Re: [ldm-users] [noaaport] Thorns amongst the roses...

Just a thought/suggestion. I was surprised at the results they found, but
the procedures were well-thought-out and looked sound.
gc



On Thu, Aug 21, 2014 at 9:34 AM, Tyler Allison <tyler@xxxxxxxxxxxxxxxx>
wrote:

> Bird01 is a less than year old dell rack mount.
>
> -Tyler
>
> On Aug 21, 2014, at 9:08 AM, Gerry Creager - NOAA Affiliate <
> gerry.creager@xxxxxxxx> wrote:
>
> There was an interesting discussion on a software-defined networks list
> about the amount of CPU and memory required to handle larger and faster UDP
> data streams. Of course, they're talking about 10gigabit and 40gigabit
> datastreams, but if your ingest machine is a little older and might be a
> little light on memory, this could be an element.
>
> gerry
>
>
> On Thu, Aug 21, 2014 at 8:59 AM, Daniel Forrest <dan.forrest@xxxxxxxxxxxxx
> > wrote:
>
>> Gilbert,
>>
>> > OK, everything is good with the new NOAAport, right? C/N of 18. Signal
>> > strength: 76. VBER: 0. Yay! But wait...
>> >
>> > I am seeing a ton of these in our ldmd.log:
>> >
>> > Aug 21 13:00:32 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13452198 to 13452266 [skipped 67]
>> > Aug 21 13:00:32 bird01 noaaportIngester[24645] WARN: Retrograde packet
>> > number: previous=13452270, latest=13452230, difference=4294967336
>> > Aug 21 13:00:32 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13452230 to 13452232 [skipped 1]
>> > Aug 21 13:00:32 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13452232 to 13452245 [skipped 12]
>> > Aug 21 13:00:43 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13452515 to 13452524 [skipped 8]
>> > Aug 21 13:00:43 bird01 noaaportIngester[24645] ERROR: Missing GOES
>> fragment
>> > in sequence, last 37/86751 this 46/86751
>> > Aug 21 13:00:43 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13452524 to 13452598 [skipped 73]
>> > Aug 21 13:00:43 bird01 noaaportIngester[24645] WARN: Retrograde packet
>> > number: previous=13452598, latest=13452540, difference=4294967354
>> > Aug 21 13:01:07 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13453270 to 13453274 [skipped 3]
>> > Aug 21 13:01:07 bird01 noaaportIngester[24645] ERROR: Missing GOES
>> fragment
>> > in sequence, last 115/86753 this 119/86753
>> > Aug 21 13:01:07 bird01 noaaportIngester[24645] WARN: Gap in packet
>> sequence:
>> > 13453279 to 13453283 [skipped 3]
>> >
>> > Is anyone else seeing this?
>>
>> I recently had a similar problem using the GOES-R simulator.
>>
>> Just a guess, but if the data is coming in via UDP and the data rate is
>> higher than it was before then it may be a case of too little kernel
>> buffer space.  You can try this (assuming this is Linux):
>>
>> cat /proc/sys/net/core/rmem_max
>> cat /proc/sys/net/core/wmem_max
>> cat /proc/sys/net/core/rmem_default
>> cat /proc/sys/net/core/wmem_default
>>
>> Save these values, if this doesn't help you can reset them.
>>
>> echo 16777216 >/proc/sys/net/core/rmem_max
>> echo 16777216 >/proc/sys/net/core/wmem_max
>> echo 16777216 >/proc/sys/net/core/rmem_default
>> echo 16777216 >/proc/sys/net/core/wmem_default
>>
>> And restart LDM.
>>
>> If this works you can add these values to /etc/sysctl.conf.
>>
>> --
>> Dan
>>
>> _______________________________________________
>> ldm-users mailing list
>> ldm-users@xxxxxxxxxxxxxxxx
>> For list information or to unsubscribe,  visit:
>> http://www.unidata.ucar.edu/mailing_lists/
>>
>
>
>
> --
> Gerry Creager
> NSSL/CIMMS
> 405.325.6371
> ++++++++++++++++++++++
> “Big whorls have little whorls,
> That feed on their velocity;
> And little whorls have lesser whorls,
> And so on to viscosity.”
> Lewis Fry Richardson (1881-1953)
>
> _______________________________________________
> ldm-users mailing list
> ldm-users@xxxxxxxxxxxxxxxx
> For list information or to unsubscribe,  visit:
> http://www.unidata.ucar.edu/mailing_lists/
>
>


-- 
Gerry Creager
NSSL/CIMMS
405.325.6371
++++++++++++++++++++++
“Big whorls have little whorls,
That feed on their velocity;
And little whorls have lesser whorls,
And so on to viscosity.”
Lewis Fry Richardson (1881-1953)
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