Module: DispatchPolicy::Repository

Defined in:
lib/dispatch_policy/repository.rb

Overview

SQL access layer for staged_jobs / partitions / inflight_jobs.

Hot paths use raw SQL via ActiveRecord::Base.connection so we get ‘FOR UPDATE SKIP LOCKED`, multi-row UPSERTs, and DELETE … RETURNING without ActiveRecord overhead. Read paths in the engine UI use the AR models in app/models/dispatch_policy/*.

Constant Summary collapse

STAGED_TABLE = 
"dispatch_policy_staged_jobs"
PARTITIONS_TABLE = 
"dispatch_policy_partitions"
INFLIGHT_TABLE = 
"dispatch_policy_inflight_jobs"
SAMPLES_TABLE = 
"dispatch_policy_tick_samples"
ADAPTIVE_TABLE = 
"dispatch_policy_adaptive_concurrency_stats"
POLICY_SETTINGS_TABLE = 
"dispatch_policy_policy_settings"
STAGE_MANY_BATCH =

Bulk version for perform_all_later. Receives an array of hashes with the same keys as #stage!. Performs one INSERT for staged_jobs and one UPSERT per (policy_name, partition_key) group. Rows per INSERT. Each row binds 8 params; Postgres caps a statement at 65_535 bind params, so we slice well under 65_535/8 ≈ 8_191 to leave headroom. A single perform_all_later with more rows than this would otherwise blow the limit and fail the whole batch.

1_000
ROLE_ROUTING_EXCLUDED =

—– role routing ———————————————————

Every public Repository method must run against config.database_role so multi-DB setups (e.g. solid_queue on a separate :queue DB, with the gem tables living there) hit the DB the staging/admission/inflight state actually lives in. Otherwise staging writes the primary DB while the tick reads the queue DB — silent job loss — and the concurrency gate counts inflight rows in a different DB than the tracker writes.

Rather than wrap ~25 method bodies by hand — and risk missing one as the API grows — we redefine each public SQL method to run inside ‘with_connection`. We capture the ORIGINAL as a bound closure and call it directly (no `super`, no prepended module): this is immune to the file being evaluated more than once in a process (dev reloader, integration suites that boot the dummy app under multiple require paths). Each evaluation re-wraps the freshly (re)defined originals exactly once, so wrappers never stack. `connected_to(role:)` nesting with the SAME role is a no-op, so the explicit `with_connection` blocks at the transaction boundaries (Tick, ManualAdmission) stay correct: the admission TX still opens entirely within one role context, preserving the shared-connection atomicity invariant. The `connection` accessor and the pure helpers are excluded — they issue no SQL of their own and always run inside an already-routed caller, so wrapping them would only add redundant role swaps in hot per-row loops (normalize_*/parse_jsonb run once per claimed row).

%i[
  connection with_connection
  normalize_partition normalize_staged parse_jsonb
  sample_filter next_eligible_clause trend_direction
].freeze

Class Method Summary collapse

Class Method Details

.adaptive_current_max(policy_name:, partition_key:) ⇒ Object

Fetch the AIMD-tuned cap for a partition. Returns nil when the row doesn’t exist yet — caller should fall back to initial_max.



795
796
797
798
799
800
801
802
803
 
# File 'lib/dispatch_policy/repository.rb', line 795

def adaptive_current_max(policy_name:, partition_key:)
  result = connection.exec_query(
    "SELECT current_max FROM #{ADAPTIVE_TABLE} WHERE policy_name = $1 AND partition_key = $2 LIMIT 1",
    "adaptive_current_max",
    [policy_name, partition_key]
  )
  row = result.first
  row && row["current_max"].to_i
end

.adaptive_record!(policy_name:, partition_key:, queue_lag_ms:, succeeded:, alpha:, target_lag_ms:, fail_factor:, slow_factor:, min:) ⇒ Object

Single-statement EWMA + AIMD update. Concurrent workers can call this in any order without read-modify-write races: every clause reads the row’s current value at the start of the UPDATE.

ewma_latency_ms_new = ewma_latency_ms * (1 - α) + α * queue_lag_ms current_max_new = GREATEST(min,

FAILED?         FLOOR(current_max * fail_factor)
OVERLOADED?     FLOOR(current_max * slow_factor)
else            current_max + 1)



814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
 
# File 'lib/dispatch_policy/repository.rb', line 814

def adaptive_record!(policy_name:, partition_key:, queue_lag_ms:, succeeded:,
                     alpha:, target_lag_ms:, fail_factor:, slow_factor:, min:)
  connection.exec_query(
    <<~SQL.squish,
      UPDATE #{ADAPTIVE_TABLE}
      SET
        ewma_latency_ms = ewma_latency_ms * (1 - $3::double precision)
                          + $3::double precision * $4::double precision,
        sample_count    = sample_count + 1,
        current_max     = GREATEST($5::int, CASE
          WHEN $6::boolean = FALSE
            THEN FLOOR(current_max * $7::double precision)::int
          WHEN (ewma_latency_ms * (1 - $3::double precision)
                + $3::double precision * $4::double precision) > $8::double precision
            THEN FLOOR(current_max * $9::double precision)::int
          ELSE current_max + 1
        END),
        last_observed_at = now(),
        updated_at       = now()
      WHERE policy_name = $1 AND partition_key = $2
    SQL
    "adaptive_record",
    [policy_name, partition_key, alpha.to_f, queue_lag_ms.to_f,
     min.to_i, succeeded ? true : false,
     fail_factor.to_f, target_lag_ms.to_f, slow_factor.to_f]
  )
end

.adaptive_seed!(policy_name:, partition_key:, initial_max:) ⇒ Object

Insert a fresh stats row for the given partition if none exists. Idempotent — runs as ‘INSERT … ON CONFLICT DO NOTHING`. Cheap to call on every admission so the gate’s evaluate path can read current_max safely without checking for existence first.



