On 3/29/21 5:24 PM, Tomas Jelinek wrote:
If you stopped a node and you want it to start and reconnect to its cluster, run 'pcs cluster start' on the node. You may also run 'pcs cluster start --all' or (in your case) 'pcs cluster start node1' on any cluster node.Maybe for better understanding: This is working via the pcsd-instances talking
to each other while all the other cluster-daemons are down on a node that has the cluster stopped. Klaus
Tomas Dne 29. 03. 21 v 16:25 Jason Long napsal(a):Thank you.Then, if a node disconnected then how it could back to the cluster chain?On Monday, March 29, 2021, 06:13:09 PM GMT+4:30, Tomas Jelinek <tojel...@redhat.com> wrote:Hi Jason, Regarding point 3: Most pcs commands operate on the local node. If you stop a cluster on a node, pcs is unable to connect to cluster daemons on the node (since they are not running) and prints an error message denoting that. This is expected behavior. Regards, Tomas Dne 27. 03. 21 v 6:54 Jason Long napsal(a):Thank you. I have other questions: 1- How can I launch a test lab?2- Why, when I stop node1 manually and then start it again, I can't browse "http://127.0.0.1:2080";? I think when I stopped node1 then Pacemaker forget to back to the chain!!! 3- Why, when I stopped node1, then "pcs status nodes" command not work? It shows me "Error: error running crm_mon, is pacemaker running?".On Thursday, March 25, 2021, 09:08:45 PM GMT+4:30, Ken Gaillot <kgail...@redhat.com> wrote:On Thu, 2021-03-25 at 14:44 +0000, Jason Long wrote:Then, how can I sure my configuration is OK? In a clustering environment, when a node disconnected then another node must replace it. Am I right? I did a test: I defined a NAT interface for my VM2 (node2) and used port forwarding: "127.0.0.1:2090" on Host FORWARDING TO 127.0.0.1:80 on Guest. When node1 is OK and I browse "http://127.0.0.1:2080"; then it shown me "My Test Site - node1", but when I browse "http://127.0.0.1:2090"; then it doesn't show anything. I stopped node1 and when I browse "http://127.0.0.1:2080"; it doesn't show anything, but when I browse "http://127.0.0.1:2090";, then it has shown me "My Test Site - node2". Could this mean that my cluster is working properly?Port-forwarding to a single VM can never allow the other VM to take over. The intent of the floating IP address is to have a single, unique address that users can use to contact the service. The cluster can move this IP to one VM or the other, and that is invisible to users. The term "floating" is intended to convey this, that the IP address is not tied to a single node, but can move ("float") from one node to another, transparently to users using the IP address. In this case, the floating IP would take the place of the 127.0.0.1 port-forwarding addresses. Instead of two port-forwarding addresses, you just have the one floating IP address. How you get that working with a reverse proxy is up to you. The Clusters from Scratch example shows how to do it with a web server, to present the concepts, and you can tailor that to any service that needs to be clustered.On Thursday, March 25, 2021, 05:20:33 PM GMT+4:30, Klaus Wenninger < kwenn...@redhat.com> wrote: On 3/25/21 9:55 AM, Jason Long wrote:Thank you so much.Now you can proceed with the "Add Apache HTTP" section.What does it mean? I did all steps in the document.Once apache is set up as a cluster resource, you should be able to contact the web server at the floating IP...