@PaulHigin Can we add some tests here as well?

Since this is a perf improvement for special command lines, I don't see a good way to add reliable tests.

Actually, offline we decided that adding a test hook to test the TryRunAsImplicitBatch() method should be sufficient to test the code path. I'll work on adding that.

Does this avoid the intermediate serialization step entirely? If so, then it’s more than a perf improvement, it also enables things that are currently problematic. In many cases a dead serialized property bag isn’t valid pipeline input, but a live object is. So Get | Set scenarios that didn’t work with implicit remoting might start to work.

@iSazonov Yes, batching will work for any remote target that supports implicit remoting.

@mattpwhite , Whoops missed this comment. Yes, batching the pipeline means "live" objects are passed and implicit commands that didn't work with de-serialized objects will likely work as batched.

@adityapatwardhan Can you update your review?

@adityapatwardhan Can you please merge these approved changes? We have users who would like to try out the experimental feature.

@adityapatwardhan Thanks!

It will be nice to share config file where the feature is turned on.

@iSazonov I created new issue to improve experimental features experience #8155

@SteveL-MSFT Thanks!

I meant that attaching a sample file to the PR will help users.

@iSazonov added example to the PR description

Something is wrong here.

PS C:\temp\PowerShell-6.2.0-preview.859-win-x64> Get-ExperimentalFeature

Name                                Enabled Source                              Description
----                                ------- ------                              -----------
PSImplicitRemotingBatching             True PSEngine                            Batch implicit remoting proxy comman...


PS C:\temp\PowerShell-6.2.0-preview.859-win-x64> Import-PSSession $s -CommandName get-Process -Prefix r -verbose -AllowClobber

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Script     1.0        tmp_a4ox23yj.min                    Get-rProcess


PS C:\temp\PowerShell-6.2.0-preview.859-win-x64> get-RProcess |where Name -like *ss
PS C:\temp\PowerShell-6.2.0-preview.859-win-x64> $test = get-RProcess
PS C:\temp\PowerShell-6.2.0-preview.859-win-x64> $test |where Name -like *ss

 NPM(K)    PM(M)      WS(M)     CPU(s)      Id  SI ProcessName
 ------    -----      -----     ------      --  -- -----------
     25     1.90       1.86       7.20     752   0 csrss
     32    11.32       5.30      72.31     868   1 csrss
     85    19.81      24.61     935.81     104   0 lsass
      3     0.57       0.62       0.27     416   0 smss


PS C:\temp\PowerShell-6.2.0-preview.859-win-x64>

You need to enable the feature via the powershell.config.json file.

PS > Get-ExperimentalFeature

Name                                Enabled Source                              Description
----                                ------- ------                              -----------
PSImplicitRemotingBatching             True PSEngine                            Batch implicit remoting proxy comman...

I am not sure about applying a prefix to the proxy command, it seems like that should be Ok. But the other two involving assignment and piping from a variable fail the "simple pipeline" checker used to determine if batching is allowed.

I am adding a verbose output that reports the checker errors so it is easier to determine if the command line is batched or not, and make it easier to address these scenarios.

Whoops, left out the powershell.config.json example:

{
    "Microsoft.PowerShell:ExecutionPolicy":"RemoteSigned",
    "ExperimentalFeatures": [
      "PSImplicitRemotingBatching"
    ]
}

Sorry that the formatting got screwed up but if you look at my post, the very first command confirms that the feature is enabled.

@jpsnover I reformatted your comment by wrapping in:

    ```powershell
    <powershell stuff here>
    ```

Looks like get-RProcess |where Name -like *ss failed to return anything. I just build master which has @PaulHigin's commit and works for me:

PS /Users/steve/repos/PowerShell> Get-rProcess | where name -like "*pwsh*"  

 NPM(K)    PM(M)      WS(M)     CPU(s)      Id  SI ProcessName
 ------    -----      -----     ------      --  -- -----------
     50    55.58      84.09      32.27    3728   0 pwsh
     63    49.50      96.32       2.48   10152   2 pwsh
     61    46.90      92.68       2.36   14056   2 pwsh

Turning on verbose output helps to see what is going on:

$VerbosePreference = "Continue"
Get-rProcess | where Name -like *ss
VERBOSE: Implicit remoting command pipeline has been batched for execution on remote target.

This was batched successfully, however, Get-rProcess proxy command is not on the target machine. I forgot to merge error stream so this error is not showing. It is easy to fix the error stream merge, but I have to think about how to convert Get-rProcess proxy wrapper command to the name of the actual wrapped command.

$test = Get-RProcess
$test | where Name -like *ss

Neither of these are pipelines that round trip data and don't need to be batched.

However,

Import-PSSession $s -CommandName Get-Process -AllowClobber
$VerbosePreference = "Continue"

Get-Process | where Name -like *ss
VERBOSE: Implicit remoting command pipeline has been batched for execution on remote target.

$test = Get-Process | where Name -like *ss
VERBOSE: Command is not a simple pipeline and cannot be batched.

100 | Get-Process | where Name -like *ss
VERBOSE: Command pipeline not supported for implicit remoting batching. : PipelineStartingWithExpressionNotSupported

The last two lines are not being batched because they do not pass the simple pipeline check. They are more complex and require parsing the AST and re-building complex commands, but I think they should be supported.