[ClusterLabs] qdevice up and running -- but questions
1. What command can I execute on the qdevice node which tells me which client nodes are connected and alive? 1. In the output of the pcs qdevice status command, what is the meaning of... Vote: ACK (ACK) 1. In the output of the pcs quorum status Command, what is the meaning of... Membership information -- Nodeid VotesQdevice Name 1 1A,V,NMW 001db03a 2 1A,V,NMW 001db03b (local) --Eric Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. ___ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
Re: [ClusterLabs] Integrate external alerts with pcs cluster
Hi Strahil,Yes. Its simple but monitoring is done by an external service which sends alarm in case state of a hardware changes. Its a complex code and multiple devices are being monitored by it. If I ask pacemaker to monitor the device, this code has to be replicated in resource agents monitor which is not an option. Instead of that, I plan to examine the alert in external service and fail the resource if alarm is critical. Hope that it clarifies the scenario.By the way, how could I fail the resource from outside. I see that option in crm_resource CLI (--fail) but not in pcs CLI.Regards,AjayFrom: Strahil Nikolov hunter86...@yahoo.comSent: Sat, 11 Apr 2020 18:50:25To: Cluster Labs - All topics related to open-source clustering welcomed users@clusterlabs.org,Ajay Srivastava ajay_srivast...@rediffmail.comSubject: Re: [ClusterLabs] Integrate external alerts with pcs clusterOn April 11, 2020 2:04:23 PM GMT+03:00, Ajay Srivastava ajay_srivastava@r ediffmail.com wrote:Hi,In my environment I have a pacemaker cluster running which hasvarious software services as resource agents.These services havedependency on some hardware components. There is a service whichmonitors the hardware and sends alerts if anything is wrong with thehardware.My plan is to add a resource agent for each hardware componentwith proper dependencies and fail this resource agent if I get acritical alert from hardware monitoring service. Please note that I donot want to use monitor functionality of resource agent as there is aservice which is already doing same thing. I have two queries here -1)Does the approach look good ? Is there a better way to implement it inpacemaker cluster ?2) I can find --fail option in crm_resource but notin pcs cli. What would be the equivalent command in pcs as I am usingpcs cli to configure the cluster ?Regards,Ajaynbsp;Hi Ajay,Sadly I dont get the logic.Based ;on your e-mail you want to create a cluster resource that will fail based on hardware issue.Yet, are you going to put other cluster resources as a dependency (for example - ordering constraint that stops some application in case some cpu has stuck for 120s) ?All the cluster needs is to know how to:- Start the resource- Monitor the liveliness of the resource- Stop the resourceBest Regards,Strahil Nikolov___ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
[ClusterLabs] Verifying DRBD Run-Time Configuration
If I want to know the current DRBD runtime settings such as timeout, ping-int, or connect-int, how do I check that? I'm assuming they may not be the same as what shows in the config file. --Eric Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. ___ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
Re: [ClusterLabs] Why Do Nodes Leave the Cluster?
Hi Strahil -- I hope you won't mind if I revive this old question. In your comments below, you suggested using a 1s token with a 1.2s consensus. I currently have 2-node clusters (will soon install a qdevice). I was reading in the corosync.conf man page where it says... "For two node clusters, a consensus larger than the join timeout but less than token is safe. For three node or larger clusters, consensus should be larger than token." Do you still think the consensus should be 1.2 * token in a 2-node cluster? Why is a smaller consensus considered safe for 2-node clusters? Should I use a larger consensus anyway? --Eric > -Original Message- > From: Strahil Nikolov > Sent: Thursday, February 6, 2020 1:07 PM > To: Eric Robinson ; Cluster Labs - All topics > related to open-source clustering welcomed ; > Andrei Borzenkov > Subject: RE: [ClusterLabs] Why Do Nodes Leave the Cluster? > > On February 6, 2020 7:35:53 PM GMT+02:00, Eric Robinson > wrote: > >Hi Nikolov -- > > > >> Defaults are 1s token, 1.2s consensus which is too small. > >> In Suse, token is 10s, while consensus is 1.2 * token -> 12s. > >> With these settings, cluster will not react for 22s. > >> > >> I think it's a good start for your cluster . > >> Don't forget to put the cluster in maintenance (pcs property set > >> maintenance-mode=true) before restarting the stack , or even better > >- get > >> some downtime. > >> > >> You can use the following article to run a simulation before removing > >the > >> maintenance: > >> https://www.suse.com/support/kb/doc/?id=7022764 > >> > > > > > >Thanks for the suggestions. Any thoughts on timeouts for DRBD? > > > >--Eric > > > >Disclaimer : This email and any files transmitted with it are > >confidential and intended solely for intended recipients. If you are > >not the named addressee you should not disseminate, distribute, copy or > >alter this email. Any views or opinions presented in this email are > >solely those of the author and might not represent those of Physician > >Select Management. Warning: Although Physician Select Management has > >taken reasonable precautions to ensure no viruses are present in this > >email, the company cannot accept responsibility for any loss or damage > >arising from the use of this email or attachments. > > Hi Eric, > > The timeouts can be treated as 'how much time to wait before taking any > action'. The workload is not very important (HANA is something different). > > You can try with 10s (token) , 12s (consensus) and if needed you can adjust. > > Warning: Use a 3 node cluster or at least 2 drbd nodes + qdisk. The 2 node > cluster is vulnerable to split brain, especially when one of the nodes is > syncing (for example after a patching) and the source is > fenced/lost/disconnected. It's very hard to extract data from a semi-synced > drbd. > > Also, if you need guidance for the SELINUX, I can point you to my guide in the > centos forum. > > Best Regards, > Strahil Nikolov Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. ___ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
[ClusterLabs] Integrate external alerts with pcs cluster
Hi,In my environment I have a pacemaker cluster running which has various software services as resource agents.These services have dependency on some hardware components. There is a service which monitors the hardware and sends alerts if anything is wrong with the hardware.My plan is to add a resource agent for each hardware component with proper dependencies and fail this resource agent if I get a critical alert from hardware monitoring service. Please note that I do not want to use monitor functionality of resource agent as there is a service which is already doing same thing. I have two queries here -1) Does the approach look good ? Is there a better way to implement it in pacemaker cluster ?2) I can find --fail option in crm_resource but not in pcs cli. What would be the equivalent command in pcs as I am using pcs cli to configure the cluster ?Regards,Ajay___ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
