When is the SignalR hub constructor called?

Question

I'm trying to debug a SignalR hub and noticed that the constructor is getting called multiple times, even with a single client. Is this the expected behaviour? I was expecting the constructor to be called only once for class initialisation, but I'm hitting my breakpoint multiple times.

not sure, but i think its a new one on every request – Mahmoud Darwish Jul 28 '13 at 23:48 — Mahmoud Darwish, Jul 28 '13 at 23:48

score 24 · Accepted Answer · answered Jul 29 '13 at 01:36

24

In SignalR Hub instance will be created per each request. So it does't matter if there is only one client or more. In fact Hub is an abstraction over PersistentConnection, if you want more precise control over the things happening behind the scene you can use PersistentConnection. Check here : https://github.com/SignalR/SignalR/wiki/PersistentConnection

answered Jul 29 '13 at 01:36

Incognito

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Even more than that. Once per invocation which can be more than per request (in the case of websockets) – davidfowl Feb 22 '14 at 09:38

score 10 · Answer 2 · answered Jul 29 '13 at 03:46

As Incognito correctly pointed out, SignalR creates a new instance of the Hub for every request. You should use static members to store information you want in the Hub for all the requests. If you wish to do some operations every time a new client connects to the hub, you should put that code in the OnConnected.

When is the SignalR hub constructor called?

2 Answers2