feat: remove OpenSearch, add ClickHouse admin page

Remove all OpenSearch code, dependencies, configuration, deployment
manifests, and CI/CD references. Replace the OpenSearch admin page
with a ClickHouse admin page showing cluster status, table sizes,
performance metrics, and indexer pipeline stats.

- Delete 11 OpenSearch Java files (config, search impl, admin controller, DTOs, tests)
- Delete 3 OpenSearch frontend files (admin page, CSS, query hooks)
- Delete deploy/opensearch.yaml K8s manifest
- Remove opensearch Maven dependencies from pom.xml
- Remove opensearch config from application.yml, Dockerfile, docker-compose
- Remove opensearch from CI workflow (secrets, deploy, cleanup steps)
- Simplify ThresholdConfig (remove OpenSearch thresholds, database-only)
- Change default search backend from opensearch to clickhouse
- Add ClickHouseAdminController with /status, /tables, /performance, /pipeline
- Add ClickHouseAdminPage with StatCards, pipeline ProgressBar, tables DataTable
- Update CLAUDE.md, HOWTO.md, and source comments

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/api/queries/admin/clickhouse.ts

@@ -0,0 +1,77 @@
+import { useQuery } from '@tanstack/react-query';
+import { adminFetch } from './admin-api';
+import { useRefreshInterval } from '../use-refresh-interval';
+
+// ── Types ──────────────────────────────────────────────────────────────
+
+export interface ClickHouseStatus {
+  reachable: boolean;
+  version: string | null;
+  uptime: string | null;
+  host: string | null;
+}
+
+export interface ClickHouseTableInfo {
+  name: string;
+  engine: string;
+  rowCount: number;
+  dataSize: string;
+  dataSizeBytes: number;
+  partitionCount: number;
+}
+
+export interface ClickHousePerformance {
+  queryCount: number;
+  insertQueryCount: number;
+  memoryUsage: string;
+  insertedRows: number;
+  readRows: number;
+}
+
+export interface IndexerPipeline {
+  queueDepth: number;
+  maxQueueSize: number;
+  failedCount: number;
+  indexedCount: number;
+  debounceMs: number;
+  indexingRate: number;
+  lastIndexedAt: string | null;
+}
+
+// ── Query Hooks ────────────────────────────────────────────────────────
+
+export function useClickHouseStatus() {
+  const refetchInterval = useRefreshInterval(30_000);
+  return useQuery({
+    queryKey: ['admin', 'clickhouse', 'status'],
+    queryFn: () => adminFetch<ClickHouseStatus>('/clickhouse/status'),
+    refetchInterval,
+  });
+}
+
+export function useClickHouseTables() {
+  const refetchInterval = useRefreshInterval(60_000);
+  return useQuery({
+    queryKey: ['admin', 'clickhouse', 'tables'],
+    queryFn: () => adminFetch<ClickHouseTableInfo[]>('/clickhouse/tables'),
+    refetchInterval,
+  });
+}
+
+export function useClickHousePerformance() {
+  const refetchInterval = useRefreshInterval(30_000);
+  return useQuery({
+    queryKey: ['admin', 'clickhouse', 'performance'],
+    queryFn: () => adminFetch<ClickHousePerformance>('/clickhouse/performance'),
+    refetchInterval,
+  });
+}
+
+export function useIndexerPipeline() {
+  const refetchInterval = useRefreshInterval(10_000);
+  return useQuery({
+    queryKey: ['admin', 'clickhouse', 'pipeline'],
+    queryFn: () => adminFetch<IndexerPipeline>('/clickhouse/pipeline'),
+    refetchInterval,
+  });
+}

