dotnet/orleans · error · InvalidOperationException

Inform grain id in format `{ id},{additionalKey}`

Error message

Inform grain id in format `{ id},{additionalKey}`

What it means

InvalidOperationException from GrainStateHelper.GetGrainId when the grain's implementation type implements IGrainWithGuidCompoundKey but the supplied id string does not split into exactly two comma-separated parts. The compound-guid format requires exactly 'guid,additionalKey' (the message has a stray backtick/braces typo but means the same format).

Source

Thrown at src/Dashboard/Orleans.Dashboard/Implementation/Helpers/GrainStateHelper.cs:22

using System.Linq;
using System.Reflection;

namespace Orleans.Dashboard.Implementation.Helpers;

internal static class GrainStateHelper
{
    public static (object?, string) GetGrainId(string id, Type implementationType)
    {
        object? grainId = null;
        string keyExtension = "";
        var splitedGrainId = id.Split(",");

        try
        {
            if (implementationType.IsAssignableTo(typeof(IGrainWithGuidCompoundKey)))
            {
                if (splitedGrainId.Length != 2)
                    throw new InvalidOperationException("Inform grain id in format `{ id},{additionalKey}`");

                grainId = Guid.Parse(splitedGrainId.First());
                keyExtension = splitedGrainId.Last();
            }
            else if (implementationType.IsAssignableTo(typeof(IGrainWithIntegerCompoundKey)))
            {
                if (splitedGrainId.Length != 2)
                    throw new InvalidOperationException("Inform grain id in format {id},{additionalKey}");

                grainId = Convert.ToInt64(splitedGrainId.First());
                keyExtension = splitedGrainId.Last();
            }
            else if (implementationType.IsAssignableTo(typeof(IGrainWithIntegerKey)))
            {
                grainId = Convert.ToInt64(id);
            }
            else if (implementationType.IsAssignableTo(typeof(IGrainWithGuidKey)))
            {

View on GitHub (pinned to fca799fa70)

Solutions

1. Ensure ids for compound-key grains are passed as 'guid,additionalKey' with exactly one comma.
2. Validate the format on the client/frontend before requesting grain state.
3. If using single-key grains, make sure the grain interface marker matches (IGrainWithGuidKey vs IGrainWithGuidCompoundKey).

Example fix

// before
var (gid, ext) = GrainStateHelper.GetGrainId(rawId, typeof(MyCompoundGrain));
// rawId = "abc" -> throws

// after
var parts = rawId.Split(',');
if (parts.Length != 2 || !Guid.TryParse(parts[0], out _))
    return BadRequest("id must be 'guid,additionalKey'");
var (gid, ext) = GrainStateHelper.GetGrainId(rawId, typeof(MyCompoundGrain));

var parts = id.Split(',');
if (parts.Length != 2 || !Guid.TryParse(parts[0], out _))
    return BadRequest("id must be 'guid,additionalKey'");
var (gid, ext) = GrainStateHelper.GetGrainId(id, type);

static bool IsValidGuidCompoundId(string id) =>
    id.Split(',') is { Length: 2 } p && Guid.TryParse(p[0], out _);

try { var (gid, ext) = GrainStateHelper.GetGrainId(id, type); }
catch (InvalidOperationException ex) when (ex.Message.Contains("grain id in format"))
{ return BadRequest("compound guid id malformed"); }

When it happens

Trigger: Dashboard invokes GetGrainId(id, implementationType) where implementationType is IGrainWithGuidCompoundKey and id does not contain exactly one comma (splitedGrainId.Length != 2). E.g. id='abc' or id='g1,g2,g3'.

Common situations: Dashboard grain-state inspection receives a malformed id from the frontend, a grain registered with a compound key invoked through a path that passes the raw key without the extension, or a client serializing only the primary key. The downstream Guid.Parse can also throw (wrapped by error 357).

Related errors

• Inform grain id in format {id},{additionalKey}
• Error when trying to convert grain Id
• The frontend cant support more than 6 silos
• Unknown Playground:Storage:Provider value '{storageProvider}
• count

AI-assisted analysis of dotnet/orleans@fca799fa70 (2026-08-13). Data as JSON: /api/errors/c7ee6da523374aa2. Report an issue: GitHub.