feat(stovepipe): Add issue summary storage

stovepipe/entity/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "ingest.go",
         "issue_log.go",
         "issue_state.go",
+        "issue_summary.go",
         "issue_tracking_state.go",
         "list.go",
         "open_issue.go",
@@ -38,6 +39,7 @@ go_test(
         "build_test.go",
         "issue_log_test.go",
         "issue_state_test.go",
+        "issue_summary_test.go",
         "issue_tracking_state_test.go",
         "project_fact_by_degree_test.go",
         "queue_state_test.go",

stovepipe/entity/issue_summary.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package entity
+
+import (
+	"fmt"
+
+	"github.com/uber/submitqueue/platform/base/id"
+)
+
+// IssueSummary is the latest read model of an issue within a queue.
+// Closed summaries retain the source of their latest transition.
+type IssueSummary struct {
+	// TaskID identifies the logical validation task and must be nonempty.
+	TaskID string
+	// UnitID identifies the validation unit; empty means a task-wide issue.
+	UnitID string
+	// Status identifies whether the issue is open or closed.
+	Status IssueStatus
+	// FirstSeenBuildID identifies the current or most recent opening.
+	FirstSeenBuildID string
+	// RequestID is the canonical decimal source request ID of the latest transition.
+	RequestID string
+	// BuildID identifies the source build of the latest transition.
+	BuildID string
+	// ChangedAtMs is when the latest transition was first recorded, in Unix milliseconds.
+	ChangedAtMs int64
+	// Version is the positive optimistic-lock version of this summary.
+	Version int32
+}
+
+// Validate checks the identity, status, timestamp, and version of a summary.
+func (s IssueSummary) Validate() error {
+	if s.TaskID == "" || s.FirstSeenBuildID == "" || s.BuildID == "" {
+		return fmt.Errorf("issue summary requires task, first-seen build, and source build IDs")
+	}
+	if err := id.Validate(s.RequestID); err != nil {
+		return fmt.Errorf("invalid issue summary request ID: %w", err)
+	}
+	if s.Status != IssueStatusOpen && s.Status != IssueStatusClosed {
+		return fmt.Errorf("invalid issue summary status %q", s.Status)
+	}
+	if s.ChangedAtMs <= 0 {
+		return fmt.Errorf("issue summary requires a positive change timestamp")
+	}
+	if s.Version <= 0 {
+		return fmt.Errorf("issue summary requires a positive version")
+	}
+	return nil
+}

stovepipe/entity/issue_summary_test.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package entity
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIssueSummaryValidate(t *testing.T) {
+	valid := IssueSummary{TaskID: "validation", UnitID: "unit", Status: IssueStatusOpen,
+		FirstSeenBuildID: "build/1", RequestID: "1", BuildID: "build/1", ChangedAtMs: 1000, Version: 1}
+	tests := []struct {
+		name    string
+		change  func(*IssueSummary)
+		wantErr bool
+	}{
+		{name: "open"},
+		{name: "closed", change: func(s *IssueSummary) { s.Status = IssueStatusClosed }},
+		{name: "task wide", change: func(s *IssueSummary) { s.UnitID = "" }},
+		{"missing task", func(s *IssueSummary) { s.TaskID = "" }, true},
+		{"missing opening", func(s *IssueSummary) { s.FirstSeenBuildID = "" }, true},
+		{"missing source build", func(s *IssueSummary) { s.BuildID = "" }, true},
+		{"missing source request", func(s *IssueSummary) { s.RequestID = "" }, true},
+		{"noncanonical source request", func(s *IssueSummary) { s.RequestID = "01" }, true},
+		{"invalid source request", func(s *IssueSummary) { s.RequestID = "build/1" }, true},
+		{"unknown status", func(s *IssueSummary) { s.Status = IssueStatusUnknown }, true},
+		{"invalid status", func(s *IssueSummary) { s.Status = "other" }, true},
+		{"missing timestamp", func(s *IssueSummary) { s.ChangedAtMs = 0 }, true},
+		{"negative timestamp", func(s *IssueSummary) { s.ChangedAtMs = -1 }, true},
+		{"missing version", func(s *IssueSummary) { s.Version = 0 }, true},
+		{"negative version", func(s *IssueSummary) { s.Version = -1 }, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			summary := valid
+			if tt.change != nil {
+				tt.change(&summary)
+			}
+			if tt.wantErr {
+				require.Error(t, summary.Validate())
+			} else {
+				require.NoError(t, summary.Validate())
+			}
+		})
+	}
+}