ui/src/api/queries/admin/opensearch.ts

@@ -1,109 +0,0 @@
-import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
-import { adminFetch } from './admin-api';
-import { useRefreshInterval } from '../use-refresh-interval';
-
-// ── Types ──────────────────────────────────────────────────────────────
-
-export interface OpenSearchStatus {
-  reachable: boolean;
-  clusterHealth: string;
-  version: string | null;
-  nodeCount: number;
-  host: string;
-}
-
-export interface PipelineStats {
-  queueDepth: number;
-  maxQueueSize: number;
-  failedCount: number;
-  indexedCount: number;
-  debounceMs: number;
-  indexingRate: number;
-  lastIndexedAt: string | null;
-}
-
-export interface IndexInfo {
-  name: string;
-  docCount: number;
-  size: string;
-  sizeBytes: number;
-  health: string;
-  primaryShards: number;
-  replicas: number;
-}
-
-export interface IndicesPage {
-  indices: IndexInfo[];
-  totalIndices: number;
-  totalDocs: number;
-  totalSize: string;
-  page: number;
-  pageSize: number;
-  totalPages: number;
-}
-
-export interface PerformanceStats {
-  queryCacheHitRate: number;
-  requestCacheHitRate: number;
-  searchLatencyMs: number;
-  indexingLatencyMs: number;
-  heapUsedBytes: number;
-  heapMaxBytes: number;
-}
-
-// ── Query Hooks ────────────────────────────────────────────────────────
-
-export function useOpenSearchStatus() {
-  const refetchInterval = useRefreshInterval(30_000);
-  return useQuery({
-    queryKey: ['admin', 'opensearch', 'status'],
-    queryFn: () => adminFetch<OpenSearchStatus>('/opensearch/status'),
-    refetchInterval,
-  });
-}
-
-export function usePipelineStats() {
-  const refetchInterval = useRefreshInterval(10_000);
-  return useQuery({
-    queryKey: ['admin', 'opensearch', 'pipeline'],
-    queryFn: () => adminFetch<PipelineStats>('/opensearch/pipeline'),
-    refetchInterval,
-  });
-}
-
-export function useOpenSearchIndices(page = 0, size = 20, search = '', prefix = 'executions') {
-  return useQuery({
-    queryKey: ['admin', 'opensearch', 'indices', prefix, page, size, search],
-    queryFn: () => {
-      const params = new URLSearchParams();
-      params.set('page', String(page));
-      params.set('size', String(size));
-      params.set('prefix', prefix);
-      if (search) params.set('search', search);
-      return adminFetch<IndicesPage>(`/opensearch/indices?${params}`);
-    },
-    placeholderData: (prev) => prev,
-  });
-}
-
-export function useOpenSearchPerformance() {
-  const refetchInterval = useRefreshInterval(30_000);
-  return useQuery({
-    queryKey: ['admin', 'opensearch', 'performance'],
-    queryFn: () => adminFetch<PerformanceStats>('/opensearch/performance'),
-    refetchInterval,
-  });
-}
-
-// ── Mutation Hooks ─────────────────────────────────────────────────────
-
-export function useDeleteIndex() {
-  const qc = useQueryClient();
-  return useMutation({
-    mutationFn: (indexName: string) =>
-      adminFetch<void>(`/opensearch/indices/${indexName}`, { method: 'DELETE' }),
-    onSuccess: () => {
-      qc.invalidateQueries({ queryKey: ['admin', 'opensearch', 'indices'] });
-    },
-  });
-}

ui/src/api/queries/admin/thresholds.ts

@@ -10,20 +10,8 @@ export interface DatabaseThresholds {
   queryDurationCritical: number;
 }
 
-export interface OpenSearchThresholds {
-  clusterHealthWarning: string;
-  clusterHealthCritical: string;
-  queueDepthWarning: number;
-  queueDepthCritical: number;
-  jvmHeapWarning: number;
-  jvmHeapCritical: number;
-  failedDocsWarning: number;
-  failedDocsCritical: number;
-}
-
 export interface ThresholdConfig {
   database: DatabaseThresholds;
-  opensearch: OpenSearchThresholds;
 }
 
 // ── Query Hooks ────────────────────────────────────────────────────────

ui/src/components/LayoutShell.tsx

@@ -184,7 +184,7 @@ function LayoutContent() {
         audit: 'Audit Log',
         oidc: 'OIDC',
         database: 'Database',
-        opensearch: 'OpenSearch',
+        clickhouse: 'ClickHouse',
         appconfig: 'App Config',
       };
       const parts = location.pathname.split('/').filter(Boolean);

ui/src/pages/Admin/AdminLayout.tsx

@@ -7,7 +7,7 @@ const ADMIN_TABS = [
   { label: 'OIDC', value: '/admin/oidc' },
   { label: 'App Config', value: '/admin/appconfig' },
   { label: 'Database', value: '/admin/database' },
-  { label: 'OpenSearch', value: '/admin/opensearch' },
+  { label: 'ClickHouse', value: '/admin/clickhouse' },
 ];
 
 export default function AdminLayout() {

ui/src/pages/Admin/ClickHouseAdminPage.module.css

@@ -33,7 +33,7 @@
   font-family: var(--font-mono);
 }
 
-.indexSection {
+.tableSection {
   background: var(--bg-surface);
   border: 1px solid var(--border-subtle);
   border-radius: var(--radius-lg);
@@ -42,7 +42,7 @@
   overflow: hidden;
 }
 
-.indexHeader {
+.tableHeader {
   display: flex;
   align-items: center;
   justify-content: space-between;
@@ -50,13 +50,13 @@
   border-bottom: 1px solid var(--border-subtle);
 }
 
-.indexTitle {
+.tableTitle {
   font-size: 13px;
   font-weight: 600;
   color: var(--text-primary);
 }
 
