Add RPC call setscriptthreadsenabled: allow to temp. throttle CPU usage #12965

1. 
   jonasschnelli commented at 8:46 am on April 12, 2018: contributor

   Bitcoin Core has been designed to synchronise/verify as fast as possible. This is usually desirable, though, on systems where other applications require a reasonable amount of CPU time (ex. desktop systems) the CPU usage maximisation of Bitcoin Core may be intrusive.

   This PR adds two RPC calls:

   • setscriptthreadsenabled allows to disable/re-enable the script verification threads during runtime.
   • scriptthreadsinfo show information about the script verification threads (enabled/disabled and num threads)

   This would be a base requirement for a “cpu throttle” feature in the GUI allowing one to temporary “throttle” verification (and therefore make the system usable for other tasks while syncing in the background)

   The concept-draft for long-term resource profile: https://gist.github.com/jonasschnelli/a3eb47147069b99d7c63d7da997b4225

   ToDo:

   • Add tests
   • Release notes
2. jonasschnelli added the label RPC/REST/ZMQ on Apr 12, 2018
3. jonasschnelli added the label Validation on Apr 12, 2018
4. in src/rpc/blockchain.cpp:1656 in 13814ae538 outdated

   1651+
   1652+UniValue setscriptthreadsenabled(const JSONRPCRequest& request)
   1653+{
   1654+    if (request.fHelp || request.params.size() != 1) {
   1655+        throw std::runtime_error(
   1656+            "setscriptthreadsenabled\n"
   

   ---

   ---

   

   promag commented at 9:01 am on April 12, 2018:

   Missing parameter state.
5. in src/rpc/blockchain.cpp:1657 in 13814ae538 outdated

   1652+UniValue setscriptthreadsenabled(const JSONRPCRequest& request)
   1653+{
   1654+    if (request.fHelp || request.params.size() != 1) {
   1655+        throw std::runtime_error(
   1656+            "setscriptthreadsenabled\n"
   1657+            "\nDisable/enable script verification threads and therefore reducing CPU usage on multicore systems.\n"
   

   ---

   ---

   

   promag commented at 9:01 am on April 12, 2018:

   Invert, Enable/disable script ...?
6. in src/rpc/blockchain.cpp:1659 in 13814ae538 outdated

   1654+    if (request.fHelp || request.params.size() != 1) {
   1655+        throw std::runtime_error(
   1656+            "setscriptthreadsenabled\n"
   1657+            "\nDisable/enable script verification threads and therefore reducing CPU usage on multicore systems.\n"
   1658+            "Disabling script verification threads may result in a significant slow-down during synchronisation.\n"
   1659+            "Has no effect on single core machines or if started with -par=<-<numcores>\n"
   

   ---

   ---

   

   promag commented at 9:04 am on April 12, 2018:

   Should be if started with -par=1?
7. 
   promag commented at 9:05 am on April 12, 2018: member

   Concept ACK.

   I think this is almost only useful when changed in the UI right?

   Could have a couple of tests to exercise these new calls and the error.

   Edit: you already have tests in the TODO 😄

8. 
   JeremyRubin commented at 6:59 am on April 13, 2018: contributor

   Couple comments on the concept:

   • Maybe add a time argument (e.g., disable for 5 hours)
   • Maybe add code to differentiate between sync and receiving a new block. I can see why you might want to background sync, but when you are getting a new block, the pause won’t be that long and it is really good for the network if this is faster
   • Perhaps also good to control how many threads get used? E.g., use 2 threads out of 4
   • Why is this better than just restarting the node with fewer threads?
9. 
   jonasschnelli commented at 8:53 am on April 13, 2018: contributor

   @promag

   I think this is almost only useful when changed in the UI right?

   I think its useful for bitcoind users as well. Assume you want to do another CPU intense task on your system, you could setscriptthreadsenabled false, do your task and setscriptthreadsenabled true. @JeremyRubin Agree with all your features… I guess they could be implemented in another PR.

   Why is this better than just restarting the node with fewer threads?

   Restarting Bitcoin-Core just to reduce it’s script verification threads seems unideal. A restart is always painful (dbcache, partial re-validation).

10. Add RPC call setscriptthreadsenabled/scriptthreadsinfo: allow to disable verification threads dfab6c6866
11. jonasschnelli force-pushed on Apr 18, 2018
12. 
    jonasschnelli commented at 8:19 am on April 18, 2018: contributor

    Needed rebase
13. MarcoFalke added the label Needs rebase on Jun 6, 2018
14. 
    DrahtBot commented at 5:20 pm on September 21, 2018: member
15. DrahtBot added the label Up for grabs on Sep 21, 2018
16. DrahtBot closed this on Sep 21, 2018

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17. laanwj removed the label Needs rebase on Oct 24, 2019
18. DrahtBot locked this on Dec 16, 2021

Contributors
jonasschnelli promag JeremyRubin DrahtBot

Labels
RPC/REST/ZMQ Validation Up for grabs