diff --git a/alerting/src/main/kotlin/org/opensearch/alerting/DocumentLevelMonitorRunner.kt b/alerting/src/main/kotlin/org/opensearch/alerting/DocumentLevelMonitorRunner.kt
index d32f4789e..7262b9260 100644
--- a/alerting/src/main/kotlin/org/opensearch/alerting/DocumentLevelMonitorRunner.kt
+++ b/alerting/src/main/kotlin/org/opensearch/alerting/DocumentLevelMonitorRunner.kt
@@ -90,11 +90,8 @@ class DocumentLevelMonitorRunner : MonitorRunner() {
             * Docs are fetched from the source index per shard and transformed.*/
     val transformedDocs = mutableListOf<Pair<String, TransformedDocDto>>()
 
-    // Maps a finding ID to the concrete index name.
-    val findingIdToConcreteIndex = mutableMapOf<String, String>()
-
-    // Maps the docId to the doc source
-    val docIdToDocMap = mutableMapOf<String, MutableList<MultiGetItemResponse>>()
+    // Maps a finding ID to the related document.
+    private val findingIdToDocSource = mutableMapOf<String, MultiGetItemResponse>()
 
     override suspend fun runMonitor(
         monitor: Monitor,
@@ -489,10 +486,7 @@ class DocumentLevelMonitorRunner : MonitorRunner() {
             )
             alerts.add(alert)
 
-            val docId = alert.relatedDocIds.first().split("|").first()
-            val docSource = docIdToDocMap[docId]?.find { item ->
-                findingIdToConcreteIndex[alert.findingIds.first()] == item.index
-            }?.response?.convertToMap()
+            val docSource = findingIdToDocSource[alert.findingIds.first()]?.response?.convertToMap()
 
             alertContexts.add(
                 AlertContext(
@@ -591,7 +585,6 @@ class DocumentLevelMonitorRunner : MonitorRunner() {
             findingDocPairs.add(Pair(finding.id, it.key))
             findings.add(finding)
             findingsToTriggeredQueries[finding.id] = triggeredQueries
-            findingIdToConcreteIndex[finding.id] = finding.index
 
             val findingStr =
                 finding.toXContent(XContentBuilder.builder(XContentType.JSON.xContent()), ToXContent.EMPTY_PARAMS)
@@ -1104,21 +1097,25 @@ class DocumentLevelMonitorRunner : MonitorRunner() {
     ) {
         val docFieldTags = parseSampleDocTags(monitor.triggers)
         val request = MultiGetRequest()
-        findingToDocPairs.forEach { (_, docIdAndIndex) ->
-            val docIdAndIndexSplit = docIdAndIndex.split("|")
-            val docId = docIdAndIndexSplit[0]
-            val concreteIndex = docIdAndIndexSplit[1]
-            if (docId.isNotEmpty() && concreteIndex.isNotEmpty()) {
-                val docItem = MultiGetRequest.Item(concreteIndex, docId)
-                if (docFieldTags.isNotEmpty())
-                    docItem.fetchSourceContext(FetchSourceContext(true, docFieldTags.toTypedArray(), emptyArray()))
-                request.add(docItem)
+
+        // Perform mGet request in batches.
+        findingToDocPairs.chunked(monitorCtx.findingsIndexBatchSize).forEach { batch ->
+            batch.forEach { (findingId, docIdAndIndex) ->
+                val docIdAndIndexSplit = docIdAndIndex.split("|")
+                val docId = docIdAndIndexSplit[0]
+                val concreteIndex = docIdAndIndexSplit[1]
+                if (findingId.isNotEmpty() && docId.isNotEmpty() && concreteIndex.isNotEmpty()) {
+                    val docItem = MultiGetRequest.Item(concreteIndex, docId)
+                    if (docFieldTags.isNotEmpty())
+                        docItem.fetchSourceContext(FetchSourceContext(true, docFieldTags.toTypedArray(), emptyArray()))
+                    request.add(docItem)
+                }
+                val response = monitorCtx.client!!.suspendUntil { monitorCtx.client!!.multiGet(request, it) }
+                response.responses.forEach { item ->
+                    findingIdToDocSource[findingId] = item
+                }
             }
         }
-        val response = monitorCtx.client!!.suspendUntil { monitorCtx.client!!.multiGet(request, it) }
-        response.responses.forEach { item ->
-            docIdToDocMap.getOrPut(item.id) { mutableListOf() }.add(item)
-        }
     }
 
     /**