How to use error logs to troubleshoot a user issue?

Support
1

A user of my Discourse in Belgium complains our site responds too slowly to clicks. I’m in California. I’ve not gotten any complaint from my other users, who so far are in Minnesota, Germany, and the Netherlands. The user in question tells me she uses Chrome on Windows. Her download and upload speeds test similarly to mine via speedof.me.

If I visit https://discourse.MY_DOMAIN.com/logs/, I see the latest entry is time-stamped just a few minutes before her email was sent. Its “info” tab reads:

Uncaught [object Object]
Url: https://discourse.MY_DOMAIN.com/assets/ember_jquery-1ed3f3559e6f967733b4088aa729ff7039dff2c09c5a5f787a214b016f58aabc.js
Line: 1
Column: 268124
Window Location: https://discourse.MY_DOMAIN.com/

Its “backtrace” tab is empty. Its “env” tab reads:

hostname    MY_APP-app
process_id    780
application_version    ab0b0344048e7e7354615286486bf0508c7c2df6
HTTP_HOST    discourse.MY_DOMAIN.com
REQUEST_URI    /logs/report_js_error
REQUEST_METHOD    POST
HTTP_USER_AGENT    Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36
HTTP_ACCEPT    */*
HTTP_REFERER    https://discourse.MY_DOMAIN.com/
HTTP_X_FORWARDED_FOR    IP_ADDRESS_IN_BELGIUM
HTTP_X_REAL_IP    IP_ADDRESS_IN_BELGIUM
time    4:25 am
params    
message    Uncaught [object Object]
url    https://discourse.MY_DOMAIN.com/assets/ember_jquery-1ed3f3559e6f967733b4088aa729ff7039dff2c09c5a5f78
line    1
column    268124
window_location    https://discourse.MY_DOMAIN.com/

How can I use this information, or what else should I do, to troubleshoot her concern?

Thank you.

1 Like
2

If it’s a single user, then it’s likely either a local client issue, or network-related.

  • Where is your site hosted?
  • Are you using CloudFlare?
  • Have you confirmed whether she is using a VPN or anything which affects her route to your server? A traceroute can help here.
3 Likes
3

Thanks for your reply.

  • Site is hosted on AWS, not CloudFlare.
  • User is very tech un-savvy, so I doubt she’s on VPN, but I could ask. I asked her to log in to safe mode and report if that improves anything, but she’s yet to reply to that (it is late in Europe now).
  • Can you recommend/link a traceroute for Discourse?
1 Like
4

Traceroute is a command line tool, present on mac (traceroute) and Windows (tracert). It will show you the network route from their computer to your server, hop by hop. I’m not aware of any good browser-based alternatives, most will show the route from the server rather than the client.

You could ask for a browser screenshot to see if there are any funky extensions installed too.

Have you ruled out local security software? I’ve occasionally seen antivirus browser extensions which proxy traffic and can cause issues.

2 Likes
5

Ah. So, I can SSH into our Discourse machine, I can see that traceroute isn’t installed, I can run apt install traceroute (installs version 2.1.0), and then I can run traceroute HER_APPARENT_IP_ADDRESS_FROM_DISCOURSE LOGS?

If I do, it outputs the following.

traceroute to 84.196.9.6 (84.196.9.6), 30 hops max, 60 byte packets
 1  * * *
 2  10.70.134.15 (10.70.134.15)  1.101 ms 10.70.134.35 (10.70.134.35)  1.079 ms 10.70.134.27 (10.70.134.27)  0.988 ms
 3  138.197.251.92 (138.197.251.92)  1.323 ms 138.197.251.94 (138.197.251.94)  1.628 ms 138.197.251.124 (138.197.251.124)  1.206 ms
 4  138.197.251.110 (138.197.251.110)  1.079 ms  1.071 ms 138.197.251.114 (138.197.251.114)  1.056 ms
 5  138.197.244.17 (138.197.244.17)  1.247 ms  1.251 ms 138.197.244.19 (138.197.244.19)  1.112 ms
 6  nyk-b3-link.telia.net (62.115.45.5)  1.866 ms  1.383 ms nyk-b3-link.telia.net (62.115.45.9)  1.331 ms
 7  * * *
 8  ldn-bb3-link.telia.net (62.115.113.21)  82.665 ms  82.486 ms  82.459 ms
 9  adm-bb4-link.telia.net (62.115.134.26)  78.418 ms adm-bb3-link.telia.net (62.115.113.210)  82.951 ms  83.025 ms
10  brx-b3-link.telia.net (62.115.116.191)  82.894 ms brx-b4-link.telia.net (62.115.116.231)  78.732 ms  78.321 ms
11  be-dgb01a-rb1-ae-20-0.aorta.net (213.46.162.13)  82.955 ms  82.970 ms be-zav01a-rb1-ae-21-0.aorta.net (213.46.162.6)  87.143 ms
12  * * *
13  * * *
14  * * *
15  * d54C40906.access.telenet.be (84.196.9.6)  94.362 ms  93.255 ms

The longest hop is the last one, 94 milliseconds, which seems reasonable. Would this indicate the route from our Discourse machine in Northern California to her computer in Belgium looks like it should be just fine? Was the Discourse log in my original post above otherwise devoid of any valuable information other than getting her apparent IP address?

1 Like
6

You would need her to traceroute to you, the route she takes out from her ISP isn’t necessarily the same route your server will take to her network.

Is the issue recent? There was a big Level3/CenturyLink outage today which definitely impacted certain transatlantic routes.

2 Likes
7

Thanks for your continued replies.

My user overnight reported that logging in via Discourse safe mode solved her problem. I’ve now asked her if she can help narrow which of the three Safe Mode checkboxes actually helps.

My challenges continue to be our time-zone difference, our language difference, and our difference in comfort with technology. I can update this thread if/when I learn more.

Thanks also for the relevant news article. This was her first time using our Discourse, so now I also wonder if that outage could be relevant.