- From: RUELLAN Herve <Herve.Ruellan@crf.canon.fr>
- Date: Fri, 22 Mar 2013 13:01:46 +0000
- To: Mark Nottingham <mnot@mnot.net>, "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>
The results for HeaderDiff were not at all those I excepted. I traced the difference to the number of compressor instances used to compress the sample files. The framework uses only one instance for all the files, while internally I used one instance for each file. I noticed that the delta2 compressor seems to use one compression context for each host. I think this is the correct behavior to obtain realistic results. I will therefore update the HeaderDiff codec to create one compression context per host. Hervé. > -----Original Message----- > From: Mark Nottingham [mailto:mnot@mnot.net] > Sent: vendredi 22 mars 2013 07:32 > To: ietf-http-wg@w3.org Group > Subject: Re: Choosing a header compression algorithm > > > On 21/03/2013, at 6:11 PM, Mark Nottingham <mnot@mnot.net> wrote: > > > 1) We need to do apples-to-apples comparison of these compressors to > see how they behave under a range of constraints (especially, memory). > > To this point, a few runs across the header corpus that I collected > (http_samples/mnot/*.har), using the current implementations (again, we > need to verify these are honouring these limits correctly, and I believe > headerdiff is going to be updated): > > 16384 Byte Buffer > ---------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.22 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=16384) 630,668 15.89 | 0.18 0.03 0.76 0.11 > headerdiff (buffer=16384) 1,699,918 9.65 | 0.49 0.03 0.90 0.21 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.26 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=16384) 575,345 24.39 | 0.26 0.02 1.06 0.12 > headerdiff (buffer=16384) 877,106 24.76 | 0.40 0.04 0.93 0.14 > > [ Note that the efficiency actually goes *down* on headerdiff for requests > when the buffer is larger here; Herve, any idea what's happening there? ] > > 8192 Byte Buffer > ---------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.24 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=8192) 646,431 15.78 | 0.19 0.03 0.76 0.12 > headerdiff (buffer=8192) 1,378,622 6.95 | 0.40 0.03 0.92 0.20 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.43 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=8192) 592,260 20.28 | 0.27 0.02 1.06 0.12 > headerdiff (buffer=8192) 914,362 15.55 | 0.42 0.05 0.93 0.14 > > > 4096 Byte Buffer > ---------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.18 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=4096) 665,642 13.35 | 0.19 0.03 0.77 0.12 > headerdiff (buffer=4096) 1,406,429 3.92 | 0.41 0.03 0.88 0.18 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.21 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=4096) 610,764 15.48 | 0.28 0.02 1.06 0.13 > headerdiff (buffer=4096) 1,009,185 7.58 | 0.46 0.05 0.93 0.13 > > 2048 Byte Buffer > ---------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.18 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=2048) 692,579 11.66 | 0.20 0.03 0.77 0.12 > headerdiff (buffer=2048) 1,632,783 2.94 | 0.47 0.03 0.90 0.19 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.20 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=2048) 633,785 12.47 | 0.29 0.02 1.22 0.13 > headerdiff (buffer=2048) 1,088,829 4.75 | 0.50 0.05 0.93 0.13 > > 1024 Byte Buffer > ---------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.22 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=1024) 752,380 11.92 | 0.22 0.03 0.84 0.13 > headerdiff (buffer=1024) 1,700,325 1.82 | 0.49 0.03 0.91 0.19 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.23 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=1024) 671,975 11.42 | 0.31 0.02 1.22 0.13 > headerdiff (buffer=1024) 1,118,599 3.53 | 0.51 0.05 0.93 0.13 > > 512 Byte Buffer > --------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.17 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=512) 1,058,090 14.23 | 0.31 0.04 0.83 0.15 > headerdiff (buffer=512) 2,120,833 1.43 | 0.61 0.03 0.93 0.16 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.14 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=512) 721,525 12.22 | 0.33 0.03 1.22 0.13 > headerdiff (buffer=512) 1,199,608 2.09 | 0.55 0.05 0.93 0.12 > > 256 Byte Buffer > --------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.18 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=256) 1,517,520 18.62 | 0.44 0.04 0.84 0.19 > headerdiff (buffer=256) 2,444,376 1.32 | 0.71 0.08 0.95 0.13 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.23 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=256) 856,632 13.21 | 0.39 0.04 1.22 0.14 > headerdiff (buffer=256) 1,201,814 1.65 | 0.55 0.05 0.93 0.12 > > 32 Byte Buffer > ------------------- > > * TOTAL: 5948 req messages > size time | ratio min max std > http1 3,460,925 0.20 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=32) 2,357,457 28.18 | 0.68 0.51 0.84 0.05 > headerdiff (buffer=32) 2,791,039 1.16 | 0.81 0.58 0.96 0.08 > > * TOTAL: 5948 res messages > size time | ratio min max std > http1 2,186,162 0.21 | 1.00 1.00 1.00 0.00 > delta2 (max_byte_size=32) 1,197,019 17.92 | 0.55 0.16 0.89 0.07 > headerdiff (buffer=32) 1,434,721 1.32 | 0.66 0.19 0.95 0.07 > > [ smaller buffer sizes caused errors in delta2 (at least) ] > > -- > Mark Nottingham http://www.mnot.net/ > > >
Received on Friday, 22 March 2013 13:02:45 UTC