Fix empty field error in the iis/application pool metricset

CHANGELOG.next.asciidoc

@@ -260,6 +260,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix incorrect usage of hints builder when exposed port is a substring of the hint {pull}19052[19052]
 - Remove dedot for tag values in aws module. {issue}19112[19112] {pull}19221[19221]
 - Stop counterCache only when already started {pull}19103[19103]
+- Fix empty field name errors in the application pool metricset. {pull}19537[19537]
 - Set tags correctly if the dimension value is ARN {issue}19111[19111] {pull}19433[19433]
 - Fix bug incorrect parsing of float numbers as integers in Couchbase module {issue}18949[18949] {pull}19055[19055]
 

x-pack/metricbeat/module/iis/application_pool/application_pool.go

@@ -46,7 +46,7 @@ func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
 		return nil, err
 	}
 	// instantiate reader object
-	reader, err := newReader()
+	reader, err := newReader(config)
 	if err != nil {
 		return nil, err
 	}
@@ -55,22 +55,25 @@ func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
 		log:           logp.NewLogger("application pool"),
 		reader:        reader,
 	}
-	if err := ms.reader.initCounters(config.Names); err != nil {
-		return ms, err
-	}
+
 	return ms, nil
 }
 
 // Fetch methods implements the data gathering and data conversion to the right
 // format. It publishes the event which is then forwarded to the output. In case
 // of an error set the Error field of mb.Event or simply call report.Error().
 func (m *MetricSet) Fetch(report mb.ReporterV2) error {
-	var config Config
-	if err := m.Module().UnpackConfig(&config); err != nil {
-		return nil
+	// refresh performance counter list
+	// Some counters, such as rate counters, require two counter values in order to compute a displayable value. In this case we must call PdhCollectQueryData twice before calling PdhGetFormattedCounterValue.
+	// For more information, see Collecting Performance Data (https://docs.microsoft.com/en-us/windows/desktop/PerfCtrs/collecting-performance-data).
+	// A flag is set if the second call has been executed else refresh will fail (reader.executed)
+	if m.reader.executed {
+		err := m.reader.refreshCounterPaths()
+		if err != nil {
+			return errors.Wrap(err, "failed retrieving counters")
+		}
 	}
-
-	events, err := m.reader.fetch(config.Names)
+	events, err := m.reader.read()
 	if err != nil {
 		return errors.Wrap(err, "failed reading counters")
 	}
@@ -81,6 +84,7 @@ func (m *MetricSet) Fetch(report mb.ReporterV2) error {
 			break
 		}
 	}
+
 	return nil
 }
 

x-pack/metricbeat/module/iis/application_pool/reader.go

@@ -9,40 +9,41 @@ package application_pool
 import (
 	"strings"
 
+	"github.com/elastic/beats/v7/libbeat/common"
+	"github.com/elastic/beats/v7/metricbeat/helper/windows/pdh"
 	"github.com/elastic/go-sysinfo"
 
 	"github.com/pkg/errors"
 
-	"github.com/elastic/beats/v7/libbeat/common"
 	"github.com/elastic/beats/v7/libbeat/logp"
-	"github.com/elastic/beats/v7/metricbeat/helper/windows/pdh"
 	"github.com/elastic/beats/v7/metricbeat/mb"
 )
 
-// Reader  strucr will contain the pdh query and config options
+const ecsProcessId = "process.pid"
+
+// Reader will contain the config options
 type Reader struct {
-	Query            pdh.Query         // PDH Query
-	ApplicationPools []ApplicationPool // Mapping of counter path to key used for the label (e.g. processor.name)
-	log              *logp.Logger      // logger
-	hasRun           bool              // will check if the reader has run a first time
-	WorkerProcesses  map[string]string
+	applicationPools []ApplicationPool
+	workerProcesses  map[string]string
+	query            pdh.Query    // PDH Query
+	executed         bool         // Indicates if the query has been executed.
+	log              *logp.Logger //
+	config           Config       // Metricset configuration
 }
 
 // ApplicationPool struct contains the list of applications and their worker processes
 type ApplicationPool struct {
-	Name             string
-	WorkerProcessIds []int
+	name             string
+	workerProcessIds []int
 	counters         map[string]string
 }
 
 // WorkerProcess struct contains the worker process details
 type WorkerProcess struct {
-	ProcessId    int
-	InstanceName string
+	processId    int
+	instanceName string
 }
 
