functions/Test-DbaNetworkLatency.ps1
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Function Test-DbaNetworkLatency { <# .SYNOPSIS Tests how long a query takes to return from SQL Server .DESCRIPTION This function is intended to help measure SQL Server network latency by establishing a connection and making a simple query. This is a better alternative than ping because it actually creates the connection to the SQL Server, and times not ony the entire routine, but also how long the actual queries take vs how long it takes to get the results. By default, this command will execute "SELECT TOP 100 * FROM INFORMATION_SCHEMA.TABLES" three times. It will then output how long the entire connnection and command took, as well as how long *only* the execution of the command took. This allows you to see if the issue is with the connection or the SQL Server itself. .PARAMETER SqlInstance The target SQL Server instance. .PARAMETER SqlCredential Optional alternative Windows or SQL Login .PARAMETER Query Specifies the query to be executed. By default, "SELECT TOP 100 * FROM INFORMATION_SCHEMA.TABLES" will be executed on master. To execute in other databases, use fully qualified table names. .PARAMETER Count Specifies how many times the query should be executed. By default, the query is executed three times. .PARAMETER WhatIf Shows what would happen if the command were to run. No actions are actually performed. .PARAMETER Confirm Prompts you for confirmation before executing any changing operations within the command. .PARAMETER Silent Use this switch to disable any kind of verbose messages .NOTES Tags: Performance, Network Website: https://dbatools.io Copyright: (C) Chrissy LeMaire, clemaire@gmail.com License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0 .LINK https://dbatools.io/Test-DbaNetworkLatency .EXAMPLE Test-DbaNetworkLatency -SqlInstance sqlserver2014a, sqlcluster Times the roundtrip return of "SELECT TOP 100 * FROM INFORMATION_SCHEMA.TABLES" on sqlserver2014a and sqlcluster using Windows credentials. .EXAMPLE Test-DbaNetworkLatency -SqlInstance sqlserver2014a -SqlCredential $cred Times the execution results return of "SELECT TOP 100 * FROM INFORMATION_SCHEMA.TABLES" on sqlserver2014a using SQL credentials. .EXAMPLE Test-DbaNetworkLatency -SqlInstance sqlserver2014a, sqlcluster, sqlserver -Query "select top 10 * from otherdb.dbo.table" -Count 10 Times the execution results return of "select top 10 * from otherdb.dbo.table" 10 times on sqlserver2014a, sqlcluster, and sqlserver using Windows credentials. #> [CmdletBinding()] [OutputType([System.Object[]])] param ( [parameter(Mandatory = $true, ValueFromPipeline = $true)] [Alias("ServerInstance", "SqlServer")] [DbaInstanceParameter[]]$SqlInstance, [PSCredential]$SqlCredential, [string]$Query = "select top 100 * from INFORMATION_SCHEMA.TABLES", [int]$Count = 3, [switch]$Silent ) process { foreach ($instance in $SqlInstance) { try { $start = [System.Diagnostics.Stopwatch]::StartNew() $currentcount = 0 try { Write-Message -Level Verbose -Message "Connecting to $instance" $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $sqlcredential } catch { Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue } do { if (++$currentcount -eq 1) { $first = [System.Diagnostics.Stopwatch]::StartNew() } $null = $server.Query($query) if ($currentcount -eq $count) { $last = $first.elapsed } } while ($currentcount -lt $count) $end = $start.elapsed $totaltime = $end.TotalMilliseconds $average = $totaltime / $count $totalwarm = $last.TotalMilliseconds if ($Count -eq 1) { $averagewarm = $totalwarm } else { $averagewarm = $totalwarm / ($count - 1) } [PSCustomObject]@{ ComputerName = $server.NetName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName Count = $count Total = [prettytimespan]::FromMilliseconds($totaltime) Avg = [prettytimespan]::FromMilliseconds($average) ExecuteOnlyTotal = [prettytimespan]::FromMilliseconds($totalwarm) ExecuteOnlyAvg = [prettytimespan]::FromMilliseconds($averagewarm) } | Select-DefaultView -Property ComputerName, InstanceName, SqlInstance, 'Count as ExecutionCount', Total, 'Avg as Average', ExecuteOnlyTotal, 'ExecuteOnlyAvg as ExecuteOnlyAverage' #backwards compat } catch { Stop-Function -Message "Error occurred: $_" -InnerErrorRecord $_ -Continue } } } end { Test-DbaDeprecation -DeprecatedOn "1.0.0" -Silent:$false -Alias Test-SqlNetworkLatency } } |