# pcs cluster stop node1 node1: Stopping Cluster (pacemaker)... node1: Stopping Cluster (corosync)... # # pcs status Error: error running crm_mon, is pacemaker running? Could not connect to the CIB: Transport endpoint is not connected crm_mon: Error: cluster is not available on this node # # curl http://192.168.56.9 <html> <body>My Test Site - node2</body> </html> Thank you about it, but I want to use these two VMs as an Apache Reverse Proxy Server. When one of my nodes stopped, then another node start servicing. My test lab use VirtualBox with two VMs as below: VM1: This VM has two NICs (NAT, Host-only Adapter) VM2: This VM has one NIC (Host-only Adapter) On VM1, I use the NAT interface for the port forwarding: "127.0.0.1:2080" on Host FORWARDING TO 127.0.0.1:80 on Guest. When I stopped node1 and browse "http://127.0.0.1:2080"; then I can't see anything. I want it shown me "My Test Site - node2". I think it is reasonable because when on of my Reverse Proxy Server (node1) stopped, then other Reverse Proxy Server (node2) started. How can I achieve this goal?Definitely not using that NAT interface I would say. It will just be able to connect you with a service running on VM1. And that doesn't make any sense seen from a high-availability point of view. Even if you setup NAT that would make the proxy on node2 visible via VM1 this wouldn't give you increased availability - rather the opposite due to increased complexity. In high-availability we are speaking of a Single Point of Failure (SPOF) which VM1 is gonna be here and what you never ever wanna have.On Wednesday, March 24, 2021, 10:21:09 PM GMT+4:30, Ken Gaillot < kgail...@redhat.com> wrote: On Wed, 2021-03-24 at 10:50 +0000, Jason Long wrote:Thank you. Form node1 and node2, I can ping the floating IP address (192.168.56.9). I stopped node1: # pcs cluster stop node1 node1: Stopping Cluster (pacemaker)... node1: Stopping Cluster (corosync)... And from both machines, I can ping the floating IP address: [root@node1 ~]# ping 192.168.56.9 PING 192.168.56.9 (192.168.56.9) 56(84) bytes of data. 64 bytes from 192.168.56.9: icmp_seq=1 ttl=64 time=0.504 ms 64 bytes from 192.168.56.9: icmp_seq=2 ttl=64 time=0.750 ms ... [root@node2 ~]# ping 192.168.56.9 PING 192.168.56.9 (192.168.56.9) 56(84) bytes of data. 64 bytes from 192.168.56.9: icmp_seq=1 ttl=64 time=0.423 ms 64 bytes from 192.168.56.9: icmp_seq=2 ttl=64 time=0.096 ms ... So?Now you can proceed with the "Add Apache HTTP" section. Once apache is set up as a cluster resource, you should be able to contact the web server at the floating IP (or more realistically whatever name you've associated with that IP), and have the cluster fail over both the IP address and web server as needed.On Wednesday, March 24, 2021, 02:41:44 AM GMT+4:30, Ken Gaillot < kgail...@redhat.com> wrote: On Tue, 2021-03-23 at 20:15 +0000, Jason Long wrote:Thanks. The floating IP address must not use by other machines. I have two VMs that using "192.168.57.6" and "192.168.57.7". Could the floating IP address be "192.168.57.8"?Yes, if it's in the same subnet and not already in use by some other machine.Which part of my configuration is wrong? Why, when I disconnect node1, then node2 doesn't replace it?The first thing I would do is configure and test fencing. Once you're confident fencing is working, add the floating IP address. Make sure you can ping the floating IP address from some other machine. Then test fail-over and ensure you can still ping the floating IP. From there it should be straightforward.On Wednesday, March 24, 2021, 12:33:53 AM GMT+4:30, Ken Gaillot < kgail...@redhat.com> wrote: On Tue, 2021-03-23 at 19:07 +0000, Jason Long wrote:Thanks, but I want to have a cluster with two nodes and nothing more!The end result is to have 2 nodes with 3 IP addresses: * The first node has a permanently assigned IP address that it brings up when it boots; this address is not managed by the cluster * The second node also has a permanent address not managed by the cluster * A third, unused IP address from the same subnet is used as a "floating" IP address, which means the cluster can sometimes run it on the first node and sometimes on the second node. This IP address is the one that users will use to contact the service. That way, users always have a single address that they use, no matter which node is providing the service.On Tuesday, March 23, 2021, 07:59:57 PM GMT+4:30, Klaus Wenninger < kwenn...