Optimize complex object assembly #539

dstepanov-yadro · 2023-07-24T11:50:34Z

dstepanov-yadro commented

2023-07-24 11:50:34 +00:00

As is: The node reads objects in memory sequentially, allocating a new buffer for each child object.

Optimization, version 1: Removed the allocation of a new buffer for each child object.

Optimization, version 2: The child object is written direct to the output stream. Side effect: previously, the object was validated first, then the payload was sent; now we send the payload first, then we validate.

See commits for realization details.

Dev-env test results on local PC: 10 readers, 10 minutes, object size 512MB

version/metric	rate, MB/s	Max process_resident_memory, GB	GC count
master branch	204	1.55	3.5K
opt v1	200	1.55 (but avg lower than master)	2.7K
opt v2	225	1.3 (1.1 avg)	2.6K

master

v1

v2

As is: The node reads objects in memory sequentially, allocating a new buffer for each child object. Optimization, version 1: Removed the allocation of a new buffer for each child object. Optimization, version 2: The child object is written direct to the output stream. Side effect: previously, the object was validated first, then the payload was sent; now we send the payload first, then we validate. See commits for realization details. Dev-env test results on local PC: 10 readers, 10 minutes, object size 512MB | version/metric| rate, MB/s | Max process_resident_memory, GB | GC count | | ------------- | ---------- | ---------------------------------| -------- | | master branch | 204 | 1.55 | 3.5K | | opt v1 | 200 | 1.55 (but avg lower than master) | 2.7K | | opt v2 | 225 | 1.3 (1.1 avg) | 2.6K | master ![image](/attachments/33aecd05-427b-45c7-9dc4-2c52b206ebf0) v1 ![image](/attachments/e4586d1c-37aa-43ed-b8df-9d7498b96d05) v2 ![image](/attachments/6763a694-c752-47fb-ad35-aad43f172d06)

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dstepanov-yadro force-pushed fix/assembling_optimizations from 5962672fae to d3128378a1

2023-07-24 11:51:49 +00:00

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dstepanov-yadro requested review from storage-core-committers 2023-07-24 12:03:51 +00:00

dstepanov-yadro requested review from storage-core-developers 2023-07-24 12:03:51 +00:00

fyrchik approved these changes 2023-07-24 13:17:12 +00:00

fyrchik reviewed 2023-07-24 13:17:33 +00:00

pkg/services/object/get/writer.go Outdated

					
				@ -51,9 +51,7 @@ func NewSimpleObjectWriter() *SimpleObjectWriter {

				func (s *SimpleObjectWriter) WriteHeader(_ context.Context, obj *objectSDK.Object) error {

					s.obj = obj

fyrchik commented

2023-07-24 13:17:33 +00:00

argh

dstepanov-yadro force-pushed fix/assembling_optimizations from d3128378a1 to 4e9e0e66fc

2023-07-25 14:29:52 +00:00

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aarifullin reviewed 2023-07-27 09:04:00 +00:00

pkg/services/object/get/assembler.go Outdated

					
				@ -11,3 +11,3 @@

				type objectGetter interface {

					GetObject(ctx context.Context, id oid.ID, rng *objectSDK.Range) (*objectSDK.Object, error)

					GetObjectAndWritePayload(ctx context.Context, id oid.ID, rng *objectSDK.Range, writer ChunkWriter) (*objectSDK.Object, error)

aarifullin commented

2023-07-27 09:04:00 +00:00

I find the idea for the such optimization as excellent, but didn't you consider to return payload from the method instead passing the writer?

type ObjectAndFriends struct {
   object *objectSDK.Object
   pld    []byte
}

for

func (r *request) GetObjectAndWritePayload(ctx context.Context, id oid.ID, rng *objectSDK.Range, writer ChunkWriter) (ObjectAndFriends, error) {
}

I am afraid that with this hack (that works perfectly anyway) we may break SRP (I am really confused when one method gets and sends something in the same place) and dependency inversion (the point to pass an instance that implements the interface gives us the opportunity that we barely can use - we pass NewSimpleObjectWriter but will we ever wrap something else?)

Fix me, if I skipped or didn't get something!

I find the idea for the such optimization as excellent, but didn't you consider to return payload from the method instead passing the writer? ``` type ObjectAndFriends struct { object *objectSDK.Object pld []byte } ``` for ``` func (r *request) GetObjectAndWritePayload(ctx context.Context, id oid.ID, rng *objectSDK.Range, writer ChunkWriter) (ObjectAndFriends, error) { } ``` I am afraid that with this hack (that works perfectly anyway) we may break SRP (I am really confused when one method gets and sends something in the same place) and dependency inversion (the point to pass an instance that implements the interface gives us the opportunity that we barely can use - we pass `NewSimpleObjectWriter` but will we ever wrap something else?) Fix me, if I skipped or didn't get something!

dstepanov-yadro commented

2023-07-27 14:01:09 +00:00

return payload from the method instead passing the writer?

Then we will have to allocate memory for the entire object, and I'm just trying to avoid this.

we pass NewSimpleObjectWriter but will we ever wrap something else

NewSimpleObjectWriter() passes only in one place. See assemblePayloadByObjectIDs: writer writes directly to response stream.

> return payload from the method instead passing the writer? Then we will have to allocate memory for the entire object, and I'm just trying to avoid this. > we pass NewSimpleObjectWriter but will we ever wrap something else `NewSimpleObjectWriter()` passes only in one place. See `assemblePayloadByObjectIDs`: `writer` writes directly to response stream.

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