Firefox 68 comes with a Firefox Account button on the Navigation Toolbar that you can click.

• https://support.mozilla.org/en-US/kb/how-do-i-know-status-my-sync

Good point. Thank you. I hadn't noticed that. That's a fast way to get to Sync Now.

But as to automatic syncing, what's the deal with that? Does it just do it by default and, if so, when? Sync Settings doesn't seem to offer any options on this.

I've added a link to a support article with more information.

I think that Firefox will sync automatically when it detects changes are being made to syncable items (there might be some idle time required). There used to be a tooltip shown if you hover the Sync Now button, but I had to look hard for it to find it when I click Synced Tabs and hover Sync Now in this menu.

Thank you. That's cool, so white with black background means that automatic syncing is happening.

Also I understand that if you are logged in, it will sync pretty continuously (as per your sync preferences). Good to know. In principle, then, I should never have to sync manually, if I am logged in. It appears that there is no way to turn off automatic syncing, except by logging out.

Well, here is a discussion about the "how often". https://support.mozilla.org/en-US/questions/1195445

Reading down, it is said that "Then as you save (say) a new bookmark on one device, that "change" will be immediately sent to the Sync server; and then immediately sent to any devices that are also running that that time; which includes the Firefox Profiles on the device you are using, if those Profiles are running simultaneously. "

That means to me that sync-ing should be a "right now" process.

But for me it doesn't. I have two machines logged in to the sync server. The account button has a dark background on both. But I change bookmarks on computer #1, and NOTHING happens to the bookmarks on #2 (after waiting several minutes), UNTIL I manually sync computer #2.

That says to me that #1 is immediately sending updates to the sync server, but #2 isn't asking for updates from the sync server unless I do a manual sync on it or restart the program. Seems to work the same way the other way around.

So sync server uploads seem to be immediate on both, but sync downloads from the server are not.

Why not? What's going on?

danll said

Well, here is a discussion about the "how often". https://support.mozilla.org/en-US/questions/1195445 Reading down, it is said that "Then as you save (say) a new bookmark on one device, that "change" will be immediately sent to the Sync server; and then immediately sent to any devices that are also running that that time; which includes the Firefox Profiles on the device you are using, if those Profiles are running simultaneously. " That means to me that sync-ing should be a "right now" process. But for me it doesn't. ...

That question thread is from a year and a half ago; Sync has received numerous new features or some features have been changed since then.

I'm not sure what the current 'timing of Sync events' are right now; I no longer use Sync.

So no one can tell me WHEN Firefox actually syncs? Not obvious to me that it is even automatic. I can manually sync, but if I don't do that, it doesn't sync.

There are services.sync.scheduler prefs present on the about:config page that determine when the next sync occurs and there are other prefs like services.sync.nextSync and services.sync.syncInterval. Some of these prefs are set automatically and can't be modified.

Well, OK, I have

services.sync.scheduler.activeInterval;600 services.sync.scheduler.idleInterval;3600 services.sync.scheduler.idleTime;300 services.sync.scheduler.immediateInterval;90

So, what does that mean?

Now, I also have

services.sync.syncInterval;600000

and I am led to believe (https://support.mozilla.org/en-US/questions/1049058) that this is the sync interval in milliseconds (that is, 600000ms = 600 seconds = 10 minutes. Is that what's going on here? The sync is done automatically every 10 minutes?

I think that all these values are seconds and 600000 would be one week (7*24*60*60) as about the absolute maximum if you would leave Firefox running .

• https://dxr.mozilla.org/mozilla-release/source/services/sync/modules/policies.js

The support.mozilla link I quoted says they are milliseconds. A sync interval of a week would be pretty stupid. Why would anyone want that???

OK, here's the answer. It was clear to me that syncs were not happening immediately, but I got the impression that they sorta happened eventually, automatically.

On computer #1 I changed my bookmarks. Computer #2 didn't see that change immediately. I immediately commanded a sync on computer #2 and the change appeared. So computer #1 UPLOADS the sync data immediately when the bookmark is changed.

On computer #1 I changed a bookmark again, and then I waited. Precisely 10 minutes later, that bookmark showed up on computer #2.

Both computers have services.sync.syncinterval = 600000 which, if in milliseconds, is 10 minutes.

So I believe that services.sync.syncinterval is how many milliseconds elapse before a computer DOWNLOADS the sync data and actually syncs its Firefox.

Now, I don't really care too much what the delay is, so I'm not going to change it. I just wanted to know *what* that delay was. Now I know, exactly what the default value is.

Actually, this is well known.

https://support.mozilla.org/en-US/questions/1056464 https://w3guy.com/force-firefox-sync/ http://forums.mozillazine.org/viewtopic.php?f=38&t=2198393