fix: eliminate cloud storage write amplification and rate limiting

brain.add() was generating 26-40 immediate cloud writes per call, causing
HTTP 429 rate limit errors and high latency on GCS/S3/R2/Azure. Three-layer
fix: (1) deferred metadata writes with dirty-marking, (2) MetadataWriteBuffer
for write coalescing, (3) retry/backoff on all cloud storage adapters.
This commit is contained in:
David Snelling 2026-01-31 09:09:36 -08:00
parent 23e1c56ae0
commit 92d9420a5c
10 changed files with 674 additions and 75 deletions

View file

@ -129,6 +129,12 @@ export class MetadataIndexManager {
private chunkManager: ChunkManager
private chunkingStrategy: AdaptiveChunkingStrategy
// Deferred write tracking: accumulate chunk/sparse index writes during add/remove
// operations and flush them in a single concurrent batch at the end.
// This eliminates per-field sequential writes that cause cloud storage rate limiting.
private dirtyChunks = new Map<string, ChunkData>() // "field:chunkId" -> ChunkData
private dirtySparseIndices = new Map<string, SparseIndex>() // field -> SparseIndex
// Roaring Bitmap Support
// EntityIdMapper for UUID ↔ integer conversion
private idMapper: EntityIdMapper
@ -651,6 +657,118 @@ export class MetadataIndexManager {
this.unifiedCache.set(unifiedKey, sparseIndex, 'metadata', size, 200)
}
/**
* Flush all deferred chunk and sparse index writes accumulated during add/remove operations.
* Writes are deduplicated (same chunk/field written once even if updated multiple times)
* and executed concurrently via Promise.all for maximum throughput.
*/
private async flushDirtyMetadata(): Promise<void> {
if (this.dirtyChunks.size === 0 && this.dirtySparseIndices.size === 0) {
return
}
const promises: Promise<void>[] = []
// Save all dirty chunks (deduplicated — same chunk written once even if updated multiple times)
for (const [_key, chunk] of this.dirtyChunks) {
promises.push(this.chunkManager.saveChunk(chunk))
}
// Save all dirty sparse indices (deduplicated — same field's index written once)
for (const [field, sparseIndex] of this.dirtySparseIndices) {
promises.push(this.saveSparseIndex(field, sparseIndex))
}
// Execute all writes concurrently
await Promise.all(promises)
this.dirtyChunks.clear()
this.dirtySparseIndices.clear()
}
/**
* Split a chunk without saving immediately returns the new chunks for deferred save.
* Used by addToChunkedIndex() to keep splits within the deferred write batch.
*/
private async splitChunkDeferred(
chunk: ChunkData,
sparseIndex: SparseIndex
): Promise<{ chunk1: ChunkData; chunk2: ChunkData }> {
const values = Array.from(chunk.entries.keys()).sort()
const midpoint = Math.floor(values.length / 2)
// Create two new chunks with roaring bitmaps
const entries1 = new Map<string, RoaringBitmap32>()
const entries2 = new Map<string, RoaringBitmap32>()
for (let i = 0; i < values.length; i++) {
const value = values[i]
const bitmap = chunk.entries.get(value)!
if (i < midpoint) {
entries1.set(value, new RoaringBitmap32(bitmap.toArray()))
} else {
entries2.set(value, new RoaringBitmap32(bitmap.toArray()))
}
}
// Create chunk objects without saving (just allocate IDs and set up data)
const chunkId1 = this.chunkManager['getNextChunkId'](chunk.field)
const chunk1: ChunkData = {
chunkId: chunkId1,
field: chunk.field,
entries: entries1,
lastUpdated: Date.now()
}
const chunkId2 = this.chunkManager['getNextChunkId'](chunk.field)
const chunk2: ChunkData = {
chunkId: chunkId2,
field: chunk.field,
entries: entries2,
lastUpdated: Date.now()
}
// Update chunk cache (for read-after-write consistency within this operation)
this.chunkManager['chunkCache'].set(`${chunk.field}:${chunkId1}`, chunk1)
this.chunkManager['chunkCache'].set(`${chunk.field}:${chunkId2}`, chunk2)
// Update sparse index
sparseIndex.removeChunk(chunk.chunkId)
const descriptor1: ChunkDescriptor = {
chunkId: chunk1.chunkId,
field: chunk1.field,
valueCount: entries1.size,
idCount: Array.from(entries1.values()).reduce((sum, bitmap) => sum + bitmap.size, 0),
zoneMap: this.chunkManager.calculateZoneMap(chunk1),
lastUpdated: Date.now(),
splitThreshold: 80,
mergeThreshold: 20
}
const descriptor2: ChunkDescriptor = {
