> 3. Why is in this cephadm still being talked about systemd? Your orchestrator > should handle restarts,namespaces and failed tasks not? There should be no > need to have a systemd dependency, at least I have not seen any container > images relying on this.
Podman uses systemd to manage containers so that it is daemonless, contrast with Docker where one has to maintain a separate daemon and use docker-specific tools to mange containers. If you assert that Podman should not exist, please take that up with the Podman folks. > 4. Ok found the container images[2] (I think). Sorry but this has ‘nothing’ > to do with container thinking. I expected to find container images for osd, > msd, rgw separately and smaller. This looks more like an OS deployment. Bundling all the daemons together into one container is *genius*. Much simpler to build and maintain, one artifact vs a bunch. I wouldn’t be surprised if there are memory usage efficiencies too. > 7. If you are not setting cpu and memory limits on your cephadm containers, > then again there is an argument why even use containers. This seems like a non-sequitor. As many have written, CPU and memory limits aren’t the reason for containerizing Ceph daemons. If there are other container applications where doing so makes sense, that’s fine for those applications. I suspect that artificial CPU limiting of Ceph daemons would have a negative impact on latency, peering/flapping, and slow requests. Ceph is a distributed system, not a massively parallel one. OSDs already have a memory target that can be managed natively, vs an external mechanism that arbitrarily cuts them off at the knees when they need it the most. That approach would be addressing the symptoms, not the root cause. Having been through a multi-day outage that was substantially worsened by the OOMkiller (*), I personally want nothing to do with blind external mechanisms deciding that they know better than Ceph daemons whether or not they should be running. If your availability and performance needs favor rigidly defined areas of doubt and uncertainty, that’s your own lookout. * A release that didn’t have OSD memory target setting yet. Having that would have helped dramatically. > 8. I still see lots of comments on the mailing list about accessing logs. I > have all my containers log to a remote syslog server, if you still have your > ceph daemons that can not do this (correctly). What point is it even going to > containers. With all possible respect, that’s another non-sequitor, or at the very least, an assumption that your needs are everyone’s needs. Centralized logging makes sense in some contexts. But not always, and not to everyone. Back around the Hammer or Jewel releases there was a bug where logging to syslog resulted in daemon crashes. I haven’t tried it with newer releases, but assume that’s long been fixed. I’m not a an [r]syslog[ng] expert by far, but I suspect that central-only logging might not deal well with situations like an OSD spewing entries when the debug subsystem level is elevated. Moreover, many of the issues one sees with Ceph clusters are network related. So when there’s a network problem, I want to rely on the network to be able to see logs? I’ve seen syslog drop entries under load, something I personally wouldn’t want for Ceph daemons. There are of course many strategies between the extremes. > 9. I am updating my small cluster something like this: I’m guessing you’ve never updated between major releases. That process tends to have additional steps and nuances, which is one of the compelling arguments in favor of orchestration: when it’s done well, most operators don’t need to rev their own homebrew orchestration to set the right flags at the right time, etc. But one of the great things about OSS is that you have the flexibility to roll you own if you so choose. > I am never going to run a ‘ceph orch upgrade start –ceph-version 16.2.0’. I > want to see if everything is ok after each command I issue. I want to see if > scrubbing stopped, I want to see if osd have correctly accepted the new > config. So you want to do all the things that an orchestrated rolling upgrade does for you. Check. > I have a small cluster so I do not see this procedure as a waste of time. If > I look at your telemetry data[3]. I see 600 clusters with 35k osd’s, that is > an average of 60 osd per cluster. So these are quite small clusters, I would > think these admins have a similar point of view as I have. Careful with those inferences. * Operators who submit telemetry may not be a representative sample * Sites may have many more than one cluster, If one has a 20 OSD lab cluster and a 1000 OSD production cluster, perspectives and processes are going to be different than someone with a single 60 OSD cluster. * Average != median > I am rather getting the impression you need to have an easy deployment tool > for ceph than you want to really utilize containers. First there was this > ceph-deploy and ceph-ansible which I luckily skipped both That’s more than a little harsh. A lot of people get a lot of value out of those tools. > The ceph daemons seem to be not prepared for container use, ceph containers > can’t use cpu/memory limits They don’t make julienne fries either. What of it? > And last but not least you totally bypass that the (ceph) admin should choose > the OC platform and not you, because he probably has more than just ceph > nodes. Nobody’s stopping you from rolling your own containers, using traditional packages, or heck even deploying with tarballs. That’s the beauty of OSS. Let’s leave Orange County out of it though. > So my question to you: What problem is it actually that your cephadm dev team > is trying to solve? That is not clear to me. Asked and answered, sir. Different ones than you’re trying to solve, which doesn’t mean that either you or upstream are wrong. There’s always room for improvement with any approach, and again the beauty of OSS is that you *can* go your own way if you so choose. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
