TSDB: RollupShardIndexer logging improvements (#88416)

1. Add trace log guards to avoid high cost method
2. Log the time it took to rollup a shard

Author: weizijun

x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/v2/RollupShardIndexer.java

@@ -127,6 +127,7 @@ class RollupShardIndexer {
     }
 
     public RollupIndexerAction.ShardRollupResponse execute() throws IOException {
+        long startTime = System.currentTimeMillis();
         BulkProcessor bulkProcessor = createBulkProcessor();
         try (searcher; bulkProcessor) {
             // TODO: add cancellations
@@ -138,11 +139,12 @@ public RollupIndexerAction.ShardRollupResponse execute() throws IOException {
         }
 
         logger.info(
-            "Shard {} successfully sent [{}], indexed [{}], failed [{}]",
+            "Shard [{}] successfully sent [{}], indexed [{}], failed [{}], took [{}]",
             indexShard.shardId(),
             numSent.get(),
             numIndexed.get(),
-            numFailed.get()
+            numFailed.get(),
+            TimeValue.timeValueMillis(System.currentTimeMillis() - startTime)
         );
 
         if (numIndexed.get() != numSent.get()) {
@@ -239,13 +241,15 @@ public void collect(int docId, long owningBucketOrd) throws IOException {
                         lastHistoTimestamp = rounding.round(timestamp);
                     }
 
-                    logger.trace(
-                        "Doc: [{}] - _tsid: [{}], @timestamp: [{}}] -> rollup bucket ts: [{}]",
-                        docId,
-                        DocValueFormat.TIME_SERIES_ID.format(tsid),
-                        timestampFormat.format(timestamp),
-                        timestampFormat.format(lastHistoTimestamp)
-                    );
+                    if (logger.isTraceEnabled()) {
+                        logger.trace(
+                            "Doc: [{}] - _tsid: [{}], @timestamp: [{}}] -> rollup bucket ts: [{}]",
+                            docId,
+                            DocValueFormat.TIME_SERIES_ID.format(tsid),
+                            timestampFormat.format(timestamp),
+                            timestampFormat.format(lastHistoTimestamp)
+                        );
+                    }
 
                     /*
                      * Sanity checks to ensure that we receive documents in the correct order
@@ -349,11 +353,14 @@ public RollupBucketBuilder init(BytesRef tsid, long timestamp) {
             this.timestamp = timestamp;
             this.docCount = 0;
             this.metricFieldProducers.values().stream().forEach(p -> p.reset());
-            logger.trace(
-                "New bucket for _tsid: [{}], @timestamp: [{}]",
-                DocValueFormat.TIME_SERIES_ID.format(tsid),
-                timestampFormat.format(timestamp)
-            );
+            if (logger.isTraceEnabled()) {
+                logger.trace(
+                    "New bucket for _tsid: [{}], @timestamp: [{}]",
+                    DocValueFormat.TIME_SERIES_ID.format(tsid),
+                    timestampFormat.format(timestamp)
+                );
+            }
+
             return this;
         }