Page Comparison

Note: This page is WIP.

Data gathered

https://docs.google.com/spreadsheets/d/1W2UgFUmEbegR7VMsnUi3rrQDAeBYyenILFHH_0YpRdQ/edit?usp=sharing

https://docs.google.com/spreadsheets/d/1Ks75ExHoLx6cxam9DRbztREzG-FpQ6f7RkS6otcYjpI/edit?usp=sharing

https://docs.google.com/spreadsheets/d/1BEQ4IBtftvssiLcdCh7npVuuUGW1DlL_y6031D2lMOw/edit?usp=sharing

Analysis

GNAT

A GNAT holds:

• channels - the name used in to send or receive
• data -  produce, send
• continuations - consume, receive

size of leaf + node + skip := (1738 + 90014 + 19134) / 2 /* - replay */ => 55443

Data and continuations size

...

• source - checksums for event tracking
• a - produce data

size of data := 7142 / 2 /* (- replay) */ => 3571 (100%)
size of a := 6372 / 2 => 3181 (89%)
size of source := 690 / 2 => 345 (10%)

Deeper dive into the AST

based on "analysis of data on transfer 3"

size of A in Data := 3185
size of pars := 2689 (84%)
size of top level random state := 494 (16%)

Continuations cost

Transfer from Bob to Alice

...

• continuation - consume data
• source - checksums for event tracking
• patterns - used for spatial matching

Size of continuations being shuffled during a transfer:

size of wks := 10372 / 2 /*(- replay)*/ => 5186 (100%)
size of continuations in wks := 7692 / 2 => 3946 (76%)
size of source := 1606 / 2 => 803 (15%)
size of patterns := 1106 / 2 => 503 (10%)

Deeper dive into the AST

based on "analysis of data on transfer 3"

size of wks := 5 186
size of continuation par := 2 536 (50%)
size of continuation top level random  := 1 088 (20%)
size of patterns := 553 (10%)
size of source := 804 (16%)

Trie size

Leaf cost

Leafs are cheap themselves, the data usage comes from the size of data stored.

Skip cost

Skip nodes take up 1.7kb for 90kb of pointerblocks.

size of skip := 1738 / 2 /* -replay */ => 869

Node cost

Other data

...

size of node:pointerblocks := 89984 / 2 /* (- replay) */ => 44992

Size on disk

LMDB

Image Added

observed size on disk := 102400 / 2 /* (-replay) */ => 51200

Observations

Takeaways/next steps

1. Work through checkpoint creation (1 step instead of 13 steps) which would reduce the amount of stored tries (less data) 

   Jira Legacy
   server System JIRA serverId 50130123-f232-3df4-bccb-c16e7d83cd3e key RCHAIN-3415

   1. estimated gain:
      1. store of top level pointerblock (4416 + 4512 + 128) instead of 44992 (80%)
      2. note: this calculation is very imprecise as the change will happen (is possible) in next rspace
   2. Address EmptyPointer stored in Node pointer block. 

      Jira Legacy
      server System JIRA serverId 50130123-f232-3df4-bccb-c16e7d83cd3e key RCHAIN-3226

      1. encode pointer type in 2 bits, not in 8 bits
      2. explore gain from storing sparse vectors
2. Continue analysis of rholang AST
   
   1. we can address the source size (which is constant but it constitutes a 10% or 15% of the data stored)
   2. there is no way of addressing the random state