Force DuplicatePolicy for Redis TS created programmatically by Cosmotech API.

Depending on target deployment environment, Redis TS can have DUPLICATE_POLICY set to BLOCK.
Until now, Redis TS created by Cosmotech API relied on target environment (without override the default value)
As we log every API calls, when API is flooded, it can lead to HTTP errors 500 when Redis is deployed with DUPLICATE_POLICY set to BLOCK (https://redis.io/docs/latest/develop/data-types/timeseries/configuration/#duplicate_policy).

To prevent that, every Redis TS will be created now with DUPLICATE_POLICY set to MAX. Doing that, will not lead to HTTP 500 error and if X Redis TS will be created with the same timestamp, only the TS with the maximum value will be kept.

Note: You should delete all previously created one. A Redis TS cannot be changed/upgraded

Author: jreynard-code

metrics/src/main/kotlin/com/cosmotech/metrics/MetricsServiceImpl.kt

@@ -10,6 +10,7 @@ import org.slf4j.LoggerFactory
 import org.springframework.context.event.EventListener
 import org.springframework.stereotype.Service
 import redis.clients.jedis.UnifiedJedis
+import redis.clients.jedis.timeseries.DuplicatePolicy
 import redis.clients.jedis.timeseries.TSAlterParams
 import redis.clients.jedis.timeseries.TSCreateParams
 
@@ -58,7 +59,12 @@ class MetricsServiceImpl(
       val metricLabels = getMetricLabels(commonLabels)
       logger.debug(
           "Creating Redis TS: $key with retention: $metricRetention and ${metricLabels.count()} labels")
-      unifiedJedis.tsCreate(key, TSCreateParams().retention(metricRetention).labels(metricLabels))
+      unifiedJedis.tsCreate(
+          key,
+          TSCreateParams()
+              .retention(metricRetention)
+              .labels(metricLabels)
+              .duplicatePolicy(DuplicatePolicy.MAX))
       if (metric.downSampling || csmPlatformProperties.metrics.downSamplingDefaultEnabled) {
         val downSamplingKey = getDownSamplingKey(metric)
         val downSamplingMetricLabels = getDownSamplingMetricLabels(commonLabels)
@@ -69,7 +75,10 @@ class MetricsServiceImpl(
                 "and ${downSamplingMetricLabels.count()} labels")
         unifiedJedis.tsCreate(
             downSamplingKey,
-            TSCreateParams().retention(downSamplingRetention).labels(downSamplingMetricLabels))
+            TSCreateParams()
+                .retention(downSamplingRetention)
+                .labels(downSamplingMetricLabels)
+                .duplicatePolicy(DuplicatePolicy.MAX))
         logger.debug(
             "Creating Redis DownSampling TS rule: from $key to $downSamplingKey, " +
                 "aggregation: ${metric.downSamplingAggregation.value}, bucketDuration: $downSamplingBucketDuration")
@@ -89,7 +98,12 @@ class MetricsServiceImpl(
         logger.debug(
             "Redis TS library cannot get current labels so it is not possible to check if labels changed")
         val metricLabels = getMetricLabels(commonLabels)
-        unifiedJedis.tsAlter(key, TSAlterParams().retention(metricRetention).labels(metricLabels))
+        unifiedJedis.tsAlter(
+            key,
+            TSAlterParams()
+                .retention(metricRetention)
+                .labels(metricLabels)
+                .duplicatePolicy(DuplicatePolicy.MAX))
       } else {}
     }
   }