[bitcoin-dev] Test Results for : Datasstream Compression of Blocks and Tx's

[bitcoin-dev] Test Results for : Datasstream Compression of Blocks and Tx's

[Peter Tschipper]

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Hi All,

Here are some final results of testing with the reference implementation
for compressing blocks and transactions. This implementation also
concatenates blocks and transactions when possible so you'll see data
sizes in the 1-2MB ranges.

Results below show the time it takes to sync the first part of the
blockchain, comparing Zlib to the LZOx library.  (LZOf was also tried
but wasn't found to be as good as LZOx).  The following shows tests run
with and without latency.  With latency on the network, all compression
libraries performed much better than without compression.

I don't think it's entirely obvious which is better, Zlib or LZO. 
Although I prefer the higher compression of Zlib, overall I would have
to give the edge to LZO.  With LZO we have the fastest most scalable
option when at the lowest compression setting which will be a boost in
performance for users that want peformance over compression, and then at
the high end LZO provides decent compression which approaches Zlib,
(although at a higher cost) but good for those that want to save more
bandwidth.

Uncompressed 60ms 	Zlib-1 (60ms) 	Zlib-6 (60ms) 	LZOx-1 (60ms) 	LZOx-999
(60ms)
219 	299 	296 	294 	291
432 	568 	565 	558 	548
652 	835 	836 	819 	811
866 	1106 	1107 	1081 	1071
1082 	1372 	1381 	1341 	1333
1309 	1644 	1654 	1605 	1600
1535 	1917 	1936 	1873 	1875
1762 	2191 	2210 	2141 	2141
1992 	2463 	2486 	2411 	2411
2257 	2748 	2780 	2694 	2697
2627 	3034 	3076 	2970 	2983
3226 	3416 	3397 	3266 	3302
4010 	3983 	3773 	3625 	3703
4914 	4503 	4292 	4127 	4287
5806 	4928 	4719 	4529 	4821
6674 	5249 	5164 	4840 	5314
7563 	5603 	5669 	5289 	6002
8477 	6054 	6268 	5858 	6638
9843 	7085 	7278 	6868 	7679
11338 	8215 	8433 	8044 	8795



These results from testing on a highspeed wireless LAN (very small latency)

Results in seconds 	
	
	
	
	
Num blocks sync'd 	Uncompressed 	Zlib-1 	Zlib-6 	LZOx-1 	LZOx-999
10000 	255 	232 	233 	231 	257
20000 	464 	414 	420 	407 	453
30000 	677 	594 	611 	585 	650
40000 	887 	782 	795 	760 	849
50000 	1099 	961 	977 	933 	1048
60000 	1310 	1145 	1167 	1110 	1259
70000 	1512 	1330 	1362 	1291 	1470
80000 	1714 	1519 	1552 	1469 	1679
90000 	1917 	1707 	1747 	1650 	1882
100000 	2122 	1905 	1950 	1843 	2111
110000 	2333 	2107 	2151 	2038 	2329
120000 	2560 	2333 	2376 	2256 	2580
130000 	2835 	2656 	2679 	2558 	2921
140000 	3274 	3259 	3161 	3051 	3466
150000 	3662 	3793 	3547 	3440 	3919
160000 	4040 	4172 	3937 	3767 	4416
170000 	4425 	4625 	4379 	4215 	4958
180000 	4860 	5149 	4895 	4781 	5560
190000 	5855 	6160 	5898 	5805 	6557
200000 	7004 	7234 	7051 	6983 	7770



The following show the compression ratio acheived for various sizes of
data.  Zlib is the clear
winner for compressibility, with LZOx-999 coming close but at a cost.

