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'fd out of range' error during one-shot query
Hello there,
I have recently been encountering an unfamiliar ‘fd out of range’ error while running one-shot queries.
I am using kdb+ 4.0 2021.04.26
I am running a process on a negative port (i.e. new thread for each client query) and low load. The method which the clients call often makes use of a one-shot IPC query to another process on our host. The other process is running on a positive port and under a low load. For intermittent periods, all usages of the one-shot IPC query fail with an error ‘fd out of range’. I haven’t been able to find any documentation on how one-shot IPC works under the covers.
Here’s a brief example:
// Server (running on negative port)
.cfg.handle:
:host:port:user:pass</p><p>method:{[] .cfg.handle"til 5";}<br></p><p></p><p></p><p><code><br></code></p><p></p><p></p><p><br></p><p>// Client<br></p>h:hopen:server_host:server_porth"method[]" / throws 'fd out of range' error
I notice the error does not contain ‘OS Reports:’ which made me think it is coming from within kdb but I could not find it documented. Also, it happens for intermittent periods (i.e. our process may be running for hours, suddenly start throwing constant ‘fd out of range’ errors for every client for a period, and then stop throwing errors later)
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2 Replies
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Formatting of the code snippet got messed up and won’t allow me to edit. See below:
/ Server (running on negative port)
.cfg.handle:
:host:port:user:pass;</p><p>method:{[] .cfg.handle"til 5";};</p><pre><p><br></p><p>/ Client</p><p>h:hopen:server_host:server_port;h"method[]"; / throws 'fd out of range' error
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