779
780
781
782
783
784
785
786
787
788
789
790
791
 
# File 'lib/dispatch_policy/repository.rb', line 779

def adaptive_seed!(policy_name:, partition_key:, initial_max:)
  connection.exec_query(
    <<~SQL.squish,
      INSERT INTO #{ADAPTIVE_TABLE}
        (policy_name, partition_key, current_max, ewma_latency_ms,
         sample_count, created_at, updated_at)
      VALUES ($1, $2, $3, 0, 0, now(), now())
      ON CONFLICT (policy_name, partition_key) DO NOTHING
    SQL
    "adaptive_seed",
    [policy_name, partition_key, initial_max.to_i]
  )
end

.bulk_record_partition_denies!(entries) ⇒ Object

Bulk-update many partitions whose pipeline this tick decided to deny. One UPDATE…FROM(VALUES…) instead of one UPDATE per partition, which cuts a tick with ‘partition_batch_size = 50` from ~50 round-trips on the deny path to one. The deny path doesn’t touch pending_count or total_admitted (admitted = 0 makes them no-ops in the per-row UPDATE), so we only write gate_state and next_eligible_at here.

Each entry: { policy_name:, partition_key:, gate_state_patch:, retry_after: }. Independent per row — the join via FROM(VALUES…) makes the bulk statement equivalent to N sequential UPDATEs in correctness terms. Note: ‘claim_partitions` runs as its own autocommitted statement, so its `FOR UPDATE SKIP LOCKED` row locks are already released by the time we reach this flush — they do NOT guard the batch. What keeps two ticks off the same partitions is the operational invariant of one tick loop per (policy, shard), reinforced by the `last_checked_at` bump on claim (a racing claim skips recently-checked rows).



329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
 
# File 'lib/dispatch_policy/repository.rb', line 329

def bulk_record_partition_denies!(entries)
  return if entries.empty?

  values_sql = []
  params     = []
  entries.each_with_index do |e, idx|
    base = idx * 4
    values_sql << "($#{base + 1}::text, $#{base + 2}::text, $#{base + 3}::jsonb, $#{base + 4}::numeric)"
    params.push(
      e[:policy_name],
      e[:partition_key],
      JSON.dump(e[:gate_state_patch] || {}),
      e[:retry_after].nil? ? nil : e[:retry_after].to_f.round(3)
    )
  end

  connection.exec_query(
    <<~SQL.squish,
      UPDATE #{PARTITIONS_TABLE} p
      SET gate_state       = p.gate_state || v.gate_state_patch,
          next_eligible_at = CASE
            WHEN v.retry_after_secs IS NULL THEN p.next_eligible_at
            ELSE now() + (v.retry_after_secs || ' seconds')::interval
          END,
          updated_at       = now()
      FROM (VALUES #{values_sql.join(", ")})
        AS v(policy_name, partition_key, gate_state_patch, retry_after_secs)
      WHERE p.policy_name = v.policy_name AND p.partition_key = v.partition_key
    SQL
    "bulk_record_partition_denies",
    params
  )
end

.claim_partitions(policy_name:, limit:, shard: nil) ⇒ Object

Lock + return up to ‘limit` partitions ready to be evaluated by the tick. Each row’s last_checked_at is bumped to now() so the next tick fairly picks others. Locked rows are released when the transaction commits.

When ‘shard` is non-nil, only partitions on that shard are claimed —this lets several tick processes work on the same policy in parallel, one per shard.



165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
 
# File 'lib/dispatch_policy/repository.rb', line 165

def claim_partitions(policy_name:, limit:, shard: nil)
  params      = [policy_name]
  shard_sql   = ""
  if shard
    params    << shard
    shard_sql = " AND shard = $#{params.size}"
  end
  params << limit

  sql = <<~SQL.squish
    WITH candidates AS (
      SELECT id FROM #{PARTITIONS_TABLE}
      WHERE policy_name = $1
        AND status = 'active'
        AND pending_count > 0
        AND (next_eligible_at IS NULL OR next_eligible_at <= now())
        AND NOT EXISTS (
          SELECT 1 FROM #{POLICY_SETTINGS_TABLE} ps
          WHERE ps.policy_name = $1 AND ps.paused
        )
        #{shard_sql}
      ORDER BY last_checked_at NULLS FIRST, id
      LIMIT $#{params.size}
      FOR UPDATE SKIP LOCKED
    )
    UPDATE #{PARTITIONS_TABLE} p
    SET last_checked_at = now()
    FROM candidates
    WHERE p.id = candidates.id
    RETURNING p.*
  SQL
  result = connection.exec_query(sql, "claim_partitions", params)
  result.to_a.map { |row| normalize_partition(row) }
end

.claim_staged_jobs!(policy_name:, partition_key:, limit:, retry_after:, gate_state_patch: nil, half_life_seconds: nil) ⇒ Object

Atomically claim up to ‘limit` staged rows for a partition (DELETE …RETURNING) and update the partition’s counters / gate_state / next_eligible_at in the same transaction.

‘limit` MUST be positive: the deny path (no rows to admit) goes through `bulk_record_partition_denies!` instead, which collapses many partitions into a single UPDATE…FROM(VALUES…) at the end of the tick.

