giles
836d32474f
The shared prerequisite for both live steps was: does a next/ kernel process hold gen_server state (flow_store) across HTTP requests? Confirmed yes. plans/ra_kernel.erl is a minimal kernel (flow_store + register the publish-digest flow, then a blocking http:listen that keeps the er-scheduler + gen_server alive); plans/ra-kernel-spike.sh boots it as a background sx_server and drives it with two SEPARATE curls: GET /start suspends instance 1, GET /resume resumes that SAME live instance → done. So durable suspend→resume across requests works on a persistent kernel. Design decision (per the discussion): chose the persistent-kernel path (B) over host-side replay-log (A). B serves BOTH durability (RA) and federation (TA) on one fed-sx-native substrate and exposes the full next/ kernel (projections, outbox, actor model); A only solves flow durability and mixes Erlang into the host process. The er-scheduler-context bug (which kills an in-process kernel, option C) does NOT bite a separate-process kernel — er-bif-http-listen spawns each handler in-scheduler, so gen_server:call completes. Gotchas recorded: a blocking listener hangs any in-process erlang-eval-ast (the kernel must be a dedicated TCP-driven process), and binary =:= is buggy (always true) so routes must pattern-match paths as byte-list binaries. RA-live + TA-live are now BUILD work (a real kernel service + the host as HTTP client + the actor model), not research — the prerequisite is proven. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
42 lines
1.8 KiB
Erlang
42 lines
1.8 KiB
Erlang
%% plans/ra_kernel.erl — RA/TA persistent-kernel SPIKE.
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%% A minimal long-lived next/ kernel: starts flow_store + registers the publish-digest flow, then
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%% blocks in http:listen — keeping the er-scheduler (and flow_store's gen_server) alive across
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%% requests. Two routes drive flow_store over HTTP: GET /start (start a newsletter flow → suspend)
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%% and GET /resume (resume instance 1 → done). If /resume completes in a SEPARATE request from
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%% /start, the gen_server persisted across requests — the persistent-kernel prerequisite for
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%% RA-live + TA-live holds.
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-module(ra_kernel).
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-export([start/1]).
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start(Port) ->
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flow_store:start_link(),
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FF = fun (_) -> [f1, f2, f3] end,
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flow_store:register_flow(bd, blog_publish_digest:build([{fetch_followers, FF}])),
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http:listen(Port, fun (Req) -> route(Req) end).
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route(Req) ->
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[{status, 200}, {headers, []}, {body, respond(field(path, Req))}].
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%% /start (bytes 47,115,116,97,114,116)
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respond(<<47,115,116,97,114,116>>) ->
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Env = [{activity, [{type, create}, {actor, alice}, {id, <<110,49>>},
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{object, [{type, article}, {category, newsletter}]}]},
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{actor, alice}],
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case flow_store:start(bd, Env) of
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{ok, _Id, {flow_suspended, _}} -> <<"start:suspended">>;
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{ok, _Id, {flow_done, _}} -> <<"start:done">>;
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_ -> <<"start:other">>
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end;
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%% /resume (bytes 47,114,101,115,117,109,101)
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respond(<<47,114,101,115,117,109,101>>) ->
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case flow_store:resume(1, morning_ts) of
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{ok, {flow_done, _}} -> <<"resume:done">>;
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{flow_done, _} -> <<"resume:done">>;
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_ -> <<"resume:other">>
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end;
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respond(_) -> <<"path:unknown">>.
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field(K, [{K, V} | _]) -> V;
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field(K, [_ | Rest]) -> field(K, Rest);
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field(_, []) -> nil.
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