Re: [ClusterLabs] corosync/pacemaker on ~100 nodes cluser
On 08/23/2016 06:26 PM, Radoslaw Garbacz wrote: > I would like to ask for settings (and hardware requirements) to have > corosync/pacemaker running on about 100 nodes cluster. Not bad ... For the SUSE HA offering we limit support to 32 nodes because after this the timing gets so critical that we can't make a support statement anymore. We do have customers with special testing / setups running ~40 nodes, but that really depends on the workload and resources you have to configure. Looks like you've found this, too. pacemaker_remote might be a chance to get more nodes, depending on the services you're running. I wonder if not a cloud solution (with some HA embedded) or a break up in smaller chunks is beneficial. It's not only about the technical capabilities but the mental capabilities of the admins limiting the reliability of such a huge cluster. Just in case, there are HPC clusters with many more nodes, but these address a total different use case. regards, Kai Dupke Senior Product Manager, HA & HPC -- Sell not virtue to purchase wealth, nor liberty to purchase power. Phone: +49-(0)5102-9310828 Mail: kdu...@suse.com Mobile: +49-(0)173-5876766 WWW: www.suse.com SUSE Linux GmbH - Maxfeldstr. 5 - 90409 Nuernberg (Germany) GF:Felix Imendörffer,Jane Smithard,Graham Norton,HRB 21284 (AG Nürnberg) ___ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
Re: [ClusterLabs] corosync/pacemaker on ~100 nodes cluser
Hi, Thank you for the advice. Indeed, seems like Pacemaker Remote will solve my big cluster problem. With regard to your questions about my current solution, I scale corosync parameters based on the number of nodes, additionally modifying some of the kernel network parameters. Tests I did let me select certain corosync settings, which works, but are possibly not the best (cluster is quite slow when reacting to some quorum related events). The problem seems to be only related to cluster start, once running, any operations such as node lost/reconnect, agents creation/start/stop work well. Memory and network seems important with regard to the hardware. Below are settings I used for my latest test (the largest working cluster I tried): * latest pacemaker/corosync * 55 c3.4xlarge nodes (amazon cloud) * 55 active nodes, 552 resources in a cluster * kernel settings: net.core.wmem_max=12582912 net.core.rmem_max=12582912 net.ipv4.tcp_rmem= 10240 87380 12582912 net.ipv4.tcp_wmem= 10240 87380 12582912 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_sack = 1 net.ipv4.tcp_no_metrics_save = 1 net.core.netdev_max_backlog = 5000 * corosync settings: token: 12000 consensus: 16000 join: 1500 send_join: 80 merge: 2000 downcheck: 2000 max_network_delay: 150 # for azure Best regards, On Tue, Aug 23, 2016 at 12:00 PM, Ken Gaillot wrote: > On 08/23/2016 11:46 AM, Klaus Wenninger wrote: > > On 08/23/2016 06:26 PM, Radoslaw Garbacz wrote: > >> Hi, > >> > >> I would like to ask for settings (and hardware requirements) to have > >> corosync/pacemaker running on about 100 nodes cluster. > > Actually I had thought that 16 would be the limit for full > > pacemaker-cluster-nodes. > > For larger deployments pacemaker-remote should be the way to go. Were > > you speaking of a cluster with remote-nodes? > > > > Regards, > > Klaus > >> > >> For now some nodes get totally frozen (high CPU, high network usage), > >> so that even login is not possible. By manipulating > >> corosync/pacemaker/kernel parameters I managed to run it on ~40 nodes > >> cluster, but I am not sure which parameters are critical, how to make > >> it more responsive and how to make the number of nodes even bigger. > > 16 is a practical limit without special hardware and tuning, so that's > often what companies that offer support for clusters will accept. > > I know people have gone well higher than 16 with a lot of optimization, > but I think somewhere between 32 and 64 corosync can't keep up with the > messages. Your 40 nodes sounds about right. I'd be curious to hear what > you had to do (with hardware, OS tuning, and corosync tuning) to get > that far. > > As Klaus mentioned, Pacemaker Remote is the preferred way to go beyond > that currently: > > http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html- > single/Pacemaker_Remote/index.html > > >> Thanks, > >> > >> -- > >> Best Regards, > >> > >> Radoslaw Garbacz > >> XtremeData Incorporation > > ___ > Users mailing list: Users@clusterlabs.org > http://clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org > -- Best Regards, Radoslaw Garbacz XtremeData Incorporation ___ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
Re: [ClusterLabs] corosync/pacemaker on ~100 nodes cluser
On 08/23/2016 11:46 AM, Klaus Wenninger wrote: > On 08/23/2016 06:26 PM, Radoslaw Garbacz wrote: >> Hi, >> >> I would like to ask for settings (and hardware requirements) to have >> corosync/pacemaker running on about 100 nodes cluster. > Actually I had thought that 16 would be the limit for full > pacemaker-cluster-nodes. > For larger deployments pacemaker-remote should be the way to go. Were > you speaking of a cluster with remote-nodes? > > Regards, > Klaus >> >> For now some nodes get totally frozen (high CPU, high network usage), >> so that even login is not possible. By manipulating >> corosync/pacemaker/kernel parameters I managed to run it on ~40 nodes >> cluster, but I am not sure which parameters are critical, how to make >> it more responsive and how to make the number of nodes even bigger. 16 is a practical limit without special hardware and tuning, so that's often what companies that offer support for clusters will accept. I know people have gone well higher than 16 with a lot of optimization, but I think somewhere between 32 and 64 corosync can't keep up with the messages. Your 40 nodes sounds about right. I'd be curious to hear what you had to do (with hardware, OS tuning, and corosync tuning) to get that far. As Klaus mentioned, Pacemaker Remote is the preferred way to go beyond that currently: http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Pacemaker_Remote/index.html >> Thanks, >> >> -- >> Best Regards, >> >> Radoslaw Garbacz >> XtremeData Incorporation ___ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
Re: [ClusterLabs] corosync/pacemaker on ~100 nodes cluser
On 08/23/2016 06:26 PM, Radoslaw Garbacz wrote: > Hi, > > I would like to ask for settings (and hardware requirements) to have > corosync/pacemaker running on about 100 nodes cluster. Actually I had thought that 16 would be the limit for full pacemaker-cluster-nodes. For larger deployments pacemaker-remote should be the way to go. Were you speaking of a cluster with remote-nodes? Regards, Klaus > > For now some nodes get totally frozen (high CPU, high network usage), > so that even login is not possible. By manipulating > corosync/pacemaker/kernel parameters I managed to run it on ~40 nodes > cluster, but I am not sure which parameters are critical, how to make > it more responsive and how to make the number of nodes even bigger. > > Thanks, > > -- > Best Regards, > > Radoslaw Garbacz > XtremeData Incorporation > > > ___ > Users mailing list: Users@clusterlabs.org > http://clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org ___ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
[ClusterLabs] corosync/pacemaker on ~100 nodes cluser
Hi, I would like to ask for settings (and hardware requirements) to have corosync/pacemaker running on about 100 nodes cluster. For now some nodes get totally frozen (high CPU, high network usage), so that even login is not possible. By manipulating corosync/pacemaker/kernel parameters I managed to run it on ~40 nodes cluster, but I am not sure which parameters are critical, how to make it more responsive and how to make the number of nodes even bigger. Thanks, -- Best Regards, Radoslaw Garbacz XtremeData Incorporation ___ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org