Closes #927 - Added buffering option to influx exporter (#928)

components/inspectit-ocelot-eum-server/build.gradle

@@ -67,7 +67,7 @@ dependencies {
 			'com.maxmind.geoip2:geoip2:2.12.0',
 			'commons-net:commons-net:3.3',
 			'org.springframework.boot:spring-boot-starter-actuator',
-            "rocks.inspectit:opencensus-influxdb-exporter:1.1",
+            "rocks.inspectit:opencensus-influxdb-exporter:1.2",
 			"org.influxdb:influxdb-java:2.15"
 	)
 	compileOnly "org.projectlombok:lombok:1.18.12"

components/inspectit-ocelot-eum-server/src/main/java/rocks/inspectit/oce/eum/server/exporters/InfluxExporterService.java

@@ -60,6 +60,7 @@ private void doEnable() {
                     .password(influx.getPassword())
                     .createDatabase(influx.isCreateDatabase())
                     .exportDifference(influx.isCountersAsDifferences())
+                    .bufferSize(influx.getBufferSize())
                     .build();
             exporterTask = executor.scheduleAtFixedRate(activeExporter::export, 0, influx.getExportInterval()
                     .toMillis(), TimeUnit.MILLISECONDS);

components/inspectit-ocelot-eum-server/src/main/resources/application.yml

@@ -135,6 +135,9 @@ inspectit-eum-server:
         # This difference will only be written if the counter has changed (=the difference is non-zero).
         # This can greatly reduce the total data written to influx and makes writing queries easier.
         counters-as-differences: true
+        # The size of the buffer for failed batches.
+        # E.g. if the exportInterval is 15s and the buffer-size is 4, the export will keep up to one minute of data in memory.
+        buffer-size: 40
     tracing:
       jaeger:
         # if jaeger exporter for the OT received spans is enabled

inspectit-ocelot-config/src/main/java/rocks/inspectit/ocelot/config/model/exporters/metrics/InfluxExporterSettings.java

@@ -3,6 +3,7 @@
 import lombok.Data;
 import org.hibernate.validator.constraints.time.DurationMin;
 
+import javax.validation.constraints.Min;
 import javax.validation.constraints.NotBlank;
 import java.time.Duration;
 
@@ -62,4 +63,11 @@ public class InfluxExporterSettings {
      * This can greatly reduce the total data written to influx and makes writing queries easier.
      */
     private boolean countersAsDifferences;
+
+    /**
+     * The size of the buffer for failed batches.
+     * E.g. if the exportInterval is 15s and the buffer-size is 4, the export will keep up to one minute of data in memory.
+     */
+    @Min(1)
+    private int bufferSize;
 }

inspectit-ocelot-config/src/main/resources/rocks/inspectit/ocelot/config/default/exporters.yml

@@ -45,6 +45,9 @@ inspectit:
         # This difference will only be written if the counter has changed (=the difference is non-zero).
         # This can greatly reduce the total data written to influx and makes writing queries easier.
         counters-as-differences: true
+        # The size of the buffer for failed batches.
+        # E.g. if the exportInterval is 15s and the buffer-size is 4, the export will keep up to one minute of data in memory.
+        buffer-size: 40
 
     # settings for trace exporters
     tracing:

inspectit-ocelot-core/build.gradle

@@ -74,7 +74,7 @@ dependencies {
             'io.netty:netty-tcnative-boringssl-static:2.0.20.Final',
 
 
-            "rocks.inspectit:opencensus-influxdb-exporter:1.1",
+            "rocks.inspectit:opencensus-influxdb-exporter:1.2",
 
             // bytecode manipulation
             "net.bytebuddy:byte-buddy:1.10.14"

inspectit-ocelot-core/src/main/java/rocks/inspectit/ocelot/core/exporter/InfluxExporterService.java

@@ -65,6 +65,7 @@ protected boolean doEnable(InspectitConfig configuration) {
                 .createDatabase(influx.isCreateDatabase())
                 .exportDifference(influx.isCountersAsDifferences())
                 .measurementNameProvider(percentileViewManager::getMeasureNameForSeries)
+                .bufferSize(influx.getBufferSize())
                 .build();
         exporterTask = executor.scheduleAtFixedRate(activeExporter::export, 0, influx.getExportInterval()
                 .toMillis(), TimeUnit.MILLISECONDS);

inspectit-ocelot-documentation/docs/metrics/metric-exporters.md

@@ -78,4 +78,5 @@ The following properties are nested properties below the `inspectit.exporters.me
 |`.retention-policy`|`autogen`| The retention policy of the database to use for writing metrics.
 |`.create-database`|`true`| If enabled, the database defined by the `database` property is automatically created on startup with an `autogen` retention policy if it does not exist yet.
 |`.export-interval`|refers to `inspectit.metrics.frequency`|Defines how often metrics are pushed to the influxDB.
-|<nobr>`.counters-as-differences`</nobr>|`true`|Defines whether counters are exported using their absolute value or as the increase between exports
+|<nobr>`.counters-as-differences`</nobr>|`true`|Defines whether counters are exported using their absolute value or as the increase between exports
+|`buffer-size`| `40` | In case the influxDB is not reachable, failed writes will be buffered and written on the next export. This value defines the maximum number of batches to buffer.