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feat(mocker): opt-in KV state-agent (KVCR) mode - #16423
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Add `--kv-state-agent` so a GPU-free deployment exercises the full KVCR router path: frontend KV router + `python -m dynamo.kv_state_agent` + mocker workers. - Each worker DP rank attaches its raw ZMQ stream to the namespace's state agent through a KvStateAttachmentOwner, with a unique CacheOwner per worker x rank, and advertises `kv_event_source_mode = state_agent_v2`. The in-process legacy relay is skipped so events are published once. - Host-pinned (G2) events are tagged `ownership: "kvcr"`; G1 events stay framework-owned. - The ZMQ sink now recovers G2 token IDs from the blocks' earlier G1 stores. AISimulate's G2 residency carries none, so ZMQ mode previously dropped every G2 event and no lower tier reached the router. - `--kv-state-agent-router-hints` advertises router-hint capability with placeholder source endpoints so the router runs its hinted lower-tier lookup; the mocker logs and ignores the hints. - The ZMQ PUB socket uses vLLM's send high-water mark (100k messages) instead of libzmq's default of 1000, so a lagging subscriber sees vLLM-like buffering. - examples/backends/mocker/launch/agg_kvcr_state_agent.sh launches the state agent, mockers and frontend. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Signed-off-by: jthomson04 <jwillthomson19@gmail.com>
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Source-only review of 7096a57. Three P2 findings below. No tests or builds were run.
| *tiers &= !tier; | ||
| if *tiers == 0 { | ||
| self.0.remove(&hash.0); |
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[P2] Keep token IDs until pending host writes complete
With a nonzero GPU-to-host transfer time, GPU eviction can occur before the host store completes. This removes the token IDs, so the later host-store event is dropped and the router misses valid host-cache blocks. Keep the token metadata until the pending host write completes.
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Fixed in 8e05987. Confirmed the race: fence_allocation lets a new owner reacquire the G1 slot while the D2H copy is in flight, so G1 Removed can precede the G2 Stored. A block that leaves every tier now keeps its token IDs in a bounded FIFO (RELEASED_BLOCK_TOKENS = 16k blocks) instead of being dropped right away. The fence stalls the rank's compute until the copy lands, so only about one scheduling pass of evictions can race it. Unit test covers G1 store → G1 remove → G2 store. A local e2e run at 1 GB/s D2H dropped 0 stores.
| if args.kv_state_agent: | ||
| attachment_owners.append( | ||
| await start_kv_state_agent_owner( | ||
| args, runtime, worker_engine_args, runtime_config | ||
| ) |
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[P2] Start the attachment owner from the resolved configuration
A supported --extra-engine-args file can set dynamo.kv_state_agent=true and dynamo.zmq_kv_events_port. Rust then disables the relay, but this CLI-only check starts no attachment owner. The worker serves requests without publishing router events. Use worker_engine_args["dynamo"]["kv_state_agent"] for this check and validate the resolved configuration.
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Fixed in 8e05987: the owner now starts from worker_engine_args["dynamo"]["kv_state_agent"], and MockerConfig::normalized() rejects kv_state_agent without zmq_kv_events_port, so an --extra-engine-args file is validated too.
| "cache_owner_id": ( | ||
| f"{_KV_STATE_AGENT_INDEXER_DOMAIN}/{_KV_STATE_AGENT_POOL}/" | ||
| f"{worker_id:016x}{rank:016x}" | ||
| ), |
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[P2] Avoid consuming new durable slots on each worker restart
The connection ID changes on restart, which creates new CacheOwner IDs. The external agent retains old slots and counts them against max_slots. If it remains running at full capacity, replacement workers cannot attach and lose KV event publication. Avoid allocating a new durable slot for each worker restart.
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Fixed in 8e05987: the CacheOwner slot (and the placeholder hint endpoint) now comes from each rank's ZMQ port. The raw endpoint is loopback, so it's unique on the state agent's host and stable across restarts. Verified: restarting the mocker against a running agent with --max-slots 2 kept 2 slots and had 0 capacity rejections.
WalkthroughMocker workers now support KV state-agent attachments, optional router hints, and raw ZMQ event publishing. The event sink tracks block-token residency, recovers token IDs for host-residency events, and optionally tags host-pinned events as KVCR-owned. A launch script starts the agent, workers, and KV-routing frontend. ChangesKV State-Agent Flow
Priority: ➖ Normal Estimated code review effort: 4 (Complex) | ~45 minutes Merge Risk: 🔵 Low · up to
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Docstring coverage is 45.71% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 35 functions across 10 files. | Write docstrings for the functions missing them to satisfy the coverage threshold. |
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The description includes the required Overview, Details, reviewer guidance, and Related Issues sections. However, the required issue reference is missing because the description states that no trackin… | Add a valid issue reference, such as Closes #1234, Relates to #1234, or a valid Linear issue reference, then update the Related Issues section before merging. |
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Check name Status Explanation Linked Issues check Check skipped because no linked issues were found for this pull request. Out of Scope Changes check Check skipped because no linked issues were found for this pull request. Title check The title clearly and concisely describes the main change: adding opt-in KV state-agent mode to the mocker.
