Web based indexing using 95% of CPU resources

I'm not sure this is the right place to post this problem, but...

While using the new web based indexing, my system completely bogged down.

First attempt was with Firefox (56.0). 95% of CPU used and 1.1gb of memory.

Switched to Chromium (Version 61.0.3163.100 (Official Build) Built on Ubuntu , running on Ubuntu 16.04 (64-bit). 95% of CPU, 500mb of memory

In both cases, I closed other open tabs and other unnecessary programs with little improvement. The image below shows the CPU usage while indexing and then after closing the browser.
My system:
Ubuntu 16.04.3 LTS
Kernel 4.4.0-97-generic (x86_64)
2x Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz
4gb memory

An older system to be sure, but I can usually run a browser with multiple tabs, other applications, and stream video at the same time without maxing out the CPU.

Cool to know there are at least two of us in the Church using Linux! I suspect there are a few others we just don't know about...

I haven't done indexing myself in several years, and I don't get on FamilySearch often myself, but my wife often uses FamilySearch with Firefox-ESR on our Debian 7/Wheezy machine. When she is on FamilySearch, her firefox-esr process is often using ~100% CPU for extended periods of time. My personal hunch is there is some exceedingly inefficient JavaScript running behind the scenes on the FamilySearch site. Unfortunately, I don't think we're likely to get a fix or improvement in efficiency. For me, my machine has enough core threads that a couple maxed out doesn't hurt.

One thing that you can do in Firefox to shed a little more light on problematic situations is to use the web developer tools. I mostly use the Web Console and Inspector. If you see messages flying by in the Web Console, that means JavaScript is executing reportable stuff. The Inspector will show you the HTML and CSS coding for what you see on the page. I haven't used the Debugger much, but it appears to show the JavaScript the page uses. You might be able to find the key to the problem there. With Firefox, the developer tools come up in a split of the original window, but you can force them to their own, separate window if you prefer. I don't know about Chromium, but Chrome has similar web developer tools but with a little different look and feel.

My experience is if there's a problem on a page (like FamilySearch tree info being entirely blank under certain conditions, a bug report sent to Help/Feedback gets escalated immediately to engineering if you provide the CSS ID strings and exact HTML attributes that appear to be at the root of the problem.

This morning, 12 hours later, the web indexing pages are running more efficiently. The CPU was only 50% and memory was less. So something must have changed.

I forgot about web developer. In Firefox, as of this morning, web developer did not report any major errors. I agree that the problem is some bad java scripts. I will monitor and update if the problem occurs again.

@melanes

To get it running even faster, you might try using the Cinnamon Desktop instead of whatever Ubuntu comes with these days. Software runs much faster on Cinnamon, in my experience (faster even than on XFCE). The learning curve if you've never used Cinnamon isn't too bad, either. Panels and shortcuts are configurable: `sudo apt install cinnamon-desktop-environment`