Raises:

  • (ArgumentError) 


208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
 
# File 'lib/dispatch_policy/repository.rb', line 208

def claim_staged_jobs!(policy_name:, partition_key:, limit:, retry_after:,
                       gate_state_patch: nil, half_life_seconds: nil)
  raise ArgumentError, "claim_staged_jobs! requires limit > 0" unless limit.positive?

  sql_select = <<~SQL.squish
    WITH claimed AS (
      SELECT id FROM #{STAGED_TABLE}
      WHERE policy_name = $1 AND partition_key = $2
        AND (scheduled_at IS NULL OR scheduled_at <= now())
      ORDER BY priority DESC, scheduled_at NULLS FIRST, id
      LIMIT $3
      FOR UPDATE SKIP LOCKED
    )
    DELETE FROM #{STAGED_TABLE} s
    USING claimed
    WHERE s.id = claimed.id
    RETURNING s.*
  SQL
  rows = connection.exec_query(sql_select, "claim_staged_jobs", [policy_name, partition_key, limit]).to_a

  # The gate_state patch may depend on how many rows we actually
  # claimed (e.g. the throttle charges its bucket for jobs admitted,
  # not for the optimistic `allowed`). When the caller passes a block
  # it receives that real count and returns the patch to persist;
  # gate-less callers pass a fixed `gate_state_patch:` instead.
  patch = block_given? ? yield(rows.size) : (gate_state_patch || {})

  record_partition_admit!(
    policy_name:       policy_name,
    partition_key:     partition_key,
    admitted:          rows.size,
    gate_state_patch:  patch,
    retry_after:       retry_after,
    half_life_seconds: half_life_seconds
  )

  rows.map { |r| normalize_staged(r) }
end

.connection ⇒ Object 



22
23
24
 
# File 'lib/dispatch_policy/repository.rb', line 22

def connection
  ActiveRecord::Base.connection
end

.count_inflight(policy_name:, partition_key:) ⇒ Object 



431
432
433
434
435
436
437
438
 
# File 'lib/dispatch_policy/repository.rb', line 431

def count_inflight(policy_name:, partition_key:)
  result = connection.exec_query(
    "SELECT count(*)::int AS n FROM #{INFLIGHT_TABLE} WHERE policy_name = $1 AND partition_key = $2",
    "count_inflight",
    [policy_name, partition_key]
  )
  Integer(result.rows.first.first)
end

.delete_inflight!(active_job_id:) ⇒ Object 



415
416
417
418
419
420
421
 
# File 'lib/dispatch_policy/repository.rb', line 415

def delete_inflight!(active_job_id:)
  connection.exec_query(
    "DELETE FROM #{INFLIGHT_TABLE} WHERE active_job_id = $1",
    "delete_inflight",
    [active_job_id]
  )
end

.denied_reasons_summary(policy_name: nil, since:) ⇒ Object

Aggregate denied_reasons jsonb across samples in window: returns { “throttle” => 12, “concurrency_full” => 3, … }



571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
 
# File 'lib/dispatch_policy/repository.rb', line 571

def denied_reasons_summary(policy_name: nil, since:)
  where_sql, params = sample_filter(policy_name, since)
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT key, SUM(value::int)::int AS total
      FROM #{SAMPLES_TABLE},
           LATERAL jsonb_each_text(denied_reasons)
      #{where_sql}
      GROUP BY key
      ORDER BY total DESC
    SQL
    "denied_reasons_summary",
    params
  )
  result.to_a.each_with_object({}) { |r, h| h[r["key"]] = r["total"].to_i }
end

.heartbeat_inflight!(active_job_id:) ⇒ Object 



423
424
425
426
427
428
429
 
# File 'lib/dispatch_policy/repository.rb', line 423

def heartbeat_inflight!(active_job_id:)
  connection.exec_query(
    "UPDATE #{INFLIGHT_TABLE} SET heartbeat_at = now() WHERE active_job_id = $1",
    "heartbeat_inflight",
    [active_job_id]
  )
end

.insert_inflight!(rows) ⇒ Object

—– inflight tracking —————————————————



383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
 
# File 'lib/dispatch_policy/repository.rb', line 383

def insert_inflight!(rows)
  return if rows.empty?

  values_sql = []
  params     = []
  rows.each_with_index do |row, idx|
    base = idx * 3
    values_sql << "($#{base + 1}, $#{base + 2}, $#{base + 3}, now(), now())"
    params.push(row[:policy_name], row[:partition_key], row[:active_job_id])
  end
  # ON CONFLICT (active_job_id) DO NOTHING covers two paths that
  # the around_perform tracker exercises on its own:
  #   1) the around_perform inflight insert runs even when the row
  #      was already pre-inserted by Tick (concurrency-gated policies);
  #   2) a stale row that survived a crash gets re-inserted by the
  #      around_perform without colliding while the sweeper is still
  #      catching up.
  # Admission proper can no longer collide here: Tick regenerates
  # active_job_id before this insert, so each admission contributes a
  # fresh UUID.
  connection.exec_query(
    <<~SQL.squish,
      INSERT INTO #{INFLIGHT_TABLE}
        (policy_name, partition_key, active_job_id, admitted_at, heartbeat_at)
      VALUES #{values_sql.join(", ")}
      ON CONFLICT (active_job_id) DO NOTHING
    SQL
    "insert_inflight",
    params
  )
end

