Merge branch 'master' of https://github.com/MicrosoftDocs/azure-docs-pr

Author: dagiro

articles/hdinsight/hadoop/apache-ambari-troubleshoot-heartbeat-issues.md

@@ -5,7 +5,7 @@ ms.service: hdinsight
 ms.topic: troubleshooting
 author: hrasheed-msft
 ms.author: hrasheed
-ms.date: 08/02/2019
+ms.date: 09/11/2019
 ---
 
 # Apache Ambari heartbeat issues in Azure HDInsight
@@ -16,7 +16,7 @@ This article describes troubleshooting steps and possible resolutions for issues
 
 ### Issue
 
-Ambari agent has high CPU utilization, which results in alerts from Ambari UI that for some nodes the Ambari agent heartbeat is lost.
+Ambari agent has high CPU utilization, which results in alerts from Ambari UI that for some nodes the Ambari agent heartbeat is lost. The heartbeat lost alert is usually transient. 
 
 ### Cause
 

articles/hdinsight/spark/apache-spark-improve-performance-iocache.md

@@ -7,7 +7,7 @@ ms.author: hrasheed
 ms.topic: conceptual
 ms.date: 10/15/2018
 ---
-# Improve performance of Apache Spark workloads using Azure HDInsight IO Cache (Preview)
+# Improve performance of Apache Spark workloads using Azure HDInsight IO Cache 
 
 IO Cache is a data caching service for Azure HDInsight that improves the performance of Apache Spark jobs. IO Cache also works with [Apache TEZ](https://tez.apache.org/) and [Apache Hive](https://hive.apache.org/) workloads, which can be run on [Apache Spark](https://spark.apache.org/) clusters. IO Cache uses an open-source caching component called RubiX. RubiX is a local disk cache for use with big data analytics engines that access data from cloud storage systems. RubiX is unique among caching systems, because it uses Solid-State Drives (SSDs) rather than reserve operating memory for caching purposes. The IO Cache service launches and manages RubiX Metadata Servers on each worker node of the cluster. It also configures all services of the cluster for transparent use of RubiX cache.
 

includes/virtual-machines-image-builder-overview.md

@@ -43,7 +43,7 @@ AIB will support Azure Marketplace base OS images:
 - Ubuntu 16.04
 - RHEL 7.6
 - CentOS 7.6
-- Windows 10 RS5 Enterprize/Professional/Enterprise for Virtual Desktop (EVD) 
+- Windows 10 RS5 Enterprise/Professional/Enterprise for Virtual Desktop (EVD) 
 - Windows 2016
 - Windows 2019