@redhat.com> wrote: On 3/23/21 4:07 PM, Jason Long wrote:Thank you. Thus, where I must define my node2 IP address? When node1 disconnected, I want node2 replace it.You just need a single IP address that you are assigning to the virtual IP resource. And pacemaker is gonna move that IP address - along with the web- proxy - between the 2 nodes. Of course node1 & node2 have IP addresses that are being used for cluster-communication but they are totally independent (well maybe in the same subnet for a simple setup) from the IP address your web-proxy is reachable at. KlausOn Tuesday, March 23, 2021, 01:03:39 PM GMT+4:30, Klaus Wenninger < kwenn...@redhat.com> wrote: On 3/23/21 9:13 AM, Jason Long wrote:Thank you. But:https://www.clusterlabs.org/pacemaker/doc/en-US/Pacemaker/1.1/html/Clusters_from_Scratch/ch06.html? The floating IP address is:https://www.clusterlabs.org/pacemaker/doc/en-US/Pacemaker/1.1/html/Clusters_from_Scratch/_add_a_resource.htmlIn the "Warning" written: "The chosen address must not already be in use on the network. Do not reuse an IP address one of the nodes already has configured.", what does it mean?It means that if you would be using an IP that is already in use on your network - by one of your cluster-nodes or something else - pacemaker would possibly activate that IP and you would have a duplicate IP in your network. Thus for the question below: Don't use the IP od node2 for your floating IP. KlausIn the below command, "IP" is the IP address of my node2? # pcs resource create ClusterIP ocf:heartbeat:IPaddr2 ip=192.168.122.120 cidr_netmask=32 op monitor interval=30s If yes, then I must update it with below command? # pcs resource update floating_ip ocf:heartbeat:IPaddr2 ip="Node2 IP" cidr_netmask=32 op monitor interval=30s On Tuesday, March 23, 2021, 12:02:15 AM GMT+4:30, Ken Gaillot < kgail...@redhat.com> wrote: On Mon, 2021-03-22 at 17:31 +0000, Jason Long wrote:Thank you. From chapter 1 to 6, I never saw anything about configuring the floating IP address! Am I wrong?Hi, Chapter 6 should be "Create an Active/Passive Cluster", which adds a floating IP, then Chapter 7 is "Add Apache HTTP Server as a Cluster Service".On Monday, March 22, 2021, 07:06:47 PM GMT+4:30, Ken Gaillot < kgail...@redhat.com> wrote: On Mon, 2021-03-22 at 08:15 +0000, Jason Long wrote:Thank you. My test lab use VirtualBox with two VMs as below: VM1: This VM has two NICs (NAT, Host-only Adapter) VM2: This VM has one NIC (Host-only Adapter) On VM1, I use the NAT interface for the port forwarding: "127.0.0.1:2080" on Host FORWARDING TO 127.0.0.1:80 on Guest. Yes, "systemctl" tell me: # systemctl is-enabled httpd.service disabled I rebooted my nodes and one of the problems solved: https://paste.ubuntu.com/p/7cQQtsXFPV/ I did: # pcs resource defaults resource-stickiness=100 When I browse "127.0.0.1:2080" then it shows me "My Test Site - node1". I have two problems: 1- When I stopped the node1 VM and refresh the page then I can't see "My Test Site - node2"? # pcs cluster stop node1 node1: Stopping Cluster (pacemaker)... node1: Stopping Cluster (corosync)... # pcs status Error: error running crm_mon, is pacemaker running? Could not connect to the CIB: Transport endpoint is not connected crm_mon: Error: cluster is not available on this nodeHi, pcs status doesn't test the web site, it shows the internal cluster status. Since the cluster isn't running on that node, it can't show anything. However the website is still active on the other node, and reachable from this node. You can confirm that by using wget or curl with the public web site URL (the floating IP address).# pcs resource defaults Error: unable to get cib I think that it must forward my requests from node1 to node2 automatically and I see "My Test Site - node2" message. 2- I start the node1 again, but when I browse "IP:80", then I can't see "My Test Site - node1" message. # pcs cluster start node1 node1: Starting Cluster... # pcs status Cluster name: mycluster Cluster Summary: * Stack: corosync * Current DC: node2 (version 2.0.5-10.fc33- ba59be7122) - partition with quorum * Last updated: Mon Mar 22 12:26:10 2021 * Last change: Mon Mar 22 12:08:02 2021 by root via cibadmin on node1 * 2 nodes configured * 2 resource instances configured Node List: * Online: [ node1 node2 ] Full List of Resources: * WebSite (ocf::heartbeat:apache): Started node2 * ClusterIP (ocf::heartbeat:IPaddr2): Started node2 Daemon Status: corosync: active/enabled pacemaker: active/enabled pcsd: active/enabled Logs are: https://paste.ubuntu.com/p/Yt4K2kPM7b/ Thank you again. On Monday, March 22, 2021, 01:12:21 AM GMT+4:30, Reid Wahl < nw...