App freezes when opening certain channels

[jurgenhaas]

Summary

We have a few dozen channels in our Mattermost instance and when opening some of them on the mobile app, it shows the latest messages, but before it shows the blue header bar with the number of unread messages, the app freezes. After a few seconds, it shows a popup where I can decide to either wait, close the app or report a problem.

For months, I've always used "waiting" and I have to do that for up to 10 minutes sometimes, before the app comes back and works OK again. Since nothing changed for a long time, I've decided to report this bug with the following error log:

type: ANR
osVersion: google/cheetah/cheetah:14/UQ1A.231205.015/2023121200:user/release-keys
package: com.mattermost.rn:6000497
process: com.mattermost.rn
installer: com.android.vending

activity: com.mattermost.rn/.MainActivity
cause: ANR Input dispatching timed out (7a23432 com.mattermost.rn/com.mattermost.rn.MainActivity (server) is not responding. Waited 5002ms for MotionEvent).
info: ANR in com.mattermost.rn (com.mattermost.rn/.MainActivity)
PID: 29915
Reason: Input dispatching timed out (7a23432 com.mattermost.rn/com.mattermost.rn.MainActivity (server) is not responding. Waited 5002ms for MotionEvent).
Parent: com.mattermost.rn/.MainActivity
ErrorId: d55f9e84-7cdd-4f2a-9ea8-7b61961dae28
Frozen: false
Load: 2.18 / 2.68 / 2.4
----- Output from /proc/pressure/memory -----
some avg10=1.26 avg60=0.33 avg300=0.15 total=250130867
full avg10=0.90 avg60=0.22 avg300=0.08 total=151675862
----- End output from /proc/pressure/memory -----
----- Output from /proc/pressure/cpu -----
some avg10=2.75 avg60=1.95 avg300=3.16 total=25947013304
----- End output from /proc/pressure/cpu -----
----- Output from /proc/pressure/io -----
some avg10=0.72 avg60=0.27 avg300=0.14 total=364140566
full avg10=0.54 avg60=0.20 avg300=0.09 total=289356019
----- End output from /proc/pressure/io -----

CPU usage from 4162ms to -4500ms ago (2023-12-26 06:58:51.388 to 2023-12-26 06:59:00.049):
  115% 29915/com.mattermost.rn: 106% user + 8.2% kernel / faults: 13076 minor
  25% 1450/system_server: 14% user + 11% kernel / faults: 35567 minor 53 major
  17% 756/surfaceflinger: 11% user + 6% kernel / faults: 86 minor
  13% 93/kswapd0: 0% user + 13% kernel
  7.1% 764/android.hardware.composer.hwc3-service.pixel: 3.7% user + 3.4% kernel
  6.7% 2246/com.android.systemui: 3.8% user + 2.8% kernel / faults: 17740 minor 8 major
  3.4% 8027/com.android.inputmethod.latin: 1.3% user + 2% kernel / faults: 19967 minor 21 major
  3.1% 2722/com.android.launcher3: 2.3% user + 0.8% kernel / faults: 319 minor 9 major
  2.6% 350/decon0_kthread: 0% user + 2.6% kernel
  1.8% 820/android.hardware.power-service.pixel-libperfmgr: 0.9% user + 0.9% kernel
43% TOTAL: 29% user + 11% kernel + 0.6% iowait + 1.3% irq + 0.5% softirq
CPU usage from 3ms to 452ms later (2023-12-26 06:58:55.552 to 2023-12-26 06:58:56.001):
  183% 29915/com.mattermost.rn: 163% user + 20% kernel / faults: 1987 minor
    97% 29915/m.mattermost.rn: 97% user + 0% kernel
    89% 29937/Signal Catcher: 69% user + 20% kernel
  86% 30072/com.Slack: 57% user + 28% kernel / faults: 1512 minor 12 major
    24% 30141/RenderThread: 24% user + 0% kernel
    20% 30072/com.Slack: 12% user + 8.2% kernel
    20% 30124/slack-instrumen: 8.2% user + 12% kernel
    8.2% 30135/WM.task-1: 4.1% user + 4.1% kernel
    4.1% 30100/binder:30072_2: 4.1% user + 0% kernel
    4.1% 30120/DefaultExecutor: 0% user + 4.1% kernel
    4.1% 30129/slack-instrumen: 0% user + 4.1% kernel
    4.1% 30136/queued-work-loo: 4.1% user + 0% kernel
    4.1% 30198/DefaultDispatch: 0% user + 4.1% kernel
  51% 1450/system_server: 13% user + 37% kernel / faults: 1012 minor
    46% 30237/AnrAuxiliaryTas: 10% user + 35% kernel
    2.7% 2152/ConnectivitySer: 2.7% user + 0% kernel
  17% 756/surfaceflinger: 12% user + 4.8% kernel
    7.3% 756/surfaceflinger: 7.3% user + 0% kernel
    4.8% 851/app: 2.4% user + 2.4% kernel
    4.8% 869/surfaceflinger: 2.4% user + 2.4% kernel
    2.4% 2893/binder:756_5: 2.4% user + 0% kernel
  7.3% 764/android.hardware.composer.hwc3-service.pixel: 2.4% user + 4.9% kernel
    4.9% 1044/binder:764_7: 2.4% user + 2.4% kernel
    2.4% 805/binder:764_1: 0% user + 2.4% kernel
  2.2% 49/rcuog/4: 0% user + 2.2% kernel
  2.2% 57/rcuop/5: 0% user + 2.2% kernel
  2.3% 350/decon0_kthread: 0% user + 2.3% kernel
  2.4% 820/android.hardware.power-service.pixel-libperfmgr: 2.4% user + 0% kernel
  3.4% 25228/kworker/0:1-memlat_wq: 0% user + 3.4% kernel
  3.7% 28287/kworker/1:1-memlat_wq: 0% user + 3.7% kernel
48% TOTAL: 32% user + 13% kernel + 0.2% iowait + 1.4% irq + 0.2% softirq

This only ever happens with 3 or 4 specific channels, not with any of the others. But for those, where this happens, it only happens sometimes - but then it's very annoying.

Also, since the error mentions the server, that doesn't respond, I've verified with the browser from the desktop, that during that time, the server is responding just fine there.

Environment Information

• Device Name: Pixel 7 Pro
• OS Version: Android GrapheneOS
• Mattermost App Version: 2.11.0 Build 6000497
• Mattermost Server Version: 9.3.0 Build 7014621505

Steps to reproduce

This only happens sometimes, but certainly once per day. No pattern to reproduce that.

[amyblais]

Opened https://mattermost.atlassian.net/browse/MM-56401.