[MM-63314] Fix ClaimJob in HA environments (#30383)

* ClaimJob now returns newly claimed job

* internal code affected by change

* test changes required

* two branches: for mysql, use transaction; for postgres, use returning

* two branches: for mysql, use transaction; for postgres, use returning

* use same millis value for LastActivityAt and StartAt

* blank commit

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/enterprise/elasticsearch/common/indexing_job.go

@@ -219,12 +219,12 @@ func (worker *IndexerWorker) DoJob(job *model.Job) {
 	logger.Debug("Worker: Received a new candidate job.")
 	defer worker.jobServer.HandleJobPanic(logger, job)
 
-	claimed, appErr := worker.jobServer.ClaimJob(job)
+	var appErr *model.AppError
+	job, appErr = worker.jobServer.ClaimJob(job)
 	if appErr != nil {
 		logger.Warn("Worker: Error occurred while trying to claim job", mlog.Err(appErr))
 		return
-	}
-	if !claimed {
+	} else if job == nil {
 		return
 	}
 

server/enterprise/elasticsearch/elasticsearch/aggregation_job.go

@@ -143,13 +143,12 @@ func (worker *ElasticsearchAggregatorWorker) DoJob(job *model.Job) {
 	logger.Debug("Worker: Received a new candidate job.")
 	defer worker.jobServer.HandleJobPanic(logger, job)
 
-	claimed, appErr := worker.jobServer.ClaimJob(job)
+	var appErr *model.AppError
+	job, appErr = worker.jobServer.ClaimJob(job)
 	if appErr != nil {
 		logger.Warn("Worker: Error occurred while trying to claim job", mlog.Err(appErr))
 		return
-	}
-
-	if !claimed {
+	} else if job == nil {
 		return
 	}
 

server/enterprise/elasticsearch/elasticsearch/aggregation_job_test.go

@@ -44,7 +44,8 @@ func TestElasticsearchAggregation(t *testing.T) {
 	mockJobStore.On("UpdateStatusOptimistically",
 		mock.AnythingOfType("string"),
 		model.JobStatusPending,
-		model.JobStatusInProgress).Return(true, nil)
+		model.JobStatusInProgress).
+		Return(&model.Job{}, nil)
 	mockJobStore.On("GetAllByType", mock.AnythingOfType("string")).Return([]*model.Job{{
 		Id:     "abcxyz123",
 		Type:   "EnterpriseElasticsearchIndexer",

server/enterprise/elasticsearch/opensearch/aggregation_job.go

@@ -142,13 +142,12 @@ func (worker *OpensearchAggregatorWorker) DoJob(job *model.Job) {
 	logger.Debug("Worker: Received a new candidate job.")
 	defer worker.jobServer.HandleJobPanic(logger, job)
 
-	claimed, appErr := worker.jobServer.ClaimJob(job)
+	var appErr *model.AppError
+	job, appErr = worker.jobServer.ClaimJob(job)
 	if appErr != nil {
 		logger.Warn("Worker: Error occurred while trying to claim job", mlog.Err(appErr))
 		return
-	}
-
-	if !claimed {
+	} else if job == nil {
 		return
 	}
 

server/enterprise/elasticsearch/opensearch/aggregation_job_test.go

@@ -60,7 +60,8 @@ func TestElasticsearchAggregation(t *testing.T) {
 	mockJobStore.On("UpdateStatusOptimistically",
 		mock.AnythingOfType("string"),
 		model.JobStatusPending,
-		model.JobStatusInProgress).Return(true, nil)
+		model.JobStatusInProgress).
+		Return(&model.Job{}, nil)
 	mockJobStore.On("GetAllByType", mock.AnythingOfType("string")).Return([]*model.Job{{
 		Id:     "abcxyz123",
 		Type:   "EnterpriseElasticsearchIndexer",