Hi @rahul2gupta, as @richgalloway said, you have a distributed environment, so at first see the documentation at https://docs.splunk.com/Documentation/Splunk/8.1.3/Installation/HowtoupgradeSplunk and at https://docs.splunk.com/Documentation/Splunk/8.1.3/Installation/UpgradeyourdistributedSplunkEnterpriseenvironment In few words: you can upgrade in one step for each machine from 7.1 to 8.1.x, the step to follo are these: check the compatibility of your apps with the new environment using the Splunk Platform Upgrade Readiness App (https://splunkbase.splunk.com/app/4698/), backup the three machines, upgrade at first Search Head, upgrade apps; upgrade Indexer, upgrade Heavy Forwarder, test the new environment. Ciao. Giuseppe
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