@redhat.com> wrote: Hi, Jason. On Sun, Mar 21, 2021 at 5:21 AM Jason Long < hack3r...@yahoo.com> wrote:Hello, I used "Clusters from Scratch" to configuration two nodes. I got below error: # pcs status Cluster name: mycluster Cluster Summary: * Stack: corosync * Current DC: node1 (version 2.0.5-10.fc33- ba59be7122) - partition with quorum * Last updated: Sun Mar 21 15:35:18 2021 * Last change: Sun Mar 21 15:29:38 2021 by root via cibadmin on node1 * 2 nodes configured * 2 resource instances configured Node List: * Online: [ node1 node2 ] Full List of Resources: * WebSite (ocf::heartbeat:apache): Stopped * ClusterIP (ocf::heartbeat:IPaddr2): Started node1 Failed Resource Actions: * WebSite_start_0 on node1 'error' (1): call=6, status='complete', exitreason='Failed to access httpd status page.', last-rc-change='2021-03-21 15:23:45 +03:30', queued=0ms, exec=1318ms * WebSite_start_0 on node2 'error' (1): call=6, status='complete', exitreason='Failed to access httpd status page.', last-rc-change='2021-03-21 15:23:47 +03:30', queued=0ms, exec=1380ms Daemon Status: corosync: active/enabled pacemaker: active/enabled pcsd: active/enabled ********* I have some questions: 1- In "Chapter 6. Add Apache HTTP Server as a Cluster Service", an important note said: "Do not enable the httpd service. Services that are intended to be managed via the cluster software should never be managed by the OS. It is often useful, however, to manually start the service, verify that it works, then stop it again, before adding it to the cluster. This allows you to resolve any non-cluster-related problems before continuing. Since this is a simple example, we’ll skip that step here." If the Apache service is not enabled they how can I connect to it via below command: # wget -O - http://localhost/server-status --2021-03-21 15:38:39-- http://localhost/server-status Resolving localhost (localhost)... 127.0.0.1, ::1 Connecting to localhost (localhost)|127.0.0.1|:80... failed: Connection timed out. Connecting to localhost (localhost)|::1|:80... failed: Network is unreachable.Pacemaker starts the httpd service by starting the ocf:heartbeat:apache resource. The article is saying that the httpd.service systemd unit should not be enabled to start automatically at boot; it should only start when the cluster starts it. That is `systemctl is-enabled httpd.service` should print "disabled".2- Below commands must be run on both nodes or just one node? # pcs resource create ClusterIP ocf:heartbeat:IPaddr2 ip="IP_That_Never_Used_In_The_Network" cidr_netmask=32 op monitor interval=30s # pcs resource create WebSite ocf:heartbeat:apache configfile=/etc/httpd/conf/httpd.conf statusurl=" http://localhost/server-status"; op monitor interval=20sJust one node.3- Why "* WebSite (ocf::heartbeat:apache): Stopped" ?The apache resource agent ran a command similar to `wget -O- -q -L -- no-proxy --bind-address=127.0.0.1 <status_url>` and got an error. It tried this on a start operation on each node, and it failed on both nodes. When a resource fails to start on a given node, the default response is to prevent it from starting on that node again until the failure is cleared.Logs are: https://paste.ubuntu.com/p/MtkfXyRX4P/ Thank you. _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/_______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/_______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/_______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/ _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/_______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
_______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
