, it is recommended to set set level_compaction_dynamic_level_bytes for
spinning disk
I am going to close this ticket.
was (Author: yanfei lei):
Since 1) We can enable CompactionDynamicLevelBytes for SSD by configuring
"RocksDBConfigurableOptions.USE_DYNAMIC_LEVEL_SIZE: true" manually.
2)From [RocksDB
wiki|[https://github.com/facebook/rocksdb/wiki/Tuning-RocksDB-on-Spinning-Disks]]
, it is recommended to set set level_compaction_dynamic_level_bytes for
spinning disk
I am going to close this ticket.
> Enable CompactionDynamicLevelBytes in FLASH_SSD_OPTIMIZED
> ---------------------------------------------------------
>
> Key: FLINK-28539
> URL: https://issues.apache.org/jira/browse/FLINK-28539
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / State Backends
> Reporter: Usamah Jassat
> Priority: Minor
>
> Investigating the RocksDB predefined options I see that
> `setLevelCompactionDynamicLevelBytes` is set for SPINNING_DISK options but
> not FLASH_SSD_OPTIMIZED.
>
> From my research it looks like this change would improve the Space
> Amplification of RocksDB [1] (which can also lead to a trade-off from
> read/write amplification [2]). It makes sense to me that this feature should
> be enabled for SSD's as they tend to have less space compared to their HDD
> counterparts.
> There is also an argument to be made to also disable it for SPINNING_DISK
> options as it could give increased read/write performance [2]
> [1] [http://rocksdb.org/blog/2015/07/23/dynamic-level.html]
> [2]
> [https://github.com/EighteenZi/rocksdb_wiki/blob/master/RocksDB-Tuning-Guide.md#amplification-factors]
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