trafficserver-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Muhammad Faisal" <>
Subject Re: High Upstream Utilization Background Fetch Plugin behavior
Date Wed, 30 Mar 2016 12:47:49 GMT
The upstream utilization remained high unless i unloaded it from ATS. 
This behavior was causing negative saving meaning high upstream and low 
downstream. But im seeing now mp4 videos are not being cached which was 
previously with background fill plugin.

Any suggestions?


------ Original Message ------
From: "Muhammad Faisal" <>
Sent: 3/17/2016 11:10:26 AM
Subject: Re: High Upstream Utilization Background Fetch Plugin behavior

>Hi Sudheer,
>I have made changes as per below let see how it goes.
>------ Original Message ------
>From: "Muhammad Faisal" <>
>To:; "" 
>Sent: 3/17/2016 1:39:42 AM
>Subject: Re: High Upstream Utilization Background Fetch Plugin behavior
>>Thanks Suheer it was an error in my plugin config. I have corrected it 
>>but exclude Content-Length <1000 will exclude objects less than 1000. 
>>What is the unit of 1000 bytes?
>>What if I add exclude Content-Length >100000000 (100MB)
>>------ Original Message ------
>>From: "Sudheer Vinukonda" <>
>>To: "" <>; 
>>"Muhammad Faisal" <>
>>Sent: 3/17/2016 1:28:44 AM
>>Subject: Re: High Upstream Utilization Background Fetch Plugin 
>>>Is there a typo in the below line?
>>>exclude Content -Length < 1000
>>>If there is, pls try changing it as below:
>>>exclude Content-Length <1000
>>>Once you change the config, you may want to functionally validate by 
>>>sending a range request for a large ( > 1000 bytes) objects to see if 
>>>it behaves correctly.
>>>"- Set Max object size to 100 or 200 MB"
>>>max object size only affects the size of the objects stored in the 
>>>Cache. It does not prevent the downloading of larger objects from 
>>>your upstream, so, it will not help with saving upstream bandwidth. 
>>>In fact, if any, it may make it worse, since ATS will basically 
>>>download the large objects for every request (however, long tail they 
>>>may be).
>>>On Wednesday, March 16, 2016 12:15 PM, Muhammad Faisal 
>>><> wrote:
>>>After more than two months of testing and great support from entire 
>>>ATS team, finally we have integrated ATS in production scenario as 
>>>transparent caching . Currently we have put limited traffic to it 
>>>approx 200mbps (1k plus users). After putting actual load on the 
>>>server i'm observing the upstream utilization has been increased. 
>>>Last stats that i have viewed are 130Mbps (upstream) and 41.6Mbps (to 
>>>clients) so there is negative impact of caching instead.
>>>It is worth mentioning that I have used background fetch plugin to 
>>>cache range requests (to improve cache performance specially 
>>>streaming). The max object size currently is set to zero. During 
>>>testing I have observed when downloading a large file the ATS were 
>>>starting object download on available upstream capacity. The large 
>>>file like ISO of 600 MB takes lots of bandwidth to fill the object 
>>>while delivering to the user according to allocated speed on next 
>>>object hit however the object was delivered from the cache.
>>>I production scenario the above behavior is causing increased 
>>>upstream utilization while the hit probability on larger objects are 
>>>I need experts opinion to improve traffic saving. What comes to my 
>>>mind is:
>>>- Set Max object size to 100 or 200 MB
>>>- Keep using background_fill plugin and exclude the larger objects 
>>>(max object size)
>>>- How to exclude larger files to being background fill above e.g 
>>>Below are my background fill configs:
>>>exclude Content -Length < 1000  (this is to exclude small object less 
>>>than 1000 bytes?)
>>>include Content-Type video/mp4
>>>exclude Content-Type text
>>>include Content-Type video/quicktime
>>>include Content-Type video/3gpp
>>>include Content-Type application/octet-stream
  • Unnamed multipart/related (inline, None, 0 bytes)
View raw message