.next_eligible_clause(retry_after) ⇒ Object 



912
913
914
915
916
917
918
919
 
# File 'lib/dispatch_policy/repository.rb', line 912

def next_eligible_clause(retry_after)
  if retry_after.nil?
    ["NULL", []]
  else
    # 5th param ($5) — caller appends params to those of the parent UPDATE
    ["now() + ($5 || ' seconds')::interval", [retry_after.to_f.round(3)]]
  end
end

.normalize_partition(row) ⇒ Object

—– helpers ————————————————————–



873
874
875
876
877
878
879
 
# File 'lib/dispatch_policy/repository.rb', line 873

def normalize_partition(row)
  out = {}
  row.each { |k, v| out[k.to_s] = v }
  out["context"]    = parse_jsonb(out["context"])
  out["gate_state"] = parse_jsonb(out["gate_state"])
  out
end

.normalize_staged(row) ⇒ Object 



881
882
883
884
885
886
887
 
# File 'lib/dispatch_policy/repository.rb', line 881

def normalize_staged(row)
  out = {}
  row.each { |k, v| out[k.to_s] = v }
  out["job_data"] = parse_jsonb(out["job_data"])
  out["context"]  = parse_jsonb(out["context"])
  out
end

.parse_jsonb(value) ⇒ Object 



889
890
891
892
893
894
895
896
897
898
899
900
 
# File 'lib/dispatch_policy/repository.rb', line 889

def parse_jsonb(value)
  case value
  when Hash, Array then value
  when nil, ""      then {}
  else
    begin
      JSON.parse(value)
    rescue JSON::ParserError
      {}
    end
  end
end

.partition_counts_by_policy ⇒ Object

Per-policy partition counts in one grouped query, keyed by policy_name → { pending, partitions, paused }. Replaces calling Partition.for_policy(name).sum/.count/.paused.count once per policy on the policies index (3N queries → 1).



721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
 
# File 'lib/dispatch_policy/repository.rb', line 721

def partition_counts_by_policy
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        policy_name,
        COALESCE(SUM(pending_count), 0)::int                 AS pending,
        COUNT(*)::int                                        AS partitions,
        COUNT(*) FILTER (WHERE status = 'paused')::int       AS paused
      FROM #{PARTITIONS_TABLE}
      GROUP BY policy_name
    SQL
    "partition_counts_by_policy",
    []
  )
  result.to_a.each_with_object({}) do |r, h|
    h[r["policy_name"]] = {
      pending:    r["pending"].to_i,
      partitions: r["partitions"].to_i,
      paused:     r["paused"].to_i
    }
  end
end

.partition_round_trip_stats(policy_name: nil) ⇒ Object

Round-trip statistics across active partitions: how stale is the most- stale partition the tick has yet to revisit? P50/P95/oldest ages help decide if partition_batch_size needs to grow or ticks need sharding.



677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
 
# File 'lib/dispatch_policy/repository.rb', line 677

def partition_round_trip_stats(policy_name: nil)
  filter_sql = "WHERE p.status = 'active' AND p.pending_count > 0"
  params     = []
  if policy_name
    filter_sql += " AND p.policy_name = $1"
    params << policy_name
  end

  # For ages (now - last_checked_at) the percentile direction inverts:
  # the 95th percentile of *age* corresponds to the 5th percentile of the
  # *timestamp* (the oldest 5% of last_checked_at values). Computing the
  # percentile directly on now()-last_checked_at would be cleaner but
  # PostgreSQL's PERCENTILE_DISC needs an ordered set on a column, so we
  # invert the percentile argument instead.
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        COUNT(*)::int AS active_partitions,
        COUNT(*) FILTER (WHERE p.last_checked_at IS NULL)::int AS never_checked,
        COUNT(*) FILTER (WHERE p.next_eligible_at IS NOT NULL AND p.next_eligible_at > now())::int AS in_backoff,
        EXTRACT(EPOCH FROM (now() - MIN(p.last_checked_at)))::float AS oldest_age_seconds,
        EXTRACT(EPOCH FROM (now() - PERCENTILE_DISC(0.5)  WITHIN GROUP (ORDER BY p.last_checked_at)))::float AS p50_age_seconds,
        EXTRACT(EPOCH FROM (now() - PERCENTILE_DISC(0.05) WITHIN GROUP (ORDER BY p.last_checked_at)))::float AS p95_age_seconds
      FROM #{PARTITIONS_TABLE} p
      #{filter_sql}
    SQL
    "partition_round_trip_stats",
    params
  )
  row = result.first || {}
  {
    active_partitions:  row["active_partitions"].to_i,
    never_checked:      row["never_checked"].to_i,
    in_backoff:         row["in_backoff"].to_i,
    oldest_age_seconds: row["oldest_age_seconds"]&.to_f,
    p50_age_seconds:    row["p50_age_seconds"]&.to_f,
    p95_age_seconds:    row["p95_age_seconds"]&.to_f
  }
end

.partition_round_trip_stats_by_policy ⇒ Object

Per-policy round-trip stats in one grouped query, keyed by policy_name. Only the fields the dashboard overview renders (in_backoff, oldest/p95 age); use partition_round_trip_stats for the full single-policy breakdown. Replaces N per-policy calls on the dashboard. Same percentile-inversion note as partition_round_trip_stats.



