## Summary
Design at:
https://github.com/openobserve/designs/blob/main/infrastructure/work-group/work_group_v2_impl.md
This PR adds slot-based distributed admission control for search queries
and fixes file dispatch consistency when a subset of querier nodes is
selected per query.
To enable this feature we need to set:
```
O2_WORK_GROUP_MAX_NODES_PER_QUERY > 0
O2_WORK_GROUP_NODE_SELECTION_STRATEGY = org | stream
```
### Slot-based admission
- Add `TryAcquire / StartQuery / ReleaseQuery` gRPC RPCs — Follow nodes
reserve slots before execution starts and self-release via
`FlightEncoderStream::drop`
- Wire slot admission in both Arrow Flight search and PromQL paths,
co-located with the existing org/user concurrency queue check
- Delegate DataFusion `target_partitions` / `memory_size` to enterprise
`get_resource_limit()`, which applies per-query slot fraction with
optional dynamic expansion
- TTL sweep interval derived from `slot_reserved_ttl_ms / 4` (min 100
ms) instead of a hardcoded 500 ms
- Move `QUERY_PENDING_NUMS` / `QUERY_RUNNING_NUMS` metric updates to
after slot admission completes (a blocked request is no longer counted
as "running")
### Consistent-hash file dispatch fix (`max_nodes_per_query > 0`)
- Add `get_node_from_consistent_hash_within(key, role, group, allowed)`
to `infra::cluster`: walks the global ring clockwise from `hash(key)`
but skips nodes outside `allowed`. Preserves all consistent-hash
properties (even distribution via vnodes, minimal remapping on
membership change) while confining dispatch to the selected subset
- `partition_file_by_hash` now passes only the selected querier nodes as
the `allowed` set, so every file maps to one of the N selected nodes —
no more fallback-to-index-0 imbalance when `strategy=org/stream`
- File-list broadcast (enterprise) pre-computes per-item target nodes
using the same filtered ring walk via `broadcast_item_targets()` in
`o2-enterprise`, so broadcast and dispatch always agree on which node
owns each file
### Proto fix
- Reserve field 10 in `QueryStatus` (was `WorkGroup` enum / varint wire
type) and move `work_group` string to field 13 — prevents wire-type
mismatch during rolling upgrades
### Other fixes from code review
- `get_first_stream_key()` now returns `"{stream_type}/"` sentinel
instead of `""` for multi-stream / cross-index queries, so
`select_nodes` always receives a non-empty deterministic key
- PromQL node selection uses `"metrics/"` stream key (consistent with
the sentinel format) instead of bare `"metrics"`
- Move `_orig_trace_id` binding inside `#[cfg(feature = "enterprise")]`
block in `FlightEncoderStream::drop`
## Key config (all default to safe/off values)
| Env var | Default | Description |
|---|---|---|
| `O2_WORK_GROUP_MAX_NODES_PER_QUERY` | `0` | Nodes per query; 0 = all
nodes (disables slot admission) |
| `O2_WORK_GROUP_NODE_SELECTION_STRATEGY` | `all` | `all` / `org` /
`stream` |
| `O2_WORK_GROUP_SHORT_SLOT_RATIO` | `0.8` | Max fraction of node slots
for short queries |
| `O2_WORK_GROUP_DYNAMIC_RESOURCE` | `true` | Expand DataFusion
allocation on idle nodes |
## Test plan
- [x] Default (`max_nodes_per_query=0`): behavior identical to before,
zero overhead
- [x] `strategy=org`, `max_nodes_per_query=3`, 10-node cluster: each org
consistently uses the same 3 nodes; files distributed evenly across
those 3 nodes (no node-0 pile-up)
- [x] Broadcast routes each file to the same node that
`partition_file_by_hash` selects at query time → cache hits on
re-queries
- [x] Slot admission: 3rd request waits when budget=2 and 2 queries
running; slots released on completion
- [x] PromQL queries respect slot budget
- [x] Rolling upgrade: old node sends `QueryStatus` without field 10
conflict
## Related
Requires companion PR in `o2-enterprise`:
https://github.com/openobserve/o2-enterprise/pull/1378🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
- Add `x-o2-mcp` header support for MCP request identification in token validator
- Wrap OpenAPI schema types with `inline()` for better documentation generation
- Update AI module imports to use new agent namespace
- fix compilation for `cloud` feature, also return early if user isn't in trial
- Enable service graph by default
PR introduces below features:
- [x] Reporting triggers to source org
- [x] Alerts Insights for detailed visibility in alerts
Enterprise features:
- [x] Patterns extraction during query - UI and API
- [x] Patterns extraction as part of ingestion process (No Sampling
today)
- [x] Settings to enable pattern extraction
---------
Co-authored-by: omkark06 <omkar@zinclabs.io>
HuaijinandHengfei Yang
Subhra264
sktrpathiandsai nikhil kethe
Ashish Kolheandgithub-actions[bot]
