Generating banner or poster image is very slow

[legrosmoi 4]

Hello dev,

As the title say, when the server generate the banner or poster image for the first time, it becomes very slow right away...

 

I understand the server need to generate them at least once, but is this normal?

 

Let's say I have more than 400 movies, on the first page (100 movies a page) the images appears fairly quick (all is good).

If I quickly go to page number 2, (movie 101-199), it becomes very sluggish

Then if I go to number three before number 2 is fully processed (all images are generated, it becomes dead slow). After maybe some few minutes, it will become responsive again.

 

In the log file the are several slow requests with 4-7 seconds response time.

 

Server v3.0.5870 (same problem on 3.0.58.21 and the one before that)

Server is dedicated to emby

    i3-4370 @ 3.70GHz

   8GB ram

   power options: high performance

 

CPU always stay at around 5-10% even when the delays occur

 

What might be causing this? Where is the bottleneck?

 

Thanks,
Jocelyn

 

 

server-63591144238.txt

[Luke 42080]

CoverArt will cause increased cpu usage when generating images. If it's too much then try disabling it for certain media types you don't need it for

[speechles 2055]

Are you save metadata and images with your media? If your drives are not local to the server, but networked to it this can slow them down. Your bottleneck is the speed of the network in MB/sec. Usually best you get is 10MB/sec. Now compound that with all your new images obtaining coverart from the server to cache and display, as new images are also being saved onto their respective networked media drives from each provider. You can see how obtain new images on the server will become a logistical nightmare until the servers local image caching can benefit you at all. All the crosstalk traffic effectively slows you to 5MB/sec bidirectional. This is why people upgrade to gigabit to gain a 10 fold increase to 100MB/sec or 50MB/sec bidirectional.

Edited February 15, 2016 by speechles

[legrosmoi 4]

Thanks for the answer.

My server drive are are local. 

 

When I have a slow down for image generation, the network utilization (in task manager) is not going over 2%.

On the server the CPU usage is not going over 5%...

 

I also tried with the CoverArt plugin disabled, no change....

 

Other idea, what can take up to 7 seconds to generate an image?

[Luke 42080]

If your source images are high resolution then sometimes it can be slow. The result is cached for subsequent visits though. To speed it up consider replacing your images with lower resolution versions

[legrosmoi 4]

I'm using the default setting at 1280pixels...

 

What library is used to process images?

[Happy2Play 9782]

Does your library already have images or is it still downloading images?  Your log looks like Emby is still trying to get the images.

 

1280 is just the minimum backdrops size.

[legrosmoi 4]

I did a scan library (several in fact) and even after the first one it always take around two hours for subsequent ones...

 

What happen if Emby doesn't find an image, does it try to get it over and over...

 

In the parameters, the server is setted to fetch primary, art, banner and thumb... Many of the movies don't have one because it is not available.

It the slow down on image that Emby try to fetch again?

 

Should I ubcheck some of those image?

[anderbytes 141]

- What if Emby could do this heavy work of optimizing images size?

- Does locking a movie for changes also makes it skip image-check / download?

- Shouldn't be a scheduled tasks for sanitizing? Health check? Remove orphan files / images / metadata?

[ebr 16185]

- What if Emby could do this heavy work of optimizing images size?

- Does locking a movie for changes also makes it skip image-check / download?

- Shouldn't be a scheduled tasks for sanitizing? Health check? Remove orphan files / images / metadata?

 

We already do the first one whenever images are requested by clients.  They are optimized for that request and cached.

 

All the other neat stuff has to be balanced with the fact that many people's servers are struggling already to keep up with long-running metadata gathering and maintenance tasks and still servicing clients for the purpose of actual use.

[anderbytes 141]

We already do the first one whenever images are requested by clients.  They are optimized for that request and cached.

 

All the other neat stuff has to be balanced with the fact that many people's servers are struggling already to keep up with long-running metadata gathering and maintenance tasks and still servicing clients for the purpose of actual use.

 

The heavy work could be done at each Emby service start.

 

Everybody understands that when a service is coming up, it could be slower because of automated scripts, and this could be one of them.

Or maybe a monthly task?

[ebr 16185]

Actually, what "everybody" (meaning users of a system at the point of use) understands is that they just hit the power button and they expect to watch something right then...

[anderbytes 141]

Actually, what "everybody" (meaning users of a system at the point of use) understands is that they just hit the power button and they expect to watch something right then...

 

But who starts up the Emby service is always the admin. And how often admins restart Emby server?

 

Normal users will still turning on their devices and watching right away.

[ebr 16185]

Not everyone has a true server setup with administration, etc.

[anderbytes 141]

Not everyone has a true server setup with administration, etc.

 

True.

Well... I'm out of suggestions  :-)

[ebr 16185]

They aren't bad suggestions.  I'm just saying all that kind of stuff needs to be prioritized and balanced with the server doing what it really needs to do - deliver media to consumers.

[legrosmoi 4]

I am still trying to figure why a request can take up to 7 seconds when the internal network and the server CPU is far from overloaded...

Can someone answer those questions please,

 

In the parameters, the server is setted to fetch primary, art, banner and thumb... Many of the movies don't have one because it is not available on the metadata provider.

 

It the slow down on image that Emby try to fetch again 'in real time' ? (outside the scan media library job)

Should I uncheck some of those image?

Will locking the metadata prevent this image fetching, if any, and thus the slowdown?

 

[Luke 42080]

scaling backdrop images can sometimes be painful, that is why, and the provider sites are now supplying 4k resolution backdrops.