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Inline comments:
Review comments at @components/src/dynamo/mocker/main.py:
- Around line 304-309: In launch_workers, ensure failures from make_engine after
KvStateAttachmentOwner startup call runtime.shutdown() before propagating the
exception, so the registered attachment intent is released.
Review comments at @examples/backends/mocker/launch/agg_kvcr_state_agent.sh:
- Around line 37-40: Replace the duplicated readiness loop in the state agent
startup flow with the shared wait_for_ready helper, passing the /live URL and
60-second timeout. Ensure an unavailable state agent causes the script to fail
before workers start.
Review comments at @lib/mocker/src/services/zmq_events.rs:
- Around line 80-99: Update `observe` to resolve or validate token IDs for every
block in a `Stored` event before mutating any map entry. If any block has
neither event-provided token IDs nor an existing entry, return `None` without
setting tier bits on earlier blocks; otherwise preserve the current processing
behavior.
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📒 Files selected for processing: 10
components/src/dynamo/mocker/args.pycomponents/src/dynamo/mocker/config.pycomponents/src/dynamo/mocker/main.pycomponents/src/dynamo/mocker/tests/unit/test_config.pyexamples/backends/mocker/launch/agg_kvcr_state_agent.shlib/llm/src/mocker.rslib/mocker/src/config.rslib/mocker/src/grouped_scheduler/dispatch.rslib/mocker/src/grouped_scheduler/tests.rslib/mocker/src/services/zmq_events.rs
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- Keep a released block's token IDs for a bounded window: G1 can reacquire a slot before its D2H copy lands, so G1 `Removed` may precede the G2 `Stored` that needs those tokens. - Resolve every block's token IDs before mutating residency, so a dropped store leaves no stale tier bits. - Start the attachment owner from the resolved config, and reject `kv_state_agent` without `zmq_kv_events_port` at normalization. - Derive CacheOwner slots from each rank's ZMQ port so a restarted worker reattaches to its durable slot instead of taking a new one. - Use the shared `wait_for_ready` helper in the launch script. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Signed-off-by: jthomson04 <jwillthomson19@gmail.com>
❌ Dynamo PR CI failed — run 38982804084 (attempt 1) on
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| Framework | Build |
|---|---|
| vLLM | ⏹️ 3 ✅ 1 |
| Other | Jobs |
|---|---|
| dynamo-runtime | ❌ 1 ✅ 7 |
Failure details
1 job failed: mypy reports 2 type errors in components/src/dynamo/mocker/ (config.py:269, main.py:336). The 3 cancelled vLLM builds were not fail-fast cancels: each hit its job timeout (vllm-runtime 1h30m, vllm-local-dev and vllm-runtime-efa 1h).
❌ dynamo-runtime / mypy: 2 type errors in dynamo/mocker (Optional types)
Job: dynamo-runtime / mypy · Failed step: Run mypy (components) · Logs: gh run view --job 117250257496 -R ai-dynamo/dynamo --log-failed
components/src/dynamo/mocker/config.py:269: error: Invalid index type "str | None" for "dict[str, str]"; expected type "str" [index]
components/src/dynamo/mocker/main.py:336: error: Argument 5 to "start_kv_state_agent_owner" has incompatible type "list[str] | None"; expected "list[str]" [arg-type]
Found 2 errors in 2 files (checked 931 source files)
mypy fails on two Optional values that are used without narrowing: a str | None key indexes a dict[str, str] in config.py:269, and a list[str] | None is passed as argument 5 of start_kv_state_agent_owner in main.py:336.
⏹️ Cancelled: 3 vLLM multi-arch cuda13.0 builds (job timeout)
- vllm-runtime / Build multi-arch cuda13.0: exceeded max execution time of 1h30m
- vllm-local-dev / Build multi-arch cuda13.0: exceeded max execution time of 1h
- vllm-runtime-efa / Build multi-arch cuda13.0: exceeded max execution time of 1h
For agents
{"pr": 16423, "run_id": 38982804084, "run_attempt": 1, "head_sha": "4c8cb6199e6f9efebebfd5e91f64eef75df4c638",
"failures": [{"job": "dynamo-runtime / mypy", "job_id": 117250257496, "failed_step": "Run mypy (components)", "signature": "mypy: 2 errors in components/src/dynamo/mocker/config.py:269 [index], main.py:336 [arg-type]", "tests": [], "log_cmd": "gh run view --job 117250257496 -R ai-dynamo/dynamo --log-failed"}]}Posted automatically by Devin for run 38982804084. Updated on every full-CI run of this PR.
