Or we could sponsor a F5 bigip virtual appliance and that should solve the load balancing. Correct me if I am wrong.
On Thu, Oct 1, 2020, 20:11 Jeroen Massar <[email protected]> wrote: > > On 20201001, at 18:23, Dirk Hohndel <[email protected]> wrote: > > > [..] > >> Just rsync/git-pull the stuff over, so that if the primary dies, that > you can switch over manually. > > > > I actually use some simple git hooks to completely automate that. The > system is actively keeping its standby in sync, and the standby does the > same with the live system if it were to become the live system. So yes, one > could switch between them. > > BUT - you can't switch in the middle of a transaction, and there's of > course a short delay, so a simple web round-robin style handoff creates a > mess. > > Additionally, I have not thought through the solution to the > authentication problem. That mysql database also runs on a VM in that same > room - and making that be redundant and consistent... that's usually when I > decide that this isn't a life-and-death critical system and go back to > doing something else :-) > > Git-hooks are indeed great for that purpose. > > Store the auth info in git, really, just have a passwd file or a file per > user (htpasswd is a great format). > Of course, if you are facebook that does not scale, as the Ops/s on git > are not very high. > > Master-slave MySQL can be done, but can give you big headaches which > typically means re-doing the initial sync. A network disruption and you > typically see the slave log stop following the master; I have only found it > finicky. > Master-Master MySQL.... just don't bother. > > >> Split-brain is the biggest issue in these kind of setups. > > > > With the way git works, as long as you don't switch in the middle of a > transaction it's actually fairly resilient. But still, I'm sure I'm missing > subtle issues that could go wrong. > > You could do it with a multi-stage git commit: > - commit happens > - in git-hook: > - flock(LOCK_EX) > - rsync or git-pull/push the tree to a different directory (git-hook > still has a lock on the first thus it won't change) > - rsync or git-pull/push the secondary directory to remote 'syncdir' > - trigger remote to swap directories from 'syncdir' to 'active' > - flock(LOCK_UN) > > That way, you only are syncing 'clean' repos, never half ones and > 'syncdir' could be dirty but 'active' is not. > > Thus might be a bit too convoluted, I am sure others have another idea > which might be better. > > >> That said though, I use private colo'd servers (because of home > connectivity not always being superb and could not get more than slow cable > speeds and upload at home still is slow), if you need a secondary/third VM > somewhere on a static IP (colo'd), don't hesitate to yell, more than happy > to donate one for Subsurface (and I am sure others here can do the same; it > is always funny the names you see on this list ;) ). > > > > Symmetrical Gb/s plus backup 200Mb/s on a different provider. Great UPS > setup (cough, cough), soon a solar setup plus Tesla PowerWall to take the > UPS setup to the ridiculous level :-) > > Well, many 1U boxes have dual-power feeds, thus just use two UPSs and two > power feeds. > > >> On Oct 1, 2020, at 5:57 AM, Attilla de Groot <[email protected]> > wrote: > >> > >>> On 1 Oct 2020, at 07:00, Dirk Hohndel via subsurface < > [email protected]> wrote: > >>> > >>> The beauty of the current situation is that outside the (grumble, > grumble) hours that I spend on this > >> > >> How / where can we do an anti-grumble, pro-infrastructure donation? > > > > > > Thank you. I got a lot of generous offers of donations and support. I > really appreciate them. But I have a simple rule. I never take money for > the work on Subsurface that I do. That makes things so much simpler. And my > day job does cover my basic and not so basic needs. > > > > > > All of you: thank you. What a nice thread to wake up to. This community > is what really makes it worth investing in Subsurface. Be it time or money. > > I think many of us here on the list have provided 'community service' in > one way or another, hence, knowing that a 'thank you' is something that > goes a long way. > > That said, if other types of resources are needed, I bet there is a pizza > place that can take orders ;) > And otherwise we'll have a drink of one or another one day! > > Greets, > Jeroen > > >
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