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d8bbc1d855
Two pool-retention sites kept the runaway-RSS pattern in #6541 visible even after #9420 and #9421: * weed/util/buffer_pool: SyncPoolPutBuffer dropped a buffer back into sync.Pool regardless of how big it had grown. After a 64 MiB chunk upload through volume.PostHandler -> needle.ParseUpload, the pool hoarded a 64 MiB byte array per cached entry for the rest of the process's lifetime. Cap retention at 4 MiB; oversized buffers are dropped so GC can reclaim the backing array. * weed/s3api/...copy.go: uploadChunkData left UploadOption.BytesBuffer unset, so operation.upload_content fell back to the package-global valyala/bytebufferpool. That pool also retains high-water buffers forever, and concurrent UploadPartCopy filled it with one chunk-sized buffer per concurrent upload. Provide a fresh per-call bytes.Buffer pre-sized to chunk + multipart framing; it's GC'd as soon as the upload returns. Tests: - weed/util/buffer_pool/sync_pool_test.go: pin the cap (oversized buffers don't round-trip), the inverse (right-sized buffers do), and nil-safety. - weed/s3api/...copy_chunk_upload_test.go: extract newChunkUploadOption and pin that BytesBuffer is always non-nil and pre-sized, and that each call gets a distinct buffer.
93 lines
3.3 KiB
Go
93 lines
3.3 KiB
Go
package buffer_pool
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import (
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"bytes"
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"testing"
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)
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// TestSyncPoolPutBuffer_DropsOversized is a regression guard for the volume-side
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// retention amplifier in https://github.com/seaweedfs/seaweedfs/issues/6541.
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//
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// volume.PostHandler -> needle.ParseUpload -> bytes.Buffer.ReadFrom grows the
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// buffer to chunk size. If we Put that buffer back as-is, sync.Pool keeps it
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// at the grown capacity for the rest of the process's lifetime. With
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// concurrent UploadPartCopy load that fills the pool with N × chunk-size
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// backing arrays that never shrink — exactly the "RSS never recedes" pattern
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// reported in the issue.
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//
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// We verify a Put + Get round trip can never round-trip a buffer larger than
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// maxRetainedBufferCap, regardless of how big it grew while in use.
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func TestSyncPoolPutBuffer_DropsOversized(t *testing.T) {
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// Drain the pool so we start from a deterministic point. sync.Pool may
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// still hold cached entries on other Ps, but for the small/big-cap
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// distinction below that doesn't matter — we assert an invariant on
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// every Get, not the identity of a specific buffer.
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for i := 0; i < 64; i++ {
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_ = SyncPoolGetBuffer()
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}
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big := &bytes.Buffer{}
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big.Grow(maxRetainedBufferCap * 4) // simulate a large upload buffer
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if got := big.Cap(); got <= maxRetainedBufferCap {
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t.Fatalf("test setup: big.Cap=%d should exceed threshold %d",
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got, maxRetainedBufferCap)
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}
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SyncPoolPutBuffer(big)
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// Any number of Gets must not return a buffer with cap > threshold.
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// (If big had been retained, sync.Pool's per-P cache would surface it
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// on the very next Get on this goroutine.)
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for i := 0; i < 16; i++ {
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got := SyncPoolGetBuffer()
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if cap := got.Cap(); cap > maxRetainedBufferCap {
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t.Fatalf("Get %d returned buffer with cap=%d, exceeds threshold %d "+
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"(regression: oversized buffers retained in pool?)",
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i, cap, maxRetainedBufferCap)
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}
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}
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}
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// TestSyncPoolPutBuffer_KeepsRightSized verifies the cap is one-sided: we
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// still pool reasonably-sized buffers so the common case (small uploads,
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// header parsing) doesn't pay an alloc per request.
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func TestSyncPoolPutBuffer_KeepsRightSized(t *testing.T) {
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for i := 0; i < 64; i++ {
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_ = SyncPoolGetBuffer()
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}
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small := &bytes.Buffer{}
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small.Grow(maxRetainedBufferCap / 2)
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smallCap := small.Cap()
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SyncPoolPutBuffer(small)
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// We don't assert pointer identity (sync.Pool can hand back any cached
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// buffer), but the previously-Put buffer should appear among Gets on
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// the same goroutine in the absence of a GC. If our cap-policy ever
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// regresses to dropping right-sized buffers, this test starts seeing
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// only fresh (cap=0) buffers and fails.
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sawPooled := false
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for i := 0; i < 8; i++ {
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got := SyncPoolGetBuffer()
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if got.Cap() == smallCap {
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sawPooled = true
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break
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}
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}
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if !sawPooled {
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t.Fatalf("right-sized buffer (cap=%d) never came back from the pool "+
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"(regression: cap policy too aggressive?)", smallCap)
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}
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}
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// TestSyncPoolPutBuffer_NilSafe documents that Put tolerates a nil buffer.
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// The volume server defers Put on a buffer obtained via Get, but defensive
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// callers in other paths may Put(nil); we should not panic.
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func TestSyncPoolPutBuffer_NilSafe(t *testing.T) {
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defer func() {
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if r := recover(); r != nil {
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t.Fatalf("SyncPoolPutBuffer(nil) panicked: %v", r)
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}
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}()
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SyncPoolPutBuffer(nil)
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}
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