Trigger a Full Crawl on SharePoint Online

function processWeb($web) {

 $subWebs = $web.Webs
 $clientContext.Load($web) 
 $clientContext.Load($web.AllProperties)
 $clientContext.Load($subWebs)
 $clientContext.ExecuteQuery()

 Write-Host "Web URL:" $web.Url -ForegroundColor White
 if( $enableAllManagedProperties -ne "skip" ) {
 Set-AllManagedProperties -web $web -clientContext $clientContext -enableAllManagedProps $enableAllManagedProperties
 }

 [int]$version = 0
 $allProperties = $web.AllProperties
 if( $allProperties.FieldValues.ContainsKey("vti_searchversion") -eq $true ) {
 $version = $allProperties["vti_searchversion"]
 }
 $version++
 $allProperties["vti_searchversion"] = $version
 Write-Host "-- Updated search version: " $version -ForegroundColor Green
 $web.Update()
 $clientContext.ExecuteQuery()

 foreach ($subWeb in $subWebs)
 {
 processWeb($subWeb)
 }
}