Receiving Queue Alerts in C#

dkalten Member Posts: 1
edited September 2023 in General Discussions #1
I'm currently running into issues trying to subscribe to alerts from my queue. I currently have my queue set up where I should be getting threshold alerts when I have 2+ msgs in the queue. From and I have gathered that i need to be reading the VPN_AD_MSG_SPOOL_HIGH alerts; however, I've tried a multitude of topic names, and i never receives any msgs regarding these alerts. I've even tried "#LOG/>" which is supposedly supposed to send all alerts, but even that gives me no msgs. I have gotten it to be able to recieve normal topic msgs, but haven't been able to figure out these alerts.
namespace SolaceTopicListener
class Program
// Copied directly from Solace's example online w/ minor changes to use settings file

public class TopicSubscriber : IDisposable
string VPNName { get; set; }
string UserName { get; set; }
string Password { get; set; }

const int DefaultReconnectRetries = 3;

private ISession Session = null;
private EventWaitHandle WaitEventWaitHandle;
private Logger logger_ = LogManager.GetCurrentClassLogger();

void Run(IContext context, string host, int port, string topic, EventWaitHandle handle)
WaitEventWaitHandle = handle;
// Validate parameters
if (context == null) {
throw new ArgumentException("Solace Systems API context Router must be not null.", "context");
if (string.IsNullOrWhiteSpace(host)) {
throw new ArgumentException("Solace Messaging Router host name must be non-empty.", "host");
if (string.IsNullOrWhiteSpace(VPNName)) {
throw new InvalidOperationException("VPN name must be non-empty.");
if (string.IsNullOrWhiteSpace(UserName)) {
throw new InvalidOperationException("Client username must be non-empty.");

// Create session properties
SessionProperties sessionProps = new SessionProperties()
Host = $"{host}:{port}",
VPNName = VPNName,
UserName = UserName,
Password = Password,
ReconnectRetries = DefaultReconnectRetries

// Connect to the Solace messaging router
Console.WriteLine("Connecting as {0}@{1} on {2}...", UserName, VPNName, host);
// NOTICE HandleMessage as the message event handler
Session = context.CreateSession(sessionProps, HandleMessage, OnSolaceEvent_);
ReturnCode returnCode = Session.Connect();
if (returnCode == ReturnCode.SOLCLIENT_OK) {
Console.WriteLine("Session successfully connected.");

topic = "#LOG/>";
returnCode = Session.Subscribe(ContextFactory.Instance.CreateTopic(topic), false);
if (returnCode == ReturnCode.SOLCLIENT_OK) {
Console.WriteLine("Waiting for a message to be published...");
else {
Console.WriteLine("Error subscribing to topic {0} : {1}", topic, returnCode);
else {
Console.WriteLine("Error connecting, return code: {0}", returnCode);

/// <summary>
/// This event handler is invoked by Solace Systems Messaging API when a message arrives
/// </summary>
/// <param name="source"></param>
/// <param name="args"></param>
private void HandleMessage(object source, MessageEventArgs args)
Console.WriteLine("Received published message.");
// Received a message
using (IMessage message = args.Message) {
// Expecting the message content as a binary attachment
if (message.BinaryAttachment != null && message.BinaryAttachment.Length > 0) {
string encoded = Encoding.UTF8.GetString(message.BinaryAttachment);
Console.WriteLine("Binary Content: {0}", encoded);
logger_.Info($"Binary Content: {encoded}");
if (message.XmlContent != null && message.XmlContent.Length > 0) {
Console.WriteLine("Message content: {0}", Encoding.ASCII.GetString(message.XmlContent));
logger_.Info("Message content: {0}", Encoding.ASCII.GetString(message.XmlContent));

private void OnSolaceEvent_(object sender, SessionEventArgs e)
// Received a flow event
Console.WriteLine("Received Session Event '{0}' Type: '{1}' Text: '{2}'",

public void HandleFlowEvent(object sender, FlowEventArgs args)
// Received a flow event
Console.WriteLine("Received Flow Event '{0}' Type: '{1}' Text: '{2}'",

#region IDisposable Support
private bool disposedValue = false;

protected virtual void Dispose(bool disposing)
if (!disposedValue) {
if (disposing) {
if (Session != null) {
disposedValue = true;

public void Dispose()

#region Main
static void Main(string[] args)
SolaceListenerSettings settings = new SolaceListenerSettings();

string host = settings.SolaceHost; // Solace messaging router host name or IP address
string username = settings.SolaceUsername;
string vpnname = settings.SolaceVpn;
string password = settings.SolacePassword;
int port = settings.SolacePort;
string topic = settings.SolaceTopic;

EventWaitHandle handle = new AutoResetEvent(false);

// Initialize Solace Systems Messaging API with logging to console at Warning level
ContextFactoryProperties cfp = new ContextFactoryProperties()
SolClientLogLevel = SolLogLevel.Warning

try {
// Context must be created first
using (IContext context = ContextFactory.Instance.CreateContext(new ContextProperties(), null)) {
// Create the application
using (TopicSubscriber topicSubscriber = new TopicSubscriber()
VPNName = vpnname,
UserName = username,
Password = password
}) {
// Run the application within the context and against the host
topicSubscriber.Run(context, host, port, topic, handle);

catch (Exception ex) {
Console.WriteLine("Exception thrown: {0}", ex.Message);
finally {
// Dispose Solace Systems Messaging API


  • marc
    marc Member, Administrator, Moderator, Employee Posts: 923 admin

    Hi @dkalten,

    Sorry for the delay in getting back to you here! Any chance you already found the issue?

    If not, have you tried to consume the log events by consuming with sdkperf? That would help us narrow down if the problem is the alert being triggered or the consumer just not receiving it.

  • UshShukla
    UshShukla Member, Employee Posts: 4 Solace Employee
    edited October 2023 #3

    Hey @dkalten ,

    Thanks for waiting. I had to research this a bit 😁!

    You haven't indicated whether you're using Cloud/Software/Appliance. I assumed Software for the purposes of my reply.

    To have the broker actually publish system events:

    • Designate a given Message VPN as a Management VPN
      • Details here
      • ⚠️ Without this, the broker will not publish system events onto the #LOG/> topic(s).
    • Set your alert thresholds on the queue as appropriate.
    • Publish

    This is how you enable publication using the Web Manager UI:

    This is how the alert appeared from my tests using the Web Manager UI:

    Hope this helps!