diff --git a/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt b/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
index 6ff38548..110cf36f 100644
--- a/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
+++ b/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
@@ -32,10 +32,10 @@ data class DataSources(
     val alertsHistoryIndexPattern: String? = "<.opendistro-alerting-alert-history-{now/d}-1>", // AlertIndices.ALERT_HISTORY_INDEX_PATTERN
 
     /** Configures a custom index alias to store comments associated with alerts.*/
-    val commentsIndex: String = ".opensearch-alerting-comments-history-write", // AlertIndices.COMMENTS_HISTORY_WRITE_INDEX
+    val commentsIndex: String? = ".opensearch-alerting-comments-history-write", // CommentsIndices.COMMENTS_HISTORY_WRITE_INDEX
 
     /** Configures a custom index pattern for commentsIndex alias.*/
-    val commentsIndexPattern: String? = "<.opensearch-alerting-comments-history-{now/d}-1>", // AlertIndices.COMMENTS_HISTORY_INDEX_PATTERN
+    val commentsIndexPattern: String? = "<.opensearch-alerting-comments-history-{now/d}-1>", // CommentsIndices.COMMENTS_HISTORY_INDEX_PATTERN
 
     /** Configures custom mappings by field type for query index.
      * Custom query index mappings are configurable, only if a custom query index is configured too. */
@@ -56,9 +56,6 @@ data class DataSources(
         require(alertsIndex.isNotEmpty()) {
             "Alerts index cannot be empty"
         }
-        require(commentsIndex.isNotEmpty()) {
-            "Comments index cannot be empty"
-        }
         if (queryIndexMappingsByType.isNotEmpty()) {
             require(queryIndex != ScheduledJob.DOC_LEVEL_QUERIES_INDEX) {
                 "Custom query index mappings are configurable only if a custom query index is configured too."
@@ -83,12 +80,34 @@ data class DataSources(
         alertsIndex = sin.readString(),
         alertsHistoryIndex = sin.readOptionalString(),
         alertsHistoryIndexPattern = sin.readOptionalString(),
-        commentsIndex = sin.readString(),
+        commentsIndex = sin.readOptionalString(),
         commentsIndexPattern = sin.readOptionalString(),
         queryIndexMappingsByType = sin.readMap() as Map<String, Map<String, String>>,
         findingsEnabled = sin.readOptionalBoolean()
     )
 
+    constructor(
+        queryIndex: String,
+        findingsIndex: String,
+        findingsIndexPattern: String?,
+        alertsIndex: String,
+        alertsHistoryIndex: String?,
+        alertsHistoryIndexPattern: String?,
+        queryIndexMappingsByType: Map<String, Map<String, String>>,
+        findingsEnabled: Boolean?
+    ) : this(
+        queryIndex = queryIndex,
+        findingsIndex = findingsIndex,
+        findingsIndexPattern = findingsIndexPattern,
+        alertsIndex = alertsIndex,
+        alertsHistoryIndex = alertsHistoryIndex,
+        alertsHistoryIndexPattern = alertsHistoryIndexPattern,
+        commentsIndex = null,
+        commentsIndexPattern = null,
+        queryIndexMappingsByType = queryIndexMappingsByType,
+        findingsEnabled = findingsEnabled
+    )
+
     @Suppress("UNCHECKED_CAST")
     fun asTemplateArg(): Map<String, Any?> {
         return mapOf(
@@ -189,7 +208,7 @@ data class DataSources(
         out.writeString(alertsIndex)
         out.writeOptionalString(alertsHistoryIndex)
         out.writeOptionalString(alertsHistoryIndexPattern)
-        out.writeString(commentsIndex)
+        out.writeOptionalString(commentsIndex)
         out.writeOptionalString(commentsIndexPattern)
         out.writeMap(queryIndexMappingsByType as Map<String, Any>)
         out.writeOptionalBoolean(findingsEnabled)
diff --git a/src/test/kotlin/org/opensearch/commons/alerting/model/DataSourcesTests.kt b/src/test/kotlin/org/opensearch/commons/alerting/model/DataSourcesTests.kt
new file mode 100644
index 00000000..5f67f2a3
--- /dev/null
+++ b/src/test/kotlin/org/opensearch/commons/alerting/model/DataSourcesTests.kt
@@ -0,0 +1,36 @@
+package org.opensearch.commons.alerting.model
+
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+import org.opensearch.common.io.stream.BytesStreamOutput
+import org.opensearch.core.common.io.stream.StreamInput
+
+class DataSourcesTests {
+    @Test
+    fun `Test DataSources construction with no comments indices`() {
+        val dataSources = DataSources(
+            ScheduledJob.DOC_LEVEL_QUERIES_INDEX,
+            ".opensearch-alerting-finding-history-write",
+            "<.opensearch-alerting-finding-history-{now/d}-1>",
+            ".opendistro-alerting-alerts",
+            ".opendistro-alerting-alert-history-write",
+            "<.opendistro-alerting-alert-history-{now/d}-1>",
+            mapOf(),
+            false
+        )
+        Assertions.assertNotNull(dataSources)
+
+        val out = BytesStreamOutput()
+        dataSources.writeTo(out)
+        val sin = StreamInput.wrap(out.bytes().toBytesRef().bytes)
+        val newDataSources = DataSources(sin)
+        Assertions.assertEquals(ScheduledJob.DOC_LEVEL_QUERIES_INDEX, newDataSources.queryIndex)
+        Assertions.assertEquals(".opensearch-alerting-finding-history-write", newDataSources.findingsIndex)
+        Assertions.assertEquals("<.opensearch-alerting-finding-history-{now/d}-1>", newDataSources.findingsIndexPattern)
+        Assertions.assertEquals(".opendistro-alerting-alerts", newDataSources.alertsIndex)
+        Assertions.assertEquals(".opendistro-alerting-alert-history-write", newDataSources.alertsHistoryIndex)
+        Assertions.assertEquals("<.opendistro-alerting-alert-history-{now/d}-1>", newDataSources.alertsHistoryIndexPattern)
+        Assertions.assertEquals(mapOf<String, Map<String, String>>(), newDataSources.queryIndexMappingsByType)
+        Assertions.assertEquals(false, newDataSources.findingsEnabled)
+    }
+}