how can q assign incoming requests to slave threads ?

Community Support
1

After a request hits .z.pg , how can it pass it to a “slave” thread while the “main” thread can service subsequent requests ?

2

Hi,

I would recommend using a gateway.

You can find a general introduction to kdb+ gateways in
http://code.kx.com/pages/db/DB_Common_Design_Principles_for_kdb+_Gateways.pdf

and a more detailed explanation of how to use a gateway to serve multiple user requests in

http://code.kx.com/pages/db/DB_Query_Routing_a_kdb%2B_Framework_for_a_Scalable_Load_Balanced_System.pdf


Regards,

Davide Corti | KDB+ Engineer | Kx | +44-7926-223284 | dcorti@kx.com

3

I know you can use a gateway but I would like to know the thread version of the answer.

4

Launch q with negative port number, that way incoming requests will be served in slave threads (with the usual limitations of what you cannot do in slave threads).

Cheers,

Oleg

5

Whats the usual limitation on slave threads ?

6

'noupdate mostly
No updating global variables, no using hopen, no OS operations, used to be some version when no #g setting was allowed, but they then fixed it. No using network handles, I’m afraid (unless they changed it recently).

You can, although, use one-shot `connsymbol"query" but it’s kind of defeats the purpose.

So… A bit useless, but you can serve selects on hdb,I suppose.

Cheers,

Oleg