Exemplo n.º 1
0
func (self *ShardData) createRequest(querySpec *parser.QuerySpec) *p.Request {
	queryString := querySpec.GetQueryString()
	user := querySpec.User()
	userName := user.GetName()
	database := querySpec.Database()
	isDbUser := !user.IsClusterAdmin()

	return &p.Request{
		Type:     &queryRequest,
		ShardId:  &self.id,
		Query:    &queryString,
		UserName: &userName,
		Database: &database,
		IsDbUser: &isDbUser,
	}
}
Exemplo n.º 2
0
func (self *ShardData) Query(querySpec *parser.QuerySpec, response chan *p.Response) {
	log.Debug("QUERY: shard %d, query '%s'", self.Id(), querySpec.GetQueryString())
	defer common.RecoverFunc(querySpec.Database(), querySpec.GetQueryString(), func(err interface{}) {
		response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(fmt.Sprintf("%s", err))}
	})

	// This is only for queries that are deletes or drops. They need to be sent everywhere as opposed to just the local or one of the remote shards.
	// But this boolean should only be set to true on the server that receives the initial query.
	if querySpec.RunAgainstAllServersInShard {
		if querySpec.IsDeleteFromSeriesQuery() {
			self.logAndHandleDeleteQuery(querySpec, response)
		} else if querySpec.IsDropSeriesQuery() {
			self.logAndHandleDropSeriesQuery(querySpec, response)
		}
	}

	if self.IsLocal {
		var processor QueryProcessor
		var err error

		if querySpec.IsListSeriesQuery() {
			processor = engine.NewListSeriesEngine(response)
		} else if querySpec.IsDeleteFromSeriesQuery() || querySpec.IsDropSeriesQuery() || querySpec.IsSinglePointQuery() {
			maxDeleteResults := 10000
			processor = engine.NewPassthroughEngine(response, maxDeleteResults)
		} else {
			query := querySpec.SelectQuery()
			if self.ShouldAggregateLocally(querySpec) {
				log.Debug("creating a query engine")
				processor, err = engine.NewQueryEngine(query, response)
				if err != nil {
					response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
					log.Error("Error while creating engine: %s", err)
					return
				}
				processor.SetShardInfo(int(self.Id()), self.IsLocal)
			} else if query.HasAggregates() {
				maxPointsToBufferBeforeSending := 1000
				log.Debug("creating a passthrough engine")
				processor = engine.NewPassthroughEngine(response, maxPointsToBufferBeforeSending)
			} else {
				maxPointsToBufferBeforeSending := 1000
				log.Debug("creating a passthrough engine with limit")
				processor = engine.NewPassthroughEngineWithLimit(response, maxPointsToBufferBeforeSending, query.Limit)
			}

			if query.GetFromClause().Type != parser.FromClauseInnerJoin {
				// Joins do their own filtering since we need to get all
				// points before filtering. This is due to the fact that some
				// where expressions will be difficult to compute before the
				// points are joined together, think where clause with
				// left.column = 'something' or right.column =
				// 'something_else'. We can't filter the individual series
				// separately. The filtering happens in merge.go:55

				processor = engine.NewFilteringEngine(query, processor)
			}
		}
		shard, err := self.store.GetOrCreateShard(self.id)
		if err != nil {
			response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
			log.Error("Error while getting shards: %s", err)
			return
		}
		defer self.store.ReturnShard(self.id)
		err = shard.Query(querySpec, processor)
		// if we call Close() in case of an error it will mask the error
		if err != nil {
			response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
			return
		}
		processor.Close()
		response <- &p.Response{Type: &endStreamResponse}
		return
	}

	if server := self.randomHealthyServer(); server != nil {
		log.Debug("Querying server %d for shard %d", server.GetId(), self.Id())
		request := self.createRequest(querySpec)
		server.MakeRequest(request, response)
		return
	}

	message := fmt.Sprintf("No servers up to query shard %d", self.id)
	response <- &p.Response{Type: &endStreamResponse, ErrorMessage: &message}
	log.Error(message)
}