Re: [Gluster-devel] Why vandermonde matrix is used in EC?

2016-11-27 Thread Xavier Hernandez
On 11/27/2016 09:58 PM, 한우형 wrote: Hi, Thank you so much for the speedy reply, but I have some more questions. 1) I understand Non-systematic encoding/decoding doesn't alter performance when one or more bricks are down. but why systematic approach has service degradation? I think when parity pa

Re: [Gluster-devel] Why vandermonde matrix is used in EC?

2016-11-27 Thread 한우형
Hi, Thank you so much for the speedy reply, but I have some more questions. 1) I understand Non-systematic encoding/decoding doesn't alter performance when one or more bricks are down. but why systematic approach has service degradation? I think when parity part is down there's no performance deg

Re: [Gluster-devel] Why vandermonde matrix is used in EC?

2016-11-24 Thread Xavier Hernandez
Hi Han, On 11/24/2016 04:25 AM, 한우형 wrote: Hi, I'm working on dispersed volume(ec) and I found ec encode/decode algorithm is using non-systematic vandermonde matrix. My question is this: why non-systematic algorithm is used? Non-systematic encoding/decoding doesn't alter performance when one

[Gluster-devel] Why vandermonde matrix is used in EC?

2016-11-23 Thread 한우형
Hi, I'm working on dispersed volume(ec) and I found ec encode/decode algorithm is using non-systematic vandermonde matrix. My question is this: why non-systematic algorithm is used? If we use systematic algorithm(not systematic vandermonde, It's not MDS) we can boost read performance. (no need to