Date: May 4, 2020
Author: Calin Culianu <calin.culianu@gmail.com>
GetBlockTemplate Light
In order to provide the most efficient mining RPCs, we have implemented the getblocktemplatelight RPC which is popular amongst various mining pools such as BTC.COM and others.
The two new RPC's are: getblocktemplatelight and submitblocklight. These RPCs reduce the round-trip time for mining software when retrieving new block templates. Transaction data is never sent between mining software and bitcoind. Instead, job_id's are returned and bitcoind later reconstructs the full block based on this job_id and the solved header + coinbase submitted by the miner, leading to more efficient mining.
A full description and specification for this facility can be found here: https://gitlab.com/bitcoin-cash-node/bitcoin-cash-node/-/blob/master/doc/getblocktemplatelight.md
Below are some benchmarks:
Bitcoin Cash Node v0.21.2 (gitlab, Merge Request 281)
getblocktemplatelight, 6000 tx mempool (1271847 bytes)
New template generation
call time, avg.: 62.025 milliseconds
Cached template (returned if you call again within 5 seconds and no new tx's)
call time, avg.: 0.917 milliseconds
Bitcoin ABC v0.21.6 (github master) + BTC.COM gbtl patch from https://github.com/btccom/bitcoin-abc-1
getblocktemplatelight, 6000 tx mempool (1271847 bytes)
New template generation
call time, avg.: 64.200 milliseconds
Cached template (returned if you call again within 5 seconds and no new tx's)
call time, avg.: 4.909 milliseconds
Winner: BCHN
For the first call to light GBT, ABC and BCHN are comparable. This is because the call is dominated by generating the new template by scanning the mempool. Subsequent calls (which are the common case) show a 4x speed improvement in BCHN over ABC, because BCHN uses better caching.
GetBlockTemplate (regular) Improvements
Bitcoin Cash Node has made some improvements to the regular mining RPC calls. The getblocktemplate call has been made up to 70% faster than the current ABC implementation. We have optimized the JSON RPC code to be much more efficient.
Below are some benchmarks:
Bitcoin Cash Node v0.21.2 (git master)
getblocktemplate, 6000 tx mempool (1271847 bytes)
New template generation
call time, avg.: 164.023 milliseconds
Cached template (returned if you call again within 5 seconds and no new tx's)
call time, avg.: 117.277 milliseconds
Bitcoin ABC v0.21.6 (git master)
getblocktemplate, 6000 tx mempool (1271847 bytes)
New template generation
call time, avg.: 262.200 milliseconds
Cached template (returned if you call again within 5 seconds and no new tx's)
call time, avg.: 200.476 milliseconds
Winner: BCHN
Between 60% - 70% speed improvement for both calls with BCHN. This is because the verbose getblocktemplate returns a large JSON object. BCHN has heavily optimized the JSON generation code to reduce overhead.
Where to get BCHN + GBT Light
v0.21.2 is coming soon! - This new facility is currently in review but will appear in the upcoming 0.21.2 BCHN release very soon.
You may see the review branch here:
Or you can download a binary pre-release here:
Links:
Instructions on how to perform this benchmark: https://gist.github.com/cculianu/20309e67ff82caa397b4460ec011ad54
Repository link of this announcement: https://gitlab.com/bitcoin-cash-node/announcements/-/blob/master/20200504_gbt_light_announcement.md
Good project indeed! Keep developing the technology to have a robust nodes around BCH. It is a laudable project.