Summary
Channels jump back in time after implementing infinite scroll
Steps to reproduce
Run Mattermost server latest versions through an Nginx reverse proxy. Access the chat with a fresh desktop Chrome browser and switch channels. Randomly the channel is jumped back in time.
Expected behavior
The latest posts should always be shown when switching to a channel.
Observed behavior
We ran into a strange behaviour after installing the version in which the infinite scroll feature was implemented. When the users switch channels the scrolling randomly jumps back in time, showing a day or week old posts. It seems to occur totally randomly and also it seems to be random how much backwards the scrolling jumps.
Multiple users experience the same problem on multiple devices and all the usual troubleshooting steps (clearing browser cache, observing browser network requests etc) have been taken. I strongly believe the problem is related to our nginx reverse proxy setup in front of Mattermost server, but cannot prove that for now.
So far I haven’t seen or heard the problem occuring on mobile devices, so it seems to be limited to desktop browsers and possibly only Chrome and other Chrome-based browsers. Chrome versions have been up to date all the time, so the problem has been observed on multiple fresh versions on both MacOS and Windows.
Vast majority of our users are using Chrome though, so I cannot confirm that the problem does not occur on other browsers. One user reported he has never seen the problem and he’s running Firefox. Another one said he has the problem with the standalone Mattermost Windows client.
We are running Team Edition 5.16.1 at the moment, but the problem has existed in all the versions between the infinite scroll release (I really cannot remember which one it was 
) and the current one. Nginx version is 1.10.3 on Debian 9.5.
Mattemost configuration is fairly standard and the Nginx website is configured like below, in case someone can spot a clear problem in the configuration:
Nginx website config
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upstream backend {
server 127.0.0.1:8065;
}
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mattermost_cache:10m max_size=3g inactive=120m use_temp_path=off;
server {
listen 443;
server_name censored.censored.com;
error_log /var/log/nginx/mattermost.access.log;
ssl on;
ssl_certificate /etc/ssl/certs/censored.com_bundle.crt;
ssl_certificate_key /etc/ssl/private/censored.com.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_dhparam /etc/ssl/certs/dhparam.pem;
ssl_ciphers ‘ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA’;
ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_stapling on;
ssl_stapling_verify on;
add_header Strict-Transport-Security max-age=15768000;
location /localimages {
root /var/www/html;
}
location ~ /api/v[0-9]+/(users/)?websocket$ {
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection “upgrade”;
client_max_body_size 100M;
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Frame-Options SAMEORIGIN;
proxy_buffers 256 16k;
proxy_buffer_size 16k;
proxy_read_timeout 600s;
proxy_pass http://backend;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-NginX-Proxy true;
proxy_pass_header Set-Cookie;
}
location / {
client_max_body_size 100M;
proxy_set_header Connection “”;
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Frame-Options SAMEORIGIN;
proxy_buffers 256 16k;
proxy_buffer_size 16k;
proxy_read_timeout 600s;
proxy_cache mattermost_cache;
proxy_cache_revalidate on;
proxy_cache_min_uses 2;
proxy_cache_use_stale timeout;
proxy_cache_lock on;
proxy_pass http://backend;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-NginX-Proxy true;
proxy_pass_header Set-Cookie;
}
location ~ /.well-known {
allow all;
}
}
server {
listen 80;
server_name censored.censored.com;
return 301 https://$host$request_uri;
}
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