range 	Zlib-1 cmp%
	Zlib-6 cmp% 	LZOx-1 cmp% 	LZOx-999 cmp%
0-250b 	12.44 	12.86 	10.79 	14.34
250-500b  	19.33 	12.97 	10.34 	11.11
600-700 	16.72 	n/a 	12.91 	17.25
700-800 	6.37 	7.65 	4.83 	8.07
900-1KB 	6.54 	6.95 	5.64 	7.9
1KB-10KB 	25.08 	25.65 	21.21 	22.65
10KB-100KB 	19.77 	21.57 	14.37 	19.02
100KB-200KB 	21.49 	23.56 	15.37 	21.55
200KB-300KB 	23.66 	24.18 	16.91 	22.76
300KB-400KB 	23.4 	23.7 	16.5 	21.38
400KB-500KB 	24.6 	24.85 	17.56 	22.43
500KB-600KB 	25.51 	26.55 	18.51 	23.4
600KB-700KB 	27.25 	28.41 	19.91 	25.46
700KB-800KB 	27.58 	29.18 	20.26 	27.17
800KB-900KB 	27 	29.11 	20 	27.4
900KB-1MB 	28.19 	29.38 	21.15 	26.43
1MB -2MB 	27.41 	29.46 	21.33 	27.73


The following shows the time in seconds to compress data of various
sizes.  LZO1x is the
fastest and as file sizes increase, LZO1x time hardly increases at all. 
It's interesing
to note as compression ratios increase LZOx-999 performs much worse than
Zlib.  So LZO is faster
on the low end and slower (5 to 6 times slower) on the high end.

range 	Zlib-1 	Zlib-6 	LZOx-1 	LZOx-999 cmp%
0-250b    	0.001 	0 	0 	0
250-500b   	0 	0 	0 	0.001
500-1KB     	0 	0 	0 	0.001
1KB-10KB    	0.001 	0.001 	0 	0.002
10KB-100KB   	0.004 	0.006 	0.001 	0.017
100KB-200KB  	0.012 	0.017 	0.002 	0.054
200KB-300KB  	0.018 	0.024 	0.003 	0.087
300KB-400KB  	0.022 	0.03 	0.003 	0.121
400KB-500KB  	0.027 	0.037 	0.004 	0.151
500KB-600KB  	0.031 	0.044 	0.004 	0.184
600KB-700KB  	0.035 	0.051 	0.006 	0.211
700KB-800KB  	0.039 	0.057 	0.006 	0.243
800KB-900KB  	0.045 	0.064 	0.006 	0.27
900KB-1MB   	0.049 	0.072 	0.006 	0.307



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Re: [bitcoin-dev] Test Results for : Datasstream Compression of Blocks and Tx's

[Jeff Garzik]

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Thanks for providing an in-depth, data driven analysis.

It is surprising that zlib provides better compression at the high end.  I
wonder if that is due to our specific data patterns - many zeroes - which
probably puts us into the zlib dictionary fast path.



