SharePoint 2013: Configure Search Topology with Powershell

The best and the only tool to configure a SharePoint 2013 Search Topology is PowerShell. in my case i had to reconfigure a midsize Server farm with one wfe and an one application Server based classical farm architecture. The script below can also be used to configure a streamlined farm architecture.

 #Define topology variables and assign servernames:

$SPApplication1 = Get-SPEnterpriseSearchServiceInstance -Identity "SEARCHSERVER/APPLICATION"
$SPWFE1 = Get-SPEnterpriseSearchServiceInstance -Identity "WFE"

#Start Search Service Instances on both servers

Start-SPEnterpriseSearchServiceInstance -Identity $SPApplication1
Start-SPEnterpriseSearchServiceInstance -Identity $SPWFE1

#Get services Status / Make sure thate Service is in started state, otherwise don't proceed with configuration and fix issue first.

#Get Search Service Instance status (started or stopped) after running the above commands
Get-SPEnterpriseSearchServiceInstance -Identity $SPApplication1
Get-SPEnterpriseSearchServiceInstance -Identity $hostWF1
#Setting up the topology
$ssa = Get-SPEnterpriseSearchServiceApplication
$newTopology = New-SPEnterpriseSearchTopology -SearchApplication $ssa

#SEARCHSERVER
New-SPEnterpriseSearchAdminComponent -SearchTopology $newTopology -SearchServiceInstance $hostApp1
New-SPEnterpriseSearchCrawlComponent -SearchTopology $newTopology -SearchServiceInstance $hostApp1
New-SPEnterpriseSearchContentProcessingComponent -SearchTopology $newTopology -SearchServiceInstance $hostApp1
New-SPEnterpriseSearchAnalyticsProcessingComponent -SearchTopology $newTopology -SearchServiceInstance $hostApp1
New-SPEnterpriseSearchIndexComponent -SearchTopology $newTopology -SearchServiceInstance $hostApp1 -IndexPartition 0

#WFE
New-SPEnterpriseSearchQueryProcessingComponent -SearchTopology $newTopology -SearchServiceInstance $hostWF1
#Activate the Topology
Set-SPEnterpriseSearchTopology -Identity $newTopology
# Verify the Topology
Get-SPEnterpriseSearchTopology -SearchApplication $ssa