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20020131: Real-time latencies




I have updated the ~ftp/pub/ldm5/rtstats/rtstats.tar.Z file with a
README.rtstats file, and repacked the tarfile to include all changes
since Nov 11.

Installation instructions are included in the README file, as well as
the pqact.conf action to store the data products if the statistics are being
sent to a local machine.

Steve Chiswell
Unidata User Support

On Thu, 31 Jan 2002, Russ Rew wrote:

> Jason and Carl,
>
> Here's the info I promised to send you on computing product latencies.
>
> First, it *is* possible to get an accurate (within 1 second) latency
> for each product just from the output of either "pqutil -w" or from
> running "notifyme -vl-" on the machine that is receiving the products
> you want latencies for.  Also, if you have good network connections to
> an LDM host and are permitted by an "ALLOW" entry, you can get
> accurate latencies for that host.  For example, if I want accurate
> product latencies on the MCIDAS feed to motherlode.ucar.edu, I run:
>
>  $ notifyme -vl- -h motherlode.ucar.edu -f MCIDAS
>  Jan 31 18:13:56 notifyme[29479]: Starting Up: motherlode.ucar.edu: 
> 20020131181356.218 TS_ENDT {{MCIDAS,  ".*"}}
>  Jan 31 18:13:56 notifyme[29479]: NOTIFYME(motherlode.ucar.edu): OK
>  Jan 31 18:15:27 notifyme[29479]:   121702 20020131181510.359  MCIDAS 000  
> pnga2area Q0 CA 1100 GOES-10_SND UNKBAND 14km 20020131 1700
>
>  ...
>
> The latency for the product "pnga2area Q0 CA 1100 GOES-10_SND UNKBAND
> 14km 20020131 1700" is the difference between the time stamp at the
> beginning of the line, "Jan 31 18:15:27", and the product injection
> time, "20020131181510.359" (which is in the format yyyymmddhhmmss.xxx)
> or 17 seconds.  Similarly with the output of "pqutil -w data/ldm.pq",
> you can just take the difference of the two times.  And the product
> size is also available as the field after the ":", 121702 bytes for
> this example product.
>
> Steve Chiswell's real-time latencies package is available from:
>
>   ftp://ftp.unidata.ucar.edu/pub/ldm5/rtstats/rtstats.tar.Z
>
> There will be a README file in the same FTP directory later this
> afternoon (if it's not already there) that describes how to install
> and use it.  Currently rtstats is being used for creating the real-time
> latencies that are plotted at:
>
>   http://www.unidata.ucar.edu/staff/chiz/latency/stats/
>
> for example
>
>   
> http://www.unidata.ucar.edu/staff/chiz/latency/stats/NNEXRAD_flood.atmos.uiuc.edu.gif
>
> Let us know if you have more questions about this.
>
> --Russ
>