-const ecsProcessId = "process.pid"
-
 var appPoolCounters = map[string]string{
 	"process.pid":                          "\\Process(w3wp*)\\ID Process",
 	"process.cpu_usage_perc":               "\\Process(w3wp*)\\% Processor Time",
@@ -62,87 +63,138 @@ var appPoolCounters = map[string]string{
 }
 
 // newReader creates a new instance of Reader.
-func newReader() (*Reader, error) {
+func newReader(config Config) (*Reader, error) {
 	var query pdh.Query
 	if err := query.Open(); err != nil {
 		return nil, err
 	}
-	reader := &Reader{
-		Query: query,
-		log:   logp.NewLogger("website"),
+	r := &Reader{
+		query:           query,
+		log:             logp.NewLogger("application_pool"),
+		config:          config,
+		workerProcesses: make(map[string]string),
+	}
+	apps, err := getApplicationPools(config.Names)
+	if err != nil {
+		return r, errors.Wrap(err, "failed retrieving running worker processes")
+	}
+	if len(apps) == 0 {
+		r.log.Info("no running application pools found")
+		return r, nil
+	}
+	r.applicationPools = apps
+
+	for key, value := range appPoolCounters {
+		childQueries, err := query.GetCounterPaths(value)
+		if err != nil {
+			if err == pdh.PDH_CSTATUS_NO_COUNTER || err == pdh.PDH_CSTATUS_NO_COUNTERNAME || err == pdh.PDH_CSTATUS_NO_INSTANCE || err == pdh.PDH_CSTATUS_NO_OBJECT {
+				r.log.Infow("Ignoring non existent counter", "error", err,
+					logp.Namespace("application pool"), "query", value)
+				continue
+			} else {
+				return nil, errors.Wrapf(err, `failed to expand counter (query="%v")`, value)
+			}
+		}
+		// check if the pdhexpandcounterpath/pdhexpandwildcardpath functions have expanded the counter successfully.
+		if len(childQueries) == 0 || (len(childQueries) == 1 && strings.Contains(childQueries[0], "*")) {
+			// covering cases when PdhExpandWildCardPathW returns no counter paths or is unable to expand and the ignore_non_existent_counters flag is set
+			r.log.Debugw("No counter paths returned but PdhExpandWildCardPathW returned no errors", "initial query", value,
+				logp.Namespace("application pool"), "expanded query", childQueries)
+			continue
+		}
+		for _, v := range childQueries {
+			if err := query.AddCounter(v, "", "float", len(childQueries) > 1); err != nil {
+				return nil, errors.Wrapf(err, `failed to add counter (query="%v")`, v)
+			}
+			r.workerProcesses[v] = key
+		}
 	}
 
-	return reader, nil
+	return r, nil
 }
 
-// initCounters func retrieves the running application worker processes and adds the counters to the pdh query
-func (re *Reader) initCounters(filtered []string) error {
-	apps, err := getApplicationPools(filtered)
+// refreshCounterPaths will recheck for any new instances and add them to the counter list
+func (r *Reader) refreshCounterPaths() error {
+	apps, err := getApplicationPools(r.config.Names)
 	if err != nil {
 		return errors.Wrap(err, "failed retrieving running worker processes")
 	}
+	r.applicationPools = apps
 	if len(apps) == 0 {
-		re.log.Info("no running application pools found")
+		r.log.Info("no running application pools found")
 		return nil
 	}
-	re.ApplicationPools = apps
-	re.WorkerProcesses = make(map[string]string)
+
 	var newQueries []string
+	r.workerProcesses = make(map[string]string)
 	for key, value := range appPoolCounters {
-		counters, err := re.Query.ExpandWildCardPath(value)
+		childQueries, err := r.query.GetCounterPaths(value)
 		if err != nil {
-			re.log.Error(err, `failed to expand counter path (query="%v")`, value)
+			if err == pdh.PDH_CSTATUS_NO_COUNTER || err == pdh.PDH_CSTATUS_NO_COUNTERNAME || err == pdh.PDH_CSTATUS_NO_INSTANCE || err == pdh.PDH_CSTATUS_NO_OBJECT {
+				r.log.Infow("Ignoring non existent counter", "error", err,
+					logp.Namespace("application pool"), "query", value)
+				continue
+			} else {
+				return errors.Wrapf(err, `failed to expand counter (query="%v")`, value)
+			}
+		}
+		newQueries = append(newQueries, childQueries...)
+		// check if the pdhexpandcounterpath/pdhexpandwildcardpath functions have expanded the counter successfully.
+		if len(childQueries) == 0 || (len(childQueries) == 1 && strings.Contains(childQueries[0], "*")) {
+			// covering cases when PdhExpandWildCardPathW returns no counter paths or is unable to expand and the ignore_non_existent_counters flag is set
+			r.log.Debugw("No counter paths returned but PdhExpandWildCardPathW returned no errors", "initial query", value,
+				logp.Namespace("perfmon"), "expanded query", childQueries)
 			continue
 		}
-		for _, count := range counters {
-			if err = re.Query.AddCounter(count, "", "float", true); err != nil {
-				return errors.Wrapf(err, `failed to add counter (query="%v")`, count)
+		for _, v := range childQueries {
+			if err := r.query.AddCounter(v, "", "float", len(childQueries) > 1); err != nil {
+				return errors.Wrapf(err, `failed to add counter (query="%v")`, v)
 			}
-			newQueries = append(newQueries, count)
-			re.WorkerProcesses[count] = key
+			r.workerProcesses[v] = key
 		}
 	}
-	err = re.Query.RemoveUnusedCounters(newQueries)
+	err = r.query.RemoveUnusedCounters(newQueries)
 	if err != nil {
 		return errors.Wrap(err, "failed removing unused counter values")
 	}
 	return nil
 }
 