stovepipe/extension/storage/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "build_store.go",
         "issue_log_store.go",
         "issue_state_store.go",
+        "issue_summary_store.go",
         "issue_tracking_store.go",
         "project_fact_by_degree_store.go",
         "queue_log_store.go",

stovepipe/extension/storage/README.md

@@ -50,6 +50,14 @@ Listing reads a bounded primary-key range in bytewise task/unit order and includ
 
 The MySQL backend uses the new `issue_state` table. Create it before deploying the updated readers. The prior `open_issue` table is not read or automatically copied; no in-repository runtime writer was enabled for it. Deployments with externally populated rows need an explicit backfill before switching readers. The repair executor still receives an `OpenIssue`, which describes an open occurrence rather than the storage record.
 
+## Issue summaries
+
+`IssueSummaryStore` retains one read model per task/unit within its queue, independently of operational `IssueState`. It supports only complete-key create, get, and CAS replacement. Closed summaries remain present; removing them would also remove the source-order information needed to reject an older opening. There is no deletion or listing operation.
+
+`RequestID` and `BuildID` identify the latest represented transition, while `FirstSeenBuildID` identifies its current or most recent opening. Source order follows request ingest order, not opaque build IDs or timestamps. Within the same request, a closing transition supersedes an opening. `Version` is only the summary's CAS guard, not the source order. The materializer must compare incoming transitions before replacing a summary; the store does not enforce lifecycle ordering.
+
+The MySQL primary key is `(queue, task_id, unit_id)` with byte-exact identity and the same identifier limits as the issue-state store. Source request IDs follow the existing canonical positive decimal ID contract. The new `issue_summary` table must exist before deploying readers or writers. This storage layer does not yet populate summaries or expose a public open-issues list.
+
 ## Issue lifecycle history
 
 `IssueLogStore` retains immutable open/closed status transitions independently of current issue state and per-build observations. Each transition is keyed by task, unit, build, and status within the bound queue. An empty unit identifies a task-wide issue. History remains when an issue closes or reopens; transitions do not carry a separate reference to the opening they belong to.

stovepipe/extension/storage/issue_summary_store.go

@@ -0,0 +1,37 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package storage
+
+//go:generate mockgen -source=issue_summary_store.go -destination=mock/issue_summary_store_mock.go -package=mock
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/stovepipe/entity"
+)
+
+// IssueSummaryStore retains queue-scoped issue read models, including closed issues.
+// Source ordering is the caller's responsibility; Version guards concurrent replacements.
+type IssueSummaryStore interface {
+	// Create returns ErrAlreadyExists if the task/unit key exists, even when closed.
+	Create(ctx context.Context, summary entity.IssueSummary) error
+
+	// Get returns ErrNotFound if the task/unit key has no summary.
+	Get(ctx context.Context, taskID, unitID string) (entity.IssueSummary, error)
+
+	// Update replaces summary only at oldVersion, writing the supplied newVersion.
+	// A missing key or stale version returns ErrVersionMismatch.
+	Update(ctx context.Context, summary entity.IssueSummary, oldVersion, newVersion int32) error
+}

stovepipe/extension/storage/mock/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "build_store_mock.go",
         "issue_log_store_mock.go",
         "issue_state_store_mock.go",
+        "issue_summary_store_mock.go",
         "issue_tracking_store_mock.go",
         "project_fact_by_degree_store_mock.go",
         "queue_log_store_mock.go",

stovepipe/extension/storage/mysql/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "build_store.go",
         "issue_log_store.go",
         "issue_state_store.go",
+        "issue_summary_store.go",
         "issue_tracking_store.go",
         "project_fact_by_degree_store.go",
         "queue_log_store.go",
@@ -41,6 +42,7 @@ go_test(
         "issue_log_store_test.go",
         "issue_state_list_test.go",
         "issue_state_store_test.go",
+        "issue_summary_store_test.go",
         "issue_tracking_store_test.go",
         "project_fact_by_degree_store_test.go",
         "queue_store_test.go",