Investigate performance and stability issues on Chrome

[philipp-classen]

Using this as a broader class of reported performance problems with Ghostery on Chrome (see
Context: https://www.reddit.com/r/Ghostery/comments/1rp0qn4/slow_to_block_immediately_after_opening_the/)

From the reports, it could happen in a "cold start" scenario. For instance, when the browser has been opened and the Ghostery service worker initializes while in parallel a heavy website is loading.

Another observation, which may or may not be related, is that try to open the Ghostery panel can hang when a website is still loading. The extension can end up in broken state or crash.

Here is a test page with which I can quite reliably reproduce it:
https://www.finanzen.net/aktien/biontech-aktie

1. Reload the page
2. Immediately click on the Ghostery icon to open the panel (while the website is still loading)
3. Right-click inspect the panel

Also, it can end in a state where the icon is highlighted as if the panel is open, but the panel stays hidden:

---

It is easier to reproduce when the browser just got restarted. So, it could be related to the performance problem.

Tested on Linux with Chromium 146.0.7680.80 and Ghostery 10.5.33.

Reports also mentioned Windows 11. At this point, it cannot be narrowed down much. I would assume, it affects all Chromium-based browsers. Also, we had reports about "cold start" performance problems on Safari in the past. Getting reports now for Chrome is relatively new (but affect at least Ghostery 10.5.32, perhaps also earlier versions).

[philipp-classen]

Here is also a potentially related bug report for Safari (started around the same time as it seems):
#3152

[philipp-classen]

Here are logs when it gets stuck (chrome://serviceworker-internals/):

Console: {"lineNumber":-1,"message":"Service Worker is not responding.","message_level":0,"sourceIdentifier":7,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/index.js"}
Console: {"lineNumber":-1,"message":"Service Worker termination by a timeout timer was canceled because DevTools is attached.","message_level":0,"sourceIdentifier":7,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/index.js"}
Console: {"lineNumber":-1,"message":"Service Worker is not responding.","message_level":0,"sourceIdentifier":7,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/index.js"}
Console: {"lineNumber":-1,"message":"Service Worker is not responding.","message_level":0,"sourceIdentifier":7,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/index.js"}
Console: {"lineNumber":-1,"message":"Service Worker is not responding.","message_level":0,"sourceIdentifier":7,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/index.js"}
Error: {"columnNumber":-1,"lineNumber":-1,"message":"DETACH_STALLED_IN_STOPPING","sourceURL":""}
Console: {"lineNumber":75,"message":"[options] Start observers...","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"onboarding\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"stats\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"redirectProtectionExceptions\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"adblockerEngines\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"customFilters\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"dnr\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"updateExceptions\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"updateExceptions\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"pausedSites\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"zapped\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"telemetry\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"pauseAssistant\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"sync\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"webRequestReporting\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":53,"message":"[options] Executing \"reporting\" observer","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":68,"message":"[pause-assistant] Updating domains: book.nationalexpress.com (add)","message_level":1,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/background/pause-assistant.js"}
Console: {"lineNumber":87,"message":"[options] Observers finished...","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":75,"message":"[options] Start observers...","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":87,"message":"[options] Observers finished...","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/utils/options-observer.js"}
Console: {"lineNumber":60,"message":"WTM [anonymous-communication] Server keys on disk are still valid","message_level":0,"sourceIdentifier":3,"sourceURL":"chrome-extension://mlomiejdfkolichcflejclcbmpeaniij/npm/@whotracksme/reporting/communication/src/server-public-key-accessor.js"}

---

Service Worker is not responding

and eventually it gets killed

DETACH_STALLED_IN_STOPPING

In the run above, it then restarted normally. But during that time, Ghostery is hanging. As a result, it will also not be able to block ads.

[philipp-classen]

I looked closer into it, but it is difficult to track down. What I believe now, is that the crash is unrelated.

Though I am still mostly unable to reproduce performance issues on my Linux host system, I can reproduce in a Windows 11 Virtual Machine. Profiling is not straightforward, since it only happens at startup (before devtools get connected). In my experience I was not able to isolate a performance bug, but I think it is rather that depending on the hardware, the operations that happen at startup just some up. CPU is a limiting factor, but also IO (reading from disk). There are some potentially expensive operations, such as initializing the adblocker (including loading from IndexedDB), but also the initialization of Never Consent (which runs a few thousand regular expression tests, but in sum did not explain that opening the panel was hanging for seconds).

As a step forward, I only see that we can add more logging to get a better understanding where most time is spent.

Regarding the crashes: With Chromium on Linux, I can easily reproduce. Just double-clicking repeatedly on the panel almost instantly crashes the extension for me. I was, however, not able to reproduce any crash on Windows in the WM with Google Chrome.

As said, I believe that the crash and the performance problems might not be related.

[loneswimmer]

I am experiencing the slow down on first launching the browser on Firefox. On Brave, it is fine.

[NDABBRU]

I'm noticing a slowdown in Chrome when opening the browser. It takes a few seconds (about 5 seconds) to start working, blocking trackers and cookies, but after that it works smoothly. This happens on older, less powerful PCs/laptops as well as on newer, more powerful PCs/laptops.
I'd like to fix this bug by optimizing the app's launch when opening the browser.

[NDABBRU]

@philipp-classen When will this bug be fixed?

[philipp-classen]

I am experiencing the slow down on first launching the browser on Firefox. On Brave, it is fine.

@loneswimmer Can you think of something that is different on your Firefox profile compared to the Brave profile? For instance, that is much older or that you have more tabs open in Firefox? Are you using it on the same operating system (Windows, Linux)?

I'm mostly trying to understand if there is a particular way to trigger this slowdown. I have only tested with Chrome yet, not so much on Firefox. Chrome and Brave should be comparable, because they share the Chromium architecture. But being able to reproduce with Firefox could be insightful to narrow it down.

[NDABBRU]

@philipp-classen news for Chrome?

Thanks.

[seia-soto]

We recently hugely shrunk the dNR rule pressure via #3255 which will help the start-up performance issue on Chromium browsers. It might not be the only problem but we're keep pushing more improvements. The changes will be available in the next release.

[NDABBRU]

@seia-soto ok thanks. When new release?

[NDABBRU]

@philipp-classen and @seia-soto If I may give you another suggestion, also improve the blocking of cookie pop-ups.

[seia-soto]

@seia-soto ok thanks. When new release?

@NDABBRU Unless there's an availability issue, we usually put release once per a week. The next one could be this Friday or Monday. The release to extension marketplaces or app store depends on time to review. You can always check the records from our GitHub releases: https://github.com/ghostery/ghostery-extension/releases and CWS.

Also, I appreciate your continuous interest on this issue. It's difficult for us to investigate and track all the symptoms because most of them are not always happening (having randomness when we try to debug; flakiness) and often unable to isolate the cause. Keep getting the feedback is really nice for us.