749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
 
# File 'lib/dispatch_policy/repository.rb', line 749

def partition_round_trip_stats_by_policy
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        p.policy_name,
        COUNT(*) FILTER (WHERE p.next_eligible_at IS NOT NULL AND p.next_eligible_at > now())::int AS in_backoff,
        EXTRACT(EPOCH FROM (now() - MIN(p.last_checked_at)))::float AS oldest_age_seconds,
        EXTRACT(EPOCH FROM (now() - PERCENTILE_DISC(0.05) WITHIN GROUP (ORDER BY p.last_checked_at)))::float AS p95_age_seconds
      FROM #{PARTITIONS_TABLE} p
      WHERE p.status = 'active' AND p.pending_count > 0
      GROUP BY p.policy_name
    SQL
    "partition_round_trip_stats_by_policy",
    []
  )
  result.to_a.each_with_object({}) do |r, h|
    h[r["policy_name"]] = {
      in_backoff:         r["in_backoff"].to_i,
      oldest_age_seconds: r["oldest_age_seconds"]&.to_f,
      p95_age_seconds:    r["p95_age_seconds"]&.to_f
    }
  end
end

.record_partition_admit!(policy_name:, partition_key:, admitted:, gate_state_patch:, retry_after:, half_life_seconds: nil) ⇒ Object

Per-partition admit-state UPDATE. Runs inside the per-partition admission TX alongside the DELETE, so pending_count / total_admitted / gate_state changes commit atomically with the claim and the adapter handoff. For the deny case use ‘bulk_record_partition_denies!`.

When ‘half_life_seconds` is non-nil, the row’s EWMA decayed_admits counter is also refreshed in the same UPDATE: previous value decays exponentially based on the elapsed wall time since the last update, then ‘admitted` is added on top. This keeps fairness state atomic with the admit (no separate write, no race) and leaves the partitions row’s lock undisturbed.



258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
 
# File 'lib/dispatch_policy/repository.rb', line 258

def record_partition_admit!(policy_name:, partition_key:, admitted:, gate_state_patch:,
                            retry_after:, half_life_seconds: nil)
  next_eligible_sql, next_eligible_params = next_eligible_clause(retry_after)
  gate_state_json = JSON.dump(gate_state_patch || {})

  params = [policy_name, partition_key, admitted, gate_state_json, *next_eligible_params]

  if half_life_seconds && half_life_seconds.to_f.positive?
    # decay constant τ such that exp(-Δt/τ) halves every half_life:
    # τ = half_life / ln(2). NULLIF guards a degenerate τ=0.
    #
    # The GREATEST(..., -700) clamp keeps `exp()` from raising
    # `value out of range: underflow` when a partition has been
    # idle for many half-lives. Postgres throws around
    # `exp(-746)` on double precision; -700 still yields a finite
    # ~9.86e-305, which is effectively zero for the EWMA. Without
    # the clamp, a partition idle long enough for Δt/τ to exceed
    # ~746 breaks every subsequent admission UPDATE on it: Tick
    # rolls back the whole TX, the staged rows return, and the
    # partition never drains.
    decay_idx        = params.size + 1
    admitted_idx_for_ewma = 3
    decay_tau        = half_life_seconds.to_f / Math.log(2)
    params << decay_tau
    decay_sql = <<~SQL.squish
      decayed_admits     = decayed_admits *
                            exp(GREATEST(
                              - COALESCE(EXTRACT(EPOCH FROM (now() - decayed_admits_at)), 0)
                                / NULLIF($#{decay_idx}::double precision, 0),
                              -700
                            ))
                          + $#{admitted_idx_for_ewma},
      decayed_admits_at  = now(),
    SQL
  else
    decay_sql = ""
  end

  connection.exec_query(
    <<~SQL.squish,
      UPDATE #{PARTITIONS_TABLE}
      SET pending_count    = GREATEST(pending_count - $3, 0),
          total_admitted   = total_admitted + $3,
          last_admit_at    = CASE WHEN $3 > 0 THEN now() ELSE last_admit_at END,
          gate_state       = gate_state || $4::jsonb,
          next_eligible_at = #{next_eligible_sql},
          #{decay_sql}
          updated_at       = now()
      WHERE policy_name = $1 AND partition_key = $2
    SQL
    "record_partition_admit",
    params
  )
end

.record_tick_sample!(policy_name:, duration_ms:, partitions_seen:, partitions_admitted:, partitions_denied:, jobs_admitted:, forward_failures:, pending_total:, inflight_total:, denied_reasons:) ⇒ Object

Records one row per Tick.run with admission and timing aggregates so the operator UI can display rates over time without sampling on the read path.



484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
 
# File 'lib/dispatch_policy/repository.rb', line 484

def record_tick_sample!(policy_name:, duration_ms:, partitions_seen:, partitions_admitted:,
                        partitions_denied:, jobs_admitted:, forward_failures:,
                        pending_total:, inflight_total:, denied_reasons:)
  connection.exec_query(
    <<~SQL.squish,
      INSERT INTO #{SAMPLES_TABLE}
        (policy_name, sampled_at, duration_ms, partitions_seen, partitions_admitted,
         partitions_denied, jobs_admitted, forward_failures, pending_total,
         inflight_total, denied_reasons)
      VALUES ($1, now(), $2, $3, $4, $5, $6, $7, $8, $9, $10::jsonb)
    SQL
    "record_tick_sample",
    [policy_name, duration_ms.to_i, partitions_seen.to_i, partitions_admitted.to_i,
     partitions_denied.to_i, jobs_admitted.to_i, forward_failures.to_i,
     pending_total.to_i, inflight_total.to_i, JSON.dump(denied_reasons || {})]
  )
end

.sample_filter(policy_name, since) ⇒ Object 



902
903
904
905
906
907
908
909
910
 
# File 'lib/dispatch_policy/repository.rb', line 902

def sample_filter(policy_name, since)
  params = [since]
  if policy_name
    params << policy_name
    ["WHERE sampled_at >= $1 AND policy_name = $2", params]
  else
    ["WHERE sampled_at >= $1", params]
  end
end

.set_policy_paused!(policy_name:, paused:) ⇒ Object

Upsert the pause flag for a policy. The tick’s claim_partitions reads this row, so toggling it takes effect for every partition of the policy — including ones created after the toggle.



