From 00c391602d39d07bf4b7241ee5f53db96265a8ff Mon Sep 17 00:00:00 2001
From: Dimitris Athanasiou <dimitris@elastic.co>
Date: Wed, 28 Mar 2018 16:05:42 +0100
Subject: [PATCH] [ML] Cap default model_memory_limit in the ML info API
 (elastic/x-pack-elasticsearch#4249)

Original commit: elastic/x-pack-elasticsearch@dc614ad37087ab72c89be5c95bff3d16d78acfb9
---
 .../xpack/ml/action/TransportMlInfoAction.java | 13 +++++++++++--
 .../rest-api-spec/test/ml/ml_info.yml          | 18 ++++++++++++++++--
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportMlInfoAction.java b/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportMlInfoAction.java
index f799e204799..ddd7d691b3e 100644
--- a/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportMlInfoAction.java
+++ b/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportMlInfoAction.java
@@ -55,13 +55,22 @@ public class TransportMlInfoAction extends HandledTransportAction<MlInfoAction.R
 
     private Map<String, Object> anomalyDetectorsDefaults() {
         Map<String, Object> defaults = new HashMap<>();
-        defaults.put(AnalysisLimits.MODEL_MEMORY_LIMIT.getPreferredName(),
-                new ByteSizeValue(AnalysisLimits.DEFAULT_MODEL_MEMORY_LIMIT_MB, ByteSizeUnit.MB));
+        defaults.put(AnalysisLimits.MODEL_MEMORY_LIMIT.getPreferredName(), defaultModelMemoryLimit());
         defaults.put(AnalysisLimits.CATEGORIZATION_EXAMPLES_LIMIT.getPreferredName(), AnalysisLimits.DEFAULT_CATEGORIZATION_EXAMPLES_LIMIT);
         defaults.put(Job.MODEL_SNAPSHOT_RETENTION_DAYS.getPreferredName(), Job.DEFAULT_MODEL_SNAPSHOT_RETENTION_DAYS);
         return defaults;
     }
 
+    private ByteSizeValue defaultModelMemoryLimit() {
+        ByteSizeValue defaultLimit = new ByteSizeValue(AnalysisLimits.DEFAULT_MODEL_MEMORY_LIMIT_MB, ByteSizeUnit.MB);
+        ByteSizeValue maxModelMemoryLimit = clusterService.getClusterSettings().get(MachineLearningField.MAX_MODEL_MEMORY_LIMIT);
+        if (maxModelMemoryLimit != null && maxModelMemoryLimit.getBytes() > 0
+                && maxModelMemoryLimit.getBytes() < defaultLimit.getBytes()) {
+            return maxModelMemoryLimit;
+        }
+        return defaultLimit;
+    }
+
     private Map<String, Object> datafeedsDefaults() {
         Map<String, Object> anomalyDetectorsDefaults = new HashMap<>();
         anomalyDetectorsDefaults.put(DatafeedConfig.SCROLL_SIZE.getPreferredName(), DatafeedConfig.DEFAULT_SCROLL_SIZE);
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/ml_info.yml b/plugin/src/test/resources/rest-api-spec/test/ml/ml_info.yml
index 1ec2b5ea7a6..ce934c1d2f6 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/ml_info.yml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/ml_info.yml
@@ -12,7 +12,21 @@
       cluster.put_settings:
         body:
           persistent:
-            xpack.ml.max_model_memory_limit: "4gb"
+            xpack.ml.max_model_memory_limit: "512mb"
+
+  - do:
+      xpack.ml.info: {}
+  - match: { defaults.anomaly_detectors.model_memory_limit: "512mb" }
+  - match: { defaults.anomaly_detectors.categorization_examples_limit: 4 }
+  - match: { defaults.anomaly_detectors.model_snapshot_retention_days: 1 }
+  - match: { defaults.datafeeds.scroll_size: 1000 }
+  - match: { limits.max_model_memory_limit: "512mb" }
+
+  - do:
+      cluster.put_settings:
+        body:
+          persistent:
+            xpack.ml.max_model_memory_limit: "6gb"
 
   - do:
       xpack.ml.info: {}
@@ -20,4 +34,4 @@
   - match: { defaults.anomaly_detectors.categorization_examples_limit: 4 }
   - match: { defaults.anomaly_detectors.model_snapshot_retention_days: 1 }
   - match: { defaults.datafeeds.scroll_size: 1000 }
-  - match: { limits.max_model_memory_limit: "4gb" }
+  - match: { limits.max_model_memory_limit: "6gb" }