-.indexMeta {
+.tableMeta {
   font-size: 11px;
   color: var(--text-muted);
   font-family: var(--font-mono);

ui/src/pages/Admin/ClickHouseAdminPage.tsx

@@ -0,0 +1,65 @@
+import { StatCard, DataTable, ProgressBar } from '@cameleer/design-system';
+import type { Column } from '@cameleer/design-system';
+import { useClickHouseStatus, useClickHouseTables, useClickHousePerformance, useIndexerPipeline } from '../../api/queries/admin/clickhouse';
+import styles from './ClickHouseAdminPage.module.css';
+
+export default function ClickHouseAdminPage() {
+  const { data: status, isError: statusError } = useClickHouseStatus();
+  const { data: tables } = useClickHouseTables();
+  const { data: perf } = useClickHousePerformance();
+  const { data: pipeline } = useIndexerPipeline();
+  const unreachable = statusError || (status && !status.reachable);
+
+  const tableColumns: Column<any>[] = [
+    { key: 'name', header: 'Table', sortable: true },
+    { key: 'engine', header: 'Engine' },
+    { key: 'rowCount', header: 'Rows', sortable: true, render: (v) => Number(v).toLocaleString() },
+    { key: 'dataSize', header: 'Size', sortable: true },
+    { key: 'partitionCount', header: 'Partitions', sortable: true },
+  ];
+
+  return (
+    <div>
+      <div className={styles.statStrip}>
+        <StatCard label="Status" value={unreachable ? 'Disconnected' : status ? 'Connected' : '\u2014'} accent={unreachable ? 'error' : status ? 'success' : undefined} />
+        <StatCard label="Version" value={status?.version ?? '\u2014'} />
+        <StatCard label="Uptime" value={status?.uptime ?? '\u2014'} />
+      </div>
+
+      {pipeline && (
+        <div className={styles.pipelineCard}>
+          <div className={styles.pipelineTitle}>Indexer Pipeline</div>
+          <ProgressBar value={pipeline.maxQueueSize > 0 ? (pipeline.queueDepth / pipeline.maxQueueSize) * 100 : 0} />
+          <div className={styles.pipelineMetrics}>
+            <span>Queue: {pipeline.queueDepth}/{pipeline.maxQueueSize}</span>
+            <span>Indexed: {pipeline.indexedCount.toLocaleString()}</span>
+            <span>Failed: {pipeline.failedCount}</span>
+            <span>Rate: {pipeline.indexingRate.toFixed(1)}/s</span>
+          </div>
+        </div>
+      )}
+
+      {perf && (
+        <div className={styles.statStrip}>
+          <StatCard label="Select Queries" value={perf.queryCount.toLocaleString()} />
+          <StatCard label="Insert Queries" value={perf.insertQueryCount.toLocaleString()} />
+          <StatCard label="Memory" value={perf.memoryUsage} />
+          <StatCard label="Rows Read" value={perf.readRows.toLocaleString()} />
+        </div>
+      )}
+
+      <div className={styles.tableSection}>
+        <div className={styles.tableHeader}>
+          <span className={styles.tableTitle}>Tables ({(tables || []).length})</span>
+        </div>
+        <DataTable
+          columns={tableColumns}
+          data={(tables || []).map((t: any) => ({ ...t, id: t.name }))}
+          sortable
+          pageSize={20}
+          flush
+        />
+      </div>
+    </div>
+  );
+}