chunkId: chunk2.chunkId,
field: chunk2.field,
valueCount: entries2.size,
idCount: Array.from(entries2.values()).reduce((sum, bitmap) => sum + bitmap.size, 0),
zoneMap: this.chunkManager.calculateZoneMap(chunk2),
lastUpdated: Date.now(),
splitThreshold: 80,
mergeThreshold: 20
}
sparseIndex.registerChunk(descriptor1, this.chunkManager.createBloomFilter(chunk1))
sparseIndex.registerChunk(descriptor2, this.chunkManager.createBloomFilter(chunk2))
// Delete old chunk from storage (this still writes immediately as it's a deletion)
await this.chunkManager.deleteChunk(chunk.field, chunk.chunkId)
prodLog.debug(`Split chunk ${chunk.field}:${chunk.chunkId} into ${chunk1.chunkId} and ${chunk2.chunkId} (deferred save)`)
return { chunk1, chunk2 }
}
/**
* Get IDs for a value using chunked sparse index with roaring bitmaps
* Now fully lazy-loaded via UnifiedCache (no local sparseIndices Map)
@ -934,7 +1052,8 @@ export class MetadataIndexManager {
// Add to chunk
await this.chunkManager.addToChunk(targetChunk, normalizedValue, id)
await this.chunkManager.saveChunk(targetChunk)
// Defer chunk save — mark dirty instead of writing immediately
this.dirtyChunks.set(`${targetChunk.field}:${targetChunk.chunkId}`, targetChunk)
// Update chunk descriptor in sparse index
const updatedZoneMap = this.chunkManager.calculateZoneMap(targetChunk)
@ -955,11 +1074,15 @@ export class MetadataIndexManager {
// Check if chunk needs splitting
if (targetChunk.entries.size > 80) {
await this.chunkManager.splitChunk(targetChunk, sparseIndex)
const { chunk1, chunk2 } = await this.splitChunkDeferred(targetChunk, sparseIndex)
// Mark split result chunks as dirty instead of the original
this.dirtyChunks.delete(`${targetChunk.field}:${targetChunk.chunkId}`)
this.dirtyChunks.set(`${chunk1.field}:${chunk1.chunkId}`, chunk1)
this.dirtyChunks.set(`${chunk2.field}:${chunk2.chunkId}`, chunk2)
}
// Save sparse index
await this.saveSparseIndex(field, sparseIndex)
// Defer sparse index save — mark dirty instead of writing immediately
this.dirtySparseIndices.set(field, sparseIndex)
}
/**
@ -980,7 +1103,8 @@ export class MetadataIndexManager {
const chunk = await this.chunkManager.loadChunk(field, chunkId)
if (chunk && chunk.entries.has(normalizedValue)) {
await this.chunkManager.removeFromChunk(chunk, normalizedValue, id)
await this.chunkManager.saveChunk(chunk)
// Defer chunk save — mark dirty instead of writing immediately
this.dirtyChunks.set(`${chunk.field}:${chunk.chunkId}`, chunk)
// Update sparse index
const updatedZoneMap = this.chunkManager.calculateZoneMap(chunk)
@ -991,7 +1115,8 @@ export class MetadataIndexManager {
lastUpdated: Date.now()
})
await this.saveSparseIndex(field, sparseIndex)
// Defer sparse index save — mark dirty instead of writing immediately
this.dirtySparseIndices.set(field, sparseIndex)
break
}
}
@ -1431,7 +1556,11 @@ export class MetadataIndexManager {
await this.yieldToEventLoop()
}
}
// Flush all dirty chunks and sparse indices accumulated during this add operation
// This batches writes that were previously sequential per-field into a single concurrent flush
await this.flushDirtyMetadata()
// Adaptive auto-flush based on usage patterns
if (!skipFlush) {
const timeSinceLastFlush = Date.now() - this.lastFlushTime
@ -1518,6 +1647,9 @@ export class MetadataIndexManager {
// Invalidate cache
this.metadataCache.invalidatePattern(`field_values_${field}`)
}
// Flush all dirty chunks and sparse indices accumulated during remove
await this.flushDirtyMetadata()
} else {
// Remove from all indexes (slower, requires scanning all field indexes)
// This should be rare - prefer providing metadata when removing
@ -1545,6 +1677,9 @@ export class MetadataIndexManager {
}
}
}
// Flush all dirty chunks and sparse indices accumulated during scan-remove
await this.flushDirtyMetadata()
}
}
@ -2233,6 +2368,9 @@ export class MetadataIndexManager {
* NOTE: Sparse indices are flushed immediately in add/remove operations
*/
async flush(): Promise<void> {
// Flush any deferred chunk/sparse writes first
await this.flushDirtyMetadata()
// Check if we have anything to flush
if (this.dirtyFields.size === 0) {
return // Nothing to flush