[Logs UI] Fix log stream data fetching (#93201)

* Use ReplaySubject and amend date comparisons

* Assess date range expressions separately

* Only add dataset filter to view in stream links if one exists

x-pack/plugins/infra/public/containers/logs/log_position/log_position_state.ts

@@ -21,6 +21,7 @@ interface DateRange {
   startTimestamp: number;
   endTimestamp: number;
   timestampsLastUpdate: number;
+  lastCompleteDateRangeExpressionUpdate: number;
 }
 
 interface VisiblePositions {
@@ -46,6 +47,7 @@ export interface LogPositionStateParams {
   startTimestamp: number | null;
   endTimestamp: number | null;
   timestampsLastUpdate: number;
+  lastCompleteDateRangeExpressionUpdate: number;
 }
 
 export interface LogPositionCallbacks {
@@ -121,6 +123,7 @@ export const useLogPositionState: () => LogPositionStateParams & LogPositionCall
     startTimestamp: datemathToEpochMillis(DEFAULT_DATE_RANGE.startDateExpression)!,
     endTimestamp: datemathToEpochMillis(DEFAULT_DATE_RANGE.endDateExpression, 'up')!,
     timestampsLastUpdate: Date.now(),
+    lastCompleteDateRangeExpressionUpdate: Date.now(),
   });
 
   useEffect(() => {
@@ -171,12 +174,18 @@ export const useLogPositionState: () => LogPositionStateParams & LogPositionCall
         jumpToTargetPosition(null);
       }
 
-      setDateRange({
+      setDateRange((prevState) => ({
         ...newDateRange,
         startTimestamp: nextStartTimestamp,
         endTimestamp: nextEndTimestamp,
         timestampsLastUpdate: Date.now(),
-      });
+        // NOTE: Complete refers to the last time an update was requested with both expressions. These require a full refresh (unless streaming). Timerange expansion
+        // and pagination however do not.
+        lastCompleteDateRangeExpressionUpdate:
+          'startDateExpression' in newDateRange && 'endDateExpression' in newDateRange
+            ? Date.now()
+            : prevState.lastCompleteDateRangeExpressionUpdate,
+      }));
     },
     [setDateRange, dateRange, targetPosition]
   );

x-pack/plugins/infra/public/containers/logs/log_stream/use_fetch_log_entries_around.ts

@@ -6,7 +6,7 @@
  */
 
 import { useCallback } from 'react';
-import { combineLatest, Observable, Subject } from 'rxjs';
+import { combineLatest, Observable, ReplaySubject } from 'rxjs';
 import { last, map, startWith, switchMap } from 'rxjs/operators';
 import { LogSourceColumnConfiguration } from '../../../../common/http_api/log_sources';
 import { LogEntryCursor } from '../../../../common/log_entry';
@@ -53,7 +53,7 @@ export const useFetchLogEntriesAround = ({
   type LogEntriesAfterRequest = NonNullable<ReturnType<typeof fetchLogEntriesAfter>>;
 
   const logEntriesAroundSearchRequests$ = useObservable(
-    () => new Subject<[LogEntriesBeforeRequest, Observable<LogEntriesAfterRequest>]>(),
+    () => new ReplaySubject<[LogEntriesBeforeRequest, Observable<LogEntriesAfterRequest>]>(),
     []
   );
 

x-pack/plugins/infra/public/pages/logs/log_entry_rate/sections/anomalies/log_entry_example.tsx

@@ -111,10 +111,14 @@ export const LogEntryExampleMessage: React.FunctionComponent<Props> = ({
       flyoutOptions: encode({
         surroundingLogsId: id,
       }),
-      logFilter: encode({
-        expression: `${partitionField}: ${dataset}`,
-        kind: 'kuery',
-      }),
+      ...(dataset
+        ? {
+            logFilter: encode({
+              expression: `${partitionField}: ${dataset}`,
+              kind: 'kuery',
+            }),
+          }
+        : {}),
     },
   });
 

x-pack/plugins/infra/public/pages/logs/stream/page_logs_content.tsx

@@ -60,6 +60,7 @@ export const LogsPageLogsContent: React.FunctionComponent = () => {
     startDateExpression,
     endDateExpression,
     updateDateRange,
+    lastCompleteDateRangeExpressionUpdate,
   } = useContext(LogPositionState.Context);
   const { filterQuery, applyLogFilterQuery } = useContext(LogFilterState.Context);
 
@@ -81,16 +82,16 @@ export const LogsPageLogsContent: React.FunctionComponent = () => {
   const prevStartTimestamp = usePrevious(startTimestamp);
   const prevEndTimestamp = usePrevious(endTimestamp);
   const prevFilterQuery = usePrevious(filterQuery);
+  const prevLastCompleteDateRangeExpressionUpdate = usePrevious(
+    lastCompleteDateRangeExpressionUpdate
+  );
 
   // Refetch entries if...
   useEffect(() => {
     const isFirstLoad = !prevStartTimestamp || !prevEndTimestamp;
 
-    const newDateRangeDoesNotOverlap =
-      (prevStartTimestamp != null &&
-        startTimestamp != null &&
-        prevStartTimestamp < startTimestamp) ||
-      (prevEndTimestamp != null && endTimestamp != null && prevEndTimestamp > endTimestamp);
+    const completeDateRangeExpressionHasChanged =
+      lastCompleteDateRangeExpressionUpdate !== prevLastCompleteDateRangeExpressionUpdate;
 
     const isCenterPointOutsideLoadedRange =
       targetPosition != null &&
@@ -101,7 +102,7 @@ export const LogsPageLogsContent: React.FunctionComponent = () => {
 
     if (
       isFirstLoad ||
-      newDateRangeDoesNotOverlap ||
+      completeDateRangeExpressionHasChanged ||
       isCenterPointOutsideLoadedRange ||
       hasQueryChanged
     ) {
@@ -124,6 +125,8 @@ export const LogsPageLogsContent: React.FunctionComponent = () => {
     bottomCursor,
     filterQuery,
     prevFilterQuery,
+    lastCompleteDateRangeExpressionUpdate,
+    prevLastCompleteDateRangeExpressionUpdate,
   ]);
 
   const { logSummaryHighlights, currentHighlightKey, logEntryHighlightsById } = useContext(