Merge branch 'develop' for issue #16

Author: bmwilli

streams-metric-exporter/README.md

@@ -265,6 +265,14 @@ streams_operator_myCustomMetric
 | **streams_operator_ip_**|streams operator input port metrics|
 | **streams_operator_op_**|streams operatore output port metrics|
 
+### Sanitization
+Metric names are sanitized (fixed) to meet Prometheus naming conventions.  This is usually not required for 99% of IBM Streams metrics, however, since IBM Streams allows special characters and white space in metric names the following conversion rules are implemented:
+
+* Replace series of one or more whitespaces with underscore (_)
+* Remove any special characters
+
+An example would be the metric "streams_operator_nItemsQueued (port 2)" would become "streams_operator_nItemsQueued_port_2"
+
 ## Metric Labels
 The prometheus metric names are not specific to streams objects (e.g. a specific job), rather, they are for an object type (e.g. operator input port).  The labels are used to identify the individual instances (e.g. job: job_1, operator: myBeacon, input port: StockTickersIn).
 Note: the streams-metric-exporter resolves operator input and output ports to names rather than indexes.  This is easier for use in queries.

streams-metric-exporter/src/main/java/streams/metric/exporter/prometheus/PrometheusMetricsExporter.java

@@ -23,6 +23,7 @@
 import java.util.List;
 import java.util.Set;
 import java.util.Map;
+import java.util.regex.Pattern;
 
 import io.prometheus.client.Gauge;
 import streams.metric.exporter.metrics.MetricsExporter;
@@ -44,17 +45,35 @@ static public MetricsExporter getInstance() {
 	}
 
 	final Map<String, Gauge> gaugeMap = new HashMap<String, Gauge>();	
+
+  // Prometheus has some rules for valid metric names
+  // We will pre-sanitize metric names before using Promethus version
+  // so that we can do the following:
+  //  - Replace all series of 1 or more white-space with underscore
+  //  - Remove all special characters except for underscore
+  // Streams 4.3 had a metric name "nItemsQueued (Port 2)" that failed.
+  private static final Pattern SPACES_PATTERN = Pattern.compile("\\s+");
+  private static final Pattern NON_SPECIAL_OR_UNDERSCORE = Pattern.compile("(\\W|^_)*");
+
+  private String sanitizeMetricName(String metricName) {
+    return Gauge.sanitizeMetricName(
+      NON_SPECIAL_OR_UNDERSCORE.matcher(
+        SPACES_PATTERN.matcher(metricName).replaceAll("_")
+      ).replaceAll(""));
+  }
 
 	public void createStreamsMetric(String metricName, StreamsObjectType type, String description) {
-		String metricFullName = getStreamsMetricFullName(metricName, type);
+    String sanitizedName = sanitizeMetricName(metricName);
+		String metricFullName = getStreamsMetricFullName(sanitizedName, type);
 		if (!gaugeMap.containsKey(metricFullName)) {
 			gaugeMap.put(metricFullName,
 					Gauge.build().name(metricFullName).help(description).labelNames(type.metricLabelNames()).register());
 		}
 	}
 
 	public Metric getStreamsMetric(String metricName, StreamsObjectType type, String... labelValues) {
-		String metricFullName = getStreamsMetricFullName(metricName, type);
+    String sanitizedName = sanitizeMetricName(metricName);
+		String metricFullName = getStreamsMetricFullName(sanitizedName, type);
 		if (!gaugeMap.containsKey(metricFullName)) {
 			// Create with default help text
 			createStreamsMetric(metricName, type, type.metricDescriptionPrefix() + ": " + metricName);
@@ -80,7 +99,8 @@ public void removeAllChildStreamsMetrics(String... labelValues) {
 	}
 
 	public void removeStreamsMetric(String metricName, StreamsObjectType type, String... labelValues) {
-		String metricFullName = getStreamsMetricFullName(metricName, type);
+    String sanitizedName = sanitizeMetricName(metricName);
+		String metricFullName = getStreamsMetricFullName(sanitizedName, type);
 		if (gaugeMap.containsKey(metricFullName)) {
 			Gauge g = gaugeMap.get(metricFullName);
 			g.remove(labelValues);