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icon5.gif   Insert images slow downs the ELOG, posted by Zbigniew Reszela on Wed Sep 9 11:41:23 2020 
    icon2.gif   Re: Insert images slow downs the ELOG, posted by Andreas Luedeke on Sat Sep 12 19:19:02 2020 
Message ID: 69216     Entry time: Sat Sep 12 19:19:02 2020     In reply to: 69215
Icon: Reply  Author: Andreas Luedeke  Author Email: andreas.luedeke@psi.ch 
Category: Question  OS: All  ELOG Version: V2.9.2-2455 
Subject: Re: Insert images slow downs the ELOG 

I found the most limiting factor of ELOG to be the file access. ELOG stores all entries in files and therefore has a lot of disk access.

We found that an AFS directory for ELOG is unusable. We tried to store our logbooks on NFS, and it was barely usable but slow. Now we use a local disk on the server, that works fine.

If you want to speed up ELOG the best approach is a dedicated server with a local SSD storage.

Zbigniew Reszela wrote:

Dear all,

First, many thanks for creating and sharing this great tool which is ELOG! Our users are very happy with it!

I have few questions about inserting images into the entries.

From time to time our users insert them directly in the editor what leads to encoding the whole image in the HTML log file and the images does not appear in the attachments list. Saving and further editing of such entries slows down the whole ELOG server which uses 100% of CPU.

I'm not sure how they do it Ctrl+C & Ctrl+V, drag & drop, etc.. What I know is that if they add it using the "Insert image" action in the editor there are no problems and the images are properly listed in the attachments.

I read in the docs:

uploading or downloading an attachement file is a single request, and causes the entire file to be loaded in server memory while the request is being processed.
This is not normally a problem for the sort of short, text-mode entries ELOG is designed to support. However, if a user starts to upload or download a large attachment file (or image) over a slow link, all other users on that ELOG server will have to wait for that transfert to finish before they can access any logbook on that server. This is why there is a low limit on the size of attachments, and why ELOG should not be used to distribute large files under intensive multi-user conditions.

but I think this is not our case. Here I talk about wrongly inserting a single image of 700KiB.

So, I'm asking:

  1. Is the behavior that we observe something already detected? If yes, which are exactly the wrong ways of inserting the images?
  2. Is it fixed in newer ELOG versions?
  3. Is it possible to disable the wrong ways of inserting the images in order to avoid such problems?

Many thanks in advance for your help!

 

ELOG V3.1.4-80633ba