368
369
370
371
372
373
374
375
376
377
378
379
 
# File 'lib/dispatch_policy/repository.rb', line 368

def set_policy_paused!(policy_name:, paused:)
  connection.exec_query(
    <<~SQL.squish,
      INSERT INTO #{POLICY_SETTINGS_TABLE} (policy_name, paused, created_at, updated_at)
      VALUES ($1, $2, now(), now())
      ON CONFLICT (policy_name)
      DO UPDATE SET paused = EXCLUDED.paused, updated_at = now()
    SQL
    "set_policy_paused",
    [policy_name, paused ? true : false]
  )
end

.stage!(policy_name:, partition_key:, queue_name:, job_class:, job_data:, context:, shard: Policy::DEFAULT_SHARD, scheduled_at: nil, priority: 0) ⇒ Object

Insert one staged_job row + UPSERT its partition. The partition’s ‘context` is refreshed on every call so admission-time gates always see the latest dynamic config.

Parameters:

  • policy_name (String)
  • partition_key (String)
  • queue_name (String, nil)
  • job_class (String)
  • job_data (Hash)
  • context (Hash)
  • scheduled_at (Time, nil) (defaults to: nil)
  • priority (Integer) (defaults to: 0) 


55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/dispatch_policy/repository.rb', line 55

def stage!(policy_name:, partition_key:, queue_name:, job_class:, job_data:, context:,
           shard: Policy::DEFAULT_SHARD, scheduled_at: nil, priority: 0)
  connection.transaction(requires_new: true) do
    connection.exec_query(
      <<~SQL.squish,
        INSERT INTO #{STAGED_TABLE}
          (policy_name, partition_key, queue_name, job_class, job_data, context, scheduled_at, priority, enqueued_at)
        VALUES ($1, $2, $3, $4, $5::jsonb, $6::jsonb, $7, $8, now())
      SQL
      "stage_job",
      [policy_name, partition_key, queue_name, job_class, JSON.dump(job_data), JSON.dump(context), scheduled_at, priority]
    )
    upsert_partition!(
      policy_name:   policy_name,
      partition_key: partition_key,
      queue_name:    queue_name,
      shard:         shard,
      context:       context,
      delta_pending: 1
    )
  end
  true
end

.stage_many!(rows) ⇒ Object 



88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
 
# File 'lib/dispatch_policy/repository.rb', line 88

def stage_many!(rows)
  return 0 if rows.empty?

  connection.transaction(requires_new: true) do
    rows.each_slice(STAGE_MANY_BATCH) do |slice|
      values_sql = []
      params     = []
      slice.each_with_index do |row, idx|
        base = idx * 8
        values_sql << "($#{base + 1}, $#{base + 2}, $#{base + 3}, $#{base + 4}, $#{base + 5}::jsonb, $#{base + 6}::jsonb, $#{base + 7}, $#{base + 8})"
        params.push(
          row[:policy_name],
          row[:partition_key],
          row[:queue_name],
          row[:job_class],
          JSON.dump(row[:job_data]),
          JSON.dump(row[:context] || {}),
          row[:scheduled_at],
          row[:priority] || 0
        )
      end
      connection.exec_query(
        <<~SQL.squish,
          INSERT INTO #{STAGED_TABLE}
            (policy_name, partition_key, queue_name, job_class, job_data, context, scheduled_at, priority)
          VALUES #{values_sql.join(", ")}
        SQL
        "stage_many",
        params
      )
    end

    rows.group_by { |r| [r[:policy_name], r[:partition_key]] }.each do |(policy_name, partition_key), group|
      upsert_partition!(
        policy_name:   policy_name,
        partition_key: partition_key,
        queue_name:    group.first[:queue_name],
        shard:         group.first[:shard] || Policy::DEFAULT_SHARD,
        context:       group.last[:context] || {},
        delta_pending: group.size
      )
    end
  end
  rows.size
end

.sweep_inactive_partitions!(cutoff_seconds:) ⇒ Object 



854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
 
# File 'lib/dispatch_policy/repository.rb', line 854

def sweep_inactive_partitions!(cutoff_seconds:)
  connection.exec_query(
    <<~SQL.squish,
      DELETE FROM #{PARTITIONS_TABLE}
      WHERE pending_count = 0
        AND status = 'active'
        AND (
          (last_admit_at IS NOT NULL AND last_admit_at < now() - ($1 || ' seconds')::interval)
          OR
          (last_admit_at IS NULL AND created_at < now() - ($1 || ' seconds')::interval)
        )
    SQL
    "sweep_inactive_partitions",
    [cutoff_seconds.to_i]
  )
end

.sweep_old_tick_samples!(cutoff_seconds:) ⇒ Object

—– tick samples sweep ————————————————-



844
845
846
847
848
849
850
 
# File 'lib/dispatch_policy/repository.rb', line 844

def sweep_old_tick_samples!(cutoff_seconds:)
  connection.exec_query(
    "DELETE FROM #{SAMPLES_TABLE} WHERE sampled_at < now() - ($1 || ' seconds')::interval",
    "sweep_old_tick_samples",
    [cutoff_seconds.to_i]
  )
end

