Bryan,

Our default_inactivity_timeout is set to 300s. We have looked at the memory 
dump in traffic.out as well, but we're stumped because the memory that is 
tracked in the dump only comes out to about 8GB and 6GB total allocated and 
used respectively while pmap -x <pid> reports around 26GB memory allocated to 
the process.

>From pmap -- 26127468 11646528 11646094    8773892  11644512 12341772 == [ 
>size rss pss referenced anonymous swap ] (KB)
>From traffic.out -- 7895071920 |         5956998576 |            | TOTAL (B)

Is this similar to run-away anon region allocation seen before? Appreciate any 
insights.

Thanks,
Peter


From: Bryan Call [mailto:[email protected]]
Sent: Friday, June 09, 2017 9:02 AM
To: [email protected]
Subject: Re: Ramdisk - 6.2.1 vs 7.0.0

What is your proxy.config.net.default_inactivity_timeout set to?  You can also 
do a dump of the memory by doing:

$ sudo kill -SIGUSR1 $(pidof traffic_server). # and look at traffic.out.

That will give a pretty good idea on where the memory is being used.

-Bryan

On Jun 8, 2017, at 3:35 PM, Jeremy Payne 
<[email protected]<mailto:[email protected]>> wrote:

ATS versions - 6.2.1
Cache disk - 18G ramdisk - /dev/ram0
Storage.config configured to use 14G of ramdisk
System memory - 32G
Traffic type - HLS Live
Connections - sustained 4k
Trafffic - 5-6gbps
Hit ratio - 97%

So it looks like I misread/misinterpreted a few things during testing 
referenced in my previous email.
It looks like my issue was never run away memory using ramdisk,
it looks like something internal to ATS that I can't seem to isolate.

Since I am not seeing this type of memory consumption with my large-file/VOD 
cache servers,
and the connection profile is much different, I am guessing what may be at 
issue is the long living
connections. ATS active timeout is currently set to 3600. This is live traffic 
so connections stay open for a hour
and then closed.  Where as with my large-file/VOD cache servers, connections 
only remain
open for as long as a file/title is being retrieved. 10-15mins max.

Has anyone seen any issues with this type of connection profile and ATS 6.2.1?

This doesnt seem to be an issue with 7.0, so not sure what may have changed 
between releases.

Thanks!



On Tue, Jun 6, 2017 at 8:32 AM, Jeremy Payne 
<[email protected]<mailto:[email protected]>> wrote:
ATS versions - 6.2.1 and 7.0.0
Cache disk - 18G ramdisk - /dev/ram0
System memory - 32G
Traffic type - HLS Live

While testing live HLS traffic, I noticed that ATS 6.2.1. continued to use 
ramdisk until
eventually traffic_server was restarted(via trafic_cop) as result of 'oom 
killer'

Testing with ATS 7.0.0 I saw memory use remain stable once the ramdisk reached 
it's
'configured' capacity.

I looked through the 7.0 changelog and didnt see anything obvious, so maybe 
someone is aware of an undocumented change which impacts ATS 'honoring' 
configured  ramdisk boundaries.
Understood ATS may not know the difference between /dev/sdX and /dev/ramX.. But 
just
putting this out to the community just in case I am missing something.

Jeremy







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