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perf(storage): tune RocksDB options #380

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Merged
MegaRedHand merged 1 commit into from
May 18, 2026
Merged

perf(storage): tune RocksDB options #380

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25 changes: 23 additions & 2 deletions crates/storage/src/backend/rocksdb.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,8 @@ use crate::api::{
ALL_TABLES, Error, PrefixResult, StorageBackend, StorageReadView, StorageWriteBatch, Table,
};
use rocksdb::{
ColumnFamilyDescriptor, DBWithThreadMode, MultiThreaded, Options, WriteBatch, WriteOptions,
BlockBasedOptions, Cache, ColumnFamilyDescriptor, DBWithThreadMode, MultiThreaded, Options,
WriteBatch, WriteOptions,
};
use std::path::Path;
use std::sync::Arc;
Expand Down Expand Up @@ -34,9 +35,29 @@ impl RocksDBBackend {
opts.create_if_missing(true);
opts.create_missing_column_families(true);

opts.set_max_open_files(-1);
opts.set_max_file_opening_threads(8);
Comment on lines +38 to +39
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@greptile-apps greptile-apps Bot May 18, 2026

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P2 set_max_file_opening_threads has no effect when max_open_files is -1. With unlimited open files, RocksDB keeps every SST file descriptor open indefinitely and never invokes the thread-pool-limited re-open path. The call is harmless but misleading; removing it reduces noise.

Suggested change
opts.set_max_open_files(-1);
opts.set_max_file_opening_threads(8);
opts.set_max_open_files(-1);
Prompt To Fix With AI 
This is a comment left during a code review.
Path: crates/storage/src/backend/rocksdb.rs
Line: 38-39

Comment:
`set_max_file_opening_threads` has no effect when `max_open_files` is `-1`. With unlimited open files, RocksDB keeps every SST file descriptor open indefinitely and never invokes the thread-pool-limited re-open path. The call is harmless but misleading; removing it reduces noise.

```suggestion
        opts.set_max_open_files(-1);
```

How can I resolve this? If you propose a fix, please make it concise.

opts.set_max_background_jobs(8);
opts.set_max_subcompactions(2);
opts.set_compaction_readahead_size(4 * 1024 * 1024);
opts.set_level_compaction_dynamic_level_bytes(true);
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P2 set_level_compaction_dynamic_level_bytes applied to the wrong options object — the named column families won't use it. open_cf_descriptors treats the first opts argument as DB-level settings; each CF is configured solely by its own ColumnFamilyDescriptor options (cf_opts = Options::default() in the closure). Setting this flag on opts only influences the default column family (which this code never opens). To activate the optimization on all CFs, move the call into the closure where cf_opts is configured.

Prompt To Fix With AI 
This is a comment left during a code review.
Path: crates/storage/src/backend/rocksdb.rs
Line: 43

Comment:
`set_level_compaction_dynamic_level_bytes` applied to the wrong options object — the named column families won't use it. `open_cf_descriptors` treats the first `opts` argument as DB-level settings; each CF is configured solely by its own `ColumnFamilyDescriptor` options (`cf_opts = Options::default()` in the closure). Setting this flag on `opts` only influences the default column family (which this code never opens). To activate the optimization on all CFs, move the call into the closure where `cf_opts` is configured.

How can I resolve this? If you propose a fix, please make it concise.

opts.set_bytes_per_sync(32 * 1024 * 1024);
opts.set_wal_bytes_per_sync(32 * 1024 * 1024);
opts.set_max_total_wal_size(256 * 1024 * 1024);
opts.set_use_fsync(false);
opts.set_enable_pipelined_write(true);

let block_cache = Cache::new_lru_cache(128 * 1024 * 1024);
let mut block_opts = BlockBasedOptions::default();
block_opts.set_block_cache(&block_cache);

let cf_descriptors: Vec<_> = ALL_TABLES
.iter()
.map(|t| ColumnFamilyDescriptor::new(cf_name(*t), Options::default()))
.map(|t| {
let mut cf_opts = Options::default();
cf_opts.set_block_based_table_factory(&block_opts);
ColumnFamilyDescriptor::new(cf_name(*t), cf_opts)
})
.collect();

let db =
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