-// fetch executes collects the query data and maps the counter values to events.
-func (re *Reader) fetch(names []string) ([]mb.Event, error) {
-	// refresh performance counter list
-	// Some counters, such as rate counters, require two counter values in order to compute a displayable value. In this case we must call PdhCollectQueryData twice before calling PdhGetFormattedCounterValue.
-	// For more information, see Collecting Performance Data (https://docs.microsoft.com/en-us/windows/desktop/PerfCtrs/collecting-performance-data).
-	// A flag is set if the second call has been executed else refresh will fail (reader.executed)
-	if re.hasRun || len(re.Query.Counters) == 0 {
-		err := re.initCounters(names)
-		if err != nil {
-			return nil, errors.Wrap(err, "failed retrieving counters")
-		}
-	}
-	// if the ignore_non_existent_counters flag is set and no valid counter paths are found the Read func will still execute, a check is done before
-	if len(re.Query.Counters) == 0 {
+// read executes a query and returns those values in an event.
+func (r *Reader) read() ([]mb.Event, error) {
+	if len(r.applicationPools) == 0 {
+		r.executed = true
 		return nil, nil
 	}
+
 	// Some counters, such as rate counters, require two counter values in order to compute a displayable value. In this case we must call PdhCollectQueryData twice before calling PdhGetFormattedCounterValue.
 	// For more information, see Collecting Performance Data (https://docs.microsoft.com/en-us/windows/desktop/PerfCtrs/collecting-performance-data).
-	if err := re.Query.CollectData(); err != nil {
+	if err := r.query.CollectData(); err != nil {
 		return nil, errors.Wrap(err, "failed querying counter values")
 	}
 
 	// Get the values.
-	values, err := re.Query.GetFormattedCounterValues()
+	values, err := r.query.GetFormattedCounterValues()
 	if err != nil {
 		return nil, errors.Wrap(err, "failed formatting counter values")
 	}
+	var events []mb.Event
+	eventGroup := r.mapEvents(values)
+	r.executed = true
+	results := make([]mb.Event, 0, len(events))
+	for _, val := range eventGroup {
+		results = append(results, val)
+	}
+	return results, nil
+}
 