.sweep_stale_inflight!(cutoff_seconds:, queued_cutoff_seconds: nil) ⇒ Object

Reap inflight rows whose owner is gone. Two tiers, distinguished by whether the row was ever heartbeated past its admission:

heartbeat_at > admitted_at  → the worker started performing and the
  heartbeat thread advanced heartbeat_at at least once. If it then
  went silent for `cutoff_seconds`, the worker died mid-run: reap.

heartbeat_at <= admitted_at → never heartbeated past admission. The
  row was pre-inserted by the Tick and the job is still waiting in
  the adapter's queue (or only just started — the first heartbeat
  fires after inflight_heartbeat_interval). Reaping these at the
  short cutoff would under-count the concurrency gate and over-admit
  whenever queue latency exceeds it. Only reap once they're older
  than the far more generous `queued_cutoff_seconds`, by which point
  the admission is presumed lost.

The Tick pre-insert writes admitted_at and heartbeat_at from the same now() (a single statement), so a never-started row has them exactly equal; one heartbeat makes heartbeat_at strictly greater.



459
460
461
462
463
464
465
466
467
468
469
470
471
472
 
# File 'lib/dispatch_policy/repository.rb', line 459

def sweep_stale_inflight!(cutoff_seconds:, queued_cutoff_seconds: nil)
  queued_cutoff_seconds ||= cutoff_seconds
  connection.exec_query(
    <<~SQL.squish,
      DELETE FROM #{INFLIGHT_TABLE}
      WHERE (heartbeat_at > admitted_at
             AND heartbeat_at < now() - ($1 || ' seconds')::interval)
         OR (heartbeat_at <= admitted_at
             AND admitted_at < now() - ($2 || ' seconds')::interval)
    SQL
    "sweep_stale_inflight",
    [cutoff_seconds.to_i, queued_cutoff_seconds.to_i]
  )
end

.tick_samples_buckets(policy_name: nil, since:, bucket_seconds: 60) ⇒ Object

Returns time-bucketed series for sparklines. ‘bucket_seconds` is the bucket width. Each row: { bucket_at:, jobs_admitted:, forward_failures:, pending_total:, ticks: }.

‘pending_total` is the AVERAGE pending observed across the ticks in that bucket — using AVG (not MAX/last) gives a smoother trend that’s resilient to a single outlier sample dragging the bucket up.



619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
 
# File 'lib/dispatch_policy/repository.rb', line 619

def tick_samples_buckets(policy_name: nil, since:, bucket_seconds: 60)
  where_sql, params = sample_filter(policy_name, since)
  bucket_param_idx = params.size + 1
  params << bucket_seconds.to_i

  # `date_bin` requires Postgres 14+. We compute the bucket via floor on
  # the epoch instead so the gem also runs on Postgres 12/13.
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        to_timestamp(floor(extract(epoch from sampled_at) / $#{bucket_param_idx})::bigint * $#{bucket_param_idx}) AS bucket_at,
        COALESCE(SUM(jobs_admitted), 0)::int AS jobs_admitted,
        COALESCE(SUM(forward_failures), 0)::int AS forward_failures,
        COALESCE(AVG(pending_total), 0)::int AS pending_total,
        COUNT(*)::int AS ticks
      FROM #{SAMPLES_TABLE}
      #{where_sql}
      GROUP BY bucket_at
      ORDER BY bucket_at ASC
    SQL
    "tick_samples_buckets",
    params
  )
  result.to_a.map do |r|
    { bucket_at:        r["bucket_at"],
      jobs_admitted:    r["jobs_admitted"].to_i,
      forward_failures: r["forward_failures"].to_i,
      pending_total:    r["pending_total"].to_i,
      ticks:            r["ticks"].to_i }
  end
end

.tick_summaries_by_policy(since:) ⇒ Object

One grouped query returning per-policy tick aggregates, keyed by policy_name. Replaces calling tick_summary once per policy on the dashboard (N queries → 1). Only the fields the overview renders.

{ "policy_a" => { jobs_admitted:, forward_failures:, ticks:,
                  avg_duration_ms: }, ... }



543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
 
# File 'lib/dispatch_policy/repository.rb', line 543

def tick_summaries_by_policy(since:)
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        policy_name,
        COALESCE(SUM(jobs_admitted), 0)::int    AS jobs_admitted,
        COALESCE(SUM(forward_failures), 0)::int AS forward_failures,
        COUNT(*)::int                           AS ticks,
        COALESCE(AVG(duration_ms), 0)::int      AS avg_duration_ms
      FROM #{SAMPLES_TABLE}
      WHERE sampled_at >= $1
      GROUP BY policy_name
    SQL
    "tick_summaries_by_policy",
    [since]
  )
  result.to_a.each_with_object({}) do |r, h|
    h[r["policy_name"]] = {
      jobs_admitted:    r["jobs_admitted"].to_i,
      forward_failures: r["forward_failures"].to_i,
      ticks:            r["ticks"].to_i,
      avg_duration_ms:  r["avg_duration_ms"].to_i
    }
  end
end

.tick_summary(policy_name: nil, since:) ⇒ Object

Aggregate counters since ‘since` (a Time). If `policy_name` is nil, aggregates across all policies. Returns a Hash with summary keys.



