Pub/sub introspection

Use the Server facet to see which channels are active and how many subscribers they have. These read-only PUBSUB queries do not need AllowAdmin.

Method	Command	Redis
`PubSubChannelsAsync`	PUBSUB CHANNELS (SHARDCHANNELS with `sharded: true`)	2.8+ (sharded 7+)
`PubSubSubscriberCountsAsync`	PUBSUB NUMSUB (SHARDNUMSUB with `sharded: true`)	2.8+ (sharded 7+)
`PubSubPatternCountAsync`	PUBSUB NUMPAT	2.8+

RespireChannel channel = "events";
RespireChannel[] active = await redis.Server.PubSubChannelsAsync(pattern: "event*");
RespireChannelSubscriberCount[] subscribers =
    await redis.Server.PubSubSubscriberCountsAsync([channel]);
long uniquePatterns = await redis.Server.PubSubPatternCountAsync();
RespireChannelSubscriberCount[] shardSubscribers =
    await redis.Server.PubSubSubscriberCountsAsync([channel], sharded: true);

Unsupported versions and denied ACL permissions surface the server error.
Channel names and patterns keep their exact bytes. Result channels own their storage after the reply and client are disposed.
Empty names, empty name lists, and an omitted versus empty pattern are distinct.
sharded alone selects the command family; the input channel's kind does not. Returned sharded names have RespireSubscriptionKind.Sharded.
WithKeyPrefix and WithPubSubPrefix are not applied. Pass ((IRespireNameResolver)view).ResolveChannel(logicalChannel) for a prefixed literal or sharded count, and ((IRespireNameResolver)view).ResolveChannel(RespireChannel.Pattern(logicalPattern)) for a prefixed CHANNELS pattern.

What the counts mean:

CHANNELS lists channels with literal subscribers; channels with only pattern subscribers are excluded.
NUMSUB counts literal subscribers only.
NUMPAT counts unique patterns, not clients or matching channels.
Sharded and ordinary counts are separate.
Results are a snapshot at execution time, not a delivery guarantee.

Results from every node

Ordinary methods query one node. In Cluster mode they give no global count and do not route sharded queries by channel. Use the OnAllNodesAsync methods to query every discovered member, including replicas and primaries without slots:

RespireServerResult<RespireChannelSubscriberCount[]>[] nodes =
    await redis.Server.PubSubSubscriberCountsOnAllNodesAsync(["events"]);
foreach (var node in nodes)
{
    if (!node.IsSuccess)
    {
        Console.WriteLine($"{node.Endpoint}: {node.Error!.Message}");
        continue;
    }
    foreach (var item in node.Value)
        Console.WriteLine($"{node.Endpoint}: {item.Channel} has {item.Subscribers} subscribers");
}

Results:

Each result has its Endpoint and either Value or the original Error.
Value on failure throws InvalidOperationException with the error as inner exception. TryGetValue(out var value) returns false and the default value instead.
Counts are not summed and names are not deduplicated across nodes. Standalone returns one result.

Discovery:

Each call runs CLUSTER NODES (needs that ACL permission) on a reachable connection.
The reporting node keeps its known address. Other members use their advertised hostname if present, else their advertised IP; the seed hostname is never substituted.
TLS validates against that host unless TlsOptions.TargetHost overrides it. Advertised addresses must be reachable and match your certificates.
Unfinished handshakes are excluded. Missing addresses, malformed or conflicting topology, and discovery failures throw before any node is queried, so you never get a partial topology presented as complete.
Membership can change after the snapshot; there is no atomic Cluster-wide view.

Execution:

One temporary connection per endpoint, at most eight active per call. Avoid overlapping polls if you need to limit total connections.
Connections close on every outcome and are not added to the routing pool. Disposing the client aborts in-progress calls.
TCP/TLS setup uses ConnectTimeout; handshakes and commands use CommandTimeout and the response watchdog. If response deadlines are disabled, pass a cancellation deadline to bound a stalled node.
Authentication and TLS settings apply. A failed node returns an error for its endpoint; other nodes can still succeed.
Cancellation before or during discovery throws. After discovery, it is recorded per node, and completed results stay available.
No command is replayed or redirected to another endpoint.

Custom IRespireServerCommands implementations, decorators, and mocks must implement or forward all six methods (three single-node methods and their OnAllNodesAsync counterparts). These queries are not available in batches or transactions.

Redis contracts: CHANNELS, NUMSUB, NUMPAT, SHARDCHANNELS, and SHARDNUMSUB.

Results from every node​

Results from every node