ui/src/pages/Admin/OpenSearchAdminPage.tsx

@@ -1,78 +0,0 @@
-import { StatCard, DataTable, Badge, ProgressBar } from '@cameleer/design-system';
-import type { Column } from '@cameleer/design-system';
-import { useOpenSearchStatus, usePipelineStats, useOpenSearchIndices, useOpenSearchPerformance, useDeleteIndex } from '../../api/queries/admin/opensearch';
-import styles from './OpenSearchAdminPage.module.css';
-
-export default function OpenSearchAdminPage() {
-  const { data: status, isError: statusError } = useOpenSearchStatus();
-  const { data: pipeline } = usePipelineStats();
-  const { data: perf } = useOpenSearchPerformance();
-  const { data: execIndices } = useOpenSearchIndices(0, 50, '', 'executions');
-  const { data: logIndices } = useOpenSearchIndices(0, 50, '', 'logs');
-  const unreachable = statusError || (status && !status.reachable);
-  const deleteIndex = useDeleteIndex();
-
-  const indexColumns: Column<any>[] = [
-    { key: 'name', header: 'Index' },
-    { key: 'health', header: 'Health', render: (v) => <Badge label={String(v)} color={v === 'green' ? 'success' : v === 'yellow' ? 'warning' : 'error'} /> },
-    { key: 'docCount', header: 'Documents', sortable: true, render: (v) => Number(v).toLocaleString() },
-    { key: 'size', header: 'Size' },
-    { key: 'primaryShards', header: 'Shards' },
-  ];
-
-  return (
-    <div>
-      <div className={styles.statStrip}>
-        <StatCard label="Status" value={unreachable ? 'Disconnected' : status ? 'Connected' : '\u2014'} accent={unreachable ? 'error' : status ? 'success' : undefined} />
-        <StatCard label="Health" value={status?.clusterHealth ?? '\u2014'} accent={status?.clusterHealth === 'green' ? 'success' : 'warning'} />
-        <StatCard label="Version" value={status?.version ?? '\u2014'} />
-        <StatCard label="Nodes" value={status?.nodeCount ?? 0} />
-      </div>
-
-      {pipeline && (
-        <div className={styles.pipelineCard}>
-          <div className={styles.pipelineTitle}>Indexing Pipeline</div>
-          <ProgressBar value={(pipeline.queueDepth / pipeline.maxQueueSize) * 100} />
-          <div className={styles.pipelineMetrics}>
-            <span>Queue: {pipeline.queueDepth}/{pipeline.maxQueueSize}</span>
-            <span>Indexed: {pipeline.indexedCount.toLocaleString()}</span>
-            <span>Failed: {pipeline.failedCount}</span>
-            <span>Rate: {pipeline.indexingRate}/s</span>
-          </div>
-        </div>
-      )}
-
-      <div className={styles.indexSection}>
-        <div className={styles.indexHeader}>
-          <span className={styles.indexTitle}>Execution Indices ({execIndices?.totalIndices ?? 0})</span>
-          <span className={styles.indexMeta}>
-            {execIndices ? `${execIndices.totalDocs.toLocaleString()} docs \u00b7 ${execIndices.totalSize}` : ''}
-          </span>
-        </div>
-        <DataTable
-          columns={indexColumns}
-          data={(execIndices?.indices || []).map((i: any) => ({ ...i, id: i.name }))}
-          sortable
-          pageSize={20}
-          flush
-        />
-      </div>
-
-      <div className={styles.indexSection}>
-        <div className={styles.indexHeader}>
-          <span className={styles.indexTitle}>Log Indices ({logIndices?.totalIndices ?? 0})</span>
-          <span className={styles.indexMeta}>
-            {logIndices ? `${logIndices.totalDocs.toLocaleString()} docs \u00b7 ${logIndices.totalSize}` : ''}
-          </span>
-        </div>
-        <DataTable
-          columns={indexColumns}
-          data={(logIndices?.indices || []).map((i: any) => ({ ...i, id: i.name }))}
-          sortable
-          pageSize={20}
-          flush
-        />
-      </div>
-    </div>
-  );
-}

ui/src/pages/AgentInstance/AgentInstance.tsx

@@ -141,7 +141,7 @@ export default function AgentInstance() {
     [chartData],
   );
 
-  // Application logs from OpenSearch
+  // Application logs
   const { data: rawLogs } = useApplicationLogs(appId, instanceId, { toOverride: logRefreshTo });
   const logEntries = useMemo<LogEntry[]>(() => {
     const mapped = (rawLogs || []).map((l) => ({

ui/src/router.tsx

@@ -14,7 +14,7 @@ const RbacPage = lazy(() => import('./pages/Admin/RbacPage'));
 const AuditLogPage = lazy(() => import('./pages/Admin/AuditLogPage'));
 const OidcConfigPage = lazy(() => import('./pages/Admin/OidcConfigPage'));
 const DatabaseAdminPage = lazy(() => import('./pages/Admin/DatabaseAdminPage'));
-const OpenSearchAdminPage = lazy(() => import('./pages/Admin/OpenSearchAdminPage'));
+const ClickHouseAdminPage = lazy(() => import('./pages/Admin/ClickHouseAdminPage'));
 const AppConfigPage = lazy(() => import('./pages/Admin/AppConfigPage'));
 const SwaggerPage = lazy(() => import('./pages/Swagger/SwaggerPage'));
 
@@ -87,7 +87,7 @@ export const router = createBrowserRouter([
               { path: 'oidc', element: <SuspenseWrapper><OidcConfigPage /></SuspenseWrapper> },
               { path: 'appconfig', element: <SuspenseWrapper><AppConfigPage /></SuspenseWrapper> },
               { path: 'database', element: <SuspenseWrapper><DatabaseAdminPage /></SuspenseWrapper> },
-              { path: 'opensearch', element: <SuspenseWrapper><OpenSearchAdminPage /></SuspenseWrapper> },
+              { path: 'clickhouse', element: <SuspenseWrapper><ClickHouseAdminPage /></SuspenseWrapper> },
             ],
           },
           { path: 'api-docs', element: <SuspenseWrapper><SwaggerPage /></SuspenseWrapper> },