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Profile and add optional bounded warm workflow execution to PHP service workers #113
Description
Outcome and first decision
Investigate optional bounded retention of live PHP service workflow execution across tasks. Begin with profiling and implement only if replay cost is material enough to justify memory and lifecycle complexity. This is a PHP SDK worker change, independent of Octane HTTP hosting and the embedded engine implementation.
Published SDK 2.2.6 already runs a persistent CLI worker and caches durable history, but Replayer constructs a fresh Fiber. History-prefix reuse reduces transfer work without eliminating instruction replay. Distinguish transport/history savings from live execution savings.
Required design and acceptance
- Profile 10/100/1000-event histories, repeated activity/timer cycles and concurrent runs. Separate queue/long-poll delay, history requests/bytes, replay CPU and task handling. Freeze exact published runtime/SDK/workloads and resources, then record the investment decision before expanding the engine change.
- Preserve the ordinary cold path and make retained execution opt-in. Bound entry count, age and retained memory with pressure handling. Entries require exact endpoint/namespace/workflow/run/build identity, validated durable history cursor and current task/lease authority.
- Define resumption, existing sticky routing and handoff behavior without introducing a new server affinity protocol by default. A miss, worker death, invalid prefix or unsupported feature cold replays. If a wire/capability change is necessary, settle the contract and coordinate shared fixtures and both runtime implementations before depending on it.
- Define commit/rollback/failure/uncertain completion-acknowledgement handling. Never resume speculative state or accept a stale attempt. Duplicate delivery must preserve durable command/outcome identity.
- Isolate handler, dependency, request/log and cancellation context per execution. Coordinate Isolate class-oriented workflow state across executions and replay #16/Release PHP 3 with fresh attributed workflow instances #111's handler lifetime work rather than bypassing the pending compatibility decision. Safe eviction must not execute business cleanup as though cancellation/completion occurred.
- Demonstrate equivalent results, failures, command identities, deterministic time/version markers and original deadlines across warm/cold execution. No recorded activity effect repeats after eviction or replacement.
- Test TTL/memory pressure, shutdown/SIGKILL, build changes, cache misses, lease loss, duplicate tasks, failed completion and uncertain acknowledgements. Cover activities/local activities, timers, supported parallel/selection operations, signals, queries, updates, cooperative cancellation/termination, continue-as-new and redrive. Unsupported retained features have an explicit tested cold fallback.
- Expose hit/miss/eviction/invalidation, retained executions/memory and replay measurements. Keep history caching, live execution and optional HTTP profile controls distinct.
- Compare cold process, warm cached history with replay, and retained execution with identical CPU/RSS budgets, three measured repetitions, hit-heavy/miss-heavy workloads and a 1 GiB aggregate worker case. Report p50/p95/p99 continuation latency, throughput/CPU, RSS, history requests/bytes, errors, unfinished work and backlog. Include a one-second timer continuation with scheduling and queue delay reported separately. Reject OOM/swapping or an unmeasured drain as gains.
- Pass affected SDK replay/cancellation/framework tests and real published-runtime conformance, then verify the released SDK and affected examples. Link embedded implementation and keep the deployment-specific outcomes explicit.
Use existing published runtime contracts first. No Server rewrite, Cloud rollout, terminal-result cache or process-local replacement for durable timers is included. No speedup is established by this proposal.
Embedded implementation is Workflow #748. Optional service-mode HTTP qualification and existing history-cache configuration are #112, paired with Workflow #747. Share semantic controls while retaining mode-specific qualification.
Activity
rmcdaniel commentedon Oct 23, 2026
Starting the required profiling decision on the current normally installed SDK3.4.1 and published Server2.11.0 before changing the replay engine. The first harness will separate real worker task/HTTP/poll/history costs from isolated replay CPU on captured canonical histories, retaining exact workload, package and resource identities. Existing history-prefix caching remains distinct from live Fiber retention. No warm execution, speedup, wire change or release is claimed by starting this measurement.
rmcdaniel commentedon Oct 23, 2026
Profiling groundwork is retained in draft213, current source
6a4b6e64f88fabc323fe5d0953d5efab4bdff84a, tree5850ccafe77761166f225d8869d72619bee1e978. No live-execution engine, version or release is added.All controls use ordinary registry SDK3.4.1 (
cb1d11e57767e20e1fdb8081024f67057ff66714), Guzzle8.3.0/PSR2/PHP8.3.36 and published Server2.11.0 imagesha256:b29157eb2cf844916debbbb3c01b3257672e0dece778a9c6fa539043a3038f02/embedded Core2.10.1. Worker and separate runtime each have1CPU/512MiB; worker swap is disabled.Earlier draft smoke runs completed14/101-event histories and repeated10/100-event pure-prefix replays, but their harness edits were not frozen before execution; they are exploratory results, not exact-source qualification. The current frozen harness is running the larger published control with an explicitly recorded resource allowance. Three managed-worker repetitions, concurrent/aggregate-budget studies, validated cache-hit controls and the investment decision remain open. Keep113 open; no execution speedup or full acceptance is established.
Exact frozen-trial receipts (gzip/base64 JSON file map)
Decode base64, decompress gzip and parse the resulting filename-to-original-text JSON map. Original SDK claim IDs and failed results are preserved.
JSON bytes
145508, SHA256d8bf358c88b0bcf073727f750117b9f4e0f8004dcbdb4d08996bb5bdebcc9137; gzip SHA25609bd96ad715853ac23a48ac72b7606567b7db6ef8919eaead3e9e866a7f0337e.rmcdaniel commentedon Oct 23, 2026
One complete frozen published-artifact control is now measured at source
0945fa2f95c0411a83c64a4a492c3cbca26b88f1, treebb146def2434b70cbf64133d930b937081d7b57f(probe/recipe). Harness SHA25689506a25fd85e728dc2d47b4c2752422156d06be86028c5e70ffcb2a85f48aea; normal registry SDK3.4.1/sourcecb1d11e, Guzzle8.3/PSR2/PHP8.3.36 and the same published Server2.11.0/Core2.10.1/imageb29157eb tuple.This is one managed run, with concurrent source/qualification work on a shared host. It does not establish a speedup, retained-execution result, three independent throughput repetitions, a cache-hit comparison or full113 acceptance. Retention remains unimplemented; complete the recorded concurrency/repetition/cache controls and investment decision before expanding the engine. The earlier failed originals stay failed. A prior1800s-prototype run produced no terminal receipt during disk pressure and retained the default600s workflow run deadline; it is excluded from comparisons and its canonical partial state is retained separately.
Exact complete control (gzip/base64 JSON file map)
JSON bytes
212368, SHA256429080abbaa6a0671ce680fe7edac0a2589a96e5538d8ab20385d7f82b7ee4e1; gzip SHA256967fad69b845251c0fc0c2d32db8a51f83aa754d9532a2e54dffcd0c778b65af. Decode base64+gzip then JSON; filenames map to unchanged original text.