STRLCPY/graphql-engine

server: don't compress small responses

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7216
GitOrigin-RevId: 0344da3c692c9dbb39329663be78734c2052d309

Brandon Simmons committed with hasura-bot 2 months ago

d966e0a9

1 parent bb46cba5

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server/src-lib/Hasura/Server/Compression.hs

		skipped 49 lines
50	50		(BL.ByteString, EncodingType)
51	51		compressResponse reqHeaders unCompressedResp
52	52		-- we have option to gzip:
53		-	\| acceptedEncodings == Set.fromList [identityEncoding, Just CTGZip]
54		-	\|\|
55		-	-- we must gzip:
56		-	acceptedEncodings == Set.fromList [Just CTGZip] =
	53	+	\| acceptedEncodings == Set.fromList [identityEncoding, Just CTGZip] =
	54	+	if shouldSkipCompression unCompressedResp
	55	+	then notCompressed
	56	+	else (compressFast CTGZip unCompressedResp, Just CTGZip)
	57	+	-- we MUST gzip:
	58	+	\| acceptedEncodings == Set.fromList [Just CTGZip] =
57	59		(compressFast CTGZip unCompressedResp, Just CTGZip)
58		-	-- we must only return an uncompressed response:
	60	+	-- we must ONLY return an uncompressed response:
59	61		\| acceptedEncodings == Set.fromList [identityEncoding] =
60		-	(unCompressedResp, identityEncoding)
	62	+	notCompressed
61	63		-- this is technically a client error, but ignore for now (maintaining
62	64		-- current behavior); assume identity:
63	65		\| otherwise =
64		-	(unCompressedResp, identityEncoding)
	66	+	notCompressed
65	67		where
66	68		acceptedEncodings = getAcceptedEncodings reqHeaders
	69	+	notCompressed = (unCompressedResp, identityEncoding)
67	70
68		-	-- \| Compress using
	71	+	-- \| Compress the bytestring preferring speed over compression ratio
69	72		compressFast :: CompressionType -> BL.ByteString -> BL.ByteString
70	73		compressFast = \case
71	74		CTGZip -> GZ.compressWith gzipCompressionParams
		skipped 1 lines
73	76		gzipCompressionParams =
74	77		-- See Note [Compression ratios]
75	78		GZ.defaultCompressParams {GZ.compressLevel = GZ.compressionLevel 1}
	79	+
	80	+	-- \| Assuming we have the option to compress or not (i.e. client accepts
	81	+	-- identity AND gzip), should we skip compression?
	82	+	shouldSkipCompression :: BL.ByteString -> Bool
	83	+	shouldSkipCompression bs = BL.length bs < 700
	84	+
	85	+	{- NOTE [Compression Heuristics]
	86	+	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	87	+	Compression is a significant source of CPU usage (and latency for small
	88	+	requests); let's be smarter about compression when we have the option.
	89	+
	90	+	Some data from cloud (omitting healthz and version), with zlib gzip at
	91	+	compression level 1:
	92	+
	93	+	~96% of requests can accept gzip responses
	94	+
	95	+	P50(uncompressed_response_size) : 150 bytes
	96	+	P75(uncompressed_response_size) : 1200 bytes
	97	+	P95(uncompressed_response_size) : 39000 bytes
	98	+	P99(uncompressed_response_size) : 95000 bytes
	99	+
	100	+	Responses smaller than 700 bytes (the common case)...
	101	+	...account for 4% of total response egress (currently)
	102	+	...account for 68% of responses
	103	+
	104	+	...have a P50 compression ratio of: 1.0 (i.e. no benefit)
	105	+	... a P75 compression ratio of: 1.3
	106	+	... a P99 compression ratio of: 2.0
	107	+
	108	+	...and FYI if we take a cutoff of...
	109	+	...2000 we get P50 ratio 0.9
	110	+	...5000 we get P50 ratio 0.8
	111	+	-}
76	112
77	113		-- \| Which encodings can the client accept? The empty set returned here is an
78	114		-- error condition and the server tecnically ought to return a 406.
		skipped 87 lines

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server/src-test/Hasura/Server/CompressionSpec.hs

1	1		module Hasura.Server.CompressionSpec (spec) where
2	2
	3	+	import Codec.Compression.GZip qualified as GZ
	4	+	import Data.ByteString.Lazy qualified as BL
3	5		import Data.Set qualified as Set
4	6		import Hasura.Prelude
5	7		import Hasura.Server.Compression
		skipped 42 lines
48	50		getAcceptedEncodings [("accept-encoding", "")]
49	51		`shouldBe` Set.fromList [identityEncoding]
50	52
	53	+	describe "compressResponse" do
	54	+	let smallVal = "xxxx"
	55	+	largeVal = BL.pack $ replicate 1000 121
	56	+
	57	+	it "compresses when required" do
	58	+	let (valOut0, encodingChosen0) = compressResponse [("accept-encoding", "gzip, identity;q=0")] smallVal
	59	+	GZ.decompress valOut0 `shouldBe` smallVal
	60	+	encodingChosen0 `shouldBe` Just CTGZip
	61	+
	62	+	let (valOut1, encodingChosen1) = compressResponse [("accept-encoding", "gzip, identity;q=0")] largeVal
	63	+	GZ.decompress valOut1 `shouldBe` largeVal
	64	+	encodingChosen1 `shouldBe` Just CTGZip
	65	+
	66	+	it "omits compression for small values" do
	67	+	let (valOut0, encodingChosen0) = compressResponse [("accept-encoding", "gzip")] smallVal
	68	+	valOut0 `shouldBe` smallVal
	69	+	encodingChosen0 `shouldBe` Nothing
	70	+
	71	+	let (valOut1, encodingChosen1) = compressResponse [("accept-encoding", "gzip")] largeVal
	72	+	GZ.decompress valOut1 `shouldBe` largeVal
	73	+	encodingChosen1 `shouldBe` Just CTGZip
	74	+

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server/tests-py/queries/compression/graphql_query.yaml

		skipped 15 lines
16	16		name: Brotli
17	17		- id: 3
18	18		name: Nothing
	19	+	- id: 4
	20	+	name: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
19	21

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server/tests-py/queries/compression/setup.yaml

1	1		type: bulk
2	2		args:
3	3
	4	+	# Arbitrary. Pad with the 'xxxx...' value to keep it above the size threshold
	5	+	# for compression
4	6		- type: run_sql
5	7		args:
6	8		sql: \|
7	9		CREATE TABLE test (id serial primary key, name text);
8		-	INSERT INTO test (name) values ('Gzip'), ('Brotli'), ('Nothing');
	10	+	INSERT INTO test (name) values ('Gzip'), ('Brotli'), ('Nothing'),
	11	+	('xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx');
9	12
10	13		- type: track_table
11	14		args:
		skipped 3 lines

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server/tests-py/queries/compression/v1_query.yaml

		skipped 12 lines
13	13		name: Brotli
14	14		- id: 3
15	15		name: Nothing
	16	+	- id: 4
	17	+	name: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
	18	+
16	19

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server/tests-py/test_compression.py

		skipped 7 lines
8	8
9	9		usefixtures = pytest.mark.usefixtures
10	10
	11	+	# A very basic test that compression seems to be working
11	12		@usefixtures('per_class_tests_db_state')
12	13		class TestCompression:
13	14
		skipped 51 lines