+func (r *Reader) mapEvents(values map[string][]pdh.CounterValue) map[string]mb.Event {
 	workers := getProcessIds(values)
 	events := make(map[string]mb.Event)
-	for _, appPool := range re.ApplicationPools {
-		events[appPool.Name] = mb.Event{
+	for _, appPool := range r.applicationPools {
+		events[appPool.name] = mb.Event{
 			MetricSetFields: common.MapStr{
-				"name": appPool.Name,
+				"name": appPool.name,
 			},
 			RootFields: common.MapStr{},
 		}
@@ -151,45 +203,36 @@ func (re *Reader) fetch(names []string) ([]mb.Event, error) {
 				// Some counters, such as rate counters, require two counter values in order to compute a displayable value. In this case we must call PdhCollectQueryData twice before calling PdhGetFormattedCounterValue.
 				// For more information, see Collecting Performance Data (https://docs.microsoft.com/en-us/windows/desktop/PerfCtrs/collecting-performance-data).
 				if val.Err.Error != nil {
-					if !re.hasRun {
-						re.log.Debugw("Ignoring the first measurement because the data isn't ready",
-							"error", val.Err, logp.Namespace("application_pool"), "query", counterPath)
+					if !r.executed {
 						continue
 					}
 					// The counter has a negative value or the counter was successfully found, but the data returned is not valid.
 					// This error can occur if the counter value is less than the previous value. (Because counter values always increment, the counter value rolls over to zero when it reaches its maximum value.)
 					// This is not an error that stops the application from running successfully and a positive counter value should be retrieved in the later calls.
 					if val.Err.Error == pdh.PDH_CALC_NEGATIVE_VALUE || val.Err.Error == pdh.PDH_INVALID_DATA {
-						re.log.Debugw("Counter value retrieval returned",
+						r.log.Debugw("Counter value retrieval returned",
 							"error", val.Err.Error, "cstatus", pdh.PdhErrno(val.Err.CStatus), logp.Namespace("application_pool"), "query", counterPath)
 						continue
 					}
 				}
-				if val.Instance == appPool.Name {
-					events[appPool.Name].MetricSetFields.Put(appPool.counters[counterPath], val.Measurement)
-				} else if hasWorkerProcess(val.Instance, workers, appPool.WorkerProcessIds) {
-					if re.WorkerProcesses[counterPath] == ecsProcessId {
-						events[appPool.Name].RootFields.Put(re.WorkerProcesses[counterPath], val.Measurement)
-					} else {
-						events[appPool.Name].MetricSetFields.Put(re.WorkerProcesses[counterPath], val.Measurement)
+				if hasWorkerProcess(val.Instance, workers, appPool.workerProcessIds) {
+					if r.workerProcesses[counterPath] == ecsProcessId {
+						events[appPool.name].RootFields.Put(r.workerProcesses[counterPath], val.Measurement)
+					} else if len(r.workerProcesses[counterPath]) != 0 {
+						events[appPool.name].MetricSetFields.Put(r.workerProcesses[counterPath], val.Measurement)
 					}
 				}
 			}
 
 		}
 	}
 
-	re.hasRun = true
-	results := make([]mb.Event, 0, len(events))
-	for _, val := range events {
-		results = append(results, val)
-	}
-	return results, nil
+	return events
 }
 
-// Close will close the PDH query for now.
-func (re *Reader) close() error {
-	return re.Query.Close()
+// close will close the PDH query for now.
+func (r *Reader) close() error {
+	return r.query.Close()
 }
 
 // getApplicationPools method retrieves the w3wp.exe processes and the application pool name, also filters on the application pool names configured by users
@@ -204,15 +247,15 @@ func getApplicationPools(names []string) ([]ApplicationPool, error) {
 	}
 	var applicationPools []ApplicationPool
 	for key, value := range appPools {
-		applicationPools = append(applicationPools, ApplicationPool{Name: key, WorkerProcessIds: value})
+		applicationPools = append(applicationPools, ApplicationPool{name: key, workerProcessIds: value})
 	}
 	if len(names) == 0 {
 		return applicationPools, nil
 	}
 	var filtered []ApplicationPool
 	for _, n := range names {
 		for _, w3 := range applicationPools {
-			if n == w3.Name {
+			if n == w3.name {
 				filtered = append(filtered, w3)
 			}
 		}
@@ -253,18 +296,18 @@ func getProcessIds(counterValues map[string][]pdh.CounterValue) []WorkerProcess
 	var workers []WorkerProcess
 	for key, values := range counterValues {
 		if strings.Contains(key, "\\ID Process") {
-			workers = append(workers, WorkerProcess{InstanceName: values[0].Instance, ProcessId: int(values[0].Measurement.(float64))})
+			workers = append(workers, WorkerProcess{instanceName: values[0].Instance, processId: int(values[0].Measurement.(float64))})
 		}
 	}
 	return workers
 }
 
-// hasWorkerProcess func checks if workerprocess list contains the process id
+// hasWorkerProcess func checks if worker process list contains the process id
 func hasWorkerProcess(instance string, workers []WorkerProcess, pids []int) bool {
 	for _, worker := range workers {
-		if worker.InstanceName == instance {
+		if worker.instanceName == instance {
 			for _, pid := range pids {
-				if pid == worker.ProcessId {
+				if pid == worker.processId {
 					return true
 				}
 			}