Re: Channel connection performance

[Marty Kraimer via Tech-talk <tech-talk at aps.anl.gov>]

I assume that, for each channel, you are calling
pvaClientChannel->connect

Instead , for each channel, call
pvaClientChannel->issueConnect

than , for each channel, call
pvaClientChannel->waitConnect

You can also just check connection status instead of calling waitConnect

Hope this helps.

Marty Kraimer



On 1/25/21 2:00 PM, Axel Terfloth via Tech-talk wrote:
> Hello,
>
> i’m new to EPICS and take a closer look at it for evaluation purpose. To obtain a better understanding I started to dig deeper by implementing some tests which are based on the C++ examples. From a functional point of view everything I tried works nicely so far. Also the performance is generally very good in most of my test scenarios. Nevertheless one issue i came across is the time required for connecting to a channel  via PVA. In this scenario I set up 4000 process variables and implement one client which implements high frequency put and get access to a quarter (1000) of these proces variables. On my machine (which runs all processes for now) if takes about 250ms for a single channel connection. Once all channels are connected is really fast. Nevertheless connecting 1000 pvs takes more than 6 minutes. I currently connect channel by channel using the PvaClient API in my tests. Is there a more efficient way to connect to a large set of channels?  I would appreciate any hint.
>
> Best regards,
> Axel Terfloth