On Sat, Nov 28, 2015 at 4:41 PM, Peter Tschipper via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Hi All,
>
> Here are some final results of testing with the reference implementation
> for compressing blocks and transactions. This implementation also
> concatenates blocks and transactions when possible so you'll see data sizes
> in the 1-2MB ranges.
>
> Results below show the time it takes to sync the first part of the
> blockchain, comparing Zlib to the LZOx library.  (LZOf was also tried but
> wasn't found to be as good as LZOx).  The following shows tests run with
> and without latency.  With latency on the network, all compression
> libraries performed much better than without compression.
>
> I don't think it's entirely obvious which is better, Zlib or LZO.
> Although I prefer the higher compression of Zlib, overall I would have to
> give the edge to LZO.  With LZO we have the fastest most scalable option
> when at the lowest compression setting which will be a boost in performance
> for users that want peformance over compression, and then at the high end
> LZO provides decent compression which approaches Zlib, (although at a
> higher cost) but good for those that want to save more bandwidth.
>
> Uncompressed 60ms Zlib-1 (60ms) Zlib-6 (60ms) LZOx-1 (60ms) LZOx-999
> (60ms) 219 299 296 294 291 432 568 565 558 548 652 835 836 819 811 866
> 1106 1107 1081 1071 1082 1372 1381 1341 1333 1309 1644 1654 1605 1600 1535
> 1917 1936 1873 1875 1762 2191 2210 2141 2141 1992 2463 2486 2411 2411 2257
> 2748 2780 2694 2697 2627 3034 3076 2970 2983 3226 3416 3397 3266 3302 4010
> 3983 3773 3625 3703 4914 4503 4292 4127 4287 5806 4928 4719 4529 4821 6674
> 5249 5164 4840 5314 7563 5603 5669 5289 6002 8477 6054 6268 5858 6638 9843
> 7085 7278 6868 7679 11338 8215 8433 8044 8795
>
> These results from testing on a highspeed wireless LAN (very small latency)
>
> Results in seconds
>
>
>
>
> Num blocks sync'd Uncompressed Zlib-1 Zlib-6 LZOx-1 LZOx-999 10000 255 232
> 233 231 257 20000 464 414 420 407 453 30000 677 594 611 585 650 40000 887
> 782 795 760 849 50000 1099 961 977 933 1048 60000 1310 1145 1167 1110 1259
> 70000 1512 1330 1362 1291 1470 80000 1714 1519 1552 1469 1679 90000 1917
> 1707 1747 1650 1882 100000 2122 1905 1950 1843 2111 110000 2333 2107 2151
> 2038 2329 120000 2560 2333 2376 2256 2580 130000 2835 2656 2679 2558 2921
> 140000 3274 3259 3161 3051 3466 150000 3662 3793 3547 3440 3919 160000
> 4040 4172 3937 3767 4416 170000 4425 4625 4379 4215 4958 180000 4860 5149
> 4895 4781 5560 190000 5855 6160 5898 5805 6557 200000 7004 7234 7051 6983
> 7770
>
> The following show the compression ratio acheived for various sizes of
> data.  Zlib is the clear
> winner for compressibility, with LZOx-999 coming close but at a cost.
>
> range Zlib-1 cmp%
> Zlib-6 cmp% LZOx-1 cmp% LZOx-999 cmp% 0-250b 12.44 12.86 10.79 14.34
> 250-500b  19.33 12.97 10.34 11.11 600-700 16.72 n/a 12.91 17.25 700-800
> 6.37 7.65 4.83 8.07 900-1KB 6.54 6.95 5.64 7.9 1KB-10KB 25.08 25.65 21.21
> 22.65 10KB-100KB 19.77 21.57 14.37 19.02 100KB-200KB 21.49 23.56 15.37
> 21.55 200KB-300KB 23.66 24.18 16.91 22.76 300KB-400KB 23.4 23.7 16.5 21.38
> 400KB-500KB 24.6 24.85 17.56 22.43 500KB-600KB 25.51 26.55 18.51 23.4
> 600KB-700KB 27.25 28.41 19.91 25.46 700KB-800KB 27.58 29.18 20.26 27.17
> 800KB-900KB 27 29.11 20 27.4 900KB-1MB 28.19 29.38 21.15 26.43 1MB -2MB
> 27.41 29.46 21.33 27.73
> The following shows the time in seconds to compress data of various
> sizes.  LZO1x is the
> fastest and as file sizes increase, LZO1x time hardly increases at all.
> It's interesing
> to note as compression ratios increase LZOx-999 performs much worse than
> Zlib.  So LZO is faster
> on the low end and slower (5 to 6 times slower) on the high end.
>
> range Zlib-1 Zlib-6 LZOx-1 LZOx-999 cmp% 0-250b    0.001 0 0 0 250-500b
> 0 0 0 0.001 500-1KB     0 0 0 0.001 1KB-10KB    0.001 0.001 0 0.002
> 10KB-100KB   0.004 0.006 0.001 0.017 100KB-200KB  0.012 0.017 0.002 0.054
> 200KB-300KB  0.018 0.024 0.003 0.087 300KB-400KB  0.022 0.03 0.003 0.121
> 400KB-500KB  0.027 0.037 0.004 0.151 500KB-600KB  0.031 0.044 0.004 0.184
> 600KB-700KB  0.035 0.051 0.006 0.211 700KB-800KB  0.039 0.057 0.006 0.243
> 800KB-900KB  0.045 0.064 0.006 0.27 900KB-1MB   0.049 0.072 0.006 0.307
>
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>

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