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<== Date ==> <== Thread ==>
Subject: Re: generalTime/epicsTimeGetCurrent and casr questions
From: Mark Rivers via Tech-talk <[email protected]>
To: "Layne (US), William C" <[email protected]>
Cc: "[email protected]" <[email protected]>
Date: Sat, 9 Mar 2019 16:31:35 +0000 
Hi William,


   I am noticing that in some of our ‘casr’ outputs, we are seeing multiple TCP connections with the same PV channel connected. Is this normal behavior?

a.       For some reason, I assumed Channel Access wouldn’t allow this. If it is normal behavior, any suggestions on ways to prevent it? (I know having the users checking would be a good way J)

I am not sure what you mean by "multiple TCP connections with the same PV channel connected"?  Do you mean from the same host?  Do they have different port numbers, like this?

    TCP client at 164.54.160.82:41108 'corvette':
        User 'epics', V4.13, Priority = 80, 108 Channels
        Channel: '13IDA:scan1.P1SP'
        Channel: '13IDA:scan1.P1EP'
        Channel: '13IDA:scan1.NPTS'
        Channel: '13IDA:scan1.EXSC'
        Channel: '13IDA:scan1.MPTS'
        Channel: '13IDA:scan1.BUSY'
        Channel: '13IDA:scan1.CMND'
        Channel: '13IDA:scan1.P1SM'
...
    TCP client at 164.54.160.82:41110 'corvette':
        User 'epics', V4.13, Priority = 80, 129 Channels
        Channel: '13IDA:scan1.P1SM'
        Channel: '13IDA:scan1.P1SP'
        Channel: '13IDA:scan1.P1EP'
        Channel: '13IDA:scan1.NPTS'
        Channel: '13IDA:scan1.EXSC'
        Channel: '13IDA:scan1.MPTS'
        Channel: '13IDA:scan1.BUSY'
        Channel: '13IDA:scan1.CMND'

If so those are just 2 different clients on the same host connecting to the same PV.  That is normal.

On the other hand I am also seeing things like this, which I am not sure is normal:

    TCP client at 164.54.160.93:60193 'Ferrari':
        User 'XAS_User', V4.13, Priority = 50, 4249 Channels
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'
        Channel: '13IDA:DAC1_7.VAL'

Mark


________________________________
From: [email protected] <[email protected]> on behalf of Layne (US), William C via Tech-talk <[email protected]>
Sent: Friday, March 8, 2019 6:18 PM
To: [email protected]
Subject: generalTime/epicsTimeGetCurrent and casr questions


Hello, haven’t posted here before so here it goes. (Recently completed some training and was encouraged to reach out more)



I figure I will start with some of the more softball questions as we are seeing various issues here:

1.       Has anyone seen issues with multiple threads using the generalTime subsystem?

a.       We are having some performance issues with a large number of clients (>100) and am trying to narrow down which futex we are spending lots of time in. I will run some tests later this week to see if the ‘timeListLock’ could be impacting them.

2.       I am noticing that in some of our ‘casr’ outputs, we are seeing multiple TCP connections with the same PV channel connected. Is this normal behavior?

a.       For some reason, I assumed Channel Access wouldn’t allow this. If it is normal behavior, any suggestions on ways to prevent it? (I know having the users checking would be a good way :))



Hope to be participating more. Thanks,



William ‘Casey’ Layne

Stage Controller – Software Engineer

Email: [email protected]<mailto:[email protected]>

 Any opinions expressed herein are my own.  They are not necessarily those of Boeing, or any other company or organization with which I am affiliated.
Replies:
Re: generalTime/epicsTimeGetCurrent and casr questions Johnson, Andrew N. via Tech-talk
References:
generalTime/epicsTimeGetCurrent and casr questions Layne (US), William C via Tech-talk
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