504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
 
# File 'lib/dispatch_policy/repository.rb', line 504

def tick_summary(policy_name: nil, since:)
  where_sql, params = sample_filter(policy_name, since)
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT
        COALESCE(SUM(jobs_admitted), 0)::int        AS jobs_admitted,
        COALESCE(SUM(partitions_seen), 0)::int       AS partitions_seen,
        COALESCE(SUM(partitions_admitted), 0)::int   AS partitions_admitted,
        COALESCE(SUM(partitions_denied), 0)::int     AS partitions_denied,
        COALESCE(SUM(forward_failures), 0)::int      AS forward_failures,
        COUNT(*)::int                                AS ticks,
        COALESCE(AVG(duration_ms), 0)::int           AS avg_duration_ms,
        COALESCE(MAX(duration_ms), 0)::int           AS max_duration_ms,
        MAX(sampled_at)                              AS last_sampled_at
      FROM #{SAMPLES_TABLE}
      #{where_sql}
    SQL
    "tick_summary",
    params
  )
  row = result.first || {}
  {
    jobs_admitted:       row["jobs_admitted"].to_i,
    partitions_seen:     row["partitions_seen"].to_i,
    partitions_admitted: row["partitions_admitted"].to_i,
    partitions_denied:   row["partitions_denied"].to_i,
    forward_failures:    row["forward_failures"].to_i,
    ticks:               row["ticks"].to_i,
    avg_duration_ms:     row["avg_duration_ms"].to_i,
    max_duration_ms:     row["max_duration_ms"].to_i,
    last_sampled_at:     row["last_sampled_at"]
  }
end

.top_denied_reason_by_policy(since:) ⇒ Object

The single most-denied reason per policy in one query, keyed by policy_name → [reason, count]. Replaces calling denied_reasons_summary per policy on the dashboard just to read its top entry.



591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
 
# File 'lib/dispatch_policy/repository.rb', line 591

def top_denied_reason_by_policy(since:)
  result = connection.exec_query(
    <<~SQL.squish,
      SELECT DISTINCT ON (policy_name) policy_name, key, total
      FROM (
        SELECT policy_name, key, SUM(value::int)::int AS total
        FROM #{SAMPLES_TABLE},
             LATERAL jsonb_each_text(denied_reasons)
        WHERE sampled_at >= $1
        GROUP BY policy_name, key
      ) t
      ORDER BY policy_name, total DESC
    SQL
    "top_denied_reason_by_policy",
    [since]
  )
  result.to_a.each_with_object({}) do |r, h|
    h[r["policy_name"]] = [r["key"], r["total"].to_i]
  end
end

.trend_direction(values, threshold_ratio: 0.10) ⇒ Object

Direction of a numeric series. Compares the average of the first third to the last third — robust to noise on the ends.



653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
 
# File 'lib/dispatch_policy/repository.rb', line 653

def self.trend_direction(values, threshold_ratio: 0.10)
  return :flat if values.size < 3

  n      = values.size
  head   = values.first(n / 3)
  tail   = values.last(n / 3)
  head_avg = head.sum.to_f / head.size
  tail_avg = tail.sum.to_f / tail.size

  return :flat if head_avg.zero? && tail_avg.zero?

  delta_ratio = (tail_avg - head_avg) / [head_avg, 1.0].max
  if delta_ratio >= threshold_ratio
    :up
  elsif delta_ratio <= -threshold_ratio
    :down
  else
    :flat
  end
end

.upsert_partition!(policy_name:, partition_key:, queue_name:, context:, delta_pending:, shard: Policy::DEFAULT_SHARD) ⇒ Object 



134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
 
# File 'lib/dispatch_policy/repository.rb', line 134

def upsert_partition!(policy_name:, partition_key:, queue_name:, context:, delta_pending:,
                      shard: Policy::DEFAULT_SHARD)
  connection.exec_query(
    <<~SQL.squish,
      INSERT INTO #{PARTITIONS_TABLE}
        (policy_name, partition_key, queue_name, shard, context, context_updated_at,
         pending_count, last_enqueued_at, status, gate_state, created_at, updated_at)
      VALUES ($1, $2, $3, $4, $5::jsonb, now(), $6, now(), 'active', '{}'::jsonb, now(), now())
      ON CONFLICT (policy_name, partition_key) DO UPDATE SET
        context             = EXCLUDED.context,
        context_updated_at  = EXCLUDED.context_updated_at,
        queue_name          = COALESCE(EXCLUDED.queue_name, #{PARTITIONS_TABLE}.queue_name),
        shard               = #{PARTITIONS_TABLE}.shard,
        pending_count       = #{PARTITIONS_TABLE}.pending_count + EXCLUDED.pending_count,
        last_enqueued_at    = EXCLUDED.last_enqueued_at,
        updated_at          = now()
    SQL
    "upsert_partition",
    [policy_name, partition_key, queue_name, shard, JSON.dump(context), delta_pending]
  )
end

.with_connection ⇒ Object

Wraps ‘block` in `connected_to(role: …)` when DispatchPolicy.config .database_role is set. Used by Tick to ensure the admission TX is opened against the same DB role that good_job / solid_queue uses, critical for multi-DB Rails setups (e.g. solid_queue on a separate `:queue` DB) where atomicity only holds when the staging TX and the adapter INSERT share a connection.



32
33
34
35
36
37
38
39
 
# File 'lib/dispatch_policy/repository.rb', line 32

def with_connection
  role = DispatchPolicy.config.database_role
  if role && ActiveRecord::Base.respond_to?(:connected_to)
    ActiveRecord::Base.connected_to(role: role) { yield }
  else
    yield
  end
end