Download Speeds

JeremyTMH

Its nice we can finally get Manga direct from J Novel but what the heck is with those terrible download speeds? No problem with LN epubs but Manga takes like forever to download, regardless of which one you try to get... Is the Manga server running on a potato or something?!

Zehd

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So how are you holding up? Because I'm a potato.

Geezer Weasalopes

@JeremyTMH I suspect it has something to do with file size.
I go with the highest resolution manga files, and they're like ten times the size of an LN file, a complete shift of one digit larger.

kuali

@Geezer-Weasalopes I found myself a little curious about this one, so I tried grabbing a couple of the Bookworm manga at different sizes to test it out.

What I found was that the largest size manga took about 20s to download, of which roughly half was actual download time (so around 60MB/s or 480mbps, which isn't a bad download rate by any means, especially considering I'm probably not on the same continent as their servers), and half was the site appearing to hang before starting said download. (At least the first time I requested a book. This startup time disappears if I ask for the same book at the same quality multiple times in a row).

With such a long delay to start the download (as opposed to almost instant startups for the light novels) I find myself wondering if perhaps the way they offer manga downloads is with an auto-generator that resizes the images running behind a cache, resulting in the extra-slow downloads each time there's a cache miss and the images have to be generated again.

Anyway, to expand on your point about file sizes:

Ascendance of a Bookworm Part 1 Volume 1:

Light Novel: 31.7MB
'Mobile' Manga: 65.9MB
'Desktop' Manga: 205MB
'4k' Manga: 430.2 MB

On a related note, I do still think the manga files are larger than they need to be.

As an example - a 4k monitor has a resolution of 3840 pixels (width) / 2160 (height), and the images in a 4k manga download are 2701 pixels wide / 3840 pixels high. This is simply too large to fit 1:1 on a 4k monitor regardless of orientation; if the monitor is in landscape, it will be 1680 pixels shorter than the image, while in portrait it would be 541 pixels too narrow.

jpwong

@kuali said in Download Speeds:

This startup time disappears if I ask for the same book at the same quality multiple times in a row

I wonder if the manga generation is done the same way as the LNs are where they're generating your copy of the ebook on first request, it would explain the lag time there. With the LN's it's adding your userdata to the copyright page, but I don't see anything like that for manga, but if the process is the same the startup time is the time the server is taking to build the epub for you.

kuali

@jpwong The thing is, I've never seen a LN lag more than a second before the download started. But all three sizes of manga lag similar amounts to each other (around 8-10 seconds when I was testing earlier) on first request. It certainly feels like the Manga request does something the LN requests do not, and 'resizing images' seemed the most likely candidate given how much time was involved.

jpwong

@kuali Keep in mind that an LN is mostly text with a few images in it, manga is all images, so packing up an LN for download should be faster than manga by default. I guess it could be resizing the images though, although that could potentially mean each generation of the ebook could result in slightly different output.

myskaros

As you may or may not know, we have had various troubles with the manga server in recent weeks, and I believe one of the attempted solutions for resolving it was clearing the cache, which includes the cache of pre-generated epubs. If you are the first person trying to download a given volume when it first comes out or after the cache has been cleared, then yes, the system must generate and upload that epub first, so that is the delay. Afterward, you should only need to download it, so it should be much faster.

If you have only been testing on volumes that happen to have had its cached copy cleared and no one else has already tried downloading it before you, then you would have to wait for the epub generation each time. If you try to download the same volume over and over, though, you should only get the long delay the first time.

kuali

@myskaros I vaguely remember something being mentioned back before Christmas, but most details from back then are locked behind a chocolatey haze...

That said, are you sure the cache isn't set to auto-expire entries? I've had the generation delay 3 times today for the exact same volume (Bookworm P1V1 at 4k) - most recently, at 00:17 and 01:33 UTC. (My 01:35 download had no delay, so it seems to be in the cache now, at least).

myskaros

@kuali I don't know any specifics, this is just what I've seen in my periphery internally. However, there have in fact been multiple instances of problems where one of the first attempted solutions has been to clear the cache, just in case. I don't know the exact dates for those occurrences.

JeremyTMH

Woop totally forgot about this...
I largely read on mobile so mostly download only the versions for mobile. Gonna buy a huge chunk of Manga down the road eventually but so far most of the time I get the good speeds for downloads but every now and then one of them has to be the stuck pipe that's slow as heck.