EPICS Home EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

Format page
for printing


Search Tech-talk
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
<== Date ==> <== Thread ==>
Subject: RE: Epics Archiver Appliance and Network Storage slowdown
From: "Manoussakis, Adamandios via Tech-talk" <tech-talk at aps.anl.gov>
To: "Shankar, Murali" <mshankar at slac.stanford.edu>, "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Date: Mon, 21 Feb 2022 06:43:35 +0000

Thanks Murali,

 

I will try to run some more tests including the one that was mentioned to make sure the transfer rates look correct.  I cant imagine the local vs NAS on this small of a setup shouldnt be vastly different.  

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Shankar, Murali via Tech-talk
Sent: Thursday, February 17, 2022 12:01 PM
To: tech-talk at aps.anl.gov
Subject: Re: Epics Archiver Appliance and Network Storage slowdown

 

>> I think for this experiment its only 6000 PVs

I think that should not take this long. Will look into this a bit here as well.

 

Regards,

Murali

 

 

From: Shankar, Murali
Sent: Saturday, February 12, 2022 8:03 AM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Epics Archiver Appliance and Network Storage slowdown

 

>> We are using the getDataAtTime endpoint

>> 40MB file from the archive

 

By this I'd guess that you are getting data for several 100,000's of PVs? The getDataAtTime API call has to look at all these 100,000 files ( with perhaps cache-misses for most of them ) and then do binary search to determine the data point. Your NAS needs to support quite a high rate of IOPS to for this to come back quickly. And this is a usecase where even the smallest latency tends to accumulate quickly. Perhaps you can consider breaking down your request into smaller chunks when using the NAS? 

 

Regards,

Murali

 

Replies:
RE: Epics Archiver Appliance and Network Storage slowdown Manoussakis, Adamandios via Tech-talk
References:
Re: Epics Archiver Appliance and Network Storage slowdown Shankar, Murali via Tech-talk
Re: Epics Archiver Appliance and Network Storage slowdown Shankar, Murali via Tech-talk
Navigate by Date:
Prev: Re: Error while installing the StreamDevice ZALA ARYANSINH via Tech-talk
Next: Frequent disconnect and auto-reconnects with Serial ASYN and Stream controlled device Ashish Sharma via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
Navigate by Thread:
Prev: Re: Epics Archiver Appliance and Network Storage slowdown Shankar, Murali via Tech-talk
Next: RE: Epics Archiver Appliance and Network Storage slowdown Manoussakis, Adamandios via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
ANJ, 14 Sep 2022 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·