The mocker invented inputs that a vLLM state-agent worker takes from its operator: CacheOwner IDs from the raw ZMQ port, which collide across hosts once the agent serves more than one, and a loopback raw endpoint. It now takes the same inputs: --kv-state-agent-raw-host, validated like dynamo_state_agent.raw_advertise_host, and --kv-state-agent-cache-slot, the first slot of the process in the canonical ID format of the vLLM KVCR manifests. --kv-state-endpoint is honored as for vLLM. Both kinds of worker now publish one raw topic per worker, derived from its CacheOwner IDs, and advertise it in their descriptors. A vLLM worker in KVCR mode sets kv_events_config.topic to it; its descriptors advertised "" while publishing the configured topic. The mocker carries it on live and replay frames, as vLLM does. A fixed-width topic per worker lets the state agent route raw streams by topic. validate_advertise_host and worker_raw_topic live in dynamo.common.kv_state_agent, shared by both. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Signed-off-by: jthomson04 <jwillthomson19@gmail.com>
|
/ok to test 4050d86 |
One mocker process stands for many workers, but every worker read the same
DYN_TOPOLOGY_* environment, so a process was a single KV-transfer island.
--kv-transfer-island-size N suffixes worker i's value for the KV transfer
domain with -{i // N}. The topology is read once per process instead of once
per worker.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: jthomson04 <jwillthomson19@gmail.com>
|
/ok to test 4c8cb61 |
Overview:
Adds an opt-in
--kv-state-agentmode todynamo.mockerso a GPU-free deployment exercises the full KVCR router path: frontend KV router +python -m dynamo.kv_state_agent+ mock workers. Mock workers attach to the state agent exactly as vLLM state-agent workers do, and ignore router hints, so this measures router cost, not KV-transfer benefit.Details:
--kv-state-agent(requires--zmq-kv-events-ports,--num-host-blocks,--kv-state-agent-raw-hostand--kv-state-agent-cache-slot): each worker DP rank attaches its raw ZMQ stream to the namespace's state agent throughKvStateAttachmentOwner, one CacheOwner per worker × rank, and advertiseskv_event_source_mode = state_agent_v2. The in-process legacy relay is skipped so events are published once.dynamo_state_agentsection:--kv-state-agent-raw-hostis the connectable host the agent dials, validated likeraw_advertise_host(sharedvalidate_advertise_host).--kv-state-agent-cache-slotis the process's first CacheOwner slot; workeri, rankrowns slotbase + i × dp + r, in the canonical ID format of the vLLM KVCR manifests (KVCR_CACHE_SLOT).--kv-state-endpointis honored as for vLLM.worker_raw_topicderives a fixed-width topic from the worker's CacheOwner IDs. A vLLM worker in KVCR mode setskv_events_config.topicto it and advertises it asraw_topic(its descriptors advertised""while publishing the configured topic). The mocker publishes it on live and replay frames, as vLLM does. Distinct fixed-width topics let the state agent route raw streams by topic.ownership: "kvcr"; G1 events stay framework-owned.dispatch.rsdropped them from the raw path; the ZMQ sink now recovers them from each block's earlier G1 store. This also applies to plain--zmq-kv-events-portsmode, which now matches the direct event-sink path.--kv-state-agent-router-hintsadvertisesrouter_hintand the worker type, with a placeholder source endpoint per CacheOwner, so the router runs its hinted lower-tier lookup. The mocker logs received hints at debug and ignores them.--kv-transfer-island-size Nsplits one mocker process into KV-transfer islands: workeri's value forDYN_KV_TRANSFER_DOMAINgets the suffix-{i // N}. Topology is still read from theDYN_TOPOLOGY_*environment, as for vLLM workers, now once per process instead of once per worker.examples/backends/mocker/launch/agg_kvcr_state_agent.sh(RAW_HOST,CACHE_SLOT).Where should the reviewer start?
components/src/dynamo/common/kv_state_agent.py: helpers shared by vLLM and the mockercomponents/src/dynamo/mocker/config.py,main.py,args.py: descriptors, CacheOwner slots, per-worker topiccomponents/src/dynamo/vllm/args.py,state_agent.py: vLLM sets and advertises its worker topiclib/mocker/src/services/zmq_events.rs: topic on live and replay frames, ownership tag,ResidentBlockTokens, send HWMlib/mocker/src/grouped_scheduler/dispatch.rs: G2 events now reach the raw sinkValidation
Local run: 1 frontend (
--router-mode kv), 1 state agent, 2 mockers (block size 64, 96 GPU blocks, 4096 host blocks), 96 requests over 8 shared ~1.5k-token prefixes.The 23 G2 stores were seen on the ZMQ wire as
CPU_PINNEDwithownership: "kvcr". No warnings or errors in any process. At scale, 2048 mocker workers on 12 processes across 3 nodes attached with per-node raw hosts and disjoint slot ranges, and the state agent consumed every per-worker topic with no raw cursor gaps.Related Issues
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